Pet Health: Know the Warning Signs of Illness in Cats and Dogs

In addition to routine check-ups and vaccinations to prevent common dog and cat diseases, there are signs owners should be on the lookout for in their pet. Posture, behavior, and physical conditional are all good indicators of a pet’s happiness and health, and changes in any of these reflect changes in the pet’s health.

To start, it’s important to know each pet and its normal behaviors. Animals, just like humans, have individual idiosyncrasies; some yowl or whimper when in pain, for example, while others are very stoic and only voice pain when it’s extreme or surprises them. One cat may like to groom himself immediately after eating, in the kitchen right next to the food dish, another may prefer total privacy.

Owners should also know the breed, if it can be identified, and be familiar with the specifics of the breed. Large breeds like Great Danes commonly suffer from hip dysplasia; several terrier breeds, if not all, have watery eyes.


Changes in posture, or in how an animal moves from standing to seated or laying, may indicate joint tenderness. If a large-breed dog begins hesitating before complying to a sit command, for example, he may be suffering from arthritis.

Physical Condition

Owners performing routine checks on eyes, coats, and skin will be able to catch early warning signs of infections, diseases, or nutritional deficits.

Eyes. Healthy pets have clear, bright eyes. Mucus or watery eyes may be normal for the breed, but it should be clear and minimal. Yellow or green discharge from the eyes, yellowing of the eye-whites, or white patches or swollen sections along the eyelid should be checked out by a vet.

Coats. Lustrous, soft fur is a sign of good health. Some hair loss is normal and, for breeds that have winter and summer coats, some animals shed a great deal in Spring. But be on the lookout for excessive or unusual hair loss, patchiness, or changes in fur luster or texture.

Skin. Healthy skin is supple and free of parasites, sores, or discoloration. Swelling, areas of tenderness, or sores that won’t heal should be checked by a vet.

Weight. Overweight pets are susceptible to all the ailments as humans, such as liver disease, heart disease, and diabetes. Underweight pets will suffer from nutrition deficiencies, which can be particularly detrimental in cats.


Generally speaking, happy healthy pets are alert, active, and energetic. Of course, breed, age and individual animal characteristics determine what active and energetic may mean. In the dog world, retrievers tend to have energy to spare while beagles have a calmer demeanor. It’s important to tell a vet about energy changes, like lethargy in a normally active pet or restlessness in a normally calm one.

Elimination habits indicate a variety of ailments, from constipation or urinary tract infection, to internal parasites. If a pet has trouble urinating or defecating, or has blood in the stool or chronic diarrhea alert a vet.

Changes in a cat’s sleeping or grooming habits are also signs of discomfort.

Other Warning Signs

  • offensive odor
  • excessive drinking
  • excessive panting
  • trouble breathing
  • excessive or unusual crying, whining, or meowing

Since animals don’t behave normally in the vet’s office, even when they are perfectly healthy, any information an owner can give a vet about changes in condition or habit helps the vet make a better diagnosis.