Senior Cat Health Glossary: Plain-Language Definitions for Owners

A vet visit for an older cat can come with a lot of unfamiliar words, and it is hard to make good decisions around terms you have to look up later. This senior cat health glossary gathers the feline medical terms you are most likely to meet, from the common diseases of old age to the symptoms and tests behind them, and explains each in plain language. Every entry links to a fuller, sourced guide if you want to go deeper. It is a reference, not veterinary advice, and the person to explain what any of it means for your own cat is always your vet.

What this senior cat health glossary covers

The terms below are grouped to make them easier to scan: the senior cat conditions and diseases of later life, the symptoms and signs you might notice at home, the language of comfort and end-of-life care, and the tests and odds and ends that come up along the way. Within each group they run alphabetically. These are owner-friendly definitions of cat health terms explained simply, not the full clinical picture, so treat each as a starting point and follow the link for the detail.

Diseases and conditions

Anemia: a shortage of red blood cells, which carry oxygen, leaving a cat weak and pale-gummed; common alongside chronic kidney disease. See anemia in cats.

Arthritis (osteoarthritis, OA): painful wear of the joints. In cats it rarely shows as an obvious limp; instead she stops jumping, slows down, and grooms less. See arthritis in cats.

Asthma (feline): chronic inflammation of the lower airways causing coughing, wheezing, and sometimes labored breathing. See feline asthma.

Cancer: a broad group of diseases; in cats the most common is lymphoma, often in the gut, and many are more treatable than owners fear. See cancer in senior cats.

Cholangitis (cholangiohepatitis): inflammation of the bile ducts and liver, one of the most common feline liver diseases, often part of triaditis. See cholangitis in cats.

Chronic kidney disease (CKD): a gradual, irreversible loss of kidney function and one of the most common diseases of old cats; caught early it is very manageable. See chronic kidney disease in cats.

Cognitive dysfunction (feline dementia): age-related decline of the brain, with disorientation, night-time yowling, and changed habits; a diagnosis of exclusion. See cognitive dysfunction in cats.

Dental disease: plaque, tartar, gum inflammation, and painful tooth resorption; extremely common and easy to miss because cats hide mouth pain. See dental disease in cats.

Diabetes mellitus: the body cannot use insulin properly, so blood sugar runs high; the classic signs are more thirst, more urination, and weight loss despite a good appetite. See diabetes in cats.

Fatty liver (hepatic lipidosis): fat overwhelms the liver when a cat stops eating, a dangerous but treatable emergency; it is why a cat who is not eating needs a vet fast. See hepatic lipidosis in cats.

FLUTD (feline lower urinary tract disease): an umbrella term for bladder and urethral problems, with straining, frequent trips, and blood in the urine. See feline lower urinary tract disease.

Glaucoma: raised pressure inside the eye that damages sight and is painful; in cats it is usually secondary to uveitis, and it is an emergency. See glaucoma in cats.

Heart disease (hypertrophic cardiomyopathy, HCM): thickening of the heart muscle, the most common feline heart disease, often silent until a crisis such as a clot. See heart disease in cats.

Hyperthyroidism: an overactive thyroid that speeds the whole metabolism, causing weight loss with a big appetite, more thirst, and restlessness. See hyperthyroidism in cats.

Hypertension (high blood pressure): usually secondary to kidney or thyroid disease; because it is silent, the first sign owners notice is often sudden blindness. See high blood pressure in cats.

IBD (inflammatory bowel disease): chronic inflammation of the gut causing vomiting, diarrhea, and weight loss; one leg of triaditis. See inflammatory bowel disease in cats.

Pancreatitis: inflammation of the pancreas, with frustratingly vague signs, that often travels with liver and gut inflammation. See pancreatitis in cats.

Triaditis: the combination of cholangitis, pancreatitis, and IBD occurring together, common in cats because the three organs share plumbing. See pancreatitis in cats.

Uveitis: inflammation inside the eye, showing as a red, cloudy, painful eye; in cats it is often a window onto a whole-body illness. See uveitis in cats.

Vestibular disease: a sudden loss of balance with a head tilt and circling, from an inner-ear or brain problem; alarming but often not a stroke. See vestibular disease in cats.

Symptoms and signs you might notice

Alopecia: hair loss; in older cats it often comes from overgrooming, which itself points to an itch, pain, or stress. See senior cat overgrooming.

Aortic thromboembolism (saddle thrombus): a blood clot, usually from heart disease, that lodges in the vessels to the back legs and causes sudden, painful paralysis; a go-now emergency. See weak back legs in a senior cat.

Blepharospasm: squinting or holding an eye shut, a sign of eye pain such as uveitis or glaucoma. See uveitis in cats.

Constipation: infrequent, hard, or difficult stools, common in older cats who are less mobile or a little dehydrated. See constipation in cats.

Diarrhea: loose or frequent stools; a passing upset if brief, a symptom worth chasing if it persists. See diarrhea in cats.

Halitosis: bad breath, which in an older cat usually means dental disease and occasionally kidney or other illness. See senior cat bad breath.

Icterus (jaundice): a yellow tint to the gums, the whites of the eyes, or the ear flaps from bilirubin building up; never a normal finding. See jaundice in cats.

Photophobia: avoiding bright light, a sign of a painful eye. See uveitis in cats.

Plantigrade stance: walking flat on the hocks rather than up on the toes, a sign of nerve damage from uncontrolled diabetes. See weak back legs in a senior cat.

Polydipsia and polyuria: increased drinking and urination, often the earliest visible signs of kidney disease, diabetes, or an overactive thyroid. See drinking more and losing weight.

Ptyalism (drooling): excessive saliva; in cats usually a mouth problem such as dental disease or an oral tumor, or nausea. See senior cat drooling.

Sneezing and nasal discharge: usually a virus or chronic rhinitis, but one-sided or bloody discharge in an older cat can mean a nasal tumor. See senior cat sneezing.

Vomiting: occasional vomiting can be normal, but regular vomiting in a senior cat is a reason to call the vet. See senior cat vomiting.

Care, comfort, and the end of life

Palliative and hospice care: comfort-focused care for when curing an illness is no longer the goal, centered on freedom from pain and gentle company. See how to comfort a dying cat.

Quality-of-life scale: a simple at-home scoring tool that weighs a cat's comfort and dignity, to help with the hardest decisions. See quality of life for a senior cat.

Senior: the life stage over 10 years old, under the 2021 AAHA/AAFP guidelines; a cat is mature from 7 to 10 and senior after that. Try the cat age calculator.

Status epilepticus: a seizure that lasts more than five minutes, a life-threatening emergency that needs a vet at once. See senior cat seizures.

Subcutaneous fluids: fluids given under the skin, often at home, a mainstay of managing chronic kidney disease. See how to give a cat subcutaneous fluids.

Tests, and other terms

Body condition score: a hands-on rating of whether a cat is too thin, ideal, or overweight, more telling than the number on the scale. See feeding a senior cat.

Echocardiography: an ultrasound of the heart, the definitive test for the thickened muscle of HCM. See heart disease in cats.

Intraocular pressure (IOP): the fluid pressure inside the eye, raised in glaucoma and measured painlessly with a tonometer. See glaucoma in cats.

Meningioma: the most common feline brain tumor, usually benign and affecting mostly older cats; a cause of new seizures. See senior cat seizures.

Nuclear (lenticular) sclerosis: a harmless bluish haze of the aging lens that does not steal sight, and is not the same as a cataract. See vision and hearing loss in senior cats.

Resting energy requirement (RER): the calories a cat needs at rest, the starting point for working out how much to feed. Try the cat calorie calculator.

Tonometer: the small instrument a vet uses to measure eye pressure and diagnose glaucoma. See glaucoma in cats.

Using this senior cat health glossary with your vet

A glossary is a map, not the territory. Knowing that jaundice means a yellow tint from bilirubin, or that triaditis ties the liver, pancreas, and gut together, will not diagnose your cat, but it will let you follow what your vet is saying and ask better questions. When one of these words lands on your own cat, take the plain definition here as a way in, read the fuller guide if you want the detail, and let your vet fill in what it means for her. That is the whole use of a senior cat health glossary: not to replace the expert in the room, but to help you meet her halfway. Biscuit has collected a fair few of these terms over her sixteen years, and understanding them has never made me her doctor, only a calmer, better-informed set of hands at her side.

Sources

The definitions here summarize the veterinary guidance sourced in each linked guide, drawn from the Cornell Feline Health Center, VCA Animal Hospitals, and the 2021 AAHA/AAFP Feline Life Stage Guidelines.