Cats conceal illness, so changes in appetite, thirst, weight, grooming or litter tray habits are often the first signs. Dental disease, obesity, kidney disease, an overactive thyroid and arthritis are among the most common problems.
A male cat straining to urinate, open-mouthed breathing and suspected poisoning are emergencies.
Cats hide pain and illness well, a habit inherited from wild ancestors for whom showing weakness was dangerous. By the time a cat is obviously unwell the problem is often advanced, so small changes in behaviour deserve attention.
Dental disease affects most adult cats to some degree. Inflamed gums and damaged teeth are painful and may show only as fussiness over food.
Obesity is widespread in pet cats and leads to diabetes, arthritis and urinary problems. Prevention is covered under feeding a cat.
Chronic kidney disease is one of the most frequent illnesses of older cats. Early signs are increased thirst and urination, weight loss and poor appetite. It cannot be cured, but special diets and medication slow it considerably when it is found early.
Hyperthyroidism, an overactive thyroid gland, also affects older cats. The typical picture is weight loss despite a ravenous appetite, restlessness and an unkempt coat. It is treatable with tablets, surgery, diet or radioactive iodine.
Diabetes is seen mostly in overweight, middle-aged and older cats and causes heavy drinking and urinating with weight loss.
Urinary tract disease causes frequent, painful attempts to urinate, sometimes with blood. Stress is a common trigger. In male cats the urethra can block completely, which is fatal within a day or two without treatment.
Arthritis is very common in elderly cats and is under-recognised because cats rarely limp. They stop jumping, groom less and sleep more. Pain relief prescribed by a vet, a warm bed, low-sided litter trays and steps up to favourite places make a large difference.
Cat flu, enteritis and feline leukaemia are infectious diseases prevented by vaccination.
Bite abscesses follow fights between cats: a painful swelling appears a few days later, often with fever and lethargy. Bites also spread feline immunodeficiency virus.
Skin disease is most often caused by fleas; see fleas, ticks and worms in cats.
Medicines intended for people or for other animals are never given to a cat without veterinary instruction.
A vet is contacted immediately, at any hour, for:
Every veterinary practice in the United Kingdom is required to provide or arrange emergency cover outside opening hours.
Some pedigree breeds carry inherited diseases, among them a heart muscle disease in Maine Coons and Ragdolls and polycystic kidney disease in Persians and related breeds. Genetic tests exist for several, and responsible breeders test their breeding cats and show the results.
A veterinary examination once a year, and twice a year from about eleven, finds many of these conditions before signs appear; blood and urine tests and a blood pressure check are often added for older cats. Veterinary treatment is paid for by the owner, and pet insurance or a dedicated savings fund covers the unexpected.