Kidney disease is the number one killer of older cats. Merlin, pictured above was diagnosed two years ago with CKD or chronic kidney disease. Our Vet 101 guest post is by Veterinarian Dr. Letrisa Miller who has a feline-only practice in Connecticut. This is the first in a three part-series on Kidney Disease.
Understanding Kidney Disease in Cats -1
- Kidney disease comes in two main types: acute and chronic. Acute kidney disease, which usually presents as kidney failure, arises suddenly over a period of a few hours to a few days. Two common causes of acute kidney disease are lily toxicosis and antifreeze poisoning. Chronic kidney disease, CKD progresses slowly as kidney function decreases gradually, usually because of small insults such as infection, inflammation, cystic disease, or (more rarely) small blood clots. This post focuses on chronic kidney disease.
- One of the most important roles is to keep water in the body when it is needed and to secrete it in the urine when it is not. If the kidneys aren’t functioning properly, a cat can become severely dehydrated even when it is spending most of its time drinking. The kidneys simply can’t retain the water and it just goes right out as dilute urine. In almost all cases, this is a symptom of chronic kidney disease.
- Kidneys also make sure that the right electrolytes are conserved or excreted. When the kidneys aren’t functioning properly, cats can have problems with potassium deficiency or retention, B vitamin deficiencies, and calcium and phosphorus imbalances. Any imbalance in this group can cause heart, digestive, or musculoskeletal malfunction. Severe imbalances can cause death.
- Four stages of kidney disease have been defined by the International Renal Interest Society, or IRIS. These are based on measures of how much work the kidneys can do. One way to think of this: A healthy kidney can do more than 100% of the work it is “assigned” (such as removing toxins from the body and conserving water). Once a cat reaches stage 4 kidney disease, the kidneys may be able to do only 10% of that work.
- The first three stages are kidney insufficiency stages, and the first two of them have very few detectable symptoms or signs. They are are also easily managed. The third stage is more symptomatic and requires more treatment.
- The fourth stage is failure and usually requires intensive treatment. However, even stage 4 can often be well managed to give a cat a good quality of life for an extended period of time.