We get lots of calls about dogs* that have eaten chocolate, especially around Easter time and no doubt you have read a lot about chocolate toxicity in your time. Today we would like to provide an antidote to the hype. By no means do we wish to play this life threatening toxicity down, we would just like to put it into perspective, and shift your focus to the hot cross bun that they are eyeing off! Have you heard about grape toxicity? I hope so, because it is, surprisingly, a far greater problem.
Say What??? Why don't you need to panic about the chocolate but you do about the grapes? Well it comes down to predictability. We know what dose of methylxanthines (the toxic component of chocolate) is likely to cause a problem in animals and by assessing the cocoa content of your chocolate, the amount your animal ate we can reasonably estimate the amount your dog ingested. Divide this amount by their weight and voila, we can predict whether you need to be concerned. Of course there are some other factors at play, mostly associated with the fat and sugar content of the chocolate and your dogs sensitivity to fat.
The other 'lovely' thing about chocolate toxicity is that if you are alert to your animal you will pick up that something is wrong early on in the course of the illness and with appropriate action there is a good chance that your dog will make a full recovery. Dogs with chocolate toxicity will initially show slight hyperawareness, as if they've had too much coffee, this will progress to agitation, tremors and finally seizures.
Grapes(/raisins/sultanas) on the other hand are a much more unpredictable beast – the lowest recorded dose of toxicity is approximately 20g/kg (approximately 4 grapes) but some dogs can consume large numbers of grapes with no ill effects. The other devastating aspect of grape toxicity is that the disease they cause, acute renal failure, is quite an insidious disease, only becoming apparent once significant damage has occurred, and often leading to death. The main symptoms of acute renal failure are excessive thirst and urination, vomiting and abdominal pain.
So what do you do if your dog ingests:
1) Gather all remnants of packaging and determine the original weight of the chocolate as well as the type of chocolate (milk/dark/cooking/white) and even better the cocoa content (listed on many premium chocolate packages)
2) Weigh the amount of chocolate 'left over'
3) Call us (or if we're closed an emergency vet) with this information so we can determine whether you need to be concerned and advise about appropriate action.
Contact a vet immediately. If we see your dog soon enough we can make them vomit up the grapes or even 'pump their stomach'.
If the grape eating event occurred more than a couple of hours prior to presenting to a vet this may not be an option and the treatment they receive will be more focused on diuresis to them to eliminate the toxins from the body and to protect the kidneys. They will also be monitored closely and if acute renal failure develops further treatment specific to this disease will be instigated.
*We get very few calls about cats ingesting chocolate or grapes, it has not been determined whether this is because cats are less likely to consume these things, whether they are more resistant to the toxin or a combination of these two factors.