Anatomy- Page 4 of 7 - Daily Dog Discoveries

I am Your Dog’s Dewclaw

June 27, 2016June 27, 2016 by Admin

Whether your dog still has his dewclaws or you never got to see them because they were removed when he was just a few days old, it’s interesting learning more abut these structures. If you have no clue what dewclaws are, you are at the right place. Many dog owners are unaware that dogs have dewclaws until they get a closer look or they have seen them all the time but just weren’t aware they’re called this way. Today we’ll be learning more about dog dewclaws, where they are located and what they look like. We will also be taking a look at their function and how they may help a dog’s performance in some dog sports. So let’s have the dog’s dewclaw do some talking to get more familiar with this is often neglected body part.

Introducing Your Dog’s Dewclaw

Hello, it’s your dog’s dewclaw talking! You may not be much familiar with me but you may have sometimes seen a breeder advertising a litter of puppies without dewclaws on a newspaper ad or you may have heard your vet talk about me. I am basically, somewhat the equivalent of your thumb, but I am located up your dog’s leg, and, unlike the rest of your dog’s toes, I generally don’t make contact with the ground when your dog is standing. I am typically found on your dog’s front legs, but in some breeds, I am present in the rear legs too. Actually, in some dogs you may find two of us on the same paw. This is seen in the great Pyrenees ans Icelandic sheepdog. Dogs with this feature are known as being “double-dewclawed.” However, sometimes in some dogs, I may be poorly connected and prone to injury, so I am surgically removed.

If you do not see me on your dog’s front leg, most likely your breeder has removed me when your dog was a puppy and less than 5-days-old. Poor me! The breeder just snipped me off using a nail clipper and the puppy obviously squealed since the procedure was done without anesthetic! You see, I am still considered pretty much useless, and often perceived as a trouble maker as many people fear that I may get snagged on stuff when the dog is playing around or working. Since I rarely touch the ground, unlike other toes, I don’t get worn down and this may cause me to grow quite long and require frequent trims. In many cases, I am simply removed so the dog can adhere to its breed standard. However, as of late, people have been discovering that I am there for some reason, rather than being a useless inconvenience worthy of being tossed away.

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I am There for a Reason!

Even though I may look like a useless structure, more and more people are discovering that I have several functions. First of all, let’s take a closer look into my anatomy. According to veterinarian and rehabilitation specialist Christine Zink, I am attached to five tendons and such tendons are attached to a muscle. Hey, don’t know about you, but to me this suggests that I must have some sort of functionality!

If you look at the Norwegian lundehund dog (which, by the way sports six toes!) and what these dogs used to do for a living, you will see how I was considered an asset more than an inconvenience. But without going back in time or visiting distant lands, you may be interested in discovering that even the average dog may actually need me.

Dogs Use Me!

Sure you likely won’t see your dog using me to send text message or engage in some innocent thumb-twiddling activity, but please stop labeling me as useless. If your dog is able of grasping a toy, bone or stick it’s often thanks to me that he has such good manual dexterity. Indeed, I can help dogs grasp objects and hold them in place so they can effectively gnaw on them.

I also play a role in helping Rover climb up, (ever known some dogs can climb trees?), and when he has a sudden itch, my extra nail can come handy in reaching certain hard- to-reach spots.

I Prevent Torque

If your dog is a working dog or simply loves the sport of agility, you may want to think twice before thinking of me as useless and snagging me off. You see, when your romps around at a fast pace and makes a tight turn, it is thanks to me that your dog’s leg doesn’t twist on itself.

Indeed, according to Christine Zink, when dogs canter or gallop, and then make a quick turn, their dewclaws get in contact with the ground, digging in to provide more traction and preventing the dogs’ legs from getting potentially twisted or injured.

” I have seen many canine athletes with carpal arthritis. Interestingly, this condition is much more common in dogs that have had their front dewclaws removed” ~ Dr. Christine Zink, veterinarian and rehabilitation specialist.

When Things Go Wrong

Did I already say that sometimes I can be a troublemaker? Because I don’t wear down as the other nails on the dog’s toes, I may grow quite long and if I am not trimmed often enough, I can even embed in the dog’s paw pad. Sometimes, I am weak and barely attached. When I flimsy like that, I tend to get caught on something and may cause pain, bleeding and sometimes even an infection. Yes, I can’t blame you, it’s annoying to deal with these inconveniences, especially when I am not structured too well, but please wait before thinking that my presence is always bad news!

Did you know? While the general trend in mammals is to have five toes at the end of a leg, fossil evidence shows that a loss of toes in cursorial animals (such as dogs) was convenient as it made for a lighter foot, allowing dogs to maintain higher speeds over long distances.

“Members of the dog family (canids) have small feet, with usually four digits in contact with the ground. The small size and weight of their limbs requires less energy to move, allowing them to run more efficiently.”~ John Buckwalter, Professor, Physical and Life Sciences, SUNY College of Technology, Alfred, NY

The Bottom Line

As seen, I carry out several functions! Perhaps this is another reason why (other than the obvious pain factor) removing me has become illegal in some countries. You see, people often remove me for cosmetic reasons only rather than medical ones, which is a shame because I am not totally useless as people often portray me. I hope this article has helped you understand me and has raised some awareness of my important functions. In the meanwhile, I wish you and your dog, a good rest of your day (and, Rover, no more thumb-twiddling please!)

Your Dog’s Dewclaw

References:

MadSci Network, Why do dogs have dewclaws? and why are they only in the front?John Buckwalter, retrieved from the web on April 10th, 2o16.
Vertebrates: Structures and Functions, By S. M. Kisia, CRC Press (April 12, 2010)
Do the Dew(claws)? by M. Christine Zink DVM, PhD, DACVSMR, retrieved from the web on Aprile 10th, 2016

Photo Credits:

Letter “D” in the image indicates the dewclaw on this dog’s front paw. Letter “E” is the carpal pad. Amos T Fairchild – own work (photo and GIMP modifications) CC BY-SA 3.0
Wikipedia, Foot of a Norwegian Lundehund. Picture taken by myself, User:ZorroIII, Creative Commons Attribution-Share Alike 3.0 Unported license.
jaimekay16, agility163, Flickr creative commons (CC BY 2.0)
Picture of dual dewclaw on hind leg of Border Collie / Burnese mountain dog 5 month old puppy, by VinCBR900 Licensed under the GFDL by the author; Released under the GNU Free Documentation License
Wonderlane Rose, a puppy, chewing on a bone, south U District near the Montlake Cut, Seattle, Washington, USA, Flickr creative commons CC BY 2.0

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I am Your Dog’s Hypothalamus

June 27, 2016June 20, 2016 by Admin

Among the many structures that are part of a dog’s brain, the hypothalamus deserves a place of honor. This is a tiny structure carrying out many important roles. Responsible for many nervous system and metabolic processes, life without a well-functioning hypothalamus would equate to a total disaster, surely leading to the wipe-out of an entire species. So today we will be discovering more about a dog’s hypothalamus, the many roles this structure plays in a dog’s life and the negative consequences when things go wrong. So let’s have the dog’s hypothalamus directly tell us his/her story!

Introducing the Dog’s Hypothalamus

Hello, it’s your dog’s hypothalamus talking! As you already know, I am a tiny structure that resides in your dog’s brain. but don’t underestimate my size! My name derives from my location, the word “hypo” is the Greek word for “under” while the word “thalamus” refers to “the part of the brain where a nerve emerges.” I am therefore called this way because I am located just below the thalamus, the dog’s relay center for sensory and motor pathways in the brain. I play an important role in connecting the dog’s nervous system with the endocrine system and do many, many things. Following is a rundown of the many tasks I am proud to accomplish!

I am a Gauge

I am responsible for maintaining homeostasis, a state of balance or equilibrium in your dog’s body despite changes that are often outside of your dog’s control. It is thanks to me therefore that your dog is able to survive and engage in normal day-to-day activities. Here is a a brief rundown of some of my important tasks:

I works as a thermostat, making sure your dog’s body temperature is maintained at a a constant level. This is known as “thermoregulation” For example, when I detect a fever and its associated rise in temperature, I will send commands so to (hopefully!) be able to lower it down to its normal levels. In the same way, should I detect cold, I will get your dog to shiver so his temperature can be brought back up.
I make sure your dog’s blood glucose levels stay within normal levels and I regulate your dog’s appetite. According to Pet Education, when glucose levels are high, as seen after a meal, insulin is released and glucose is therefore allowed to access the cells within me. This increase in glucose therefore decreases the sensation of hunger. However, after a while, once blood glucose levels drop, since the cells within me have less glucose available, I will trigger a sensation of hunger so that I am replenished with glucose again.
I ensure your dog’s blood pressure stays within a normal level. By the way, normal in dogs is considered Systolic 140, Diastolic 75 mm Hg.
I monitor your dog’s body water content and electrolyte balance triggering thirst so your dog drinks and replenishes those fluids as needed.
I regulate your dog’s sleep, keeping an eye on those wake-sleep cycles and circadian rhythms.

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I am a Working Partner

You’ll often find me working on controlling hormones that are released by the pituitary gland, also known as the ‘master endocrine gland’ of your dog’s body. You see, the pituitary gland and I are close friends connected by a slender stalk. Upon receiving a signal from the nervous system, I secrete special neurohormones which are responsible for stopping or starting the production of pituitary hormones (releasing or inhibiting factors). Several of these hormones play a role in maintaining homeostasis as discussed above. The hormones include the following:

Anti-diuretic hormone (ADH,) also known as vasopressin: a hormone secreted by the posterior pituitary gland that causes the kidneys to conserve water by concentrating urine and reducing its volume. Basically, an osmoreceptor, a smart sensory receptor that’s primarily present in me, detects changes in the dog’s blood level of dilution. If the blood is too concentrated or diluted, a signal is sent to the me so that I can increase or decrease vasopressin (ADH) in an effort to return the dog’s blood concentration to normal.
Corticotropin-releasing hormone (CRH): a hormone that tells the dog’s anterior pituitary gland to trigger the adrenal glands to release corticosteroids, as a response to physiologic, psychologic or emotional stress (the “fight or flight” response.)
Gonadotropin-releasing hormone (GnRH): a hormone that tells the anterior pituitary to release follicle stimulating hormone (FSH) and luteinizing hormone (LH). These are hormones that work as a team to ensure the dog’s ovaries and testes work normally.
Thyrotropin releasing hormone (TRH): a hormone that causes the release of thyroid stimulating hormones (TSH), responsible for releasing thyroid hormones.
Oxytocin: a hormone that is known to help release breast milk and that stimulates contractions of the muscles of the uterus during birth.
Prolactin-releasing hormone (PRH) a hormone that tells the anterior pituitary to induce the production of breast milk courtesy of prolactin.
Prolactin-inhibiting hormone (PIH)a hormone that inhibits prolactin, and thereby, inhibits milk production.
Growth hormone-releasing hormone (GHRH): a hormone that tells the anterior pituitary to release growth hormones.
Growth hormone-inhibiting hormone (GHIH,) also known as somatostatin,: a hormone that tells the anterior pituitary to inhibit growth hormones.

Did you know? Darcy F. Morey, in the book “Dogs: Domestication and the Development of a Social Bond” explains how the hypothalamus was a structure that sustained significant changes in the neurochemical features of domesticated foxes in Belyaev’s famous farm fox experiment.

When Things Go Wrong

When I secrete insufficient amounts of corticotropin- releasing hormone (CRH) it can trigger secondary hypoadrenocorticism (Cushing’s disease). Basically, here’s what happens. I secretes corticotropin-releasing hormone, CRH, which acts on the pituitary gland, triggering it to release adrenocorticotropic hormone (ACTH), which in turn stimulates the adrenal gland to produce cortisol. The cortisol then returns to the hypothalamus and the pituitary gland which regulate the production of CRH and ACTH. Now, sometimes adrenal glands are affected by tumors which cause them to release excessive cortisol. The more cortisol the adrenal glands secrete, the less CRH and ACTH are secreted, which, you named it, leads to problems.

Even though it’s possible for thyroid problems to arise due to a dysfunction taking place anywhere in the hypothalamic-pituitary-thyroid axis, according to Merck Veterinary Manual the chances for this happening are fortunately quite low considering that over 95 percent of clinical cases of hypothyroidism derives from destruction of the thyroid gland, a condition known as primary hypothyroidism.

I also play a role in the onset of diabetes. Remember how I explained how I cause a sense of hunger when my cells are not receiving glucose? Well, in diabetes, despite the production of glucose, my cells are unable to receive any glucose so they keep informing the body that it is hungry and needs food! So affected dog will eat more, but since the glucose doesn’t ever get to reach my cells, it will build up in the bloodstream, and sometimes at dangerous levels!

Did you know? In a study by Denis Burdakov, Simon M Luckman, and Alexei Verkhratsky the authors explain that the brain risks becoming irreversibly damaged when it’s deprived of glucose, even if just for a few minutes! The incredible importance of having adequate concentrations of glucose is likely why the brain itself has evolved to becoming the main means for monitoring and responding to changes in glucose, rather than relying on other peripheral organs like the liver!
Last but not least, in certain circumstances, I can become damaged such as in the case of a car accident, a surgery gone wrong, degeneration due to old age or the presence of a tumor (usually detectable via MRI). When this happens, the symptoms you notice will vary based on the part of me that’s damaged. As you can imagine, since I carry out so many tasks the health repercussions can be many!

The Bottom Line

As seen, I am quite an important structure! Actually, I think I play the most important role in the dog’s endocrine system. By telling the pituitary gland to release certain hormones, I make sure that all the internal processes of your dog’s body are working normally as they should. Hey, here’s an interesting final fact for you: I am an area of the brain that has well-documented differences between males and females. Just thought this is another interesting fact you may be interesting in that makes me even more unique!

Yours truly,
Your dog’s hypothalamus

References:

Dogs: Domestication and the Development of a Social Bond, By Darcy F. Morey, Cambridge University Press; 1 edition (April 12, 2010)
Introduction to Veterinary Anatomy and Physiology, By Victoria Aspinall, Melanie Cappello, Butterworth-Heinemann; 2 edition (May 4, 2009)
Pet Education, Diabetes Mellitus in Cats: Causes & Characteristics, retrieved from the web on June 20th, 2016
Long Beach Animal Hospital, Cushing’s, (Hyperadrenocorticism), retrieved from the web on June 20th, 2016

Photo Credits:

Wiki Vet, Canine Brain Cross Section Courtesy of BioMed Image Archive, Creative Commons Attribution Non-Commercial No-Derivatives 3.0 License.

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I am Your Dog’s Meniscus

June 27, 2016June 13, 2016 by Admin

You may have never heard about your dog’s meniscus, or you may have heard it the very first time when your vet took an x-ray and noticed some damage to this structure. Truth is, the dog’s meniscus is a body part that lives for the most part in the shadow, but that can awaken abruptly though when it starts to give problems. So today, we’ll be learning more about this structure, it’s function and the symptoms it may cause when dogs are hurting in this area, but as usual, we’ll let the dog’s meniscus do most of the talking.

Introducing The Dog’s Meniscus

Hello, my name is meniscus and I am a”C-shaped” structure found right by your dog’s hind knee, but to be more correct, let’s call it your dog’s stifle. To be exact, I sit right between your dog’s tibia and femur where special ligaments just like seat belts keep me nicely strapped in place. What does my name mean? Meniscus derives from the ancient Greek word meniskos which means “lunar crescent.” I likely got my name because my shape closely resembles a half moon. You may be interested in learning that the plural of meniscus is menisci, considering that there are actually two of us by your dog’s tibia: the inner side one is called the “medial meniscus” while the outer side one is called the “lateral meniscus.”

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I Act as a Shock Absorber

I am made of porous material but tend to release synovial fluid when I am compressed so that the surface of your dog’s femur and tibia glide together and don’t risk being damaged by friction. My shock absorbing effect therefore allows your dog to romp happily without worrying about those joint structures getting damaged.

When Things Go Wrong

When everything goes well, I keep those joints nicely lubricated and your dog romps happily about without ever noticing me. However, sometimes I can give signs of trouble, especially when your dog’s tibia and femur is no longer stable at it should be. This tends to happen when there is some sort of injury to the dog’s anterior cruciate ligament tear that stabilizes the joint. When this happens, I may get wedged in between these unstable parts, which is often seen happening with the medial meniscus which is less mobile compared to the lateral one, explains Ann L. Johnson, Dianne Dunning in the book “Atlas of Orthopedic Surgical Procedures of the Dog and Cat” Repeated friction of me can therefore lead to the early onset of degenerative joint disease, and if I move about repeatedly, I can also cause damage to the dog’s femur bone. Common signs of damage to me include hind leg pain and lameness in dogs. Stabilizing the joint is therefore key to minimizing damage.

Did you know? According to Douglas H. Slatter, author of the book “Textbook of Small Animal Surgery Volume I, statistically, dogs with a partial ligament tear have quite a low chance for developing meniscus damage; whereas, dogs with complete tears have an 80 percent chance for developing this complication.

I hope this article has helped you understand me better. As seen, I am quite an important structure! So if your dog’s knee for some reason or another becomes unstable, keep in mind the risk for potential damage to me and neighboring structures. Your dog’s knee and I will thank you! Yours respectfully,

Your Dog’s Meniscus

Photo Credits;

Dog meniscus damage and tear.Source: By Mysid [Public domain], Wikimedia Commons

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Dog Breeds With Webbed Feet

November 26, 2016June 9, 2016 by Admin

Webbed feet consist of toes connected by a membrane and are characteristic of animals with a history of spending time in aquatic environments. Just like flippers, the main function of webbed feet is to help animals effectively paddle through water. On top of helping water creatures propel themselves through water, webbed feet also help them walk over muddy surfaces. Animals with webbed feet therefore have a history of leading an amphibious life (able to live both on land and in water). While dogs are terrestrial animals, some dog breeds are known for having webbed feet, however, there is a substantial difference between their feet and the webbed feet of animals who spend time in the water.

“If It Waddles Like a Duck”

Water and land creatures such as ducks, frogs, geese, swans and otters are known for having webbed feet.

Because these animals spend a good amount of their life in water, their feet are heavily webbed, and when they walk on land, they may not be very “dexterous” walking over land as terrestrial animals (think ducks, swans and geese waddling).

Dogs, on the other hand, being terrestrial animals, tend to have minimal webbing between their toes.

As cursorial animals that walk on their toes, their feet have been crafted in such a way as to allow them to effectively walk and run over land.

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A Touch of Webbing

If you carefully take a peak at the feet of dogs, you’ll likely notice how they all have a bit of “webbing” in between one toe and another. This is normal.

Even humans have a certain extent of “webbing” with some skin found between one finger and another.

This “webbing” though is quite a far cry from the webbing we see in animals who spend more time in the water.

However, interestingly, there are some dogs breeds who have more webbing compared to others. Let’s therefore focus on several dogs breeds with webbed feet.

Dogs Breeds With Webbed Feet List

Dog breeds who have more webbing compared to other dogs are those that have been selectively bred to work in water. This is something that has been noticed for quite some time and is even mentioned by Charles Darwin in the book ” The Variation of Animals and Plants Under Domestication.”

In the book, Darwin mentions how Isidore Geoffrey noticed that in Newfoundlands the webbing reached the third phalanges, while in other dog breeds it extended just up to the second.

According to the American Kennel Club those webbed toes therefore play an important role for water-retrieving dog breeds, helping them swim.

What dog breeds have webbed feet? Following are several dog breeds with a history of working in water and known for having webbed feet:

List of Dog Breeds With Webbed Feet

Portuguese water dog:
Otterhound
Newfoundland
German Wire-haired Pointer
Nova Scotia Duck Tolling Retriever
Weimaraner
Chesapeake Bay Retriever
Wirehaired Pointing Griffon
American Water Spaniel
Labrador retriever

Did you know? All the embryos of terrestrial vertebrates have webbed feet, but later on, as they develop and form, through a process known as apoptosi (a process of programmed cell death) the webbing it then eliminated, explains Nelson Çabej in the book “Epigenetic Principles of Evolution.”

References:

The Variation of Animals and Plants Under Domestication, Volume 2. Voorkant · Charles Darwin. J. Murray, 1868.
American Kennel Club, Glossary, retrieved from the web on June 9th, 2016
Epigenetic Principles of Evolution (Elsevier Insights) 1st Edition by Nelson R. Cabej, Elsevier; 1 edition (December 5, 2011)

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I am Your Dog’s Supraorbital Whiskers

June 27, 2016June 6, 2016 by Admin

A couple of weeks ago, we discovered the dog’s inter-ramal tuft, a solitary tuft of whiskers found under the dog’s chin. Today instead, we’ll be discovering the dog’s supraorbital whiskers. Mother Nature hasn’t placed those whiskers casually in a meaningless fashion. Instead, whisker placement was strategically thought with a dog’s survival and well-being in mind. So why do dogs have supraorbital whiskers? Let’s listen to the dog’s supraorbital whiskers story and discover more about them.

Introducing Your Dog’s Supraorbital Whiskers

Hello, it’s your dog’s supraorbital whiskers talking! As the name implies, we are a tuft of whiskers found on top of your dog’s eyes. The word “supraorbital” indeed means “situated above the orbit of the eye, where in humans the eyebrows are located. ”

Indeed, many people confuse us and think we are the equivalent of human eyebrows. Eyebrows in humans have a specific purpose: to prevent salty sweat from pouring down from the forehead to the eye socket. It is thanks to the eyebrow’s arched shape and slant to the side therefore that sweat flows sideways.

Dogs are not equipped with eyebrows for the simple fact that they do not sweat in the same way we do, explains Stanley Coren, in the book “How to Speak Dog.” So if we aren’t the equivalent of human eyebrows, what is our original function?

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The Dog’s Antennae

Your dog’s whiskers are unlike any other hairs found on your dog’s body. Whiskers are made of stiffer and thicker hairs that sprout from a hair follicle that is highly innervated (supplied with nerves.) The purpose of these nerves is to relay important information in regards to the dog’s surrounding environment. Whiskers are also known as “vibrissae,” which comes from the Latin word “vibrio” which means “to vibrate.” Basically, when these hairs get in contact with something in the dog’s environment, they “vibrate” like antennae and transmit information to the dog’s brain so that the dog can make decisions about how to navigate around obstacles. For instance, the whiskers on the dog’s upper lip may help him determine whether he can squeeze through a tight space without risking getting stuck; whereas the whiskers on the dog’s chin help provide information about obstacles found under the chin, which is a blind spot.

Did you know? According to Grammarist, both in the U.S. and Canada, the plural of the word antenna is antennae when used to depict the flexible sensory appendages found on insects and other animals; whereas antennas is used to depict the metallic apparatus used for sending electromagnetic signals.

A Protective Device

Back to us, your dog’s supraorbital whiskers, we sit there just above your dog’s eyes for a very good reason: to protect them. Your dog’s eyes are quite delicate and oh, so very important structures for his survival! A dog’s eyes can easily be poked or injured by protruding objects such as branches.

The moment we therefore detect something dangerously close to your dog’s eyes, the dog’s blinking reflex is triggered so that your dog can close his eyes before they have a chance of being harmed. You may have seen us in action before but didn’t really think much about it when you pet your dog’ face, and inadvertently touch us causing your dog’s eye to blink. Pretty cool, no?

I hope this article has helped you understand us better! As seen, we are there for a very good reason!

Yours truly,

Your Dog’s Supraorbital Whiskers

References:

How To Speak Dog, By Stanley Coren, Atria Books; New edition edition (April 17, 2001)

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I am Your Dog’s Philtrum

June 27, 2016May 30, 2016 by Admin

At some time or another, you may have noticed how your dog has a small indentation at the the top of his upper lip right under his nose. This vertical groove is also seen in humans, and at a first glance, it may seem to have no particular function; however, in dogs there are chances it has a distinct role that’s worthy of mentioning. So today, let’s hear this small structure’s story.

Introducing Your Dog’s Philtrum

Hello, it’s your dog’s philtrum talking! Yes, this is my actual name, but I am also more formally known as “medial cleft.” I am that little indentation at the top of your dog’s upper lip. I may look a bit insignificant, but rest assured I am there for a reason.

My name derives from the ancient Greek word “philtron” meaning “love potion” possibly because according to the National Human Genome Research Institute back in time, the Greeks thought I was one of the most erogenous parts of the body. This may also be why the Ancient Romans referred to me as “Cupid’s Bow.” Other than the Disneyian image of Lady and the Tramp’s spaghetti-eating kiss, dogs may care less about being romantic though, so let’s get straight to the facts.

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A Sensory Purpose

In humans, other than possibly having an erogenous role, I really don’t seem to carry any other functions. For this reason I am often considered a vestigial structure with no particular role other than perhaps making the application of lipstick difficult in the dark! In mammals though speculation suggests that things may be a tad bit different.

According to the”e-Study Guide Illustrated Anatomy of the Head and Neck“ I am responsible for carrying moisture from the mouth to the rhinarium, your dog’s moist surface area of the nose. Courtesy of capillary action, I therefore may contribute to keeping your dog’s nasal area moist. As you may already know, having a wet nose aids your dog’s sense of smell as tiny water droplets that carry scent are more readily absorbed.

Did you know? According to veterinarian Allen M. Shoen, the nasal philtrum is an important acupuncture point. Known as GV-26, this point is used for treating shock and cardiovascular collapse.

CLEFT PALATE PUPPY — Puppy with cleft palate

A Residual Reminder

In animals and humans, I am a reminder of time spent in the womb. You see, during fetal development at some point the nose and the lips fuse together and I am the result. Correct timing is of the essence here. When the two parts grow and fuse together everything goes well.

Fail to grow and fuse together though, and a puppy or baby is born with a birth defect known as a “cleft palate” that requires corrective surgery.

According to the Veterinary Surgery Small Animal Textbook, in order to correct the issue, the puppy’s philtrum, nasal planum and oronasal barrier need to be reestablished. Left untreated, severe cleft palates may cause difficulty nursing aspiration pneumonia, regurgitation, and malnutrition.

As seen, I am an interesting structure that was worthy of discovering! I hope you have found this article helpful! Yours respectfully,

Your Dog’s Philtrum

References:

National Human Genome Research Institute, Anatomy of the Philtrum, retrieved from the web on May 30th, 2016
e-Study Guide for: Illustrated Anatomy of the Head and Neck: Biology, Human …By Cram101 Textbook Reviews, Cram101; 4 edition (Jan. 1 2014)
DVM360, Veterinary medical acupuncture in critical care medicine (Proceedings), Allen M. Schoen, MS, DVM, retrieved from the web on May 30th, 2016
Veterinary Surgery: Small Animal: 2-Volume Set, 1e 1 Har/Psc Edition by Karen M. Tobias DVM MS DACVS (Author), Spencer A. Johnston VMD DACVS (Author), Saunders; 1 Har/Psc edition (December 26, 2011)

Photo Credits:

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

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Do Dogs Have a Belly Button?

June 27, 2016May 27, 2016 by Admin

Among humans, belly buttons are quite noticeable whether they are “outies” or “innies,” but among dogs things are far more secretive and you might need to go on some sort of treasure hunt in search of them. If you have already tried to look everywhere under all that fur with little success, you may have been tempted to shrug your shoulders and assume dogs just don’t have one. So do dogs have belly buttons or not? Today, our mission is to discover whether it’s worthy to keep looking for one or to throw in the towel and give up.

Discovering Those Buttons

Before going on a treasure hunt in search of our dog’s belly button, it’s worthy discovering a bit more about belly buttons in dogs. We affectionately call it belly button, but to be precise the technical term is navel or if we want to be more clinically correct, the ideal term is “umbilicus.” For this article though, we’ll stick to belly button because we think it’s cuter.

What’s really a belly button though and how is it formed? It might not look like it, but a belly button is simply scar tissue that has formed at the site where the umbilical cord was once attached. Therefore, we can say that the belly button is simply a “memory” reminiscent of the good old days when we were still in our mother’s belly and our umbilical cords were attached to our mom’s placenta so that we could be supplied with oxygen-rich blood.

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A Trait of Placental Mammals

Not all animals have belly buttons though. In order for an animal to have a belly button, it must have a history of having an umbilical cord attached to a placenta. So animals like birds who hatch eggs or marsupials who incubate their little ones in their pouch, don’t fit the description.

Therefore, the only animals that can have belly buttons are animals that fall under the category of “placental mammals.”

According to the University of California Museum of Paleontology, these are mammals that prior to birth, are nourished through a placenta. Examples of placental animals include humans, cats, dogs and several non-egg laying farm animals such as goats, cows and sheep.

For ease of explanation, we can therefore state that when there’s an umbilical cord, there’s likely a belly button hiding somewhere.

Going on a Treasure Hunt

Just because your dog’s belly button isn’t readily visible, doesn’t mean it’s not there! For sure, you’ll have an easier time finding it in puppies, shortly after the umbilical cord shrivels and detaches. Afterward, as the puppies develop, their small belly buttons start becoming more and more difficult as their permanent adult coats come in.

Fact is, those belly buttons aren’t as relevant as ours. Unlike our belly buttons that are readily noticed, theirs are barely visible often resembling a small barely visible white line or scar. For some dogs, the only indication of its presence is that small tuft of hair you find right below the end of your dog’s rib-cage.

Pushing the Wrong Button

“Outies” are quite common among humans, but in the dog world if you notice something sticking out from the dog’s abdomen, you’re likely looking at an umbilical hernia, explain Caroline Coile and Margaret H. Bonham in the book “Why do Dogs Like Balls.” An umbilical hernia is simply a protrusion found around the dog’s umbilical area caused by some fat or a portion of abdominal lining or abdominal organ. Generally, the soft bulge doesn’t cause any particular complications other than looking unsightly, but they can sometimes warrant an emergency trip to the vet when a loop of the intestines become trapped, explains veterinarian Debra Primovic.

References:

Pet Place, Umbilical Hernia in Dogs, Dr. Debra Primovic, retrieved from the web on May 27th, 2016
University of California Museum of Paleontology, Eutheria, the Placental Mammals, retrieved from the web on May 27th, 2016
Why Do Dogs Like Balls?: More Than 200 Canine Quirks, Curiosities, and Conundrums Revealed, D. Caroline Coile PhD (Author), Margaret H. Bonham, Sterling (September 2, 2008)

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I am Your Dog’s Inter-Ramal Tuft

June 27, 2016May 23, 2016 by Admin

You might have never heard about your dog’s inter-ramal tuft, but rest assured, you have likely noticed this anatomical feature on your dog many, many times. This technical sounding word simply refers to that little batch of whiskers found under your dog’s chin. It may feel tempting at times for some dog owners to grab a pair of scissors and remove these hairs, but it’s worthy of thinking it over twice, especially after we discover why these hairs are there in the first place and the important role they play in a dog’s life. So today, let’s have the dog’s inter-ramal tuft do the talking so that we can better understand these facial hairs and tell us their story.

Introducing the Dog’s Inter-Ramal Tuft

Hello, and thank you for stopping by and listening to my story! I am your dog’s inter-ramal tuft, a solitary tuft of hair found under your dog’s chin. My name may appear a tad bit technical and some people like to refer to me as simply the “tuft of whiskers under the chin.” This is fine with me too, as I technically fall under the whisker category.

You see, when people think about dog whiskers, they tend to mostly think about the hairs sprouting from the dog’s muzzle, right above the lips. These whiskers are known as “mystacial whiskers” perhaps because they appear in the area where in humans mustaches tend to grow. Dogs have more whiskers though, such as those found on top of the eyes (superciliary), by the cheeks (genal) and then under the chin (yup, that’s me, the inter-ramal tuft!) As other whiskers, I am made of thick hairs that often sprout from a dark little spot of skin.

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I Transmit Information

Not many people give thought to dog whiskers, but they are not there just for decoration, they actually have a purpose. You see, dog whiskers are a tad bit different from the rest of your dog’s hair. They are thicker, longer hairs that are equipped with hair follicles that are heavily innervated with sensory nerves. You can think of them as powerful antennas that provide sensory information. Basically, when something in your dog’s environment rubs against them, they tend to vibrate and stimulate nerves in the hair follicles, explains veterinarian Dr. Mary Fuller. The stimulated nerves then transmit information to the brain under the form of feedback about their surroundings. If you think about it, this explains why whiskers are also known as “vibrissae.” The word vibrissae comes from the Latin word “vibrio” which means to “vibrate.”

The World Below Me

Think cars and only trucks have blind spots? Think again! Dogs have blind spots too and one of them is just under their chins. Now you know why your dog has sometimes a hard time seeing that treat you just tossed him that is right under his nose! While your dog’s mystacial whiskers provides your dog with sensory information about what is on his left and what is on his right, I provide your dog with information on what is found right beneath his head so to keep him informed and safe.

So it is thanks to me, the inter-ramal tuft, that your dog is able to tell how close or far his head is from his food bowl and water bowl. I also help dogs when they go on their digging adventures and try to fit their heads in holes or inside tunnels or when they sniff with their noses close to the ground. From an evolutionary standpoint, I have a history of helping dogs they were digging with their noses and nosing around looking for foods near the ground.

Take Good Care of Me

As seen, I am not just sitting there thumb dwindling all day nor am I am there for decorative purposes. I perform some important functions to keep your dog’s head protected and safe. I therefore tend to cringe when I see dogs going to the groomer and having me chopped off just to provide for “a cleaner” outline of the jaw. Many times groomers are forced to chop me off, as it would be very difficult to avoid me as the dog’s facial hairs are trimmed off (think poodles). However, the good news is that once trimmed off, I will readily grow back. In the meanwhile though, according to veterinarian Roger L. Welton, your dog will need to adjust to the way he senses his surroundings.

I hope this has helped you understand me better! Hiding, down right under your dog’s chin, I live a bit in the shadow, so it is easy to forget about me! Now that you know me better, you can have a better idea of what I do when you watch your dog navigate the world. In the meanwhile, I send you dear regards.

Your Dog’s Inter-ramal Tuft.

Did you know? According to Stanley Coren, there are several areas of the dog’s brain purposely crafted to register tactile information. Out of all these areas, nearly 40 percent is dedicated to the regions of the dog’s facial area, particularly the areas of the dog’s upper jaw.

References:

Vet Street, What’s the Deal With… Whiskers? by Dr. Mary Fuller, retrieved from the web on May 23, 2016.
Psychology Today, Why do Dogs Have Whiskers, by Stanley Coren, retrieved from the web on May 23, 2016

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Discovering Dogs With Stunning Brown Eyes

August 2, 2016May 22, 2016 by Admin

They say eyes are the windows to the soul, and those brown eyes in dogs are truly expressive! When it comes to dogs, Mother Nature seems to have equipped the majority of dogs with brown eyes and made it the default color, but occasionally you may stumble on dogs with other eye colors. This seems to also be a common pattern in many other animals, with brown being the most popular color on the palette when it comes to eye colors. Despite the fact that dogs are likely the most varied looking animal on earth (they come in so many shapes, colors and sizes!) it may seem a bit peculiar that Mother Nature got a bit stingy in the eye color department, but for sure she was generous in giving those brown eyes different hues. Whether your dog has amber eyes, hazel eyes or light brown, medium brown or dark brown eyes they sure have quite an expressive touch!

A Matter of Melanin

What determines how dark a dog’s eyes will become? Genetics aside, it’s a matter or melanin. The colored eye part of the eye that encircles the dog’s black pupils is known as the “iris” and its pigmentation varies from one dog and another depending on its concentration of melanin, a pigment that is responsible for giving color to skin, coat and eyes.

Therefore, dogs with brown eyes have a greater concentration of melanin in their iris compared to dogs with lighter colored eyes. Without melanin, dogs would be albino and have a white coat, pink skin and likely their eyes would be pinkish in color.

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Age of Onset

Melanin production doesn’t start from the get-go. Because of this, most puppies are born with blue eyes. As the pups develop, their eyes will turn their permanent color at around 2 months of age, explains Stanley Coren in the book: “Do Dogs Dream? Nearly Everything Your Dog Wants You to Know. ” By this time, most puppies will therefore develop brown eyes. No change by this time frame may be indicative that the blue eyes are likely to stick around in dogs genetically prone to having blue eyes.

Coat Color Matters

The shade of eye color in dogs can also vary based on coat colors. For example, according to Powerscourt Cocker Spaniel Breeders, in a puppy with a merle coat, the blue eyes will fail to darken because the merle gene dilutes the melanin pigment, therefore the blue eye color becomes permanent in this case.

When it comes to brown eyes, certain shades are exclusively seen in certain coat colors. For instance, according to Dog Genetics, liver dogs always have amber eyes as the liver gene dilutes the brown eyes to amber and the nose is diluted to light brown. Amber eyes may range from light brown as seen in the Pharaoh hound and Anatolian shepherd, to yellow or even almost grey as seen in the Weimaraner. Amber eyes are also popular in dogs with a blue or isabella coat, and sometimes amber or copper eyes are present in dogs with black pigment.

A Softer Look

Most dog breed standards call for dark brown eyes in our canine companions. Interestingly, canines in the wild instead have lighter colored eyes compared to our domesticated dogs. Wolves, which are the dog’s ancestors, often sport an eye color ranging from gold, to amber or light brown with hues of yellow or even gray, claims Lisa Dube Forman, an American Kennel Club Dog Show Judge for Irish Wolfhounds and Afghan Hounds.

There may be chances that domesticated dogs were selectively bred to have darker eyes due to cosmetic appeal. Lighter colored eyes referred to as the yellow “bird of prey” color is often frowned upon in several breed standard (it’s a serious fault in the Rottweiler and means for disqualification in the cane corso and Polish lowland sheepdog breed) as it tends to give dogs an unappealing harsh look according to the American Kennel Club.

Dogs With Beautiful Brown Eyes

References:

Dog Genetics, Eye Colors, retrieved from the web on May 22nd, 2016
Do Dogs Dream?: Nearly Everything Your Dog Wants You to Know, By Stanley Coren, W. W. Norton & Company; 1 edition (July 16, 2012)
Encyclopedia of K9 Terminology By Edward M. Gilbert, Jr, Patricia H. Gilbert, Dogwise Publishing (August 30, 2013)
American Kennel Club, Glossary, retrieved from the web on May 22nd, 2016
Powerscourt, W. W. Norton & Company; 1 edition (July 16, 2012) retrieved from the web on May 22nd, 2016
The Canine Chronicle, The Eyes Have It, By Lisa Dube Forman, retrieved from the web on May 22nd, 2016

Photo Credits:

Siberian Husky with brown almond-shaped eyes. by 878photo CC BY-SA 3.0

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Discovering The Function of a Dog’s Carpal Pads

December 5, 2016May 20, 2016 by Admin

Hey, what’s that foot pad doing all alone on the dog’s front legs, right above the wrist? One may wonder at this point whether it’s a vestigial structure, in other words, an anatomical feature that no longer seems to have a purpose in the dog’s life. Last time we checked, it just sat there and Rover didn’t seem to put it to good use. However, just because we haven’t seen our dogs putting that foot pad to use, doesn’t mean that it’s useless and not worthy of existing! So today, we’ll be discovering the fascinating function of a dog’s carpal pads.

A Lesson in Anatomy

To better understand the function of the dog’s carpal pads, let’s first learn more about paw pads. Upon lifting your dog’s front paw (avoid doing this if your dog doesn’t like having his paws handled) you will notice several paw pads.

The largest of all is the central heart-shaped metacarpal pad surrounded by the several smaller digital pads associated with each toe. These paw pads are made of thick layers of fat and connective tissue and comprises five (yes, you heard it right five!) layers of skin so your dog can walk comfortably over several terrains. A little bit higher, on the inside of the leg is the dewclaw, another digit with its associated nail.

Then, hanging around the wrist area, you’ll find the dog’s carpal pad. This pad is similar in structure to the other paw pads but it doesn’t have an associated nail, it’s only found on the dog’s front feet and it’s also known as “stopper pad.”

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Do these little hints help you get an idea about what’s the original purpose of the dog’s carpal pads?

Did you know? According to the book “Peak Performance EBook: Coaching the Canine Athlete, by Canine Sports Productions, the skin on the dog’s foot pads is the thickest skin on your dog’s body.

Anti-lock Braking System

So far, we know that a dog’s carpal pads hang around the dog’s wrist area, that they are made of very tough skin and that they are only present on the dog’s front legs. We also know that they are sometimes referred to as “stopper pads.” So what’s the purpose of these pads? If you are still scratching your head, no worries! Their functions aren’t as obvious as we barely can see them in action unless we can witness stop action movements when dogs run at full speed.

According to veterinarian Chris Zink, in the midst of when a dog canters, there’s a brief moment when the carpal pad makes contact with the ground as the other front leg and the rear legs get ready for the next stride. During this time, should the dog decide to make a quick turn or stop abruptly, the carpal pad, along with its associated dewclaw, provides extra traction, and should the dog decide to stop, it’ll work as a braking device, hence its name “stopper pad.”

Bumper and Balancing Act

If you also watch carefully as your dog lands after a jump, you may also notice how the carpal pad makes contact with the ground.

In this case, according to the book “Peak Performance EBook: Coaching the Canine Athlete” the carpal pad functions as a bumper or cushion as the leg hits the ground.

Last but not least, the dog’s carpal pad may also help dogs stay balanced and avoid falls when dogs are walking on steep, slippery slopes.

As seen, those carpal pads are functional and quite important too!

References:

With A Flick of the Wrist, by Chris Zink, DVM, PhD (as seen in Dogs In Canada – September 2003) retrieved from the web on May 20th, 2016.
Peak Performance EBook: Coaching the Canine Athlete, By Canine Sports Productions, Amazon Digital Services LLC

Photo Credits:

Paw (dog) showing pads, by Amos T Fairchild – own work (photo and GIMP modifications) CC BY-SA 3.0
Flickr, Creative Commons, Lil Shepherd, On the Turn, CC BY 2.0

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