Toxic foods for dogs: grapes, raisins and sultanas
We had a small vet emergency last weekend. I am fairly diligent about watching my toddler when she has a pack of sultanas, as I know they are dangerous for the dogs. And so far Cress and Eddie have paid little attention when they spill on the floor or a single sultana is left on her high chair. On Sunday however I got distracted and five minutes later I found Eddie with a tiny chewed sultana packet up the end of the hallway. The problem I had is there was no way of knowing if she had happened upon the empty packet which my little girl had discarded or if she had taken a partially full packet and decided to consume its contents. Of course there were lots of questions asked but our 1-and-a-half year old witness had less than consistent testimony. So I called the vet and told them what had happened. They said bring her straight up and they would give her an injection to make her vomit. Half an hour later Eddie had been given the injection and she had vomited 22 sultanas, enough to make a little dog like her (9kg / 20lbs) sick.
So what is the issue with grapes, raisins and sultanas for dogs?
Grapes, raisins and sultanas have been shown to cause acute renal failure (the sudden development of kidney failure) in some dogs. This finding was first identified in 1998 and by 2001 the American Society for the Prevention of Cruelty to Animals (ASPCA) Animal Poison Control Centre (APCC) had documented enough cases for it to be classed as a real syndrome. In 2003 members of the Veterinary Information Network took part in a survey and 7.4% of respondents indicated they had treated at least 1 case of grape, raisin or sultana toxicosis.
Even though there has been some research, the reason as to why some dogs develop renal failure after eating grapes, raisins and sultanas is still unknown. Further work is needed to understand the toxicity and if there are other environmental factors that cause it to occur.
The toxic dose
Dogs that are affected by these foods can develop kidney failure 72 hours after ingestion. But how do you know when your dog has had a toxic dose? This is the hard part, as my vet informed me some dogs can eat relatively large volumes of grapes, sultanas and raisins without any issues while other dogs can consume one or two and become ill. Estimated amounts of fresh grapes associated with kidney injury are approximately 32g or 1.1oz per kilogram of your dog’s weight. Raisins and sultanas are slightly more powerful: from 11-30g or 0.39-1.06oz per kilo of your dog’s weight. BUT a study in 2005 looked at 10 dogs who had suffered renal failure after ingesting greater than or equal to 3g (0.11oz) per kilogram of raisins or dry matter of grapes (dry matter is calculated as 20% of grape weight). As you can see there are no hard and fast rules so if you suspect your dog has ingested any grapes/raisins/sultanas call your vet.
If your dog has eaten grapes, raisins or sultanas they might have some of the following symptoms:
- not eating
- abdominal pain
- increased drinking
Clinical signs your vet may look for in a blood test include things like increased blood urea nitrogen, creatinine, phosphorus, calcium. Plus they would ask about reduced urination or no urination.
If your dog has consumed these foods within the past two hours (as our dog Eddie did) your vet will most likely induce vomiting via an injection (hydrogen peroxide or apomorphine) followed by activated charcoal. If your dog has eaten a significant amount, started vomiting themselves or ingested the food several hours prior, intravenous fluid therapy might be suggested. In severe cases dialysis of the blood and peritoneal dialysis might be used to support the kidneys.
Grapes, sultanas and raisins are popular foods in many households (ours especially) so it is best to be vigilant and ensure that your dogs do not come in contact with these foods. Don’t leave them lying around at their level or any place that they can access. I have made a new rule that my daughter now only has sultanas when we are out of the house. As for grapes she eats them at the dinner table under supervision.
But even if you have no children around the house you can easily slip up by leaving out raisin toast, fruit cake or — particularly at this time of year — a hot cross bun. So keep all these foods in your cupboard or fridge and make sure they are not shared with your four-legged loved one.
Even if your dog doesn’t get ill the stress and cost of an emergency vet trip is never a great way to spend your day.
Please note: Puppy Tales provides these articles for information purposes only. For any health problems with your pet always seek immediate veterinary advice from your local veterinarian.