Tanya's Comprehensive Guide to Feline Chronic Kidney Disease

For a complete list of CKD symptoms, or to look up a symptom which is bothering you, please see the Index of Symptoms and Treatments, where all the symptom are listed alphabetically, with quick links to each individual symptom and appropriate treatment options.

Miscellaneous Symptoms Back to Page Index

Hiding

It is relatively common for CKD cats to hide, perhaps in a cupboard or under a bed, or somewhere up high. This is because the cat does not feel well - it is instinctive for cats to hide when they feel ill so as to minimise the risk of attacks by predators. As your cat improves with treatment, you should find s/he will hide less, though a CKD cat may always require more rest and peace than a healthy cat.

One thing to be aware of is that some cats may take this a step further and go away from home to hide. Therefore if you usually let your cat go outdoors, I would be careful or perhaps restrict access until you know your cat is stable once again.

Seeking You Out

Conversely, some cats will seek you out, and want to snuggle more. This may even happen with cats who previously were somewhat stand-offish. This may simply be because the cat does not feel well and wants you close for comfort and reassurance.

Pain

I am often asked if CKD cats are in pain. No, the typical CKD cat is not in pain. Some of the symptoms of CKD can be uncomfortable, e.g. dehydration is often described as feeling like a hangover, but they are not painful, and in most cases are easily treatable.

In some situations a CKD cat may be experiencing pain e.g. from toothache or a kidney infection or when passing a kidney stone, or if s/he is having trouble breathing. Again, most painful conditions can be treated.

Cats who are in pain or discomfort are unfortunately very good at hiding it (this is instinct, in order to protect them from predators). One possible symptom is restlessness, moving around from one spot to the other. However, there are a number of other possible causes for restlessness, so don't panic if you see this symptom.

Washington State University College of Veterinary Medicine discusses possible signs of pain.

Purring

Everybody knows that cats purr when they are content or happy. However, fewer people realise that a purr is not automatically a good sign, because cats may also purr when they are in discomfort or pain. Some years ago, a cat was run over by a car in front of my eyes. I ran to the cat and rescued it from the road but s/he died in my arms within a minute or two - the cat purred the entire time.

The precise mechanism of purring is not known, but it is thought to produce endorphins or "feel good" hormones in a cat, and, in the case of a cat in pain, this may help the cat cope with the pain, or comfort the cat in some way.

Also, if your cat's purr develops a rattle, this can sometimes indicate fluid build-up. So please do not assume that your cat must be well simply because s/he is purring.

About has some information on why cats purr.

Animal Voice discusses whether the purr helps in some way with healing.

Increase in Appetite

Believe me, this is incredibly rare in a CKD cat! If you see it, it most likely is caused by hyperthyroidism. Alternatively, a cat who has had a seizure will often feel suddenly very hungry afterwards.

Hair and Coat-Related Symptoms Back to Page Index

Hair or Fur Loss

One study, Anagen effluvium in chronic renal failure (2001) Suwanwalaikorn S, Sivayathorn A, Chiba M, Vareesangthip K, Manonukul J, Tsuboi R & Ogawa H, Presentation to the European Hair Research Society Conference 2001, found that the sudden loss of hair is not unknown in human CKD patients. In all cases, no specific reason was found but the hair grew back without treatment. The same may apply to cats, but please also see alopecia below. Sometimes cats will develop hair loss at the site of sub-cutaneous fluids; this is not normally of concern.

Cats with food allergies may also lose their hair. One of our cats, Harpsie, had food allergies, and lost the fur around his neck in a ring, like a collar. He also lost fur in other areas. You can read more about his experiences here.

Pet Education has some information on causes of hair loss in cats.

Alopecia (pulling out hair)

Possible causes include food or other types of allergy. If allergies are ruled out, this may be a symptom of hyperthyroidism.

If your cat is scratching rather than pulling out hair, it might be because of an uraemic itch, i.e. caused by the levels of toxins in the blood. Itching is fairly common in cats with high phosphorus levels, particularly if the high phosphorus levels go untreated, resulting in secondary hyperparathyroidism. Alternatively itching may indicate a Vitamin B deficiency or be a sign of an essential fatty acids deficiency. Itching on the face in particular may be a side effect of the medications used to treat hyperthyroidism. Occasionally itching can be a sign of liver problems; if this is the case, your cat's bloodwork should show elevated liver values.

Pet Place has some information about hair loss in cats.

Dull Coat/Dandruff/Spiky Fur

This reflects the general loss of condition of a CKD cat, and is also influenced by dehydration. The body is fighting a tough battle with CKD and concentrates its efforts on its more critical functions; a glossy coat is not one of them. Occasionally spiky fur may indicate a lack of essential fatty acids, or may be a symptom of hyperthyroidism.

Coat Colour Change

If you look at the photograph of Thomas on the homepage, you'll notice his back looks brown rather than black like his head and face. This is partly because the photograph was taken in the summer, when Thomas loved sunbathing, which seemed to turn his black coat brown. This is relatively common in black cats, and is known as "rusting". However, his coat also changed colour in winter when he was first diagnosed. My vet told me this often happens to dark-haired cats when they are ill - the body has more important things to focus on than the cat's coat. Getting the CKD under control should help with this problem - it did help with Thomas.

Low protein diets may also be a factor in coat colour change, because tyrosine, an amino acid, is important for the production of coat colour, but low protein diets contain less tyrosine than normal diets. The carnivore connection to nutrition in cats (2002) Zoran D Journal of the American Veterinary Medical Association 221 pp1559-67 explains more about this (see page 3). The addition of tyrosine to the diet may help, but this is not essential, and should not be done without your vet's approval. See also Dull coat/dandruff/spiky fur.

If your cat has any Siamese genes, the points may darken as a cat ages. The coat colour of Siamese and Himalayans (colourpoint Persians) is actually determined by temperature changes. As cats age, their circulation often worsens, so their extremities become cooler and their points get darker. However, sick cats with Siamese genes who have a raised temperature (e.g. because of an infection) may actually develop lighter colour fur. In either case, it is normally nothing to worry about.

Red hair in black cats is reversed by addition of tyrosine to the diet (2002) Morris JG, Yu S & Rogers QR The American Society for Nutritional Sciences Journal of Nutrition 132 pp1646S-1648S discusses how the absence or presence of tyrosine in the diet affected the coat colour of healthy kittens.

What makes a black cat's coat turn reddish brown is an article from Cat World.

The University of Alaska has some info on Siamese coat colour changes.

Treatment Options Back to Page Index

It is possible to treat all of the above symptoms, in many cases effectively, and details can be found in the Treatments section.

Back to Page Index

This page last updated: 03 November 2011

Links on this page last checked: 23 October 2011