Did you know dog poisoning can be caused by some types of food? For example, some dog owners (and uneducated trainers) have used grapes, sultanas or raisins as treat for their dog. Many pet dog owners enjoy sharing a bunch of grapes with their canine friend. As much as dogs seem to like them, grapes, sultanas and raisins can be very toxic to dogs, if enough of them are eaten.
Dog poisoning can occur if the animal eats approximately 30 gm of grapes per kilo of body weight, or 10-30 gm per kilo of body weight of sultanas or raisins. It doesn’t seem to matter what color or variety of grapes are eaten, though some dogs can eat grapes and sultanas with no problems at all. There doesn’t seem to be a relationship between the number of grapes eaten and body weight, and the development of poisoning. However, there is an anecdotal report of an 8 kg (approx 17 lb) dog being poisoned by only 3 or 4 grapes. Several theories have been put forward as to the toxic ingredient in grapes and sultanas, however the actual toxin and how it works hasn’t been identified. Latest information suggests it may be a chemical known as an ochratoxin.
The main effect of grape poisoning in a dog is the damage to the microscopic tubules in the kidneys, so symptoms relate to kidney failure. Your dog will become ill within hours after eating grapes; he’ll stop eating, have severe abdominal pain and start to vomit. As the condition progresses, he’ll become more and more depressed, and his kidneys will stop producing urine. His blood tests will show an increased level of urea and creatinine; two substances that are filtered from the blood and excreted by the kidneys. If the kidneys aren’t doing their job, blood levels will climb. These substances are a useful indicator of kidney function.
There’s no specific antidote for grape poisoning; your dog will have his stomach flushed and given activated charcoal if it has only been a few hours since he ate the grapes. He will also need aggressive treatment for acute kidney failure, with hospitalization and intravenous fluids for up to a few weeks. Your vet will regularly monitor blood urea and creatinine levels to get an idea of how your dog is progressing.
If poisoning is caught early, before your dog shows any symptoms of kidney failure, he should survive. However, if his kidneys have shut down and he’s not producing any urine, the prognosis is poor, and he’s unlikely to survive.
Preventing this poisoning is straightforward – don’t allow your dog to eat grapes, sultanas or raisins, and don’t feed them as a treat. However, this may be a challenge if your dog is a scavenger or steals food from the kitchen bench. Therefore, it’s best to keep these in cupboards, the refrigerator, or up high enough where you dog cannot reach them
Harvey, A. Dr., BVSc (Hons). (2010). *Article primarily written by Dr. Audrey Harvey and re-printed with her permission.
Disclosure Note: This article only serves as a guide and is based on research from various sources, both online and in print, including article(s) written by DVMs, dog trainers, groomers, and/or other qualified experts. Please check with your DVM for any questions regarding the information provided in this article. Thank you.