As descendents of wolves, dogs have developed teeth that are specifically meant for tearing and ripping through meat. They are born with 28 teeth that are replaced with 42 permanent ones between the ages of 2 months and 7 months. Dogs have different types of teeth, each set performing a particular function depending on its position in the jaw. The anterior teeth are meant for holding and tearing, and are made up of 12 incisors and 4 long canines. The posterior teeth (premolars and molars) are designed for crushing food into smaller particles that are easily swallowed.
The salivary glands are also located in the jaws. Their function is to produce saliva that moistens food and starts the digestion process. The tongue is used to direct food to the rear of the throat, lick up tiny bits of remaining food and lap up water. Licking can also be a way for dogs to display affection and subservience.
The stomach, small intestine and large intestine all together form what is called the gastrointestinal system. This system breaks down food into valuable nutrients, takes in water, and gets rid of waste products. There are many symptoms of digestive problems such as vomiting or diarrhoea; these can be as a result of viral infections, worms, trauma, or eating bones or foreign objects.
The urinary system gets rid of nitrogenous waste matter from the breakdown of proteins, and also regulates the level of fluids. The kidneys clean the waste products and then send the waste to be stored in the urinary bladder. Urine is excreted through the urethra which, in males, acts as a conduit for sperm during mating. Female dogs are more susceptible to infections of the urinary tract, which usually show up as recurrent leaks of urine that may be tinged with blood.
Straining while urinating or defecating could be a sign of urinary or digestive problems. Therefore it is important for a dog owner to keep an eye out when the dog is eliminating waste, and to check the nature and colour of the waste. The veterinarian may need a sample of the urine and faeces. Diarrhoea typically expresses itself as repeated, soft or fluid faeces of a different colour than usual (yellow, gray, or black). Traces of blood in the faeces require veterinary attention. Repeated yet fruitless attempts to excrete waste can signify severe constipation or bowel blockage. A quick veterinary check up is needed if the dog has a tense, aching belly or is producing small quantities of blood-spattered, gel-like faeces.
A dog rubbing its rear end along a surface is usually linked with impacted anal glands, which is not a digestive issue. Found in a layer of muscle at the 4 and 8 o’clock positions around the anus, the anal glands hold a stinking secretion that is usually discharged during bowel movement. The secretions usually become thick and block the duct, resulting in pressure, irritation, and ultimately infection. A dog’s anal glands need to be manually and regularly cleaned by a veterinarian.