Dr. Jill Richardson's article is posted here with permission from the
ASPCA Animal Poison Control Center
1-888-426-4435

Problems with dogs and grapes, by Jill Richardson, DVM

The ASPCA Animal Poison Control Center has received more than 50

well-documented reports of dogs developing acute kidney failure after

ingesting grapes or raisins.

Veterinary toxicologists at the Center began noticing this trend in

1999. As more cases were reported enough was generated in the

database to help veterinarians identify and treat dogs at risk. In

all of the cases the ingredients for potential acute kidney failure

were the same. The grapes and raisins ingested were from a variety of

sources. Some were commercially prepared products of various brands

purchased at grocery stores and some were grown in private back

yards. The cases aren't from any specific region, but instead came

from across the U.S.

According to preliminary data, the affected dogs began vomiting

within six hours of ingesting the grapes or raisins. Most of the

time, partially digested grapes or raisins could be seen in the

vomit, fecal material or both. At this point, some dogs would stop

eating and develop diarrhea. The dogs often became quiet and

lethargic and showed signs of abdominal pain. These clinical signs

lasted for several days and sometimes even weeks.

In a vast majority of the cases, the dogs continued to vomit and

became depressed, at which point veterinary care was sought. The

results of the blood tests showed consistent patterns. Elevations in

creatinine and BUN, as well as hypercalcemia and hyperphosphatemia

have been reported. Tile abnormal blood levels would increase

anywhere between 24 hours to several days after the dogs ate the

fruit.

Kidney damage was evident in most cases within 72 hours from

ingestion. As the kidney damage developed, some dogs would produce

only small amounts of urine. When they could no longer produce urine,

death occurred. In some cases, dogs that received timely veterinary

care still had to be euthanized. Only half the dogs that received

aggressive treatment, which include intravenous fluids and

medications, had fully recovered.

In an attempt to determine causative agents or disease processes,

veterinary toxicologists at the Center have screened the suspected

grapes and raisins for various pesticides, heavy metals, and

mycotoxins (fungal contaminants) and so far, all results have come

back negative. In the cases where the grapes were grown in private

yards, owners confirmed that no insecticides, fertilizers or

antifungals had been used on the fruit.

As for treatment, the first line of defense is decontamination.

Inducing vomiting in recent ingestion and administering activated

charcoal helps prevent absorption of potential toxins. Dogs should be

hospitalized and placed on a diuresis of intravenous fluids for a

minimum of 48 hours. The blood work should be monitored daily for at

least three days following the ingestion. If all blood work is normal

I after three days, it's unlikely that kidney failure will occur. If

a dog shows evidence of kidney failure, fluids must be continued, and

other medications should be used to stimulate urine production.