Diseases of Older Cats

However observant you are, cats are good at hiding symptoms and may be very sick by the time you notice anything and see the vet. You might wonder why this is. It is an evolutionary survival trait – a sick cat attracts the attention of a larger predator; hiding symptoms may be great in the wild, but presents a problem in the home where early detection means treatment is more likely to be successful. There are many excellent cat care books (many are well illustrated) detailing feline ailments. You can also do a web search, email an on-line vet or phone your regular vet. This section concentrates on conditions more common in older cats.

Kidney Failure

The kidneys filter the blood and remove metabolic waste products which are excreted in the urine. If these waste products (e.g. urea) are not removed, blood toxin levels rise making your cat ill. The kidneys are usually the first organs to wear out. Kidney disease is ultimately fatal; early diagnosis can slow its progress. Some breeds are susceptible to kidney problems e.g. hereditary polycystic kidney disease (PKD). Due to the wear and tear of a lifetime of service, the kidneys wear out. Chronic nephritis (inflamed kidneys) resulting in scarred and shrunken kidneys, is the most common cause of chronic kidney failure in older cats.

Chronic kidney disease (Chronic Renal Failure, CRF) is a progressive, fatal condition as kidney function progressively decreases and don’t filter the blood properly. At the same time, protein is lost through the kidneys and can be detected in the urine. Supportive treatment (special diet, dialysis, drug treatment) can extend your cat’s life and give good quality of life for several months but he will lose too much kidney function to survive. He may show no symptoms until only 30% kidney function is left and his blood urea levels are extremely high.

Symptoms of kidney failure include poor appetite, weight loss, increased or excessive thirst, increased urination, bad breath, mouth ulcers and vomiting. If he goes outdoors he may show an unusual preference for drinking greenish standing water or pond water. In the later stages he may suffer seizures or coma as toxins accumulate and circulate in the blood and affect his brain. Death due to blood toxicity is slow and usually unpleasant as other organs are being poisoned.

As kidney function reduces, they produce more urine to flush out the metabolic wastes and your cat drinks more water. This is the body’s version of dialysis. The kidneys can only process a limited amount of fluid per day. Potassium, an essential mineral, is lost in the urine and low potassium levels in the blood (hypokalaemia) further damages the kidneys, causing a vicious cycle. Your vet may prescribe potassium supplements to counteract this. The effects of kidney failure can be reduced, but not cured, by medication and a low-protein, low-sodium, low phosphorus diet, which produces fewer waste products. These foods are commercially available in the US. In the UK they are available on a vet prescription. Plenty of fresh water is crucial.

Due to the cat’s low blood volume, human-style dialysis (fluid therapy) on a kidney machine is not possible. Your vet may inject extra fluid into a vein, under the skin or into the abdomen. This increases the blood volume, blood pressure in the kidneys is increased and they filter better. The effect is temporary and frequent dialysis is distressing to most cats and may require regular anesthesia which is riskier for older cats.

In the US, kidney transplants are experimental procedures in cats. The donor cat can survive on one kidney, but when the donor ages it will probably suffer kidney failure at an earlier age as there is less kidney tissue to begin with. Owners of the recipient cat must undertake to provide a loving, permanent home for the donor whose life expectancy has possibly been reduced in order that their cat lives longer. There is a huge cat overpopulation problem in the US. A sensible (but unpalatable) solution is to remove kidneys from anaesthetized cats due for destruction and then euthanize them immediately. This would eliminate the need for donor cats and use tissues which are otherwise incinerated.

In the UK, a new drug treatment for CRF was announced in 2001. It is still being trialled and is not yet generally available from vets. Fortekor is a daily tablet which can increase survival time by up to three times. It works by normalizing the blood pressure within the kidney so they filter much better. It also reduces urinary protein loss. Fortekor is not a cure, but it slows down progression of disease and gives the cat a good quality of life.


A cat’s chances of developing cancer increase with age, but cats are less prone to cancer than are dogs or humans. Cancer occurs when normal cells go rogue and start to multiply out of control. Something goes wrong with the genes inside the cell and it doesn’t know when to stop. This may be a random hiccup in the cell or may be due to cell damage due an accumulation of carcinogens (cancer-causing substances) in the body because the liver is not good at removing these. Infectious-diseases or poor immune system are also factors. Chemotherapy can give some cats a short-term remission from some types of cancer and therapies (including homeopathy) may be given to improve the immune system.

Feline Leukemia Virus (FeLV) causes lymphosarcoma. FeLV is contagious, but vaccinable. It is always fatal because of persistent secondary infections (a bit like secondary infections and cancers kill human AIDS sufferers). Symptoms are variable and non-specific so a blood test is needed. Tumors associated with FeLV commonly occur in the lymph nodes, kidneys and intestines and might only be detected by blood tests, X-rays, ultrasound scans or biopsies. Lymphosarcoma is incurable and ultimately painful. Euthanasia is recommended.

Unspayed or late-spayed female cats are at increased risk of mammary (breast) tumors. Approximately 85% of mammary tumors are malignant and the cancer often spreads to other tissues. If detected early, surgical removal can give several more years of active life as happened with one of my oldies. The tumors generally recur and become more aggressive. My own cat had a second surgery 3 years after the first. She recovered, but the tumors re-grew and affected multiple sites in her body within 3 months of the second surgery and she was euthanized 3 months after that.

Early detection is essential to improve the prognosis and some types of cancer can be "cured" completely by radical surgery e.g. amputation an affected limb. The symptoms are often non-specific and confusing, so general debility (persistent general malaise) or unusual lumps and bumps should be investigated by the vet.

Skin Problems

Skin and coat reflect internal health, any changes indicate problems inside. The hair is naturally thinner between the eyes and ears; this becomes more obvious as the cat ages. Fur may cease to grow underneath a collar. Dull, dry, oily and/or unkempt fur (so called "staring" coat) are signs that something is wrong. Fur-plucking and sucking are sign of stress. If you groom your cat regularly you will spot any changes, these could be minor or could be early warning signs of another condition.

As your cat gets older his skin becomes more fragile and less elastic. His fur may thin as his body expends less effort on maintaining his coat. Skin irritations and wounds heal more slowly. Age-related nutritional deficiencies and hormone problems can affect his skin and fur causing alopecia (balding), flaky skin and feline acne. Oil of Evening Primrose (Efamol, Efavet) in the diet is beneficial to the skin. Some owners wipe Tea Tree Oil on the skin, but this is toxic to cats. Tea Tree Oil toxins are absorbed through the skin (faster through broken skin) and build up in the liver and fatty tissues because the cat cannot break them down. Older cats have less fatty tissue so they are at greater risk from Tea Tree Oil toxins building up in the liver.

If you notice skin or fur problems, get the vet to rule out disease or serious disorders. Poor coat and skin may be treated with fatty acid supplements. Oil of Evening Primrose contains naturally occurring hormone-like substances can sometimes be used in place of corticosteroid treatments for example if the steroid treatment causes unpleasant side effects.

Muscles, Bones and Joints

Older cats may suffer chronic degeneration of muscles, joints and vertebral discs. Vertebral discs are cartilage disks between the segments of the backbone; these are the culprits in "slipped" discs. Arthritis occurs when the cartilage at the end of a bone (where the joint is e.g. the knee) wears away. The ends of the bone are no longer protected – a little like not having enough oil to lubricate parts of a car engine.

Many owners refer to their cats as being "rheumaticky", meaning he has stiff joints or is limping. If his joints become painful, he becomes less active and may become lame, stiff, reluctant to move or may suddenly stand still after getting up (due to painful joints). He may become irritable or vocal due to discomfort and may resent being handled or even stroked in certain places.

Osteoarthritis is the most common form of feline arthritis and is a degenerative condition of the cartilage at the ends of the bones; it erodes away. Sometimes it results from an injury or disease. Rheumatoid arthritis is less common and is an auto-immune condition where the body attacks its own tissues, resulting in arthritis.

The vet may need X-ray to confirm the diagnosis. Treatment varies according to the type and severity of arthritis. It can’t be prevented or cured, but the pain of inflamed joints can be alleviated. Anti-inflammatories and painkillers help in the earlier stages. Steroids and certain supplements may also be used. You might try a cold compress to cool the joint and reduce swelling, but most cats don’t like damp things being applied to their body. Cod Liver Oil (Vitamin A&D fish oil) helps lubricate the joints while certain food supplements help support or build cartilage. Acupuncture helps in some cases.

Thyroid Problems

Hyperthyroidism (overactive thyroid gland) is one of the most common endocrine (hormonal) problem in older cats. It seems to be becoming more common, but vets are not sure whether this is because it is genuinely on the increase, whether it is due to lifestyle and/or longevity or whether it was previously under-diagnosed or mis-diagnosed. My first cat exhibited symptoms now associated with hyperthyroid, but in her lifetime the diagnosis was "Old cats just get thin and bony" (she lived to the age of 19 and was not in any pain).

Hyperthyroid is due to the thyroid glands producing too much thyroid hormone. The thyroid may be enlarged or may have a tumor. This speeds up the metabolism and the rate at which your cat burns calories; it may damage the heart and kidneys as they must work harder. Left untreated, it can lead to heart, kidney or liver failure. Symptoms include hyperactivity, rapid heartbeat, scruffy fur, drastic weight loss as weight is burned off, increased appetite, bulky plentiful faeces (e.g. lots of soft, putty-colored faeces), thirst and increased urination. Your vet can diagnose hyperthyroid with a simple blood test.

He may perform a biopsy (tissue sample) of the thyroid gland to check for a tumor. Treatment includes radioactive iodine treatment (effective but expensive), chemotherapy (for a tumor), surgical removal (common with very good success rate) and oral medication (pills). A cat can have both thyroid glands removed and still enjoy excellent health, often without medication as sufficient thyroid hormone is produced elsewhere in its body.

Hypothyroidism (under-active thyroid gland), is due to the thyroid gland not producing enough thyroid hormone. It is rare in cats and can be corrected with hormone supplements. Symptoms include hair loss and dry skin, weight gain despite appetite remaining the same, lethargy and irritability.

Heart and Circulatory Disorders

Some cats born with heart defects show no symptoms until later in life, when there is increased stress on the heart and circulatory system. Heart disease usually occurs in middle-aged cats (6-8 years old) often as a result of another condition such as hyperthyroidism or kidney disease. Many symptoms of heart disease (lack of energy and appetite, decreased activity, long rest periods) are overlooked because they are also symptoms of normal old age.

More obvious symptoms are a tendency to lie flat on the breastbone and reluctance to move from that position. Your cat may pant or breathe with its mouth open due to fluid building up in his chest leaving less room for his lungs to expand. His hind limbs may be suddenly paralyzed, his paws will be unusually cool because they have a poorer blood supply. In extreme cases, lack of oxygen supply gives him a bluish-gray tongue and/or gums and he loses consciousness after mild exercise (including walking).

The most common form, cardiomyopathy, causes the heart muscle to enlarge or thicken. This causes a strain on the heart which beats faster to compensate. As the heart loses its ability to pump blood, other organs are affected due to poor blood pressure. Fluid leaks out of the lungs and accumulates in the chest causing respiratory symptoms. Parts of the body furthest from the heart (the paws) feel cool and may be pale due to poor blood supply. Your cat will be generally lethargic and may even faint. Heart disease is serious; a number of modern drugs may improve the condition temporarily though these do not work for all cats.

Anemia (lack of iron in the blood) is common in older cats. There are many causes including parasites, poor diet, internal bleeding etc. Anemia is easily detected by blood tests and treatment includes detecting and treating the cause as well as treating the anemia itself. Potassium, present in blood and cells, is essential especially for muscle cells including the heart. Lack of potassium causes severe muscle weakness. Milk lack of potassium (mild hypokalaemia) in older cats is associated with lethargy and low activity levels, poor appetite, poor coat and mild anemia.

Thromboembolism (blood clots) can occur in cats of all ages for a variety of reasons. Saddle Thrombus is more common in older cats and is often referred to as a "stroke" as the effects resemble a stroke. It occurs when a blood clot blocks the artery serving the hind legs at the point where the artery forks into two branches. This can cause severe damage to the hind limbs due to a temporary or permanent loss of oxygenated blood. If the clot moves and your cat recovers, there will be fragments of the clot in the bloodstream and these may hit the lungs, heart or brain. After saddle thrombus, a cat may be left with a characteristic hock-walking gait due to muscle damage. Some cats have a good quality of life for several years under veterinary treatment.

Respiratory Diseases and Problems

Feline upper respiratory tract infections (FRTIs) range from "colds", caused by various viruses, through to full-blown "cat flu" caused by Feline Calicivirus (FCV, also called Feline Rhinotracheitis Virus), Feline Herpesvirus (FHV) and Chlamydia. Regular vaccinations protect against cat flu. Cats with colds or cat flu need supportive treatment. They can’t smell their food and may lose their appetite. Symptoms include puffy, reddened eyes, runny eyes and runny nose.

He will probably snuffle and sneeze and mucus will build up around his nostrils. Only one of these viruses is theoretically transmissible between cats and humans – this is Chlamydia psittaci; it is not a major cause of cat flu and humans are far more likely to catch it from infected parrots as psittacosis. It is possibly transmissible between cats and humans, but in practice I know of no cases of psittacosis being caused by cats. However colds and cat flu are easily transmitted between cats through sneezing and nasal discharge.

Short-nosed breeds are more likely to suffer from (or show symptoms of) respiratory tract ailments as their nasal passages are more easily clogged up. Older cats tend to have an acquired immunity to the viruses, however secondary bacterial infections may be more serious to an older cat. Warmth, rest and prescription antibiotics and decongestants are required. Humidity (steam bath) may ease breathing. Disinfection of his surroundings removes infectious snorted-out mucus.

Pneumonia can be a complication of cat-flu and is usually due to a secondary bacterial infection. Symptoms are like severe flu and he produces lots of mucky (yellow/greenish) mucus, either coughed up or snorted out of the nose. His face becomes crusty with dried mucus and he will look pretty miserable. With no sense of smell, he may refuse to eat or drink and may dehydrate. Force feeding may be needed. Prognosis depends on his general state of health.


Diabetes is caused by degeneration of insulin-producing cells in the pancreas (in the Islets of Langerhaans to be precise). Decreased insulin reduces the ability of body cells to take up glucose (sugar) from the blood; this is Type I diabetes (diabetes mellitus). It is more common in middle-aged and older cats and is being diagnosed more frequently in cats. Whether it is genuinely on the increase, whether it is more common because of longevity and/or lifestyle or whether was previously under-diagnosed or mis-diagnosed is not known. Obesity is a contributory factor and cats are becoming progressively more obese due to living entirely indoors or becoming bored and inactive.

Symptoms include unquenchable thirst, excessive urination, diarrhea, dehydration, lethargy (even coma) and a ravenous appetite yet the cat loses weight. There are 2 types of diabetes and the vet will test the cats blood or urine for glucose levels to see if the pancreas is producing the right amount of insulin. Depending on which type of diabetes your cat has, the condition can be controlled by diet and/or by daily insulin injections or oral hypoglycemia (sugar-lowering) agents, which aid in the metabolism of carbohydrates. A high-fibre diet helps regulate the rate at which nutrients are taken into the body cells. Several small meals each day will keep blood sugar levels more stable.

Type I diabetes (diabetes mellitus, sugar diabetes) is due to your cat producing too little insulin. This is the most serious and most common form. He cannot properly metabolize sugar in its blood and sugar is excreted in his urine. Insulin injections are required. Some cases respond well to insulin pills and there is progress with insulin nasal spray in humans which may also become available to cats. Your vet will train you to give insulin injections and to test your cat’s urine.

Type II diabetes (too much insulin) is less serious and less common; it is found in older cats who have been consuming too many sugars (carbohydrates) over a long period of time. They have worn out the insulin producing part of the pancreas. A high-fibre, low-calorie diet may be prescribed.

Liver Disease

In comparison to humans, cats do not have very efficient livers. They are specialized carnivores and rely on their prey’s livers to have done the work beforehand. The liver can regenerate itself to some extent depending on how badly it is damaged and whether it can be "rested" for a while. Obese cats are more prone to liver disease. A common symptom of liver failure is jaundice – the skin turns yellowish as the body tries to get rid of toxins through the skin; by the time this is noticeable the damage may be irreversible.

Breaking down toxins is hard work and just like other parts of the body, the liver degenerates. Toxins (such as Tea Tree Oil) accumulate in the liver if they cannot be broken down. Liver tumors may also occur. Liver disease symptoms include vomiting, lethargy, poor appetite and jaundice. Neurological signs also occur – such as bizarre behavioral traits – caused by toxic chemicals reaching the brain and triggering strange behaviors. There is no cure for degenerative liver disease, but a prescription diet reduces the strain on the liver so its remaining function lasts longer. Medication helps reduce the signs of disease. As your cat gets older, he may need food which puts less strain on his liver.

Your cats can suffer liver damage from not eating for 2 or 3 days. When his stomach is empty, his body uses up fat stores for fuel. Unfortunately your cat’s liver is not very good at metabolizing fat for energy and fat begins to accumulate in the liver. Next, the body burns muscle for fuel. The result is weight loss, diarrhea, anemia and a general wasting away.

Hepatic lipidosis (fatty liver disease) happens when fatty deposits accumulate in the liver. As well as generalized symptoms of illness; your cat will produce pale faeces and dark urine. If he can be persuaded to start eating again, his liver starts to function correctly. He needs highly nutritious food quickly, perhaps via a feeding tube through his skin and directly into his stomach. However, symptoms may not be noticed until the damage is too severe to be reversed. Afterwards he may need a low protein, lower fat diet to ease the strain on his liver.

Brain, Nervous System, Behavior and Senility

Senility is a gradual process and may be barely noticeable until the cat begins house-soiling or an indoor/outdoor cat gets lost frequently or wanders erratically. Just like the kidneys, liver and heart, your cat’s brain degenerates and his memory and behavior change. Genetics plays a part in determining when and how fast these changes occur – sometimes as young as 12 years old, sometimes not at all, even in a cat of 20+ years old. Stray and feral cats rarely if ever live long enough to become senile.

If by chance a feral cat becomes senile, or if a senile cat is abandoned or becomes lost, he soon falls prey to a predator or to misadventure caused by his own diminished cognitive (thought) function. A rare disorder called Feline Spongiform Encephalopathy (FSE), the feline analog of BSE prion disease in cattle, may resemble senility in much younger cats which have eaten BSE infected feeds.

A senile cat is forgetful of his own well-being. He may venture into risky areas, be unable to find his way back home, not remember to come in from the rain or be unable to find his litter box or food bowl. He may yowl, seem confused, demand feeding because he has forgotten that he has just eaten not because he dislikes the food you served (if led to the food bowl he starts eating at once rather than waiting for you to serve more desirable food).

He may become incontinent because he forgets to control his body functions, not from bowel or bladder disease. He may show repetitive behaviors such as walking in circles, plucking fur or aimless movements. Anyone who has seen programs about Alzheimer’s Disease in humans will recognize similar symptoms in their cat, though they may choose to deny that it is happening. Your vet will determine whether the behavior is due to illness, injury (e.g. head trauma) or senility.

Some cats remain clean but become "delightfully dotty" or "slightly scatty". Given help with grooming, several litter-boxes to prompt their failing memory and a safe environment, they remain contented pets, remaining happy in their own slightly confused manner and with no awareness of their reduced circumstances. A senile cat who wanders must be confined to the house and/or an escape proof garden or outdoor run.

At present there is no treatment for feline senility though senile dogs benefit from a drug called Anipryl which the natural destruction of the neurotransmitter dopamine in the brain. Because senility is progressive, the effect of the drug wears off over a period of time. It has prolonged the quality of life for some dogs for 6-12 months. Many canine drugs are toxic to (or not licensed for use in) cats so there is currently no equivalent feline treatment. This is likely to change as veterinary medicine continues to advance.

A seizure or convulsion is sudden, uncontrollable and often violent thrashing. Muscles contract and spasm violently and erratically, your cat may fall over and may lose bladder and bowel control. He may scratch and bite and as with human epileptics, the usual advice is to avoid interfering except to prevent him from injury. If you need to restrain him to prevent injury or must move him out of danger, either wear leather gauntlets or cover his body with a towel, coat or blanket and restrain him that way. Lie him on his side if possible. If you have to pull his tongue forward to prevent choking, you will almost certainly be bitten, but this may be a small price to pay unless there is any danger of rabies.

Unless he is a known epileptic, a fit (seizure, convulsion) indicates a serious problem e.g. head injuries, infectious disease, brain, tumor, allergy, undiagnosed epilepsy, liver disease or poisoning. The cause must be diagnosed and treated appropriately. Although you may be panicking, make a mental note (and write it down later) of details to aid diagnosis e.g. rapid heart beat, hyperventilation, bluish tongue/gums, odd behavior before the fit etc.

If the fit lasts more than two minutes or several fits occur in a 24 hour period, make an emergency visit to the vet. Some fits remain unexplained one-off occurrences due to a combination of conditions that are never repeated. Some cats die during or after a fit, possibly due to a brain hemorrhage or an undiagnosed condition reaching its crisis point.

True strokes are rare in cats. Either kitty-strokes are milder than in humans because of differences in the brain structure and function, or cats simply recover faster and more completely than humans. Following a stroke, your cat may be temporarily blind (permanent blindness is less common) or partly paralyzed and may lose control of his bladder or bowel. Most vets advise a "wait and see" approach. Once the initial effects have worn off, many cats recover fully with little more than a head tilt, minor tremor or slightly wobbly gait as a reminder.

Some cats become anxious and yowl as their sight and hearing deteriorate. Night-time calling usually occurs at dusk and dawn (cats are naturally crepuscular i.e. active at dusk/dawn) especially in the evening after you have gone to bed and he feels lonely. Try letting him sleep in the bedroom near you, or install a baby intercom and use it to talk to him (if he is not deaf). He may yowl in the daytime if you suddenly go out of his sight – he requires reassurance. Yowling also accompanies senility and deafness and sometimes high blood pressure (hypertension) which may be associated with kidney failure. If there is no medical cause, some cats respond to anti-anxiety medications. If you don’t want to use prescription medication you could try Bach Flower Remedies (Rescue Remedy or one of the anxiety-specific remedies).