Animals – Poisonous chocolate

With the festive season approaching, I thought it might be a good time to revisit some of the information contained in the “Death by Chocolate” article I wrote about three years ago. Some of the foods we love can be dangerous for our pets, especially those pets that fit into the “food hover” category.

The theobromine in chocolate can cause poisoning. There tends to be less in light chocolate than dark chocolate and some is in cola drinks and tea. Signs of poisoning start with vomiting, diarrhoea and urinating excessively. But muscle tremors, a fast and irregular heartbeat and hyperactivity may develop and can end in seizures and death. Depending on the type of chocolate, a 20kg dog would need to eat at least 60g to 192g before any symptoms are seen.  It would require the eating of about 1.125kg to 3.6kg of chocolate to kill a 20kg dog.    

The caffeine in coffee and some energy drinks can be toxic in excess, producing similar symptoms to chocolate poisoning. I might expect a 20kg dog would have to drink four cups of “ordinary” coffee before any symptoms were seen.

Macadamia nuts are potentially poisonous for dogs. A 20kg dog would need to eat at least 40g before you would see any signs, which include vomiting, muscle tremors and wobbliness.

Grapes and raisins will cause kidney damage if eaten in big enough quantities. A 20kg dog would have to eat at least 420g of grapes or 66g of raisins before seeing any symptoms.  These include vomiting, diarrhoea, drinking and urinating lots, shaking and lethargy. Onions, garlic and chives can cause anaemia in dogs – they go pale, breath fast and have no energy. This poisoning can be accumulative and slow in onset. Cats can tolerate far fewer vegetables than dogs.

There is a warning for pilots in Nepal that goes, “Some of our clouds contain rocks”.  This reminds me of the hidden danger in baited hooks left around where your pets can get at them. If I got $20,000  every time I’ve seen a cat or dog with a fishhook in its mouth or stomach, I would be able to buy a house in Auckland!  Because metal shows up well on X-Rays, the location of swallowed hooks can usually be found easily. Most swallowed hooks will make it to the stomach where surgery to remove them is relatively straightforward. Though a hook stuck in the oesophagus (gullet) as it travels through the chest could mean dangerous and expensive surgery. If you find your animal with fishing line coming out of its mouth, and nothing else in its mouth, don’t pull the line. If the animal is not totally stressed by the presence of the line in its mouth, don’t cut it short. Take him or her to your vet. 

David Haugh, Wellsford Vet Clinic
www.vetsonline.co.nz/wellsfordvet