Grapes of wrath

Bosephus Johnson lumbered slowly into the exam room after his owner James. James was concerned that Bo just wasn't doing right; his appetite had been down for about a week, he was drinking more water than usual, and he had vomited a few times since yesterday.

It was easy to tell Bo felt sick; normally the 100-pound golden retriever was all tail-wags and kisses, but today he looked wilted with his head down and his tail low and limp. Except for some mild dehydration, Bo's physical exam was normal.

As Bo was an active dog who followed his owner around their little ranch all day, I asked the James if Bo could have gotten into something that might have poisoned him but he couldn't think of anything. "We need to do a blood test and a urine test to figure out what's going on with Bo," I told him. "We should have the results in about an hour; I will give you a call and let you know what we find."

The results of the tests showed that Bo's kidneys were failing. This was leading to the build up of toxins in his blood and the loss of appetite, depression, increased drinking and vomiting. This type of acute kidney failure could be caused by poisoning, infection or autoimmune disease, but there was no evidence of infection or autoimmune disease. The kidneys' job is to eliminate toxins that are produced by the metabolic processes taking place within the body, while conserving water. Although there are two kidneys in the body, only one is needed for adequate function.

Signs of kidney failure do not occur until more than 50 percent of the total kidney function is lost. Unfortunately, the kidney is not capable of repairing itself when it has been damaged, and failure of the kidneys often leads to failure of the animal.

Despite hospitalization and aggressive therapy, Bo's kidney failure progressed and James made the difficult decision to put him down. I told James that Bo must have gotten into something somewhere that caused his kidney failure. "You know I've been thinking about that and I remembered the day before he started acting sick, he had been into a box of grapes we picked from our vines. But he has eaten grapes before." James said. "Could that have anything to do with it?" "It may well have had everything to do with it," I replied.

Cases of kidney failure in dogs and cats that have eaten grapes and raisins have been on the rise in the last several years, although Bo was the first case that I treated where grape consumption was confirmed. The toxic agent has not been identified, although it does not appear to be a fungal toxin or pesticide, and it does not appear to be related to grape seeds.

Even 10 to 15 grapes or raisins can be a toxic dose and signs usually appear within 72 hours. There is no explanation as to why only some of the dogs and cats that eat raisins or grapes get ill, or why a dog like Bo can eat grapes for years without getting sick, and then suddenly become gravely ill after eating them. Because of the mysterious nature of grape toxicity, veterinarians now recommend that no grapes or raisins be fed to dogs or cats, and that you should talk to a vet if you know your dog or cat has eaten them.

While on the subject of unusual pet poisons, I'll mention that pet owners should be aware that, when dogs eat sugarless gum or other products which contain the artificial sweetener known as xylitol, they can experience a severe drop in blood sugar resulting in collapse, seizures and liver damage. As little as 1-3 pieces of gum consumed by a 20-pound dog can cause problems. Also, in anticipation of the Easter season, don't forget that chocolate ingestion can cause tremors or seizures and ingestion of Easter Lilly is another cause of kidney failure in our pets.

Dr. Tesluk practices at Ashland Veterinary Hospital.

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