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.