Chocolate contains a chemical called theobromine which is very toxic to dogs. They may vomit, start to tremble and become hyperactive. Their heart starts beating very quickly and in severe cases seizures and death can occur.
Recently, there have been health warnings about cocoa bark matting and cocoa shells which are sometimes used as ornamental garden mulch – some dogs that have eaten these due to their attractive smell have suffered theobromine poisoning as a result.
Caffeine can be toxic to dogs in high levels and signs are similar to those of chocolate poisoning. It is important to store tea bags out of the reach of your pet and dispose of your coffee grounds carefully.
Antifreeze contains a compound called Ethylene glycol. Unlike most poisons which are bitter, it has a sweet taste and so is attractive to both cats and dogs. If consumed, ethylene glycol will cause crystals to form in the kidneys leading to kidney failure. Care must be taken when using these products to wash away any spillages and properly dispose of packaging.
Rodenticide / rat bait
Rodenticide / rat bait contains a toxin called coumarin which prevents the blood from being able to clot. Dogs will generally scavenge rat bait from gardens, however cats can also occasionally be affected by eating a rat which has been poisoned. When poisoned with this type of product, an animal may be sick and then show signs of blood loss, e.g. having pale gums or bruising, rapid breathing or collapse.
Slug bait contains a product called metaldehyde. Affected dogs will usually vomit, become agitated and start to seizure. Even with prompt treatment this poisoning can be fatal.
Most species of lily are toxic to cats as they cause the kidneys to fail. All parts of the plant are toxic. Cats will usually be sick and then become depressed and extremely ill rather quickly. If you are given lilies as a gift, make sure you put them where your cat can’t get at them and won’t be dusted by the pollen.
Onions are toxic to both dogs and cats due to the presence of N-propyl disulfide which causes changes to both dog’s and cat’s red blood cells leading to anaemia, and organosulfur which causes disease when absorbed through the intestine. If you give your pet human food as a treat, ensure it does not contain onion.
The exact substance that causes toxicity from grapes is not known but even a small quantity can cause kidney failure in some dogs (the lowest reported fatal dose was three grapes). Because of the unpredictable nature of this toxicity, it is recommended that you contact your Vet immediately if your pet has eaten any grapes or raisins.
The sugar substitute xylitol which is found in sugar-free gums can cause a massive release of insulin in dogs. This can cause the blood sugar levels to drop very low, resulting in weakness, seizures and even death. Swift action is required to stabilise these patients.