[From Tufts December 2011 Issue]
Q: I have read on several Web sites that eating acorns and oak leaves can cause acute or chronic renal failure in dogs. Is this true? And, if so, how can you tell if a dog that eats acorns or oak leaves has damaged kidneys if he doesn’t have any symptoms?
New Smyrna Beach, Florida
While acorns and oak leaves do contain a toxin called gallotannin, renal failure from it has not been reported in dogs. There are probably two reasons for this. First, the acorns would have to be chewed to release the toxic substance; and second, dogs just don’t ingest large enough quantities of leaves.
Renal failure is seen in animals such as cows, sheep, goats and horses, which ingest large quantities of acorns and/or oak leaves while grazing. A bigger risk for dogs is that an acorn may be too large to pass through the intestine. The resulting intestinal obstruction could require surgery to remove the acorn. In addition, acorn ingestion in dogs can result in moderate to severe abdominal pain, vomiting and diarrhea. So — start raking up those acorns!
Although acorns and oak leaves would not be a cause of renal failure, it is still useful to know the signs. These include excessive drinking and urinating, loss of appetite, vomiting and dehydration. To test kidney function, your veterinarian would run blood tests and perform a urinalysis. Unfortunately, none of these tests become abnormal until your dog has already lost at least two-thirds of kidney function.
Linda Ross, DVM, MS, DCVIM