Cat and dog anatomy

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The cardiovascular system includes the heart and blood vessels. The cardiovascular system performs the function of pumping and carrying blood to the rest of the body. The blood contains nutrients and oxygen to provide energy to allow the cells of the body to perform work.


Artist drawing of the outside of a dog heart with labels for the atriums, ventricles, aortic arch, pulmonary artery, and coronary vessels.
Artist drawing of the inside of a dog heart with labels for the valves, ventricles, papillary muscles, septum, chorda tendinea and left ventricle free wall.


Artist drawing of the inside and outside of a cat heart with labels for all major parts.

The Lymphatic System includes lymph nodes and lymph vessels throughout the body.

Artist drawing of a dog with lymph system illustrated. A second inset drawing illustrates and labels the details of one lymph node and lymphocytes.

The musculoskeletal system includes all the muscles, bones and joints.

  • Shoulder
  • Elbow
  • Rear Leg
  • Stifle (knee)


Artist drawing of the shoulder of a dog, illustrating how the scapula and humerus fit together, with an inset drawing of the humerus head.


Artist drawing of the elbow of a dog. Three separate close up illustrations of the joint, from inside, outside and front.

Rear Leg

Artist drawing of a rear leg of a dog. Pelvis, femur and tibia are illustrated for positioning. Second illustration show how the quadriceps muscles attach to the femur and patella.

Stifle (knee)

Artist drawing of a knee (stifle) illustrating how the quadriceps tendon attaches. All major parts are labeled.
Artist drawing of a knee (stifle) without the quadriceps tendon. All major parts are labeled.

The respiratory system is responsible for taking in oxygen and eliminating waste gases like carbon dioxide. Because dogs and cats do not sweat through the skin, the respiratory system also plays an important role in regulation of temperature.

The respiratory system includes the:

  • Mouth and Nose
  • Trachea
  • Lungs and Smaller Airways (bronchi and bronchioles)

Dog Mouth


Cat Chest

Dog Chest

The organs of special senses allow the animal to interact with its environment; sight, taste, smell and hearing.

Cat Eyes

Artist drawing of a cat's face and the eye and all its parts.

Dog Eyes

Artist drawing of a dog's eye and face.

Dog Ears

Artist drawing of a dog's face and parts of the inner ear.

The urinary system is responsible for removing waste products from blood and eliminating them as urine. The genital organs are involved in reproduction.

The urinary system includes the:

  • Kidneys
  • Ureters
  • Urinary Bladder
  • Urethra
  • Genital Organs



Lower Urinary and Genital Tract

Genital Organs Male (prostate)

Genital Organs Female

The pictures in this section are reprinted with permission by the copyright owner, Hill’s Pet Nutrition, from the Atlas of Veterinary Clinical Anatomy. These illustrations should not be downloaded, printed or copied except for personal, non-commercial use.