Adopting a Senior Cat: The Realistic Medical Package

Quick answer

An older cat can look completely well and still be carrying two treatable diseases.

Adopting an older cat is one of the better decisions you can make. It is also the one where the brochure and the reality diverge most, so here is the honest version.

Four conditions dominate feline old age: chronic kidney disease, hyperthyroidism, osteoarthritis, and dental disease. Many senior cats have two of them at once. Almost all of it is manageable rather than catastrophic, but only if you go looking for it, because a cat will not tell you.

• Ask the shelter for bloodwork and a dental assessment. If there is none, plan a senior screen in the first weeks.
• Weight loss is the single most useful early warning sign, and it is invisible without a scale.
• Arthritis in cats almost never causes a limp. It causes a cat that stops jumping.
• Twice yearly veterinary checks are the standard for a senior cat, not once.
• Budget for ongoing costs, not just the adoption fee: prescription diet, medication, and repeat blood tests.

:::danger
Never give a cat paracetamol (acetaminophen), ibuprofen, naproxen, or aspirin.

Cats lack the enzyme capacity other mammals use to process paracetamol safely. A single tablet meant for an adult human can kill a cat. It damages the blood's ability to carry oxygen and causes liver failure, and the cat becomes dull, swollen in the face and paws, and grey or brown in the gums.

Human anti-inflammatories cause stomach ulceration and kidney injury, and an older cat with reduced kidney reserve is the least able to survive them.

A stiff senior cat is exactly the animal an owner is tempted to medicate from the bathroom cabinet. There are licensed feline pain treatments. Ask your vet for one instead.
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Why a senior cat can look fine and not be

A cat is descended from a solitary hunter that is also prey to larger animals. An animal in that position that advertises weakness does not survive long, and the instinct to conceal illness does not switch off in a living room.

So the signs of serious disease in an old cat are quiet and easy to reinterpret. Sleeping more becomes "settling in". Not jumping becomes "she is getting on". Eating less becomes "he is a fussy old thing". Every one of those is also the first line of a real diagnosis.

This is why adopting an older cat is a screening decision more than a nursing decision. A physical examination and a set of blood and urine results tell you in one afternoon what watching the cat would take a year to reveal.

The four conditions to expect

Chronic kidney disease.

The commonest serious illness of older cats. The kidney loses the ability to concentrate urine first, so the earliest change at home is a cat drinking more and producing larger, heavier clumps in the tray. Later come weight loss, a poor coat, nausea, and reduced appetite.

It is diagnosed on blood and urine together, not blood alone. A urine sample matters because dilute urine can be the only abnormal finding early on. Treatment is a therapeutic renal diet, control of blood phosphate and blood pressure, and attention to hydration. Many cats live well for years after diagnosis.

Hyperthyroidism.

An overactive thyroid, usually caused by benign overgrowth of thyroid tissue. The classic picture is a cat that eats enthusiastically and still loses weight, is restless, vocalises at night, vomits intermittently, and has a coat that looks unkempt because grooming is disorganised rather than absent.

It is diagnosed with a blood thyroid hormone measurement alongside a general panel. It is one of the most rewarding diagnoses in feline medicine because it responds to treatment, whether that is daily medication, a therapeutic iodine-restricted diet, surgery, or radioactive iodine. Left untreated it damages the heart and the kidneys.

Osteoarthritis.

Extremely common in older cats and consistently under-recognised, because cats do not limp. A cat with painful joints changes its behaviour instead. It jumps less, or hesitates and then chooses a lower route. It misjudges landings. It grooms less over the back and hindquarters so the coat there mats or looks greasy. It may stop using a tray with high sides, or sleep somewhere new because the old spot is now too high.

Cats also get arthritis in the spine and elbows, not only the hips, and the pain is chronic rather than dramatic. Weight control, soft accessible resting places, ramps or steps, and a licensed feline pain medication under veterinary supervision change these cats noticeably.

Dental disease.

Periodontal disease and tooth resorption are both common in older cats, and tooth resorption in particular is genuinely painful. Cats go on eating through it, sometimes swallowing dry food whole, so the appetite tells you nothing.

Look instead for dropping food, chewing on one side, pawing at the mouth, a sudden preference for wet food, and breath that has become offensive. Proper assessment needs a general anaesthetic and dental radiographs, because much of the disease sits below the gum line. Owners are often surprised at how much brighter a cat becomes after painful teeth are dealt with.

Low, warm, non-slip, and reachable without a jump. That combination solves most of what an arthritic cat struggles with.

The ones people forget

High blood pressure.

Usually secondary to kidney disease or hyperthyroidism. Its most devastating consequence is bleeding at the back of the eye and retinal detachment, which produces sudden blindness in a cat that was fine yesterday. A senior cat with dilated pupils that no longer respond to light, bumping into things, needs to be seen the same day. Blood pressure should be measured as part of a senior check, not only after something goes wrong.

Diabetes.

Increased thirst and urination again, this time usually with a good or increased appetite and weight loss. Overweight cats are at higher risk. Many cats respond well to treatment, and some go into remission with the right diet and prompt treatment.

Cancer.

Lymphoma is the one owners meet most often in cats. Weight loss, vomiting, diarrhoea, and a reduced appetite are the usual presentation. Not every mass is a death sentence, and treatment decisions are quality-of-life decisions.

Cognitive dysfunction.

Disorientation, loud night-time vocalising, changed social behaviour, and house soiling in a cat with no medical cause found. It is a diagnosis of exclusion, so hyperthyroidism, hypertension, pain, and deafness are ruled out first.

What to ask before you commit

Shelters vary enormously in what they know. Ask anyway, and write the answers down.

The first veterinary visit

Book it for the first fortnight, before anything is wrong, so you have a baseline to compare against later.

A useful senior consultation covers weight and body condition, muscle condition over the spine and hips, a full oral examination, palpation of the neck for a thyroid nodule, heart and chest listening, abdominal palpation including the kidneys and thyroid, blood pressure, and blood and urine testing that includes kidney values, a thyroid hormone level, and how concentrated the urine is.

Bring the shelter paperwork and your own notes. If the cat has an unknown history, that first set of results becomes the reference point for the rest of its life with you.

Setting the home up

Start the cat in one room with everything it needs, not the whole house. A single quiet room with food, water, a tray, a hiding place, and a high-but-reachable perch lets an old cat build confidence without having to navigate territory it cannot yet map.

Put the litter tray on the same level the cat sleeps on. Older cats do not climb stairs at three in the morning to be polite. Use a large tray with at least one low side, or cut a low entry into a covered tray.

Separate the resources. Food, water, and tray in three different places, because cats do not like eating next to their toilet and will quietly stop using one of them if you make them choose.

Give warmth and traction. Older cats lose body condition and feel the cold, and hard flooring is genuinely difficult for a stiff cat. Rugs or runners on the routes it uses most, a warm bed at floor level, and a step or box beside any favourite high spot remove most of the daily obstacles.

Keep water easy to reach and away from the food. A cat with kidney disease that drinks more needs multiple water stations, not one bowl at the far end of the flat.

A coat that has become dull or matted over the lower back often means the cat can no longer twist to groom there.

The routine that catches problems early

Weigh the cat monthly on a digital scale and write the number down. Body weight is the most sensitive home measurement you have, and a steady downward trend appears long before you can see it by eye. Weigh yourself holding the cat and subtract if you have no pet scale.

Count what comes out of the tray. Suddenly larger or more numerous urine clumps are a real finding, and so is a cat that starts producing nothing.

Once a week, run your hands along the spine and hips and note whether the bones feel more prominent than last time.

Look in the mouth when the cat is relaxed, even briefly. Red gum margins, a broken tooth, or a smell that was not there before all justify an appointment.

Watch what the cat chooses to jump onto. A cat that stops taking a route it always took has told you something.

Take a short phone video of anything odd. Behaviour in the consulting room is rarely the behaviour you came in about.

What never to do

Do not treat pain, stiffness, or a limp with anything from the human medicine cupboard. Paracetamol and ibuprofen are lethal to cats, not merely unsuitable.

Do not give a cat medication prescribed for a dog, or leftover medication prescribed for a different cat, without asking. Doses and drug choices differ, and some routine dog products are fatal to cats.

Do not accept "it is just his age" as the end of a conversation, from yourself or from anyone else. Old is not a diagnosis. Slowing down has a cause, and the cause is usually treatable.

Do not change an established therapeutic diet because the cat seems bored of it. Renal and thyroid diets are treatments. Discuss alternatives with the vet rather than swapping to a supermarket food.

Do not put an old cat straight into a house with resident cats and hope. Territory disputes are stressful, and stress in an older cat surfaces as cystitis, appetite loss, and hiding.

Do not free-feed and stop weighing. Losing track of intake is how a cat loses a fifth of its body weight before anyone notices.

When to get help

Go immediately for straining in the litter tray with nothing produced, breathing with effort or with an open mouth, collapse, sudden loss of use of the back legs, or sudden apparent blindness.

Book within the week for increased thirst, weight loss, a drop in appetite, vomiting more than occasionally, a change in litter tray habits, new night-time vocalising, or a cat that has stopped jumping.

Book a baseline appointment even if nothing is wrong, in the first fortnight after adoption. It is the cheapest and most useful appointment you will make for this cat.

The aim is not a cat with no diagnoses. It is a cat whose diagnoses are known, treated, and no longer costing it comfort.