Failing Kidneys in Pets
Chronic Renal Failure in Cats and Dogs
There are many pets who have kidney trouble as they get older, better known as Chronic Renal Failure or CRF.
The causes of CRF are usually not obvious, mostly being genetic. Long term infections as of the teeth can minimally contribute to this disease process, if not actually cause it. In cats a virus know as Feline Infectious Peritonitis can cause CRF as well. Any obstruction that is partial and long term can cause it as can toxins including certain drugs if overused or overdosed. Certain cancers are also a cause.
The clinical signs often start with increased water intake and urination which can over time become excessive, Appetite eventually decreases due to the lack of the ability of the kidneys to get toxins out of the body which creates nausea. Weakness follows as water and potassium levels drop from lack of ability to keep such in the body. Also, certain hormones decrease which can cause the body to stop making red blood cells that are the oxygen carrying cells, which result in weakness from anemia.
Diagnosis of this disease is done by routine lab tests requiring urine specimens and blood samples. Such things as how well the urine is concentrated, loss of protein in to the urine, and evidence of infection or crystals in the urine will be checked. The blood sample will show how much toxins are building up and any imbalance in calcium and phosphorus which can also occur as well as check red blood cell counts. Blood potassium levels don't always reflect in the cell levels of potassium, but if blood levels are low you can bet in the cell levels are low. (Normal blood levels of potassium may not rule out low celluar levels though)
Treament consists of handling any underlying known cause, if there is one. The main treatment includes maintaining normal fluid levels in the body known as hydration. An adage is "Dilution is the solution to pollution." Therefore we give the animal lots of fluids to help flush out the toxins the body normally builds up from breaking down proteins and such. If the disease is mild and the animal is eating and drinking well an increase in water intake by mouth may be adequate. If more severe then additional fluids may be need to be given either under the skin in the fat (subcutaneous fluids) periodically. Or if more severe the pet may need to be hospitalized and given fluids directly in the vein until eating and drinking again.
Other usefull maintenance treatments are supplemental potassium and sometime protein restricted (yet very high quality protein) diets. The catch-22 there is sometimes pets already have a decreased appetite and changing their food may worsen that. It is more important to get food in than to restrict protein if push comes to shove, though fish and other super high protein sources should be avoided. Check with your veterinarian for the recommendations for your specific situation here.
Some pets need phosphorus binding medicines as the kidneys also affect calcium and phosphorus levels and phosphorus can get quite high and create more trouble.
Pet Kidney Disease Vitamins
If anemia is present, B-vitamins especially B-12 and iron may help, but often a supplemental hormone known as erythropoietin needs to be given to stimulate the red cell production. In fact since B and C vitamins are water soluble they can be lost in excess in CRF and may need to be supplemented. (Cats actually will have decreased appetities due just to low B-vitamin levels). The fat soluble vitamins (A, D, and E) aren't lost this way, so don't over supplement them.
Various stomach calming products may be used as well as appetite stimulants if needed.
Also, some pets develop high blood pressure with CRF which can worsen the disease so medicines to lower blood pressure may need to be added as things progress.
Unfortunately there isn't a cure for most situations with CRF, but there are many ways to make the animal more comfortable and extend quality life.
If you think your pet has this disease, consult your veterinarian as soon as possible to get on a treatment program to help keep your beloved pet around as long as possible.
Dr. Jan