My dog's been poisoned - help!
Most cases of canine poisoning are caused by dogs eating toxic items, although poisons may also be inhaled or absorbed through the skin.
The body’s protective mechanisms defend dogs from many poisons, with hairs and mucus forming a natural filter in the nose; thick skin and hair acting as an external barrier; and digestive systems safeguarding against many potential poisons by rejecting them due to taste, or removing them by vomiting or diarrhoea.
Despite this, there are potential dangers lurking in our houses, garages, gardens and countryside, and knowing how to prevent and treat poisoning incidents can be a life saver.
What problems can occur?
Some poisons are caustic and cause internal burns, others are toxic to the nervous system, while others cause haemorrhage or damage particular cells or organs.
Rodent poisons, such as difenacoum, and slug and ant killers are some of the most common poisons that cause problems in dogs, with slug pellets being particularly significant because some dogs find them palatable.
These types of poisons can cause nervous symptoms that rapidly progress from trembling to fits, collapse and death. Alternatively, they may cause internal bleeding and death due to blood loss.
Garden chemicals such as glyphosate and paraquat cause symptoms ranging from caustic internal damage and digestive disorders to muscle weakness, breathing difficulties, collapse and death, and even bone meal can cause severe disease.
Plants too can be poisonous, particularly to puppies, who are much more inclined to chew and play with twigs, flowers and bulbs than are adult dogs.
Symptoms of vomiting and diarrhoea are common with poisonings and, in severe cases, other signs of disease such as excitability, trembling, weakness and collapse can occur.
If you, or your neighbours, are working on a car, it’s important not to leave antifreeze or fluid from drained engines lying unattended. This is because ethylene glycol seems particularly palatable to dogs and causes severe kidney damage that is often fatal.
Even while out walking, there are risks for the unwary dog. In the summer, blooms of blue-green algae on stagnant water are extremely dangerous. Exposure while swimming in or drinking such water causes vomiting, dribbling, muscle fasciculations, liver damage, convulsions and even sudden death.
Adders lurking in the undergrowth will bite if they are disturbed and their venom results in severe swelling at the site of the bite, as well as dribbling, vomiting, depression, bleeding, collapse, shock and even death. As with most poisons, early and specific treatment gives the best chance of recovery.
The most frequent causes of poisoning in the home include medicines and foods. Consumption of owners’ medicines by unsupervised dogs is surprisingly common given how hard it can be to get dogs to take their own medication!
Sadly, some of these cases are caused by owners administering medicines such as ibuprofen and paracetamol to dogs to relieve apparent pain, in the mistaken belief that such medicines will help. In fact, they can cause potentially fatal liver or kidney damage in dogs.
Other drugs, from oral contraceptives to cannabis, also cause poisoning as puppies in particular will chew up just about anything they can find. It’s important that all human and canine medical products should be kept safely out of reach.
In the kitchen, access to large amounts of almost any food can cause signs of toxicity when the digestive system is overloaded, so keep cupboards closed and worktops clear in order to avoid problems with vomiting, diarrhoea and gastric dilations.
Eating large quantities of raisins has been reported to kill some dogs and, while the toxic mechanism and the fatal dose are not fully understood, it’s advisable to avoid access to raisins.
Chocolate is one of the most common sources of poisoning in dogs. It causes vomiting and hyperactivity, followed sometimes by convulsions and death. As little dark chocolate as six grammes per kilogramme of a dog’s bodyweight is potentially fatal so chocolate treats (except specific doggy chocolate) should be avoided and dogs should not be left alone with the Christmas presents or with chocolate cakes and sweets.
Treatment has to be specific to the type of poisoning for the best chance of recovery. Because of this, it’s extremely helpful if owners can give the vet the packaging of any poisons, or a piece of any plant that has been eaten so that the exact toxin can be identified and treated.
However, in most cases of oral (by mouth) poisoning, inducing vomiting can be a very useful first step to reduce absorption of poisons, though this is really only effective if performed immediately after a dog has eaten the toxin.
Oral dosing with charcoal powder and other adsorbents can help to reduce absorption of poisons, and medicines can be used to aid passage through the intestines.
Other non-specific treatments for poisoning include putting the affected dog on a drip to maintain hydration of vital organs (blood tests often give helpful information about this), using sedatives and painkillers to try to control the animal’s symptoms, and keeping affected dogs as quiet as possible.
Specific treatments include using medicines to promote blood clotting in dogs who have taken anti-coagulant rodenticides, and using medicines to control seizures in dogs who have been exposed to neurotoxins.
Medicines can be used to try to lessen the formation of ethylene glycol crystals in the kidneys and thus reduce kidney damage, and adder anti-venom is available for treating dogs who have been bitten by an adder.
Most poisonings are easily preventable. It is common sense to keep dogs in a safe and enclosed environment at home where medicines and garden chemicals are locked away and access to inappropriate food, toys and plants is prevented. Puppies should be watched when out in the garden, and should be taught not to dig up and chew garden plants.
When out on walks, dogs should be kept within sight and should (if possible!) be well-trained and controlled to prevent poisoning and injury. Finally, it’s important to
remember not to give dogs any medicines other than those dispensed by your vet for the animal in question.
Glossary of terms
Adsorbent — product that sticks to toxins and helps them pass through intestines.
Anticoagulant — product that stops blood clotting properly.
Fasciculations — muscle tremors.
Gastric dilation —stomach swelling that can lead to an emergency.
Haemorrhage — loss of blood.
Neurotoxin — a nerve poison.
Palatable — tastes nice.
Rodenticide — product that kills rodents.
Most common causes of poisoning
Human painkillers, such as ibuprofen, diclofenac, paracetamol.
Garden pesticides, herbicides and fertilizers (like paraquat, glyphosate).
Ethylene glycol (antifreeze).
Chocolate. Some poisonous plants