Yes, actually they do! It’s a commonly held belief that cats don’t suffer from arthritis, but it’s unfortunately a myth. 

What is arthritis?

Arthritis just means “inflammation of the joints”, but when we use the term, we’re usually talking about osteoarthritis. This is the common “wear and tear” arthritis that older cats (and dogs, and horses, and people!) get, after a lifetime of activity.

As a general rule, there are three causes of arthritis:

1. Normal loading on an abnormal joint – this is why you often see early onset of arthritis in cats who have injured a limb; the joint heals but may not be in perfect alignment, so there is increased wear.
2. Abnormal loading on a normal joint – typically in obese cats, carrying excess weight.
3. Normal loading on a normal joint for an abnormal length of time – in other words, old age!

There are other kinds of arthritis as well (septic arthritis, caused by infection, and immune arthritis, caused by certain diseases of the immune system), but osteoarthritis is by far the most common.

What does arthritis do to the joint?

In a joint, the bones don’t actually touch each other – they’re covered with a substance called cartilage, which acts as a kind of biological teflon, allowing the bones to glide smoothly over each other. To reduce friction even more, the joint is filled with a fluid (known, imaginatively, as joint fluid) which provides lubrication. This fluid is made by the synovial membrane which lines the inside of the joint capsule (the fibrous “balloon” around the joint that holds it together and keeps the fluid inside).

Whatever the underlying cause, arthritis results in wearing of the cartilage. As it is worn down, the cat’s body tries to compensate by producing extra lubricating fluid (resulting in swelling and pain). It may try to repair the cartilage, but this is unlikely to be successful, and so the joint tends to respond by growing extra bone around the edges to try and stabilise itself. Eventually, the cartilage “non-stick” layer is worn down until bone is grinding on bone.

So what are the symptoms?

All the symptoms of arthritis come down to joint pain and joint stiffness. An arthritic joint is usually:

• Filled with fluid (a synovial effusion).
• Painful (because of the cartilage damage, the excessive fluid, and the inflamed synovial membranes).
• Less mobile (because of the excess fluid and the extra bone growth).

Well my cat doesn’t limp, so he must be fine.

NO! Unlike dogs (who want everyone to know about it if they’re in pain!), cats will try to hide it for as long as possible. It’s very common for owners just to think their cat is suffering from old age, when actually they’re in severe pain because the common symptoms are:

• Reduced physical activity
• Reluctance to jump or climb
• Being less playful
• Grumpiness or bad temper
• Going off on their own to curl up away from people

What can be done about it?

The first thing to do if you suspect your cat has arthritis is to make an appointment to see one of our vets. Fortunately, there’s a lot you can do to help once the condition is diagnosed, and there are medications that are highly effective at relieving the symptoms.

• Management options include:
  1. Use of ramps – climbing stairs is difficult for an arthritic cat, so ramps can really help.
  2. Sunken or shallow litter trays – it can be hard for them to hop into a litter tray, so using a shallow tray, or one which is sunken or has a ramp, can be really helpful (as long as they can climb out again!)
  3. Use of ramps – climbing stairs is difficult for an arthritic cat, so ramps can really help.Sunken or shallow litter trays – it can be hard for them to hop into a litter tray, so using a shallow tray, or one which is sunken or has a ramp, can be really helpful (as long as they can climb out again!)
  4. Warm, comfortable sleeping places – yes, cats are great at finding these on their own, but it never hurts to help! A warm, well padded surface helps to minimise the pain from arthritic joints.
  5. Weight loss – 25% of UK cats are obese, and some studies suggest as many as 60% are overweight. Loss of one body condition score (for example, going from 7/9 to 6/9) is as effective in relieving arthritic pain as a dose of painkillers.
• Medical treatments:

Painkillers are the mainstay of managing an arthritic cat, especially the non-steroidal family of drugs (NSAIDs). However, NEVER use human painkillers in cats – many are lethally poisonous. It is also illegal to give a cat a human medication unless on a prescription written out by your vet. There are a wide range of different treatments available, mostly as tasty liquids to put on your cat’s food, so talk to one of our vets before you try anything else!

Joint supplements containing the “building blocks” for healthy cartilage (such as glucosamine and chondroitin are very popular. They may have an effect in some cats, but there isn’t much research into how effective they are.

If you think your cat is arthritic, make an appointment to see one of our vets so we can get them up and about again!

CKD means Chronic Kidney Disease – it’s also known as kidney failure and chronic renal failure. It is a progressive condition causing the cat’s kidneys to gradually stop working. 

What do a cat’s kidneys do?

The kidneys have four main functions.

Firstly, they regulate the cat’s water and salt balance. If the cat is dehydrated, they retain water – producing smaller amounts of more concentrated urine – whereas if they have drunk too much, the kidneys produce larger volumes of more dilute urine. At the same time, they control the amounts of various salts in the cat’s blood – sodium, potassium, calcium, phosphate and others.

They also have a vital role in getting rid of waste products. The most important are urea (a breakdown product from protein in the diet) and creatinine (a waste product produced by the muscles). These chemical wastes are actively concentrated in the cat’s urine.

As well as water balance, the kidneys also help to regulate blood pressure, via a cascade of enzymes in the blood that cause the blood vessels to constrict (raising the pressure) or dilate (dropping it).

Finally, they help to control the numbers of red blood cells in the blood by releasing a hormone called erythropoietin (of cycling cheat fame!) which tells the bone marrow to make more.

What causes CKD?

There is a range of possible causes, including damage to the kidneys by infections or toxins; tumours in the kidneys; and some birth defects. There is also a genetic condition called polycystic kidney disease (PKD), where kidney tissue is progressively replaced with large fluid-filled cysts (it’s most common in Persians and related breeds).

However, in most cases, the cause is far simpler – degeneration due to old age and a high protein diet. As obligate carnivores, cats need a lot of protein in their diet to survive, but this means the kidneys have to work harder to remove the breakdown products than the kidneys of herbivores such as horses – so chronic, long-term damage is much more common.

Fortunately, there is a great deal of functional reserve – a cat can survive perfectly well if only ? of their kidney tissue is working properly. As a result, CKD is rarely seen in young cats – it is probably developing, but until ? of their kidney volume has failed, there won’t be any symptoms.

What cats are at risk?

All cats – some estimates suggest that as many as half of all cats who reach 15 years old have clinical CKD. Even really well cared for pets – and big cats like lions in zoos – are at the same risk.

OK, so what are the symptoms?

The symptoms are usually subtle and vague to begin with, but get gradually worse with time as more of the kidney tissue fails and more waste products build up in the blood. Typical signs include:

• Increased production of dilute urine; this may cause incontinence.
• Increased thirst
• Dehydration
• Weight loss
• Poor coat quality
• Loss of appetite
• Lethargy
• Muscle weakness (due to salt imbalances in the blood stopping the muscles from working properly – usually low potassium levels)
• Vomiting (due to the build-up of toxins)
• Bad breath (often it smells metallic, as blood urea levels rise)
• Seizures, collapse and death will eventually follow

Cats may also develop anaemia (causing pale gums and shortness of breath) and high blood pressure (which can cause blindness or strokes).

How is CKD diagnosed?

CKD is usually diagnosed with a combination of blood tests and urine tests. We do blood tests to look for increased urea, creatinine and, sometimes, a newly discovered marker for kidney function called SDMA. Elevated levels suggest kidney disease.

The most important urine test we can do is the urine specific gravity, which tells us how well the kidneys are concentrating the cat’s urine. A normal cat should have a specific gravity of over 1.035, whereas a CKD cat often has a value well below this. In addition, protein in the urine can sometimes be a marker of kidney problems.

We’ll use these same parameters to monitor their progression, as well as regular blood pressure checks.

How can it be treated?

CKD in cats cannot be cured. However, it can be managed, with changes in lifestyle, diet, and medications.

Cats with CKD have higher than normal water requirements, so making sure they always have access to fresh water is vital. Some cats don’t like to drink still water, so there are a variety of water fountains available for them!

A specialist renal diet is really important – these are specially formulated to support the kidney’s function (less phosphate and protein, to reduce the kidney’s workload, and more potassium). However, not all cats accept these diets; if not, a phosphate binding agent and (sometimes) supplemental potassium must be added to their normal food.

The mainstays of drug treatment in CKD are medications to reduce protein leakage out of the damaged kidneys, and control blood pressure. ACE inhibitors (like benazepril) and a new drug telmisartan are most commonly used because these have both effects. Sometimes, medication specifically to reduce blood pressure (such as amlodipine) is also needed.

What about transplants?

At the moment, it is illegal to carry out kidney transplants in cats in the UK because of concerns over the welfare of the donor cats, and worries about the risks of establishing a black market in feline organs.

However, cats with CKD can survive for many months or even years with appropriate care and treatment.

If you think your cat may be showing signs of kidney disease, make an appointment to see one of our vets as soon as possible. Early diagnosis makes treatment much more effective!

FIP, or Feline Infectious Peritonitis, is a viral disease of cats that is almost universally fatal. However, it’s a really complicated condition, and (bizarrely) the “FIP Virus” probably isn’t transmissible from cat to cat in most cases. 

OK, so what causes it?
There’s a virus in cats called Feline Coronavirus (FCoV). This virus usually causes mild diarrhoea, as it replicates in the cells of the cat’s gut lining (as a result, it may also be called Feline Enteric Coronavirus, FECV). About 25% of pet cats have or are exposed to this virus, but that number goes up to over 80% in multi-cat households and may reach 100% in large colonies.

Now, most cats, once infected, are a bit poorly and have diarrhoea for a few days, but then recover. In the meantime, however, they have shed the virus (mainly in the faeces) to every other cat in the area. Some cats develop a strong, long-term immunity to it, but for most, their immunity fades over time, and they then become reinfected later.

How does that relate to FIP though?
The problem occurs when one of the virus particles in the cat’s body mutates in a specific way. This mutation (which occurs periodically but randomly as a result of the way the FCoV replicates itself) means that the virus can no longer replicate in the gut lining, but instead attacks the cat’s immune system and blood vessels. We call this the FIP Virus, but really it’s just a damaged and defective Feline Coronavirus. The good news is that, because it doesn’t replicate in the intestine, it is very unlikely to be spread to other cats; but the bad news is that it is a much, much more serious infection.

Some cats are able to mount a very strong “cell-mediated” immune response and kill the virus rapidly at this stage – these cats never develop the disease, despite being infected with the mutated FIP Virus.

Most cats, however, are unable to do this, and instead make antibodies – which doesn’t kill the virus, and in fact makes the symptoms worse. These cats will almost always die of the infection.

What cats are at risk?
Any cat infected with FCoV – this is predominantly younger cats (80% of FIP cases are less than two years old), and those in multi-cat homes or large colonies.

What are the symptoms?
The initial symptoms (that may persist for days or even weeks) are very vague and non-specific – typically lethargy, loss of appetite and a low fever. If the cat’s immune system cannot clear the virus at this stage, the condition will progress to one of the two main forms of the disease (although some cats may develop both simultaneously).

Wet FIP (also known as Effusive FIP)

• This is characterised by damage to blood vessels, so they leak fluid. This causes fluid build-up and inflammation in body cavities.
• Peritonitis – fluid in the abdomen, causing a pot-bellied appearance.
• Lumps or masses forming in the abdomen – these aren’t tumours but are essentially abscesses (pyogranulomas) in the gut, lymph nodes or other organs.
• Liver failure, causing jaundice.
• Pleural effusion – fluid in the chest, causing difficulty breathing. Many infected cats eventually suffocate or drown.
• These cats usually deteriorate rapidly, and die or have to be put to sleep in a matter of days or at most weeks.

Dry FIP (also known as Non-Effusive FIP)

• This occurs when the immune system is able to slow down the replication of the virus, but not stop it completely. It is characterised by chronic inflammation of blood vessels in the organs.
• Inflammation of the eyes (about 30% of cases) causing changes in shape and colour of the iris and fluid, bleeding into the eye, and often severe pain and sensitivity to light.
• Inflammation of the brain (encephalitis, and/or meningitis, also seen in about a third of cases), causing wobbliness, paralysis or seizures.
• Inflammation of any other organ, causing it to gradually fail.
• Cats with dry FIP will eventually die, but it is usually a much slower disease process, with cats surviving for potentially many months.

How do you diagnose it?

The only way to conclusively prove that the cat has FIP is by taking a biopsy (a surgical sample) of an infected tissue and sending it off to a lab to check if the mutated virus is present – blood tests cannot distinguish between normal FCoV and FIP virus. Unfortunately, many cats with the disease are too sick for surgery, so we would usually diagnose it based on the clinical signs, and the exact nature of the fluid (in wet FIP).

Can it be treated?

FIP remains a challenging and difficult disease to treat, however there have been significant recent developments in the management of this once fatal condition. Recent research has shown that some newer anti-viral drugs such as remdesivir, may be effective following trials in Australia. Remdesivir injection and GS-441424 tablets have recently become legally available in the UK, although they are a novel treatment, have not undergone extensive trials and are available only under special licence. The drug has been used to treat human viral infections including SARS-CoV-2 (COVID-19). Initial experience has been positive with response rates of 80-95% and therefore we have reason to be optimistic for the future, however the treatment remains very expensive and requires a long course of treatment. We look forward to learning more about the treatment of FIP over the next few years.

Please see icatcare.org for further information on FIP.

If you are concerned your cat may have FIP, make an appointment for them to be seen by one of our vets as soon as possible.