Chronic Kidney Disease in Pets
By: Jessica Groeneweg, DVM
Kidney Disease is a concern in our pets, both dogs and cats. However, cats are more likely to have kidney disease at some point. Over 30% of cats will have kidney disease at any age in their lives. When cats get older, almost half of the cat population acquires some form or stage of kidney disease. This causes sickness and death in many cats.
The kidneys are a set of two bean-shaped organs—one on either side of the abdomen. These organs have many functions in the body, the least of which is filtering the blood from waste products that the body produces. The kidneys also have functions in metabolism, red blood cell production, essential absorption, and regulation of blood pressure.
Kidney damage can have many causes. Different parts of the kidney can be damaged. To understand this, you need to understand a bit about how the kidney is designed. It is made up of thousands of microscopic parts. Nephrons are the functional aspect of the kidney. The nephrons include a glomerulus, a section that filters waste from the blood. Blood gets sent through very small capillaries to the glomerulus, then 5% of the blood, plasma, and waste is sent to the tubule. This is the start of urine. The tubules absorb and process this primary urine to reabsorb water, electrolytes, proteins, and other things the body needs. The rest is sent down ureters to the urinary bladder where it is then sent out of the body as waste.
When the kidneys get damaged, the glomerulus, the tubules, or other aspects of the kidney can deteriorate. If this deterioration is ongoing for more than 3 months, it is considered chronic.
Chronic kidney disease has many risk factors. Some of these include:
- breed (especially Persian, Main Coon, Abyssinian, Siamese, Burmese, and others)
- acute kidney disease (infection, toxin, NSAIDs, etc)
- thin body condition
- dental disease
Most cats won’t show symptoms of chronic kidney disease until over 70% of the kidney is no longer functional. Signs can include:
- decreased appetite
- weight loss
- increased drinking and urination
- bad breath
- oral ulcers
- seizures, etc
What you need to know:
- Chronic kidney disease is irreversible. With treatment, the disease process can be slowed down, giving your cat comfort, decreased pain and suffering, and a longer life.
- If it is an acute kidney disease, aggressive management can either reverse it or improve it.
- Chemistries are needed to look at kidney function, hematologies to assess the red blood cell count, and urine analysis to check current kidney function and its associated problems.
- There is now a test for a new value called SDMA that detects early kidney disease.
Routine bloodwork—especially in older animals—is recommended to prevent advanced kidney disease, among many other underlying diseases and illnesses that clinically healthy animals can be hiding inside. See your veterinarian for yearly bloodwork and physical exams.