Dog internal systems, organs

Canine muscular system: The dog has nine muscle groups comprised mainly of the dorsal, head, neck, thorax, abdomen, pelvic region, trunk, tail and pelvic and thoracic extremities. The muscles are joined to the bones by tendons. Dogs have both voluntary muscles that are used for movement etc… and involuntary muscles such as the heart and lungs that provide the life support system of the dog. There are also muscles that allow for the control of the dog's hair and whiskers both on its muzzle and on certain parts of its body.

Canine respiratory system: Oxygen reaches the dog's lungs by way of the nasal canals, larynx and trachea. The right lung is always slightly larger than the left and the lung cavity is separated from the abdomen by the diaphragm.
Canine digestive system:
The dog's digestive system is what is responsible for turning foods into usable substances for the dog's bodily organs.

  • Beginning in the mouth the food is chewed and becomes mixed with saliva. It then passes down through the esophagus that runs inside of the dog's neck and through the diaphragm into the stomach.
  • The dog's stomach, which varies in size according to the build of the dog, is held up by ligaments. When a dog has a full stomach it is very dangerous for it to play or jump as the stomach can become twisted on itself. This is a life threatening condition that can only be treated by emergency surgery.
  • The dog's stomach is connected to the intestines where all of the nutritious substances are filtered out of the food. The small intestine is connected to the liver and pancreas whereas the large intestine ends at the dog's anus.

Canine urinary system: The urinary system is where the soluble wastes are disposed and usable fluids reclaimed. The kidneys are responsible for filtering the wastes out of the body's fluids and sending this on to the bladder. The bladder holds this liquid waste until it exits the body through the urethra.

Male dog genitals: The canine male genital apparatus is made up of the testicles in the scrotum and the penis that is covered by a sheath of skin and only becomes visible when erect. When copulating the dog's penis engorges and this is why male and female dogs can be seen stand back to back after the act of copulation. Do not try to force them apart as this can cause internal injury to both sexes. Once the males penis losses its rigidity they will separate on their own.

Female dog genitals: The female canine's genital apparatus consists primarily of the ovaries, the uterus and the vagina.

Canine anal glands: A dog's anal glands are the two small sacks bracketing the anus. They release a fluid that covers the dog's feces when eliminating. This anal sack fluid carries important information and dogs "read" this information by smelling the feces of other dogs.

seeFIDODog MorphologyInternal Dog MorphologyThe dog's internal systemsDog Sensory Organs