My clinic, for whatever reason, has had a bit of a rash of cases involving known or suspected exposure to toxins recently, with three serious situations in the past few weeks.
I thought it might be a good time to discuss two of the more common threats our pets face from toxins in their immediate environment, especially as the warmer weather arrives and we spend more time outdoors. These two poisons are widely available, and indeed their intended use is to kill specific pests, so the fact that they can cause significant harm in our pets is no surprise. What perhaps is surprising is how commonly our pets, especially dogs, will find a way to get into them.
One recent case we saw was a dog that ate an entire package of rat poison. Rat poison is a particularly nasty toxin. The active ingredient in rat poison for many years was the anti-coagulant warfarin. Warfarin works by inhibiting an enzyme that recycles vitamin K, which is an essential factor in the process of normal blood clotting. This causes a gradual depletion of the active form of vitamin K and leads to an inability to form normal blood clots. Because it takes time for the body’s stores of this essential factor to be depleted, it can take two or three days for the poison to show its effects. Essentially, the rat (or pet) bleeds to death. Warfarin has now been replaced for the most part with more potent versions that are much longer acting. They do the same thing but they do it more aggressively, and they stay in the system, exerting their effects for much longer.
Another deadly toxin that we worry about our patients getting into in the coming summer months is in many slug and snail baits. Many of these products contain the toxin metaldehyde. Slug and snail baits are often flavoured and seem to be particularly appealing to many dogs. The exact way metaldehyde works is not well understood, but we do know what the end result is for the poor patient ingesting it. Within an hour of ingesting enough of this poison, which can be as little as an ounce or two for a 10-pound dog, the pet may start to vomit and will rapidly progress to showing tremors and a significantly elevated heart rate. The tremors often progress to a full-blown seizure and result in a rapid increase in body temperature. Many cases of metaldehyde toxicity are rapidly fatal.
As with many toxins, the first step in treatment is often getting as much toxin out of the patient as possible, by getting the pet to vomit as much of whatever it is they ate as they can. This is why it’s so important to see your vet as soon as possible after a known or suspected exposure. Often within a couple hours of eating the contents of the stomach have moved on. Once whatever was eaten has entered the intestines, it’s too late. It may be a day or two after that before the effects of the poison become apparent.
The next step is often to administer an agent such as activated charcoal to bind up whatever toxin remains in the digestive system so that it can’t enter the bloodstream.
After that, specific treatment may be required, such as a lengthy course of daily oral vitamin K administration in the case of rat poison, or aggressive supportive care while the body hopefully metabolizes and eliminates the toxin, as is the case in metaldehyde and many other poisonings.
It is so important to remember how many of these commonly found products can be deadly to our pets. In almost every case I have seen of exposures to these toxins, the pet owner truly thought they had taken all the right precautions, and never expected their pet to be at risk. Remember that dogs especially can be very tenacious when it comes to getting into something they have decided they just need to get into. If you know or suspect your pet may have ingested a toxin, seeking immediate veterinary attention is vital. It may be hours or even days before the effects are noticeable and by that time it may be too late for the best possible treatment options. Always remember to bring whatever packaging or information you have at home on the product that was ingested – the treatment and prognosis can be very different even for different types of the same toxin.
There are of course many other commonly found products, plants and substances that are toxic to our pets. For an excellent resource, take a look at the ASPCA poison control website at aspca.org/pet-care/animal-poison-control. They also have an excellent mobile app that contains a database of common pet toxins, their effects, and advice on what to do if you suspect your pet may have been exposed.