Kidney failure is a common health problem in middle-aged and elderly animals. It is the result of damage to the cells, which filter natural poisons (the normal waste produced by the body’s internal processes) out of the blood for removal in your pet’s urine. In time, so much kidney tissue is affected that these waste products can no longer be eliminated and build up inside the blood stream. The damage is irreversible and the pet eventually dies. Your pet may still have many months of good quality life after diagnosis of kidney disease with proper treatment and good co-operation between you and your vet.
• What causes kidney damage?
A gradual reduction in the ability of the kidneys to do their job is an inevitable part of the ageing process and occurs at varying rates in different animals. This condition, which vets call chronic renal failure is very common in animals over seven years old. Sudden or acute kidney failure can also occur as a result of poisoning, bacterial and viral infections, blockage of the tubes leading from the kidneys to the bladder or heart disease. These cases need emergency care and even if successfully treated by your vet, your pet may still suffer long term kidney damage.
• What happens to a pet with kidney disease?
The kidneys have a lot of spare capacity for filtering blood, so symptoms of disease may only appear when about three-quarters of the kidney cells have permanently stopped working. One of the first indications of disease is the animals’ loss of ability to produce concentrated (dark) urine. So to get rid of the same quantity of waste material your pet has to produce larger volumes of more diluted urine. Your pet will be thirstier than usual and has to urinate more often than normal. As the disease worsens a number of other symptoms may appear. Your pet may seem depressed and lose interest in food, vomit regularly, lose weight and its coat becomes dull. You may also notice bad breath and ulcers in its mouth.
• How can I be sure that my pet has kidney disease?
Some of these symptoms also occur in other disease such as diabetes. Your vet will want to test samples of blood and/or urine to look for an increase in poisons. Your pet may also be X-rayed or scanned with ultrasound to show that the kidneys have become shrunken and abnormally shaped.
• What can be done to treat kidney disease?
Although damaged kidneys can not be repaired there is much that can be done to make your pet feel better. Many animals that are producing abnormally large amounts of urine become severely dehydrated. Your vet will want to give extra fluids to counter this and give medication to treat the secondary effects of the disease such as mouth and stomach ulcers. Anaemia is a common problem in animals with advanced disease and in some animals this may be countered with medication. Monthly anabolic steroid injections or tablets may be prescribed to help correct anaemia, stimulate the appetite and improve general well being.
• What can I do to help?
The most important thing in helping your pet lead a life as normal as possible is to reduce the workload on the remaining healthy kidney tissue, this can be done by altering your pets’ diet. There are special diets that have lower levels of protein and phosphorus to reduce the amounts of waste products in the blood. They also have extra amounts of those vitamins and minerals, which may be flushed out in your pet’s urine when it drinks a lot. “Hills Prescription Diet K/D (Kidney Diet) is available in both canned and dry formula. Avoid giving your pet leftovers or treats which may interfere with the new diet. Affected animals often feel nauseous and lose interest in their food, it may help if your warm the food or hand feed it while it is getting used to the new food. Feed it ‘little and often’ and throw away uneaten food. Always make sure your pet has plenty of fresh, clean water at all times. Allowing your pet to go thirsty will make the problem rapidly worse.
• What is the long term prospect for my pet?
If the damage to the kidneys is related to ageing, your pet may live for several years after diagnosis. As with other diseases if you can keep your pet comfortable there is a good chance that it will survive for many months. Your pet will need regular check ups by your vet and possibly changes to its medication. By weighing your pet often, watching its behaviour and checking how much food and water it consumes, you will be able to provide your vet with valuable information on controlling the disease.
© Forrest Hill Vets (2000) Ltd