Rodent poisons are toxic to other mammals including dogs. While the toxicity of different baits does vary, all legally available baits are variations of the type of poison in Warfarin and have the same effect: they cause internal bleeding leading to death. The poison does not work instantly and the animal needs to eat sufficient bait to raise the concentration of the poison in their blood to a critical level. So for a large dog the amount that must be eaten is substantially more than that required to kill a mouse or rat.
Risk of rat treatments for dogs
Baits should always be placed in secure cavities or inside locked bait boxes, so no dog or animal bigger than a rat, should have access to them. However, dogs may find dead or dying rats, but they usually only chew or bite them, so are only exposed to the small amount of poison in the rats body tissues (that is usually too little to cause the dog any problems). It is rare for a dog to eat the whole carcass in which case they may swallow the larger amount of poison that’s retained by the bait in the stomach of the rat. Even then, due to the larger size of the dog, it will usually require the dog to eat several whole rats, which is rather unlikely. It is true that some dog breeds are more likely to eat a whole rat but the risk is mainly to the smaller dogs like terriers. If there is a suspicion that a family’s pet dog has been exposed to baits, then a prompt visit to the vet is advised, where the treatment is usually injections of vitamin K to reverse the poison’s effect on blood thinning. A more drastic action is to pump out the dog’s stomach contents if it was likely a large amount of bait had been consumed.
If baits are placed securely and dog owners check their gardens each morning on the days after fresh baits are laid, then the risk of a dog eating bait is extremely low and the risk of it finding more than one poisoned rat is also low. Unfortunately, poison baits are the only effective long term treatment for rodents.