Most people tend to associate poisoning in dogs with artificial chemicals such as snail baits, rat poisons, insecticides and agricultural chemicals. Although these substances cause the vast majority of poisonings, we shouldn’t overlook that there are a number of food hazards which are toxic to our dogs.
Raw onions, soup and even discarded pizzas containing cooked onions have all been reported to cause poisoning in dogs, and more rarely in cats. In dogs, ingestion of as little as 30g per days of raw onions for 3 days can produce haemolytic anaemia. Oxidising agents in onions are thought to be to blame, which cause damage to erythrocytes, resulting in the production of Heinz bodies and methaemoglobinaemia.
Chocolate contains a xanthine compound, theobromine, that is toxic in sufficient quantities. Examples of other xanthine compounds are caffeine and theophylline. The toxicity from all of these compounds is similar. It takes a fairly large amount of chocolate to cause problems.
Xanthenes affect primarily the central nervous system, the cardiovascular system and peripheral nerves. There is a diuretic effect as well. So the sign seen with toxicity include hyperexcitability, hyperirritability, increased heart rate, restlessness, increased urination, vomiting and muscular tremors or tenseness. Under some circumstances these signs can lead to secondary problems like hyperthermia. In severe cases, seizures or cardiac arrest can occur. Death can result from severe intoxication. If you suspect chocolate poisoning and your dog or cat is showing clinical signs of the problem, it is important to contact your vet.
Although not a usual part of the diet, mushrooms occasionally pop up in our gardens and dog walking areas, especially in autumn. Poisoning has been reported in dogs after eating or simply playing with toxic mushrooms. Highly toxic varieties can cause paralysis, coma and death.
Dogs in particular are renowned for their scavenging habits, greed, and apparent lack of discrimination when choosing what they will eat. However, their ability to vomit readily and efficient mechanisms to deal with ingested toxins protect them to a large degree from food poisoning. Despite this, garbage poisoning is a common problem, often caused by the ingestion of pre-formed staphylococcal enterotoxins.
