Kidneys are amazing and so precious…
Kidney disease has carried off way too many of my patients in the past few months. It’s a sad and frustrating condition because there’s usually so little we can do to stop it.
At vet school, I remember thinking that kidneys are the most incredible of all our organs – no wonder we studied for endless weeks to figure them out. They are responsible for so many things. Through intricate chemical pathways, they regulate the amount of water in the body and, therefore, affect blood pressure, guard against dehydration, and determine how often we run to the bathroom. Kidneys also eliminate waste products produced by food molecules absorbed into the bloodstream. Red blood cell production in our bone marrow is stimulated by a chemical produced by the kidneys.
Even the liver doesn’t seem as complex in how it functions. But liver has one big advantage over kidneys. It can regenerate and recover from fairly severe damage. Once kidney cells die, they don’t come back.
Now, dogs and cats at least, don’t need all of the kidney capacity they have and will often have lost more than 50 per cent of functioning tissue before we start to see signs of illness. Usually, the first symptom is increased urination and thirst. In the jargon of my profession, this is called PUPD for polyuria, polydypsia. Next, pets develop poor appetites and vomiting.
These signs are also seen with diabetes, but blood and urine tests can quickly differentiate the two. If I had to have a sick pet, I’d wish for diabetes which can be survived for years. The prognosis for survival after diagnosis with chronic kidney disease is often as short as three or four months, occasionally only as many weeks.
So why did I slip in that word “chronic”? Well, there are some diseases of the kidneys associated with poisonings or infections that develop quite suddenly and can be halted if treated quickly. Exposure to the bacteria leptospirosis or toxins such as antifreeze can quickly cause this form of life-threatening “acute” kidney failure. But it’s the slowly progressive loss of function associated with age we see most commonly.
If your pet is drinking and peeing larger volumes than is normal, make a vet appointment and be prepared to take a urine sample. There may be some hard choices ahead. One of the patients we recently lost was on three medications daily and came in for fluid injections twice a week. It took an enormous commitment from his family to treat him, but for the few extra months he survived, he was one of the happiest, most energetic dogs I’ve ever known.
Cats diagnosed with kidney disease tend to live longer, although they are harder to medicate than their canine counterparts. I have several feline kidney patients still purring along several years after diagnosis.
I wish there was a handy list of preventive measures that guard against chronic kidney disease. Some studies have linked severe dental disease with kidney damage, so keeping your pet’s teeth clean may help. Other than that, just like us, they should be encouraged to drink lots of water every day.
Dr. Fiona Gilchrist,
Hillcrest Animal Hospital – Trenton/Quinte West
January 2013
