Jeff Kahler: Concerned owners have questions about cat’s kidney disease diagnosis

Tabitha is a 13-year-old cat, living with Madeline and Frank, that spends all of her time indoors. She is currently up to date on all her vaccinations and, according to Madeline, is the ruler of the household.

Recently, Tabitha had begun to drink more than normal and was not eating very well. As a result, she began to lose weight. Tabitha was taken to her veterinarian where a blood test and urinalysis revealed that she has kidney disease. Frank and Madeline are upset by the news and have questions concerning what might be expected for Tabitha.

I am sure that Madeline and Frank have discussed Tabitha’s condition with their veterinarian so for them this may be redundant, but I will share my thoughts on renal failure in cats and the possible outcomes with this disease.

Renal disease is most often put into two categories based on onset of the disease. One form is called acute, which comes on quickly and can be devastatingly fast in its progression to death. The other is chronic, which implies a slower onset. Ironically, the acute form in most cases comes with a better long-term prognosis.

Acute renal disease –sometimes called acute renal failure – can occur as a result of many different insults to the kidneys. These can be toxin-related and sometimes infectious. These cats appear to become suddenly very sick with vomiting lethargy and have a lack of appetite. Left untreated, these cats can progress rapidly to death.

Conversely, if these cats are brought to their veterinarian when the symptoms are new, diagnosis is straightforward and proper treatment usually results in a cure. The one cause of acute renal failure that does not fit this good prognosis if caught early is ethylene glycol toxicity. This is the substance commonly found in car radiators called antifreeze or coolant. If this stuff gets into a cat or dog – or human for that matter – and it is not discovered within about six to eight hours of ingestion, the prognosis is usually grave.

Tabitha likely does not have acute kidney (renal) disease. That’s the good news. What she likely has is chronic renal disease. This condition is caused by a gradual decline in renal function over time.

Cats have a tremendous amount of kidney reserve and do not show much in the way of symptoms or changes in their blood work until they are down to less than one-eighth of total kidney function. This can be a good thing as they slowly wear out; however, it can make it extremely difficult to diagnose as a progressing disease before they lose most of their kidney function.

Tabitha shows changes in her blood work indicating a kidney problem, which means she is down to one-eighth or less of total function. This process is progressive and ultimately is not curable, but the progression can sometimes be slowed.

When I am faced with a case of chronic kidney disease in a cat, I try to determine what ability the kidneys might still have. Armed with the blood work results that provided the initial diagnosis, I recommend hospitalizing the cat and run them on intravenous fluids for 24 to 48 hours, then recheck the blood work.

If the kidneys improve, it gives an indication that the kidneys have some ability to respond. I then outline a home-care program that generally includes a special diet designed to take some of the pressure off the kidneys.

In many cases, I also will teach clients how to administer fluids under the skin, which helps keep the cat hydrated. This can be very important because with the kidneys not working properly, water is wasted through the urine and these patients become dehydrated.

Eventually these cats do reach a point where we no longer have a good quality of life. But until that point, many do very well with what amounts to a minimum of treatment.

Jeff Kahler is a veterinarian in Modesto. Questions can be submitted to Your Pet in care of LifeStyles, The Modesto Bee, P.O. Box 5256, Modesto 95352.