Cats are very good at hiding signs of illness. They are prey animals as well as predators in the wild and have evolved the ability to hide disease, even when it is serious. This can make identification of illness extremely challenging for the cat owner. It is very important to consult your veterinarian if your cat shows any of these subtle signs.

1. Inappropriate elimination
A cat that urinates or defecates outside of the litter box is telling you that something is wrong. Urination outside of the box can indicate multiple issues, including diabetes mellitus, kidney disease, lower urinary tract disease (infection, bladder stones, and stress related bladder inflammation), hyperthyroidism, or cancer. Defecation outside of the box can indicate problems with the gastrointestinal tract such as inflammatory bowel disease, parasites, constipation, or cancer.  Getting into and out of the box may also become painful for a cat with arthritis or musculoskeletal issues.

2. Changes in vocalization
The change in the pitch and sound of a cat’s meow may indicate that there is a problem in the area of the larynx or that a systemic illness is occurring. Cats that vocalize or howl more frequently than usual may be suffering from hypertension or hyperthyroidism.  Stress or pain can also increase vocalization in cats.

3. Bad Breath
Admittedly, cats may not always have the freshest breath, but a sudden change in odor may indicate significant dental disease, oral cancer, or even an underlying systemic illness, such as kidney disease.

4. Changes in Activity
A decrease in activity or change in daily routine can be a general indicator of illness.

5. Changes in food or water consumption
Decreased or increased water and/or food consumption may be an indicator of various illnesses.  Increased water consumption may be a result of kidney disease or diabetes mellitus.  Increased food consumption may indicate gastrointestinal disease or hyperthyroidism.  Decreased food and water consumption may occur secondary to many illnesses, all of which are serious.

6. Unexplained weight loss or gain
Sudden unexplained weight loss may be caused by hyperthyroidism, gastrointestinal disease, cancer, diabetes mellitus, or a whole host of illnesses. Weight gain and obesity can puts cats at risk for diabetes mellitus and arthritis issues.

7.Changes in Social Interactions
Cats are typically social and enjoy interacting with people and other pets.  Changes in interactions with others in the household may indicate pain, stress, or illness.

8. Signs of stress
Stressed cats may hide more, eat less food, interact less with others in the household, inappropriately urinate of defecate, and appear outwardly agitated.  Ruling out physical ailments that could result in stress is very important.

9. Changes in grooming behavior
A decrease in typical grooming behaviors is a sign of some sort of underlying health issue. It may indicate pain, anxiety, decreased energy or be secondary to obesity. Over grooming can indicate a skin issue or psychological disorder.

10. Changes in sleeping habits
Cats normally sleep during a large portion of the day. When they seem to be sleeping more than normal, it could be a sign of an underlying disease process.  If they are sleeping much less than usual, it may indicate hyperthyroidism, pain, or stressors within the household.

All of the above subtle signs of illness in felines may not be easy to pick up, especially if the changes are gradual. Veterinary wellness exams once to twice yearly are especially important for this reason. They can prevent many diseases and illnesses from reaching an advanced stage and keep our kitties happy and healthy.