Unfortunately, when your cat is sick, it can't tell you so it's up to you as a pet owner to train yourself to be observant. A good way to keep tabs on your pet's health is to make an informal, physical exam part of your weekly cat-care routine. You may actually make it easier for your veterinarian to treat your cat because you will be bringing your pet in to see him or her before an illness has progressed too far.

Outlined below are some basic areas to evaluate in assessing your cat's health.

Eyes, Ears, Nose and Mouth: The eyes of a healthy cat are clear, bright and free of redness or discharge. The nose should be cool and moist, with no secretions. The ears should be clean and dry, with pale pink skin inside and on the external flaps, and there may be a small amount of clear or dark wax in them.

The mouth should have pink gums and lips, and the breath should be free of odor. If your cat's eyes are red, have a cloudy or mucus discharge, are coated with film, or if your cat has an increased sensitivity to light or is squinting, it may have an injury or infection and should be checked over by your veterinarian. A small amount of dried mucus in your cat's eyes is normal, the equivalent of sleep in human eyes. There may be more or less sleep at times because of dust, dirt, smog or other irritants in the air.

If your cat is shaking its head persistently, pulling its ears flat against its head or frantically scratching them, or if its ears have a foul odor, excessive wax or unusual discharge, it may have ear mites or an infection and need medical treatment.

A sticky or brownish discharge from the nose, runny eyes and sneezing are symptoms that your cat has a cold. A veterinarian should probably treat all cats with a cold. A small percentage of cats that are untreated go on to develop pneumonia or sinus infections that can plague them the rest of their lives, she says.

If your cat has bad breath, it may have a digestive disturbance, infected teeth or gums, or a urinary ailment. (The only exception is if your cat has been eating fish or other aromatic food.) Bluish or ashy colored lips, and sores or ulcers in the mouth are other signs to be concerned about.

Coat And Skin: Your cat's coat should be unbroken, smooth and soft to the touch. Its skin should be clean and free of sores, rashes and eczema. A healthy cat grooms itself regularly and rarely has matted hair.

To examine your cat's skin and coat, part the fur in several places all over the body including the legs, neck, chin and head. Signs to look for are a dull coat or dry skin, excessive shedding (except in spring), lumps or masses, swelling, bald patches, open sores, excessive parasite infestation and intense biting or scratching at the skin.

In states like California, Florida and Texas, fleas have the warmth to live year-round and the biggest skin problems by far is flea allergy dermatitis. It usually starts as tiny scabs around the neck and at the base of the tail. Patches of hair loss or brittle, broken hairs can accompany it. If the condition goes untreated, it can eventually involve the entire body. You should also check the spaces between the digits on your cat's paws. If your cat spends time outdoors, briars, stones, foxtail, sand and the salt that is used for melting snow can easily irritate the inter-digital area.

Weight Veterinarians estimate that 30 percent or more of pet cats in the United States are overweight. Obese cats have a greater incidence of liver problems, heart disease, diabetes, pancreatitis and arthritis. One way to determine if your cat needs to lose weight is by doing a body condition score on it.

If your cat is in good body condition you should be able to rub your hands over the rib cage and with gentle pressure you should be able to count each of the ribs. If you're looking down at the cat, behind the ribs there should be an indentation at the waist. When you look at it from the side, they belly should be tucked up somewhat and should not be dragging on the ground.