A variety of things can cause an infection of the kidneys or kidney failure in cats and dogs. Understanding how these diseases originate and how each affects your pet’s health can help you better care for your cat or dog.
A bacterial infection in one or both kidneys may begin with an infection elsewhere in the body. It may also result from a blockage in the urinary tract, or originate from bacteria in the bloodstream. With this type of kidney disease, your pet may show signs of pain in the kidney area, high fever, and blood in the urine. If an infection goes untreated, you may see signs of kidney failure. However, often infections can be effectively treated with antibiotics.
When kidney functions shut down, it’s known as kidney failure or renal failure. It can occur at any stage of life, but the chances increase as cats and dogs age. Cats are about three times more likely to develop kidney failure compared to dogs.
Kidney failure may be acute, meaning the symptoms come on suddenly, or chronic, meaning that the disease progresses slowly and symptoms may not be evident for some time. The majority of renal failures in cats and dogs are due to chronic kidney failure in which the kidneys become less able to perform their functions over time as the kidneys’ “filters,” called nephrons, die off. When about three-quarters of the nephrons have been lost, your cat or dog may begin drinking more and urinating excessively. By the time these symptoms of chronic kidney failure are noticeable the damage is usually extensive and irreversible.
In some cases, dogs and cats suffer from a sudden and profound decrease in kidney function which progresses very quickly. Sudden renal failure like this is called acute kidney failure. It often begins with a specific event such as during shock, poisoning, or restrictions to your pet’s blood flow. It’s less common than chronic kidney failure, but extremely dangerous; often cats and dogs will not survive longer than several weeks following the onset of symptoms.
Common causes of kidney failure include:
- Polycystic kidney disease: Cysts gradually replace normal kidney tissue in this disorder, which is most common among Persian and Exotic cats and Cairn Terrier and Beagle dogs.
- Blockage in the urinary tract: Kidney tumors, stones, or infections can cause urine to back up, which will damage the kidneys.
- Bacterial infections: These might include leptospirosis and Lyme disease in dogs. While bacterial infections can usually be treated with antibiotics, certain cases may not respond to treatment or may go undiagnosed, leading to irreversible damage in the kidneys.
- Viral diseases: Hepatitis, herpes, feline infectious peritonitis in cats, and other viruses can cause inflammation and kidney failure.
- Disruptions in blood flow: Shock, trauma, or other circumstances may result in inadequate blood flow to the kidneys, which can cause them to shut down quickly.
- Toxins and poisons: Dangerous foods, chemicals, and certain types of medications can cause acute kidney failure.
- Degenerative changes: Advanced age itself may cause the kidneys to breakdown and stop functioning correctly.
Often, veterinarians cannot tell for certain what caused renal failure in a particular pet.
This information is for informational purposes only and is not meant as a substitute for the professional advice of, or diagnosis or treatment by, your veterinarian with respect to your pet. It has, however, been verified by a licensed veterinarian for accuracy.