In this section we'll address the hair coat.
A dog's or cat's hair coat typically contains primary hairs and their associated finer, secondary hairs. The secondary hairs make up the cat's undercoat and are more numerous than primary hairs.
There's also considerable breed and individual variation observed in the numbers and types of hairs.
All dogs and cats shed their coat; it doesn't matter if it's long or short hair.
Hair growth is not continuous but occurs in a growth phase and a rest phase. Growth phase takes six to eight weeks, and the rest phase is more variable. It is at the beginning of a new growth phase that the newly forming hairs push out the old hairs and shedding occurs. The whole process is strongly influenced by photoperiod because hair follicle activity increases in response to increasing day length. The result is that shedding decreases during the winter, which also contributes to the development of a think winter coat.
Sometimes it's easy to forget that pets have a very different physiology than we do, and thermoregulation is an excellent example. Dogs and cats often have a more difficult time in the heat than we do because they cannot sweat in the same way; they don't have sweat glands throughout their skin. They do have a few sweat glands on the bottoms of their feet, but these do not play a huge role in thermoregulation. Dogs thermoregulate mostly by panting. And cats usually pant only when they're severely overheated, stressed, or in acute pain.
Cats can also dissipate some body heat through the evaporation of saliva off the coat while grooming. But for the most part, dogs and cats simply lack efficient means of ridding their bodies of excess heat.
So we need to keep this in mind and not put our pets in situations where extreme heat can harm them.
Pets should never be left in a parked car during warm or sunny weather. When it's hot outside it only takes minutes to reach dangerous temperatures inside the car, even in the shade and even if the windows are cracked. On sunny days the outside temperature doesn't even need to be that warm for a parked car to quickly become oven like inside due to the sun beating down. This means trouble for pets locked inside who will suffer from heat exhaustion or worse.
The exercise routine also needs to be modified during extreme temperatures by avoiding exercise during midday and watching dogs for excessive panting or salivation.
There is also no such thing as having too much fresh water available and proper grooming is essential.
Proper grooming can help our dogs deal with the heat, and contrary to popular belief, this means helping our dog keep its natural coat healthy, not shaving it. Many people clip or shave their dogs in the summertime with the intention of keeping them cool, but this may actually be counterproductive. The canine coat is designed to hold heat near the body in the winter, but also to insulate against the heat from the sun in the summer. In many cases leaving your dog's hair coat intact will actually provide a cool microenvironment and can also act as a sunscreen to protect the skin from UV radiation and sunburn.
Our pets can get sunburn and skin cancer just like we can. Too much sun can also cause skin ulceration, which then opens the door for opportunistic bacterial, fungal, and parasitic infections. Excessive sun exposure can also trigger some autoimmune skin diseases. Pets with lighter coloring and shorter hair are the most susceptible. Even indoor cats can get sunburn, as some ultraviolet radiation can pass through windows.
Brushing and combing or pets is essential to maintaining a healthy coat, as well as to prevent matted fur, which can be extremely painful. A matted coat can also trap moisture on the skin, creating an ideal environment for skin infections.
With the diversity of hair coat types and lengths, each dog or cat will have individual grooming needs.
Cats have a special kind of hair, the vibrissae (or whiskers). The whiskers are stiff, thick hairs found on the muzzle and above the eyes. Carpal hairs are also found on the back of the forepaw or carpal joints. These hairs are sensitive to air currents and provide sensory information about the precise position of the head and legs.
The whiskers are also protective because they portray information about objects close to the face. Stimulation of the whiskers above the eyes also triggers a protective blink reflex.