A Simple Guide to Understanding Dog Anatomy

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dog body inside lookDog anatomy is as complex as human anatomy. Anatomy is the study of the structures which reside within an animals body. Anatomy will vary from species to species, but if you get a good understanding of the basics of dog anatomy, then learning about other species will be a piece of cake!

What is Canine Anatomy and Why is it Important?

Dog anatomy simply the study of the anatomical and visible features that is encompassed within our canine companions. Anatomy does not just look at the physical characteristics of a system; instead, dog anatomy tells veterinarians how the various body systems work together to produce life.

Without a proficient foundation in dog anatomy, a veterinarian could not be a vet, a surgeon, or even a pharmacologist.  This is because dog anatomy is not just about knowing and memorizing structures, it is also about understanding the physiology and the biochemistry of the body.

Dog Anatomy & Physiology Explained: How Does CBD Oil Work in Your Pups Body?

So, how does dog anatomy work in relation to cbd oil?

To understand how CBD oil for dogs works, we must first understand what the endocannabinoid system is.

The endocannabinoid system is present in all living creatures, and it consists of enzymes, endocannabinoids, and cannabinoid receptors. The two most important cannabinoid receptors studied are the CB1 and CB2 receptors.

CB1 receptors are found all over the central nervous system of dogs and cats. Its primary function is to modulate pain, movement,  and memory in animals.

In contrast, the CB2 receptors are scattered throughout different organs in the body. For example, CB2 receptors can be found on an animals pituitary gland, gastrointestinal tissue, and even bladder.

Now cannabinoids are the chemical substances that interact with cannabinoid receptors to produce various physiological changes. Three types of cannabinoids can bind to receptors in your dog’s brain. These are the endogenous cannabinoids—which means the body creates these; there are synthetic cannabinoids, and then there are phytocannabinoids

A cannabis plant is responsible for the production of phytocannabinoids. Now the cannabis plant will produce many types of phytocannabinoids, some of these include delta-9-tetrahydrocannabinol aka THC, tetrahydrocannabinol, and cannabidiol.

Now, THC is responsible for producing that “high” effect associated with cannabis. However, CBD oil for dogs will contain pretty much only cannabidiol and no THC, so you’re not putting your dog at risk of becoming ‘stoned.’

Cannabinoid receptors in dog anatomy

Why CBD Oil Works So Well for Dogs!

So now that we have a basic understanding of how the endocannabinoid system works, we can dive in further to see how it works to benefit our dogs and cats.

To understand how CBD oil for dogs benefits Fido, we’ll have to come back to our CB1 and CB2 receptors.  For the entire process to begin, picture a lock and key.  The key, in this case, is your cannabidiol found in CBD oil and the lock are the receptors.

When the key—cannabidiol binds to a receptor—the lock various processes occur. If cannabidiol binds to a CB1 receptor in your dog’s brain, then chemicals such as dopamine, GABA, serotonin, noradrenaline, and histamine are released.

  • Dopamine release would improve blood flow
  • The serotonin release would decrease any anxiety and stimulate relaxation.
  • Histamine is involved in regulating inflammatory responses

Now, CB2 receptors are also activated when in contact with cannabidiol. When CB2 receptors are activated, they play a critical role in releasing anti-inflammatory cytokines. In other words, CB2 receptors can significantly influence ones inflammatory and immune response.

If you’re interested in CBD oil for dogs, check out Honest Paws: a CBD brand for all types of doggies.

5 Fun Facts About the Anatomy of a Dog

Do you want to impress your friends at a party? here are some fun facts about dog anatomy you can throw at them!

  1.  The raw meat and grain-free diet is a big hype! There’s no denying that a lot of people today firmly believe that dogs must be fed on raw meat, low grain diet because they are carnivores! This is not true, scientists firmly believe that dogs are actually omnivores as they are biologically capable of utilizing plant-based protein for energy.
  2. Did you know that dogs have a third eyelid? A dog’s third eyelid is also known as the nictitating membrane and it’s pretty much remains retracted all the time. Sometimes, the third eyelid may prolapse completely and this condition is called a cherry eye.
  3. Although they have very few taste buds, they compensate with their incredible sense of smell. Did you know dogs have more than 300 million olfactory receptors! A scientist once said that a dog can smell and locate a rotting fruit from miles away.
  4. Ever wonder why dogs sniff each other’s butts? Every dog has anal sacs, and each anal sac produces stinky oily fluid. The scent produced by the anal sacs allows a dog to mark its territory.  Think of the anal sacs as the dog’s body odor!
  5.  Did you know a female dog can have a litter of puppies that belong to different fathers? A female dog can mate with multiple males and can store their sperm for up to 12 days.

What’s Within a Dog Skull: Parts of the Canine Skull and More!

The skull of a dog can be broken down into two parts—facial and cranial. The facial region of a dog skull is made up of several bones, and these are the:

  • Lacrimal bone
  • Zygomatic bone
  • Nasal bone
  • Maxilla
  • Palatine bone
  • Incisive bone, and
  • Vomer bone.

As we further back towards the dog skull, we come to the cranium. Now the cranium is too made up of multiple bones, however, let us keep things simple by focusing on the neuro(cranium). The cranium is a term used to describe the bones that surround the brain. It is composed of a:

  • Occipital bone
  • Temporal bone
  • Parietal bone
  • Frontal bone
  • Ethmoid bone
  • Sphenoid bone

Through years of selective breeding, dogs are considered the only species of animal who have three different types of skull shape.

Mesaticephalic is the term given to dogs with a normal skull conformation. Examples of dogs that fall into this category are your Golden Retrievers and Beagles!

Dolicephalic refers to dogs that have a more extended and more substantial facial conformation.

Many dog breeds have a Dolichocephalic facial component, some of these breeds include the Afghan hound, Doberman Pinscher, Great Dane, and Rough Collie.

Finally, Brachiocephalic refers to dogs with a shorter facial conformation. The most notorious Brachiocephalic dog breeds include the Boston Terrier, Pug, Bulldog, and Boxer.

Understanding the Cardiovascular System of Dogs!


This is the sound your dog’s heart would make if you placed a stethoscope near it. The cardiovascular system is part of the circulatory system. It consists of the heart, blood vessels (veins and arteries), and lymphatics.

Let’s break things down even further and start at the heart.

Just like in human beings, a dogs heart will have four chambers—two atria and two ventricles. Within the heart are also four major blood vessels and these are a cranial and caudal vena cava. a pulmonary trunk, and a pulmonary vein.

So, on the left side of the heart, oxygenated blood (think of this as blood which has a lot of oxygen to give) enters the left atrium of the heart through the pulmonary veins.

From there it enters the second chamber of the heart—the left ventricle—and it is then forcefully expelled through the aorta. In veterinary medicine, this is referred to as the system circulation. In other words, the left side of the heart is responsible for taking in oxygen-rich blood and sending it through to the heart and the rest of the body.

Now, on the right side of the heart, deoxygenated blood aka blood with little to no oxygen enters the left atrium of the heart. It enters the left atrium through two blood vessels a caudal and cranial vena cava.

The caudal vena cava brings oxygen-poor blood from the lower half of an animals body. And, the cranial vena cava brings oxygen-poor blood from the upper half of the body.

After entering the right atrium, the oxygen-poor blood flows into the right atrium and will then be pumped out through the pulmonary trunk. So, where is all this oxygen-poor blood going? back to the lungs for oxygen of course!

dog drawings of dog digestive system

Where Things Get Broken Down: Understanding the Dog Digestive System

Have you ever wondered how Fluffy the dog takes his delicious CBD oil dog treats and converts them into energy?

The dog digestive system is a complex pathway that not only involves the mechanical breakdown of food, but it also consists of the absorption of nutrients.

The digestive system begins at the mouth, where food is mechanically and chemically broken down into particles. Saliva is an essential component in the process of digestion. In human beings, saliva contains an enzyme called amylase.

This enzyme is responsible for the breakdown of carbohydrates. However, the saliva of our dogs and cats don’t don’t produce any enzymes. Instead, the function of their saliva is to naturally lubricate food, making it easier to travel down the esophagus.

As the food leaves the mouth, it enters the esophagus. The esophagus is a long muscular tube that propels food down to the stomach. Now, these contractions that move food into the stomach are called peristaltic waves, and the central nervous system controls it.

Once the food enters the stomach, it undergoes further chemical and mechanical digestion. The stomach of a dog contains small folds which help with the process of grinding and breaking food down. During the churning process, gastric enzymes such as pepsin, rennin, and hydrochloric acid are secreted for the chemical breakdown of the food.

Finally, at the end of this entire process, the churned up food will enter the small intestine. There are three parts to the small intestine—the duodenum, jejunum, and ileum. The first part of the small intestine is the duodenum, and it has a close relationship with the pancreas.

The pancreas of a dog has two functions—an endocrine and exocrine function. The exocrine pancreas is responsible for secreting pancreatic juices and other enzymes into the duodenum. The purpose of the pancreatic juice is to neutralize any stomach acid that may have entered the duodenum. While the purpose of enzyme secretion is to begin the breakdown of proteins, carbohydrates, and fats.

The food then slowly beings to flow through the various other parts of the small intestine—the jejunum and ileum. If you were to look at a photomicrograph of the surface of the small intestine, you would see tiny little crypts and hair like structures.

These crypts are known as the crypts of liberkühn, and overtop of them lie villi (aka the hair-like structures). The purpose of these structures is to provide a greater surface area, so that food and nutrients can be absorbed more efficiently.

Finally, as food exits the small intestine, it enters the large intestine. Now, the large intestine is where all the water from the food bolus is absorbed back into the body.

The large intestine consists of few parts—a colon, caecum, and rectum. No digestion occurs in the colon of a dog; instead, the primary function of the colon is to store the digested food and collect any electrolytes, vitamins, and fatty acids that may be present.

This is essentially the final stage of digestion as eventually when the time is right, your pupper will release their colon contents out through their rectum.

Do Dogs have Taste Buds?

Does your dog love to eat bananas? what about salty foods?

Yes, even our canine companions have taste buds, but they don’t have as many compared to us humans. It is estimated that dogs have about 1,700 tastebuds, of these they can determine sweetness, sour, salty, and bitter foods. In addition to this, dogs also have a unique tastebud for water. Now, us humans don’t have a tastebud for water, but at least we have over 9,000 tastebuds.

Is your Dog Panting: Let’s Learn About the Respiratory System of the Dog

The respiratory system of a dog is quite a complex system. So, to keep things simple, let us learn the basics.

The respiratory system is composed of the nose, mouth, trachea, bronchi, and alveoli. This system is crucial as it is what helps us breathe, without a proper functioning respiratory system an animal will experience shock, hypoxia, and death.

When a dog inhales, they take in oxygen through the nose and mouth. The gaseous oxygen is then transported through the nasal cavity down through to the trachea.

The trachea is known as the windpipe, and it is merely a  long cylindrical tube that is composed of cartilage, muscle, and ligaments. As air flows down the trachea, it reaches the bronchi. Now the bronchi split into two halves—which is known as a bifurcation. The first half of the bronchi will branch into the right side of the lung and the second half of the bronchi will branch to the left.

As the respiratory bronchi get smaller and smaller, they begin to form a network of sacs. These sacs are referred to as the alveolar sacs, and it is where gas exchange will occur.

The respiratory system of a dog, Dog body temperature

So, what is gas exchange? And what the heck are alveoli?

Don’t worry it’s a pretty simple process.  Remember, how the heart sends deoxygenated blood back to the lungs?

A meshwork of capillaries will surround every alveolus. So, when a dog breathes in air, the oxygen travels into the alveoli sac and diffuses into the blood capillaries. This is how an animal receives oxygenated blood!

The oxygenated blood is now part of the circulatory system, where it will eventually reach the heart. The heart then pumps the deoxygenated blood back to the lungs through the veins. The deoxygenated blood contains carbon dioxide which readily diffuses across the capillary walls and to the alveoli.

So, when an animal exhales, then they are merely getting rid of that carbon dioxide. It’s that simple!

Do Dogs Sweat? What you Need to Know About Panting!

Sure, dog anatomy is exciting and all. But, have you ever wondered if dog sweat?

Sweating is the physiological response a body has when it wants to cool down. For a mammal to sweat, they require specialized sweat glands. However, dogs don’t have any sweat glands under their body, on their back, etc.

However, dogs do have sweat glands in areas where there is no fur. For example, dogs do have sweat glands on their paw pads. So although they do have sweat glands in certain regions, sweating is not the primary way dogs cool down.

Instead, dogs use another mechanism to cool themselves down on a hot summers day, and this is called panting.

The process of panting is a form of thermoregulation. Panting is an evaporative mechanism which allows a dog to cool down by increasing their breath per minute and taking shallow breaths.

How Does a Muscular Dog Move? Dog Muscle Anatomy

In dog anatomy, the muscular-skeletal system is composed of bone (the skeleton), cartilage, tendons, ligaments, and muscles. When working together in complete synchrony theses apparatus produce the ability to walk, run, and jump.

In canine anatomy, there are three types of muscle groups. Smooth muscles line the internal organs, such as the bladder, the esophagus, and stomach.  Cardiac muscles are nonstriated muscle fibers specific to the heart. And, finally, skeletal muscles are those that are attached to the extremities of a dog.

The next part of the musculoskeletal system is ligaments. Ligaments simply hold bones together, in other words, they form bone to bone attachments.  In dog anatomy, or in fact, human anatomy as well—the main function of ligaments is to stabilize joints during movement.

Tendons are often confused with ligaments, but they are distinctively different!

Tendons are fibrous tissue that attaches the bone to the muscle. These tissues are highly flexible and when placed under pressure, tendons are able to initiate movement through muscle contraction.

The Urogenital System of Dogs: How the Female Dog Anatomy is Different from Males!

The urogenital system of a dog comprises of the urinary tract and the sex organs. Starting at the urinary tract, the kidney is the first organ of the urogenital system. The kidney is a bean-shaped organ whose main function is to regulate electrolyte balance, produce hormones, and eliminate waste.

Attached to each of the kidneys are tube-like structures called ureter and each ureter directs the pre-formed urine into the bladder. So, when a dog needs to urinate, then the urine leaves the bladder via the urethra.

So, how is female dog anatomy different from that of male dog anatomy?

muscular dog running

Apart from their reproductive organs, the urinary tract system is essentially the same for both genders. The female dog anatomy will consist of ovaries, a uterine horn, a uterus, uterine body, cervix, and vagina.

The male dog anatomy on the other hand simply consists of the testis which is where sperm production occurs. A spermatic cord and various sex glands such as the prostate and vesicular glands.

So, What Cool thing about the Anatomy of a Dog Fascinated You?

Learning about dog anatomy is no walk in the park!  But, by learning your dog’s anatomy, you will slowly be able to understand your dog’s health a lot better.

Do you have questions about dog anatomy? let us know in the comments below!

Common Questions you May have on Dog Anatomy

What is the Urogenital System of a Dog?

Do Dogs have Taste Buds?

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