Six Fascinating Ways Dogs Release Pheromones

 

Dogs are known to communicate through chemical messages known as pheromones, which carry out several important functions. The term pheromone derives from the Greek word “pherein” which means “to transport” and the word “mone” meaning hormone. The term is therefore utilized to depict those volatile, odorous substances that are secreted for the purpose of causing a physiological reaction in the dogs who receives them.

For sake of comparison, the mechanism is similar to an answering service system. A person leaves a message on the answering machine that is then relayed to the receiver when he presses a button. Since dogs do not have a phone or an answering machine, they rely instead on special glands meant to emit pheromones, and a special organ, the Jacobson organ, located in the roof of the mouth with ducts leading to the nose and the mouth, meant to pick up these messages. Dogs can emit pheromones in a multitude of ways so today we’ll be taking a look at six fascinating ways dogs release pheromones.

puppies nursing1) Intermammary Sulcus Pheromones

Shortly after being born, puppies are exposed to special pheromones produced by mother dog. These pheromones are secreted by the sebaceous glands found in mother dog’s intermammary sulcus, the area in between her breasts where they are detected by the puppies upon nursing.

Because these pheromones have the power to provide calm, comfort and a sense of well-being to the puppies, they’re called Dog Appeasing Pheromones (DAP). Nowadays, DAP is produced synthetically (Adaptil) and sold under the form of special sprays, plug-ins and collars that are used as calming aids for dogs.

Their purpose is to provide reassurance, especially when dogs are exposed to new environments that require acclimatization. It has been found that the reassurance properties of DAP persist into adulthood and can therefore provide comfort to dogs of any age.

” The use of pheromones should not be reduced to treatment of behavioral disorders (potentially associated with psychotropes or a behavioral modification program) but should be included in a strategy of improving the welfare of pets in veterinary structures (during examination and hospitalization) and in breeding networks (separation from the mother and transport).” Pageat P, Gaultier E. 2003

2) Anal Gland Pheromonesdog-rear

Anal glands, also known as “scent glands” are paired sacs that are found around each side of the dog’s anus approximately at the 4 0’clock and 8 o’ clock position.

When dogs defecate, their feces pass through the glands which are lined with sebaceous glands that secrete a semi-oily, brownish fluid that contains pheromones and is used for identification purposes. Dogs who stumble upon a dog’s feces can therefore learn more about the dog’s sex, age and general identity courtesy of these pheromones.

Yes, this explains why dogs are so interested in sniffing other dogs’ poop at the park! Other than used for identification purposes, feces left behind work may also work as powerful territorial posts, telling other animals to stay away as “Rover lives here.”

On top of secreting fluid when dogs have a bowel movement, sometimes the anal glands may empty when a dog is particularly frightened. In this circumstance, a dog’s anal glands are likely emitting alarm pheromones which are picked up by other dogs. For example, in a veterinary hospital setting, frightened dogs may leave traces of pheromones from their anal glands. It is possible that such pheromones may cause a behavioral and/or physiological response in the dogs who detect them, but studies are still needed to pinpoint the exact dynamics.

” The function of  spontaneous emptying of the anal glands during fear has not been extensively studied, but may be related to the release of alarm or aggression-inhibiting pheromones.” ~ Sarah Heath, Veterinary Specialist in Behavioural Medicine.

dog marking3) Urogenital Pheromones

Those pheromones aren’t only coming from the anal glands, turns out dogs secrete pheromones also from the vulval, preputial area and urinary tract area. Several of these are emitted for reproductive purposes, and with a powerful sniffer as seen in dogs, this isn’t even surprising.

Females in heat produce pheromones from their reproductive tracts that are meant to be picked up by male dogs even miles away. When female dogs in heat urinate, their urine is rich in these pheromones which indicate whether she is receptive.

Yes, think about it as a hot chick after a first date leaving a message that says “call me.” The specific compound has been identified as methyl p-hydroxybenzoate,  and according to a study, when this compound was applied to spayed female dogs, it caused male dogs to attempt to mount. Quite a powerful potion that is!

And of course, every body knows about a dog’s fixation with pee. Dogs will urine mark on vertical surfaces leaving pheromones behind that can be easily detected at “nose-level” for other dogs to check out.  Dogs tend to react differently to pee: some just carefully sniff it and then leave the area, while some others will pee on top of it. This habit is what has triggered the marketing of potty training pads or pee posts treated with synthetic pheromones for the purpose of grabbing a dog’s attention and hopefully enticing  him to eliminate on them next time nature calls.

4) Interdigital Pheromonesdog paw pads

Did you know? Dogs have also special glands located in between the toes (interdigital) which are also capable of emitting pheromones. When dogs are scratching dirt after eliminating it’s likely that they are basically leaving behind these pheromones for other dogs to detect.

Interdigitial glands are therefore used for marking, but are also used for alarm, explains veterinarian Dr. Bonnie V. G. Beaver in the book “Canine Behavior: Insights and Answers.

Perhaps this provides another facet as to why stressed dogs tend to sweat from their paws. Along with the sweat, they may be leaving behind important alarm messages that will give other dogs a “head’s up” about the presence of a threat.

dog ear5) Ear Pheromones

Ever wondered why dogs are so attracted to each others’ ears? Those doggy ears have special ceruminous and sebaceous glands which also contain pheromones.These pheromones are similar to the dog appeasing pheromones released from mother dog, only that they’re applied to a wider basis for social purposes this time, suggests  veterinary behaviorist Dr. Cam Day.

Interestingly, these pheromones found in the skin around the ears, make the ears attractive to younger animals creating a cohesion effect with their social group. Adult dogs though may be interested in ears too, and it’s not unusual seeing dogs sniffing each other’s ears as part of their greeting ritual.

“Dog appeasing pheromones have a calming effect on puppies. It has also been isolated from the ears in some adult dogs and may play a role in social communication and cohesion.” ~Nicola Ackerman

6) Facial Pheromonesdogs-sniffing

As with the ears, dogs are often also attracted to sniffing each others’ mouths. This is because the mouth area also emits pheromones, more specifically the labial (lip) area. Many dogs often greet other dogs by first sniffing under their tails, but afterward they may decide to move to other interesting areas where pheromones may also be present such as the lips, remarks Tracie Hotchner, in the book “The Dog Bible: Everything Your Dog Wants You to Know.”

The primary pheromone secreting glands in the dog are the labial, auricular, perianal, genital (vulvar or preputial), interdigital (pedal) and mammary complexes of sebaceous glands. Most of the information appearently enters via the vomeronasal organ “~Dr. Bonnie Beaver

To Sum it up: Here are Areas Where Dogs Tend to Secrete Pheromones (excluding the intermammary sulcus as seen in mother dog)

pheromones-body

 

References:

  • Pageat, P.; Gaultier, E. (2003). “Current research in canine and feline pheromones”. The Veterinary Clinics Small Animal Practice. 33 (2): 187–221
  • Donovan,C.A. (1969) Canine anal glands and chemical signals (pheromones). J. Am. Vet. Med. Assoc., 155, 1995–1996.
  • Veterinary Nursing Journal, Volume 22, Issue 9, 2007, Understanding pheromones, by Sarah Heath
  • Sex pheromone in the dog, Goodwin M, Gooding KM, Regnier F. Science. 1979 Feb 9;203(4380):559-61.
  • The Consulting Veterinary Nurse, By Nicola Ackerman, Wiley-Blackwell; 1 edition (September 4, 2012)
  • Canine Behavior: Insights and Answers, By Bonnie V. G. Beaver, Saunders; 2 edition (January 5, 2009)

 

10 Dog Dental Disease Complications

 

Dog dental disease complications are not uncommon and more and more dogs are affected when preventive steps are not taken. According to the American Veterinary Dental College, by three years of age, most dogs have signs of periodontal disease. Left untreated, dog dental disease causes complications which are not minor and some of them can significantly affect a dog’s health, even leading to major problems at times. Being aware of these complications is important so to recognize early signs of trouble, or even better, take better care of a dog’s teeth preventing dental disease from occurring in the first place. As the saying goes “an ounce of prevention is worth a pound of cure” when it comes to dog health.

dog-dental-disease-complicationsHow it All Starts

Perhaps, a more accurate term for depicting dog dental disease in dogs in this article is “periodontal disease,” which is  the most common form of dental disease affecting pets. The term periodontal means “around the tooth” therefore, periodontal disease is a condition that affects anything surrounding a dog’s teeth including bone, gums, and all the structures that hold the teeth in place.

Here’s what happens in periodontal disease in dogs: after a dog eats a meal, a white colorless film develops on his teeth.  This film, known as plaque, is what people feel upon passing their tongue on their teeth when they are not brushed in a timely matter. At this stage, this microbial biofilm is easy to remove and can be easily scraped off. Simply brushing the dog’s teeth removes this film.

Problems start when this film is not removed. Courtesy of minerals in a dog’s saliva (mostly, dissolved calcium), the plaque starts to harden, and in a few days, it calcifies turning into what’s known as tartar or calculus, an unsightly yellow/brown coating that is difficult to remove. The bristles of a tooth brush will do little at this point. Also, from smooth, the surface of the dog’s teeth coated with tartar gets rough, which attracts more and more tartar build-up and soon a vicious cycle is formed. As the tartar accumulates, it starts collecting under the gums which is when all sorts of complications start to set in.

idea tipDid you know? Just because a dog’s teeth are white doesn’t meant they are free of dental disease. Periodontal disease can be present under the gum line in perfectly white teeth, where it is not visible to the naked eye.

bad-breath yawn1) Dog Bad Breath

As plaque and eventually tartar start building up, a dog’s breath will start becoming increasingly stinky. Dental disease is often the culprit for those whiffs of odor coming from Rover’s mouth. “Doggy breath” is typically caused by mild dental disease, while severe dental disease causes severe halitosis, points out veterinarian Dr. Barchas.

“If a dogs breath is offensive then the shift from normal bacteria to those that cause periodontal disease has occurred. It is an indication that there are problems that need to be addressed.”~Dr. Brett Beckman, President, American Veterinary Dental Society

2) Dog Gingivitisdog teeth

Plaque is formed by a combination of bacteria, carbohydrates, food particles and saliva. When plaque accumulates by the dog’s gum line, its toxins irritate the dog’s gums causing them to become inflamed, swell, bleed and get infected. Gingivitis is the medical term used to depict the inflammation of the gums caused by a bacterial infection. The good news is that gingivitis is reversible with thorough teeth cleaning and polishing along with the owner’s daily care, as no bone loss has occurred at this stage, explains veterinary dentist Dr. Jean Hawkins. While gingivitis is simply a mild form of gum disease, left untreated though, it will develop into a more serious periodontitis.

“Gingivitis is the early form of periodontal disease in which inflammation is confined to the gingival soft tissues. Animals that have Stage I (gingivitis) periodontal disease have gingivitis with no attachment loss. “~Sandra Manfra Marretta, veterinary dentist

dog sick sleep3) Dog Immune System Issues

As the dog’s body detects the presence of bacteria by the gums, the immune system is stimulated and jumps into action to fight the infection. Soon, white blood cells gather along with other inflammatory mediators to the affected area.  However, this immune system response tends to wreck more havoc than doing good when there is a severe build-up of plaque and tartar. When  enzymes released from the white blood cells reach the periodontal space so to fight bacteria, they cause damage to the supporting structures of the tooth. On top of that, left untreated, periodontal disease becomes chronic leaving the body in a state of chronic inflammation and disease.

“The pet’s body and immune system are forced to fight a chronic battle every minute of the day against the invading organisms.”Animal Dentistry & Oral Surgery

4) Dog Pathological Fractures

A pathological fracture doesn’t occur in a healthy bone as a result of an accident, but rather it is a fracture that develops because of an underlying disease. An example of a pathological fracture is a dog’s leg breaking because of bone cancer. With periodontal disease, a pathological fracture may occur as the bone weakens more and more if it’s localized to the lower jaw. According to Veterinary Dental Specialties & Oral Surgery, pathological fractures of the jaw are more common in older, small breed dogs.

Did you know?  Only about five percent of dogs develop cavities, while periodontal disease, is five times more common in dogs than in people. Why is that? Low cavities are explained because most pet food is low in simple sugars. While the reasons behind the high numbers of periodontal disease in dogs is because dogs have a more alkaline mouth  than humans which attracts plaque and their teeth aren’t brushed every day, says Colleen O’Morrow, a veterinary dentist in Manitoba, Canada in an article for PetMD.

tooth-loss-dog5) Dog Gingival Recession

In a healthy mouth, the dog’s gums adhere to the teeth like a cuff. Gingival recession is when the dog’s gums recede pulling away from the tooth and even exposing the roots which are normally covered by bone and gums. Periodontal disease in both dogs and humans is known for causing the gums to recede.

6) Dog Oronasal Fistulas

When there is severe dental disease, an oronasal fistula may form due to bone loss. What is an oronasal fistula? It’s an opening that communicates between the dog’s mouth and the posterior part of the dog’s respiratory tract. According to Animal Dentistry & Oral Surgery Specialists LLC, fistulas are more commonly found by the dog’s top canines, while the incisor region is less affected. Because this opening shouldn’t be there, affected dogs develop infections of their respiratory tract due to food and saliva draining into the dog’s respiratory tract. Fortunately, oronasal fistulas in dogs can be prevented by teamwork provided by the owner brushing the dog’s teeth and routine dental care provided by the family veterinarian and a dental specialist.

7) Dog Tooth Root Abscessescarnassial

While a tooth root abscess is more commonly seen when a tooth is broken or cracked, sometimes the culprit may be periodontal disease. When tartar buildup continues to go untreated, infection can easily form around the root of the tooth since periodontal disease often leaves the inner layers of the tooth exposed. When the upper carnassial tooth is involved, since the roots of this tooth are long and reach below the eye, affected dogs may develop signs that are often confused with an eye problem. At some point, the abscess may cause the tissue below the eye to swell and get inflamed and the abscess may eventually burst causing pus to seep out.

” Once the abscess bursts, the pressure will be relieved and the tooth will often be less painful.” ~Michigan Animal Hospital

Anesthesia-free cleanings are mostly cosmetic.
Anesthesia-free cleanings are mostly cosmetic as they fail to reach under the gums.

8) Dog Bone Loss

Something important for dog owners to acknowledge is that bone loss is something that is not visible by just looking at a dog’s teeth. According to the American Veterinary Dental College, bone loss can only be seen with x-rays of the mouth. Bone loss happens when the dog’s gums pull away and bacteria reach teeth roots and the jawbone, releasing toxins that eat away bone tissue, which can happen easily since it’s no longer protected by healthy gums. The more severe the stage or periodontal disease, the more severe the bone loss.

9) Dog Tooth Loss

As tartar keeps accumulating, bacteria will keep secreted toxins which weaken the dental structures that keep a dog’s teeth is place. Connective tissue fibers, ligaments and bone start providing less and less support. Soon, the bone around the tooth is destroyed leading to loose, painful teeth which can affect the dog’s ability to eat properly and even digest.

“It’s not unusual for middle aged dogs to lose teeth. In most cases this occurs when there is gum disease (gingivitis) which can then spread to the tissue that holds the tooth in (periodontitis).” Dr. Pete

dog pain goes away at the vet10)Dog Systemic Disease

The most scary complication of dental disease in dogs is that it can cause systemic diseases affecting important organs such as the kidneys, liver and valves of the heart. How does this happen? Because a dog’s gums are very vascular, bacteria from the mouth can easily gain access to the dog’s bloodstream and circulate through the dog’s body. While these bacteria may be filtered out by the livers and kidneys, tiny abscesses may develop on these organs which disrupts their normal functioning. When these bacteria happen to attach to the dog’s heart valves instead, they can cause endocarditis, an inflammation of the inner layer of the heart which often includes the heart valves. Not to mention, diabetes and other health problems.

” As the animal chews its food, the infected and inflamed gums bleed, and a shower of very aggressive bacteria enters the blood stream. These germs are carried throughout the body and can cause infection in many areas.”~ Dr. Fraser Hale, veterinary dentist.

Disclaimer: this article is not meant to be used as a substitute for professional veterinary advice. If your dog shows signs of dental diseases, please see your vet for proper treatment.

References:

  • American Veterinary Dental College, Periodontal Disease, retrieved from the web on Sept 8th, 2016
  • Animal Dentistry & Oral Surgery Specialists LLC, Oronasal and oroantral fistula in cats and dogs,  retrieved from the web on Sept 8th, 2016
  • American Veterinary Dental College, Stages of Pet Periodontal Disease, retrieved from the web on Sept 8th, 2016
  • Eukanuba, Vital Health Care and Management of Competitive Dogs,  retrieved from the web on Sept 8th, 2016
  • Healthy Mouth, Periodontal Disease in Dogs and Cats, retrieved from the web on Sept 8th, 2016

Photo Credits:

Total loss of attachment (clinical attachment loss, CAL) is the sum of 2: Gingival recession, and 3: Probing depth by LesionOwn work, CC BY-SA 3.0

Dog Word of the Day: Sloppy Sit

 

There are normal sits and then there are sloppy sits in the world of dogs. While many dogs tend to sit sloppily, it’s important to consider that at times, sloppy sitting in dogs can be an early sign of a medical problem. Not all dogs show outward signs of discomfort or pain when they are hurt, and many dogs are pretty stoic when it comes to hiding their chronic pain, often causing small manifestations to be missed by dog owners. Sitting sloppy may be one of them, therefore it’s important to carefully evaluate whether there’s a physical problem at the bottom of this behavior, preferably with the aid of a veterinarian to play it safe.

sloppy sit 1A Dog’s Sloppy Sit

What does it mean for a dog to sit sloppy? Normally, when a dog sits, the rear legs are tucked nicely under the hips and kept close to the body. In a sloppy sit, the legs are kept loosely and off to one side or perhaps one or both legs are stretched outwards in front as seen in the dog in the picture on the left.

The sloppy sit in dogs is often compared to the position of a lady riding a horse with the legs placed sideways. Also known as lazy sit, slouch or frog sit, a sloppy sit is a sit often seen from a dog who may be tired, lazy or simply relaxed.

Sloppy sits are often seen in puppies. On several occasions, a puppy may be seen sitting with his hind legs to the side, but is that something to worry about?

According to veterinarian Dr. Gwen, sitting with the legs to the side is a common puppy posture that is commonly seen when pups are going through those awkward growing stages. At times, this type of sit can be seen when puppies are getting a bit lazy during training. Because sloppy sits in dogs and puppies can be also due to medical problems, it’s a good idea to mention this habit to the vet.

dog pain goes away at the vetPossible Medical Problems

There are several possible medical conditions behind dogs who sit with their legs to the side, especially when it’s a new behavior that pops out almost out of the blue. So it’s best to see the vet rather than chalking it up to laziness.

Hip dysplasia, for example, often causes pain in dogs and dog may sit sideways as a way to adjust their bodies to prevent discomfort. Dogs affected by hip problems often become sore after running and may have a hard time getting up from a sitting or lying down position.

The yellow Lab in the picture below, sits this way because he was in a car accident and had to have surgery on his hip, but the surgery didn’t go too well so he was left a bit crippled.

Other orthopedic problems causing a dog to sit with the legs splayed out are arthritis, a temporary inflammatory response, knee pain caused by luxating patellas quite common in smaller dogs, and if a dog is sitting to the side and also limping on a rear leg, a torn cruciate ligament may also be a possibility.
 Sometimes sitting sloppy is not related to an orthopedic problem, but something else. Back pain caused by a herniated disk, anal gland problems and a painful tail are other possibilities among several others.

sloppy sit dogGetting a Straighter Sit

After ruling out medical problems, dog owners mat wonder how to fix a sloppy sit. While this may not be a big deal with owners training their dogs to simply be companions, those who have special ambitions such as putting titles on their dogs, may need to be a bit more picky about getting nice, square sits.

Many dog trainers frown upon sloppy sits as a side-saddle sit can result in loss of precious points in the obedience ring.

A good way to fix sloppy sits, if you’re using a clicker is to click and reward only straight sits, so that sloppy sits eventually start reducing and eventually fade.

For obstinate cases, it may help to ask a dog to sit when he is between two piles of books or when “in drive” such as ready to pounce to get a ball or when doing fast fronts in a sequence so that the dog is ready to sprint in action.

Of course, the earlier a straight sit is taught, the better, as sitting sloppy can become a bad habit once muscle memory kicks in if allowed to happen all the time. With young puppies instead it’s simply a matter of timing as things start to get better in the sitting department once they develop their muscular-skeletal system, explains dog trainer Pamela Reid in her book ”Ex-celerated Learning”.

Disclaimer: this article is not meant to be used as a substitute for professional veterinary advice. If your dog has trouble sitting or lying down, see your vet to rule out medical problems.

References:

Pamela Reid, Excel-Erated Learning: Explaining in Plain English How Dogs Learn and How Best to Teach Them, James and Kenneth Publishers; 1st edition (February 1996)

 

Where Do You Measure a Dog’s Height?

 

Getting your dog’s weight is pretty much straightforward, all you need is a large scale, your dog and some tasty treats, but how do you take a dog’s height? Measuring a dog’s height at one time or another may be necessary such as when you need to purchase a doggy door or if you’re planning to enroll your dog in some type of dog sport or activity. In humans, height is easily measured by standing against a wall and marking the position on top of the head using a measuring tape, but in dogs taking a dog’s height is different. So today’s trivia question is:

Where do You Measure a Dog’s Height?

A At the top of the skull

B At the top of the ears

C At the base of the tail

D At the top of the shoulders

The correct answer is: drum roll please

drum

 

 

The correct answer is D, a dog’s height is measured at the top of the shoulders.

square built dog withersDog Withers Definition

A dog is measured where the shoulders are the highest, the area that is technically referred to as the dog’s “withers.” This is the area where the dog’s neck and shoulders meet and is used to measure the height of both dogs and horses as it’s the tallest point of the body, obviously excluding the head.

Did you know? Some dog breeds are required by standard to be “square” which means that their height from withers to the ground is supposed to measure approximately the same as the length of the body measured from the withers to the base of the tail. Examples of squarely built dogs are the Maltese, poodle and the boxer.

dog height measureHow to Measure a Dog’s Height

To measure your dog’s height in 3 easy steps, you will need your dog of course and some measuring tape (or a yard stick.)

  1. Make sure your dog is standing straight without leaning or shrinking to the ground. He should be on an even, level surface with the head carried in normal position. Small dogs can be measured on a table.
  2. Starting at the top of the withers, run the measuring tape parallel to the dog’s front leg so that it falls perpendicular to the ground.
  3. Record the measurement for future reference.

Did you know? To measure dogs with precision, professional dog show judges use what’s called a “wicket.”

 

dog door measurementMeasuring for a Dog Door

If you are purchasing a dog door, your dog’s height at the withers is important as you need to make sure he can easily fit through the flap without the need for crouching. Consider that the top of the dog door’s flap opening should be at, or even better, over, your dog’s height. Adding an inch or two to the pet door’s height may be helpful. For large growing puppies though, things may be challenging due to their rapid growth, so unless you plan to upgrade to a larger door once your puppy turns adult, you’ll have to have an idea of how tall your puppy will turn to be.

idea tipTip: bigger is better when it comes to door dogs. Best to err on the side of caution and end up with a slightly larger door, than a door that is too small for your dog to fit through.

Measuring for Agilitydog agility

In the sport of agility, how can one calculate how tall a dog agility jump should be?  The answer is fairly easy: the height of the jump is based on the height of the dog! By measuring a dog’s height at the withers one can therefore attain an insight as to the height of the obstacles he should jump. Just to have an idea, the American Kennel Club has this jump height regulation:

  • 8 Inches: For dogs 11 inches and under at the withers.
  • 12 Inches: For dogs 14 inches and under at the withers.
  • 16 Inches: For dogs 18 inches and under at the withers.
  • 20 Inches: For dogs 22 inches and under at the withers.
  • 24 Inches: For dogs over 22 inches at the withers.
  • 26 Inches: Dogs may be entered at this height at their owner’s discretion.

 

dog show judgeMeasuring for the Show Ring

Measuring the height of a dog for the show ring may also be important so to ensure the dog meets the height requirements for his breed standard. While for some breeds some minor differences are negligible, in others being outside of that height range can be means for disqualification. So of course, measuring the dog at the withers at home with precision is important before entering the show ring. Judges may at times decide to verify the height at dog shows using a wicket which they are allowed to use only one time and must get it right that first time around. Because of the possibility of getting measured by a judge, it’s not a bad idea to get the dog used to being around the wicket  and measured with it as some dogs not used to it may get easily spooked.

 

References:

  • American Kennel Club, A bit of a sticky wicket, retrieved from the web on Sept 6, 2016
  • American Kennel Club, Regulations for agility trials, retrieved from the web on Sept 6, 2016

 

I am Your Dog’s Bones

 

Whether your dog is chasing squirrels or romping around the yard with a ball in his mouth, his bones are always there to support him. Movement is the well-orchestrated effort of nerves, muscles and bones working together and making it all happen. A dog’s skeleton is composed of a variety of bones of different shapes and sizes meant to provide structural framework and general support for his whole body. So today, let’s discover more about dog bones, the various tasks they carry out throughout a dog’s life and potential problems a dog’s bones may encounter.

dog bonesIntroducing Your Dog’s Bones

Hello, it’s your dog’s bones talking today! Yes, there are many of us! Wondering how many bones dogs have? Dogs have over 300 bones, but if you want exact figures, we are closer to give or take 319, depending on how many bones are in a dog’s tail. If you’re looking for a comparison between the number of dog and human bones, consider that humans have about 206, so yes, dogs definitely win in the bone quantity department– if there was ever a contest for that!

Let’s start off by looking a bit at our composition. We are mostly made of minerals, primarily calcium and phosphorus and are somewhat, like onions, that is, we’re composed of many layers. Most of us are covered by a protective layer known as periosteum that’s responsible for delivering blood and nutrients to us. Periosteum also contains cells that help us grow and repair. If you’re wondering what periosteum looks like, imagine that white thin layer that lies between an egg and its shell. Yes, that pretty much looks like us.  Right under the layer of periosteum is compact bone, the smooth and very hard bone people are most familiar with when they think about us. Under the compact bone is what’s known as cancellous bone, also known as spongy or trabecular bone. As the name implies, this is the spongy part that is often found at the ends of the dog’s bones and joints. Finally, comes the innermost part of us, the bone marrow that carries important functions. Put together all these parts, and you get an idea of our composition. Now, let’s get a rundown of what we do.

idea tipDid you know? Despite their significant differences in size, Chihuahuas and Great Danes have approximately the same number of bones.
Illu long bone

We Provide Protection

We do our best job to protect your dog from getting hurt. If you look at your dog’s ribs, you will notice how we are arranged like a shield meant to protect your dog’s important internal organs such as the heart and lungs. Your dog’s thick skull is also there to protect that brain from dangerous concussions. Yup, being thick-headed is good thing for dogs!

Fun Fact:  The bones of the dog’s ears are there for neither protection nor support, but rather their primarily role is sound transmission, allowing dogs to use their sense of hearing, explains veterinarian Race Foster.

dog locomotion bonesWe Allow Movement

As mentioned, it is thanks to the teamwork between nerves, muscles and bones that your dog is capable of romping around. Many of us fit together like jig-saw puzzles connecting to their neighboring bones. Areas where we join one another are called joints which play a great role in locomotion. We interlock together in different ways, for example, the dog’s hip is an example of a ball and socket joint while the dog’s elbows are hinge joints.

We Produce Cells

When people think about us, they often get a mental picture of bones seen in a museum or those big  knuckle bones fed to their dogs, and this makes sense, as most likely those are the only types of bones people will ever see. But we are far from the dead, dry bones seen at museum exhibits. When we are still in the body of a live person, animal or dog, we are well alive, so much so that we grow, repair and even create blood cells. You see, in our bone marrow, that dark tissue found in hollow bones, special stem cells work hard to produce red and white blood cells.

We Store Minerals

Not many people think of bones as a warehouse for important substances the body needs. We store fat and several important minerals and keep them ready for when dogs need them. These minerals are constantly moved around, being deposited and taken out as needed. All this is coordinated by the parathyroid gland which produces a special hormone which tells us to release calcium into the bloodstream as needed.

When Things Go Wrongdog pain goes away at the vet

Many things can go wrong with us as we’re not indestructible. One of the most common problems affecting us are fractures, which can happen to many of us. We also may be subjected to issues when puppies grow if owners are not attentive enough to care for us. We may also get infections and problems associated with low calcium levels in the blood. Here’s a brief rundown of several problems we may encounter. This is not a complete list, but just a few problems that may affect us.

Dog Bone Fractures

When we are subjected to high impact accidents as when hit by car, we can dislocate and/or break and cause significant pain. Some types of fractures (like to toe fractures) may just need a splint, but others may require expensive and complex surgical repair. Sometimes we also can break due to an underlying condition that weakens us.

Dog Bone Cancer

When cancer affects us, dogs may suffer from what’s called a “pathological fracture” as we are destroyed from the inside out. While this fracture can affect any bones, the dog’s bones of the leg are most susceptible. What happens it that, as bone is destroyed, it’s replaced in part by tumorous bone, but this is not as strong as real bone and therefore the leg becomes prone to fracturing. Unfortunately, there’s no way to repair this type of fracture surgically.

Dog Bone Infection

Yes, we can sometimes get infected too. Osteomyelitis is the medical term for infection of the bone or bone marrow and it can be caused by bacteria or a fungal infection. In the case of bacteria, an infection in the body may spread to us, or the infection may be more localized. Bacteria may enter from bites, wounds or injuries or even complications from a surgery affecting the bone. Fungal infections affecting us include coccidiomycosis, blastomycosis, and cryptococcosis. Dogs affected by fungal infections that involve the bones usually develop pain, a fever and swelling.

Problems With Growth Plates

When puppies are born, they are equipped with all the bones they need, but as they grow, their bones need to increase in length. You see, us bones tend to grow from areas of immature, soft bone that are called growth plates which are located by the ends of the puppy’s bones. These growth plates are weak and can be prone to injury or even fractures, explains veterinarian Dr. Race Foster. It’s important therefore not to overexercise puppies such as jogging them on hard surfaces. As the puppy grows, we grow and finally harden with calcium and minerals, a process that is known as “closing the growth plates.“Generally, by one year of age the puppy’s growth plates close and significant bone growth ends.

“Vitamin D deficiency is characterized by an inadequate mineralization
of the bone and growth plates, also know as rickets.” Dr. Sally Perea

puppies nursingEffects of Low Calcium

As mentioned, we store minerals and this includes calcium. When dogs give birth and have a large litter, sometimes they may lose too much calcium at once which may cause what’s known as hypocalcemia (low calcium), milk fever or eclampsia. What basically happens in dog eclampsia is that mother dog’s body cannot keep up with the increase demands for calcium associated with nursing. When this happens, blood levels of this mineral become suddenly depleted and her parathyroid gland is not fast enough to start removing it from the bone. With not enough levels of calcium circulating in the body, affected dogs develop a stiff gait, fever and rapid breathing and death can occur if no treatment is given. While well-meaning dog owners may supplement calcium during a dog’s pregnancy, doing so is not recommended, explains Dr. Race Foster. Wrong amounts of  supplementation during pregnancy and inappropriate calcium to phosphorous ratios can actually trigger eclampsia  in the first place.

warning cautionDid you know? Too much of a good thing applies to calcium as well. While breeders and dog fanciers may advocate giving puppies calcium supplements, this is risky business. Too much calcium in puppies is detrimental to their development and can cause skeletal deformation, warns veterinary nutritionist Dr. Jennifer Larsen.

Aging Bones in Dogs

After years and years of providing locomotion, protection and support, sadly we start feeling the effects of time. As time goes by, the cartilage that cushions joints starts to wear down. Without this protection, us bones are left rubbing against each other, which causes friction and damage to us over time. Large dogs are mostly affected, and the weight-bearing joints such as hips, elbows and knees are particularly vulnerable.  Bones spurs may also appear. While there is no cure for old age, there are supplements and medications that can fortunately reduce inflammation and pain.

As seen, us bones do a whole lot, but we are also prone to problems! Make sure you keep us in good shape and report to your vet immediately as soon as you notice problems. I hoped this helped you discover more about us! Best regards,

Your dog’s bones Dog Pawprint

Disclaimer: this article is not meant to be used as a substitute for professional veterinary advice. If your dog is having health problems, please see your vet for proper diagnosis and treatment.

 

References:

  • Pet Education, Skeletal Anatomy: Bones, Joints and Muscles in Dogs, retrieved from the web on September 5th, 2016
  • Pet Education, Eclampsia (Puerperal Tetany, Milk Fever, Hypocalcemia) in Dogs, retrieved from the web on September 5th, 2016
  • Focus on Nutrition, Feeding Large Breed Puppies, retrieved from the web on September 5th, 2016
  • Nutrient Requirements of Dogs and Cats. National Research Council of the National Academies. The National Academies Press, Washington, DC, 2006

Photo credits:

Lateral view of a dog skeleton, Wilhelm Ellenberger and Hermann BaumUniversity of Wisconsin Digital Collections Public Domain

Fuelbottle~commonswiki Public domain

Do Dogs Bite Their Tongues?

 

dog tongueA dog’s tongue is often hanging out and it almost always seems to have a nice reservoir of steady saliva ready to greet human friends, but dog tongues are prone to being bitten too. Sure, this doesn’t happen too often fortunately, but when it does, it can be a scary event for those watching. With a dog’s sharp teeth, biting the tongue can do quite some damage, but luckily Mother Nature has provided dogs with ways to prevent this from happening–at least, not too often. Chewing requires a well-orchestrated interaction between the tongue and jaw and a precise mechanism that prevents dogs from biting their tongues. Without such a mechanism, dogs would end up chewing more tongue than kibble. Not a great evolutionary advantage for sure!

“Dogs do occasionally bite their tongues. Fortunately, they don’t seem to chomp down too hard, or they might end up tongue-less. They seem to bite them less often than people bite their own tongues, perhaps because with constantly hanging it out of their mouths, they naturally have a mechanism that automatically pulls it from the path of their own teeth.”~D. Caroline Coile, Margaret H. Bonham

dog eatingDog Biting Tongue While Eating

In humans, biting the tongue is often a “side effect” of civilization. Eating fast, eating while talking or just  eating while being distracted from other people, the quintessential iPhone or the TV, is often what causes us to bite our tongues. The pain when we bite our tongue seems to tell us that we should pay more attention in the future to what we chew on! But what about dogs? Some dog seem like they’re biting their tongues while eating. You may hear these dogs whining briefly almost as if  saying “ouch!”

While dogs don’t have work schedules or talk with others while enjoying their meals, dogs are fast eaters by nature and therefore this can perhaps make them prone to biting their tongues at times, but if this happens often, it may be a sign of localized swelling,  presence of a mass or even a dental malocclusion causing teeth to snag on the tongue. So if your dog whines while eating, see your vet,  it may also be possible he might not be biting his tongue, but is actually suffering from a mouth or dental problem.

dog playDog Biting Tongue While Playing

When dog play vigorously, accidents can happen. In dogs, biting the tongue while playing is not that uncommon and it makes sense considering that that tongue is often out and “in the way” when a dog romps around a lot such as during vigorous play. It can happen in particular when dogs are fetching items with their mouths or when they trying to catch things such as a tug toy or a flirt pole and miss, with the end result of “ouch!”biting their tongues.

Dog Biting Tongue During Seizures

Seizures cause involuntary spasmodic movements and dogs affected are often seen violently paddling their feet, twitching their muscles, chewing and foaming at the mouth. Contrary to popular belief, dogs do not swallow their tongues during a seizure, but they can manage to bite it. Trying to move the tongue out of the way  may seem like a good solution but this practice is not recommended as the dog’s uncontrollable chewing movements may cause an accidental bite, warns Dr. Etienne Cote in the book “Clinical Veterinary Advisor: Dogs and Cats.”

Protected by Natural Mechanismsdog panting tongue

Let’s face it: the tongue is in a vulnerable position being in the middle of a dog’s sharp teeth, but evolution has considered keeping that tongue out of harm’s way from all the friction going on when dogs, people and other animals chew their foods. We might not know yet exactly what mechanism prevents dogs from biting their tongues on a constant basis, but in mice, a study has shown that special premotor neurons, responsible for controlling jaw and tongue muscles, play a role in preventing the mouth from closing unless the tongue is simultaneously retracted.

Fast Healers

Luckily, tongue injuries heal very well because the tongue has excellent vascular supply, explain Dale Kressin and Steve Honzelka, two board-certified veterinarians specializing in animal dentistry. Here’s a hint: look under your tongue using a mirror and you’ll see how rich in vascular supply it is. However, the fact that the tongue has a lot of vascular supply also means that, when injured, it tends to produce copious amounts of blood which can be scary to dog owners to witness. According to veterinarian Dr. Kara McCarthy though, it’s unlikely for a dog to bleed to death from biting his tongue.

In the event of an injury derived from a dog biting his tongue, it’s best to keep the dog calm as, the more the excitement, the higher the blood pressure and the more the bleeding. Generally, bleeding from tongue lacerations starts slowing down after 5 to 10 minutes. Applying a bit of pressure to the area, if the dog allows it (don’t do this of course if your dog resents having his mouth handled), may help form a clot. Ice on the area or offering a bowl of ice water can help constrict the blood and help clotting, suggests Dr. Christian.  If the bleeding persists though, a vet visit is in order, possibly to have the tongue injury cauterized. At times, dogs may also need stitches if the cut is long or deep. Generally, minor laceration tend to heal in 7 to 10 days. Feeding moistened food, canned food or gruel that is easy to lap up while the tongue heals, may be helpful.

Disclaimer: this article is not meant to be used as a substitute for veterinary advice. If your dog has injured his tongue, please see the vet.

 

References:

  • eLife, Monosynaptic premotor circuit tracing reveals neural substrates for oro-motor coordination, Edward Stanek et al. Duke University Medical Centre, United States,  April 30, 2014
  • Why Do Dogs Like Balls?: More Than 200 Canine Quirks, Curiosities, and …By D. Caroline Coile, Margaret H. Bonham,  Sterling (September 2, 2008)
  • Vet Info, My dog bit her tongue and it won’t quit bleeding. What do I do. retrieved from the web on September 4th, 2016
  • My Pet’s Dentist, Tongue Lesions in Pets, retrieved from the web on September 4th, 2016

 

The Truth About Scruff Shaking Dogs for Discipline

 

When it comes to training dogs, there are several different types of methods and techniques, but training methods focusing on confrontational, punishment-based techniques are known to cause unnecessary stress and fear in dogs. One method that has been promulgated by television shows and books is scruff shaking, basically grabbing the puppy or dog by the scruff and shaking when he is misbehaving.  The practice of scruff shaking dogs has been around for many years and has often been portrayed as species typical behavior, meaning that it’s based on what dogs do to other dogs. Turns out though that studies prove otherwise.

scruff shaking dogsA Deeper Insight

Scruff shaking is based on the belief that mother dogs correct their  puppies by biting and shaking them by the scruff of the neck. There is also belief that dogs use scruff shakes with other dogs. As mentioned, several television shows and some books have promulgated a dangerous “scruff shaking trend” in the past years suggesting it as a way for humans to correct undesirable behavior in dogs. By shaking the puppy or dog’s scruff, or poking fingers into the puppy’s neck, it has been suggested that dog owners can emulate the scruff shaking carried out by mother dog or applied among dogs.

“That’s what the (mother dog) does to discipline them.” I sometimes wonder if the people who propose these strange and barbaric practices have ever seen a dog before.  (Mother dogs) do not discipline puppies by scruffing them.”~ David Ryan PG Dip (CABC) CCAB

Violence Begets Violencedog aggression

Scruff shaking is based on positive punishment, meaning that its timely application is meant to reduce and stop an unwanted behavior. When positive punishment-based techniques are used to modify dog behavior, a vast array of side effects may occur.

Scruff shaking along with alpha rolls and other punishment-based, physical approaches not only negatively affect the dog and owner bond, but also heighten the chances for defensive aggression.

The owner’s hands soon become a threat rather than a source of rewards, and dogs may  learn to respond to any hand movement towards them with defensive behaviors such as growling, snapping and even biting.

According to a study conducted by Meghan Herron, DVM, DACVB, Frances Shofer, DVM and Ilana Reisner, DVM, DACVB, of the Matthew Ryan Veterinary Hospital of the University of Pennsylvania, it was found that when dog owners resorted to harsh confrontational techniques, dogs responded with aggression.

More precisely, just to get an idea: 43 percent of dogs responded with aggression when being hit or kicked, 39 percent reacted to an alpha roll, 38 percent responded aggressively to having an owner grab their mouth and take out an object forcefully and 26% percent responded defensively when given a scruff shake. 

” Punishment is like carpet bombing. The behavior you wanted to target gets hit but so can a huge portion of the dog‘s whole repertoire.”~ Jean Donaldson

Mother dog gently "nibbling" her pup.
Mother dog gently “nibbling” on  her pup.

What Studies Say

In dogs, shaking by the neck is part of the predatory sequence meant to kill prey. It would be very counterproductive for a normal mother dog to do that. Mother dogs may carry their pups in their mouths to move them from one location to another and when they do so, they are very gentle.

The belief that scruff shaking is a species typical behavior carried out by mother dogs is unfounded and several studies have proven that.

In a study involving the observation of the interactions between mother dog and pups, out of 190 breeders, 97.2 percent reported never witnessing mother dog shaking her puppies by the scruff. (Hallgreen 1990) Even among thousands of cases involving aggression in dogs, scruff shaking was reported as being rare and unusual (Schilder and Netto, 1991) Based on this evidence, scruff shaking is not only harmful and potentially dangerous, but also totally inappropriate.

“Normal mother dogs do not scruff or shake their offspring. Rather, they shape the puppy’s behavior with a complex physical language which uses self-inhibition from the start. Good canine moms use visual signals or simply walk away; even their physical responses do not include actual biting. By the way, they are also extremely tolerant of puppy indiscretions and we could learn quite a lot from their patience.” Reisner Veterinary Behavior Services, LLC

Alternative Methods

Dogs should perceive hands as sources of good things.
Dogs should perceive hands as sources of good things.

Scruff shaking doesn’t teach the dog which behavior is desired from the dog. It risks teaching dogs to fear hands and the owner and, as seen, it could trigger defensive behaviors. Teaching the dog an alternate, incompatible behavior that can replace the undesirable one, is often a successful approach.

Owners dealing with behavior problems should consult with a dog trainer or behavior consultant focusing in force-free behavior modification techniques. If your dog is exhibiting behavioral issues, please get professional help. Grabbing a dog by the scruff dog is definitely not the answer.

“When we engage in such behaviors toward our dogs, we are not telling the dog we are “boss,” instead we are telling the dog we are dangerous creatures to be avoided or fought off. There is no “dominance” in these scenarios—only terror and the instinct to defend oneself against attack.” ~Association of Professional Dog Trainers.

 

References:

  • The Culture Clash by Jean Donaldson, James & Kenneth Publishers (January 19, 1996)
  • Herron M.E., Shofer F.S., Reisner I.R. 2009. Survey of the use and outcome of confrontational and non-confrontational training methods in client-owned dogs showing undesired behaviors. Applied Animal Behavior Science, 117, pp. 47-54.
  • The Other End of the Leash, Confrontational Techniques Elicit Aggression, retrieved from the web on September 3rd, 2016
  • Association of Professional Dog Trainers, Dominance and Dog Training, retrieved from the web on September 3rd, 2016
  • Karen Overall, Manual of Clinical Behavioral Medicine for Dogs and Cats, Mosby; 1 Pap/DVD edition (July 9, 2013)

 

Eight Facts About Sleep Dogs Want You to Know

 

“Let sleeping dogs lie,” says the famous adage, and those are surely words of wisdom when dogs hit the pillow. As in all living creatures, sleeping is important in dogs, and while dogs don’t have tight work schedules as people do, they still benefit from getting all the sleep they can get. Along with quantity of sleep, the quality of sleep is also something that’s important. In a previous article we looked at different dog sleeping position meanings, today instead we’ll be taking a peek at fascinating facts about dog sleep that dogs would like you to know.

dog sleep 91) We Love to Sleep in Human Beds…

Roll Over Rover! According to a survey conducted by Novosbed, a company selling luxury memory foam mattresses, an astounding 71 percent of pet owners confessed sleeping with their pets, with 43 percent of them sleeping with them every night, 23 percent reporting only sleeping with them occasionally and 5 percent (drum roll please!) sneaking their pet in bed when their significant others were out of town.

Pets also seem to have their favorite resting spots, with 52 percent sleeping at the foot of the bed, 23 percent snuggling right next to their owners, 14 percent sleeping under the covers and 11 percent sharing a pillow. This news is really nothing new, a while back the American Animal Hospital Association (AAHA) had found that 60 percent of cats and dogs slept in the owner’s bed or in their bedroom.

2) And the Best Part is it’s Good for You Too!

Some people may frown upon people who share their beds with their pooches, but for those who do sleep with their furry friends, here’s a great incentive to keep doing that. According to a survey conducted by the Center for Sleep Medicine at the Mayo Clinic in Arizona, pet owners who sleep with their dogs and cats may actually be getting better ZZZs. Despite what sleep experts have said for years, it was found that only 20 percent of owners found their pets to be disruptive; whereas, 41 percent felt that their pets were unobtrusive and even beneficial for their sleep. Perhaps it’s time for doctors dealing with sleep disorders to consider having more people share their sleep environment with a furry friend.

3) We Go Through REM Sleep Too…dog sleeping belly up

Just like people, dogs go through various different stages of sleep. The first stage of sleep mainly comprises low frequency electrical activity, and as such, it’s know as slow wave sleep. After a while, the dog then enters the rapid eye movement stage (REM), which, as the name implies, is characterized by rapid eye movements and much more than that.

During the REM stage (as dog owners can attest) dogs are often seen breathing faster, moving their legs, twitching their ears, chewing and even barking in their sleep! It all makes sense though when we think that the REM stage is when animals and people are dreaming. Have fun dreaming about eating that sandwich left unattended on the table and chasing rabbits Buster!

4) But Doggy REM can Sometimes get Out of Hand

In some dogs, movement carried out during REM sleep may be excessive and sometimes may even appear violent. There are reports of dogs exhibiting excessive running movements of the limbs, dogs attacking inanimate objects and some even propelling themselves across the floor. While these movements may appear similar to seizures, affected dogs can be awaken and show no coordination problems or confusion which is in contrast with what happens during a seizure, explains board-certified veterinarian Dr. Linda Shell. There’s a chance that dogs may be prone to developing a sleep disorder that has observed in people and that goes by the name of REM behavior disorder.

dog wetting bed while lying down5) As we Age We May Wet the Bed…

In humans, wetting the bed is associated with young children, but in dogs it’s mostly a matter of aging and it seems to affect mostly female spayed dogs. It’s called “Primary sphincter mechanism incompetence“(PSMI) also known as hormone-responsive urinary incontinence”or “estrogen-responsive incontinence” or more simply “spay incontinence. “A study,  found that about 1 out of 5 female dogs affected by this condition get it after they are spayed.

Here’s what basically happens. Strong sphincter muscles help keep good tone and prevent urine from escaping, but as spayed dogs age, these muscles tend to weaken causing leakage of urine when they’re resting or sleeping, explains veterinarian Dr. Marie. While senior spayed females dogs are mostly affected, this condition can also affect younger dogs (and occasionally males too). Fortunately, this type of incontinence can be  remedied with prescription veterinary drug known as phenylpropanolamine (yeah, try to pronounce that! )

6) And Get Disrupted Sleep Too.

Aging is sure no fun, and as dogs live longer lives, dog owners witness more and more problems related to old age such as arthritis, incontinence and canine cognitive dysfunction, the canine version of Alzheimer’s disease. Affected dogs show several signs along with disrupted sleep-wake cycles, which means that instead of resting peacefully, they’ll spend their nights pacing and vocalizing. A particularly distressing aspect of this whole ordeal is the fact that dog owners have a difficult time finding a way to comfort their dogs when they are affected by this condition, explains veterinary behaviorist Dr.  Karen Overall.  

7) Stress Affects Us as Well..dog lip licking

People are often tossing and turning at night when they are stressed by a multitude of problems, but stress can affect a dog’s sleep too. Sure, dogs don’t have to worry about balancing their checkbooks or filing for divorces, but they are sure prone to stress such as from loud noises, exposure to other animals and side effects of harsh, aversion-based training techniques (which should never be used! read ASVAB’S position statement) While some dogs are plain old lazy (think greyhounds and English bulldogs), consider that dogs who seem to sleep a whole lot may be stressed.

“Stressed dogs usually will not experience a satisfying sleep which is why they are always trying to sleep.”~James O’ Heare

 

dog sleeping8) So Please Let Us Sleeping Dogs Lie

So yes, dogs needs their daily amounts of beauty sleep too and if dogs are stressed, it’s paramount to work on reducing their stress levels. Dogs denied adequate levels of stress often pay the consequences under the form of behavioral problems and and impaired learning abilities, explains veterinarian Dr. H. Ellen Whiteley in the book “Understanding and Training Your Dog Or Puppy.”  Want a dog who likes to hit the snooze button? Perhaps try going with one of those giant dog breeds.

“Some very large breeds of dogs, like Newfoundlands, Saint Bernards, and mastiffs, often spend a great deal of their lives sleeping—perhaps up to sixteen or even eighteen hours a day. ” ~Stanley Coren

You may also like: How much do dogs sleep on average? and Do Dogs Sleep With Their Eyes Open? Dog Pawprint

 

References:

  • Are Pets in the Bedroom a Problem?, Lois E. Krahn, MDcorrespondencePress enter key for correspondence information, M. Diane Tovar, RCP, Bernie Miller, RPSGT, RCP, CCSH Center for Sleep Medicine, Mayo Clinic, Scottsdale, AZ
  • DVM360, Identifying and managing behavioral changes in older dogs and cats, retrieved from the web on September 2nd, 2016

 

The Mystery Behind Those Ridges On the Roof of Dog’s Mouth

 

If you ever looked inside your dog’s mouth while he was yawning or perhaps panting, you may have noticed several ridges on the roof of his mouth. If you have been wondering what those ridges are, consider that you’re in good company; several dog owners have been wondering about those mysterious ridges too. As with most body parts in dogs, Mother Nature didn’t place those ridges on the roof of the dog’s mouth just for decoration; turns out, those ridges carry out several important functions.

dog mouth ridgesA Lesson in Anatomy

Dogs aren’t the only animals to have ridges on the top of their mouth. Humans actually have them too! If you feel the roof of your mouth with your finger or tongue, just a bit behind your front teeth, you may feel the presence of those ridges too. Those ridges are mostly located by the front part of the roof of the mouth (hard palate) while the back part is relatively smooth and soft as it’s made of tissues (soft palate). In dogs, those ridges in the mouth start just after the incisive papilla and they are quite prominent, which is possibly why they gain so much interest.

For those wondering, those ridges also have a name. They’re called rugae palatinae, or more simply palatal rugae. The term rugae simply means “ridges” while palatinae  simply means regarding the palate. According to  the McCurnin’s Clinical Textbook for Veterinary Technicians, the numbers of these rugae in dogs may vary generally ranging between 8 and 10.

Did you know? In brachycephalic dogs, these ridges are closely positioned rather than spaced out causing hair, debris and bacteria to accumulate there. (The CUSP, April 2005)

Interesting Functionsridges dog mouth

Also known as transverse palatine folds, those ridges in a dog’s mouth as mentioned aren’t there just for decoration; rather, they carry out some important functions. According to a study conducted by Crompton AW and Musinsky C., when dogs drink, it’s thanks to these ridges that water is prevented from falling out of the dog’s mouth as the dog’s tongue is protruded. Basically, what happens is that a tight contact between the tongue’s surface and the ridges helps trap the liquid ingested from the previous lapping cycle. On top of helping a dog lap up water without spilling out, those ridges are also helpful when dogs are eating. According to M. Lynne Kesel author of Veterinary Dentistry for the Small Animal Technician those ridges apparently also aid in swallowing

“X-ray videos of dog lapping reveal the dexterity with which their tongues trap previously lapped aliquots between the rugae on the roof of their mouths and the dorsal surface of the protruding tongue, in order to access the next aliquot without losing the previously ingested one.”~The Royal Society

CLEFT PALATE PUPPY
Puppy with cleft palate

The Importance of Fusion

Since the roof of the mouth ( palate) separates the mouth from the nasal cavities, it’s important that it’s nicely sealed. During infancy, the right and left sides of the dog’s palate are fused together so to prevent problems. However, in some cases, these parts may not fuse together correctly and newborn puppies present with what is called as a “cleft palate.” A cleft palate in puppies is life threatening because these puppies are not able to nurse properly and fluids can easily up into their nasal passages and airways causing aspiration pneumonia.

Did you know? The rugae of the palate are quite unique. Indeed, in humans, they can be used as a reliable guide in forensic identification when fingerprints are not available.

 

References:

  • McCurnin’s Clinical Textbook for Veterinary Technicians, By Joanna M. Bassert, John Thomas, Saunders; 8 edition (April 19, 2013)
  • How dogs lap: ingestion and intraoral transport in Canis familiarisBiol Lett. 2011 Dec 23;7(6):882-4. doi: 10.1098/rsbl.2011.0336. Epub 2011 May 25
  • Thexton A. J.McGarrick J. D. 1988 Tongue movement of the cat during lapping. Arch. Oral Biol. 33, 331339.doi:10.1016/0003-9969(88)90066-0 (doi:10.1016/0003-9969(88)90066-0)

Photo Credits:

British Veterinary Journal, Volume 61, January 1, 1905

Wikipedia, Cleft lip in a Boxer by Joel MillsOwn work, Cleft lip in a six week old Boxer puppy. CC BY-SA 3.0

 

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