Dogs will eat all sorts of unlikely things.  In fact, the more disgusting they are the better!  This means there is a real risk of poisoning on the average farm, where there are very many potential poisons.  As a lifestyle farmer, you should know the risks, to make sure that your farm dog or household pet doesn’t fall victim to accidental poisoning. 

This article lists the most common poisons, and while the risks of some are well known, the danger of others is not so widely appreciated.  Also listed are a few other common but hazardous substances that can cause potentially fatal digestive disorders in dogs, and some of these too may surprise you.

The following are among the most common poisons of farm dogs.


  • Anticoagulants like Talon and Pest-Off are readily available over the counter and are widely used to kill rabbits, rats, mice and possums. 
  • They can take weeks to kill and they are very persistent in the environment.  
  • They commonly poison dogs that eat the poisoned baits and they can also cause secondary poisoning when dogs eat poisoned carcases.
  • Signs (weakness, pale gums and breathlessness caused by internal bleeding) may not develop until a week or so after eating the poison.
  • Vitamin K treatment from your vet is often successful if started early but has to be continued for weeks. 


  • Cholecalciferol (Campaign) can poison dogs that eat poisoned bait or poisoned carcases.
  • Cholecalciferol interferes with calcium metabolism and poisoned animals usually die within a few days. 
  • Your vet may attempt treatment for cholecalciferol poisoning but it is often unsuccessful.


  • Dog owners should take particular care near areas where 1080 poison has been used as dogs are extremely susceptible to the poison.
  • There is no antidote and it causes every appearance of extreme distress in dogs, and the signs can last for hours before the dog dies.  It’s very distressing! 
  • Poisoned carcases can remain poisonous to scavenging dogs for many months if they have been preserved in very dry conditions. 
  • Treatment usually isn’t effective unless the dog can be made to vomit immediately after it has eaten the carcase (see below).


  • Cyanide capsules (Feratox) are one of the best poisons for humane and effective rabbit and possum control as they kill quickly when the animal bites into them. 
  • Only licensed operators may use cyanide.  They usually put it out in capsules in peanut butter bait in packets stapled to posts or trees.
  • The operators usually remove the bait stations soon after they have been laid, so there is no cyanide left in the environment. 
  • Unfortunately, dogs may be attracted to the peanut butter and if they eat it they usually die quickly, and treatment is hopeless.

Ethylene glycol (antifreeze)

  • Antifreeze has a sweet taste and dogs (and cats) may lick from the puddles of it under vehicles. 
  • The early signs may include vomiting and diarrhoea but signs of kidney problems then develop.
  • Treatment by your vet may be successful if started early.

Other potential poisons

  • Organophosphates and carbamates (used as insecticides on ruminants or on plants).
  • Lead (in old car batteries and old paint).
  • Metaldehyde (slug bait).
  • MCPA and 2,4D (herbicides).
  • Zinc, aluminium or magnesium phosphide (new possum poison).
  • Blue-green algae in ponds.

Making your dog vomit

  • If you know or suspect that your dog has eaten poisoned bait or poisoned animals, you should make it vomit and take it to your vet immediately.
  • It can be made to vomit by drenching it with a concentrated household salt solution, or by pushing a crystal of washing soda (sodium carbonate) down its throat.  Don’t use caustic soda!
  • There is little point in doing this if more than an hour has passed since it ate the poison. 
  • Then contact your vet immediately.
  • Try to find out exactly what poison was eaten and how much.

National Poisons Centre

  • For more information about potential poisons, contact the National Poisons Centre, Dunedin, on 0800 764 766 at any time for free advice on poisons and poison prevention as well as emergency advice in the event of a poisoning. 
  • The main purpose of the National Poisons Centre is to help deal with human poisoning cases but it is happy to help with animal cases too. 

Other dangerous substances

There are other hazards around the farm that your dog might eat apart from poisons.  Here are just a few to look out for: 

  • CIDRs (intra-vaginal devices used for oestrus control in ruminants) and intra-ruminal capsules (long-acting anthelmintics or monensin) and any other plastic device with animal material on it.
  • Ear tags (on ears discarded from home-kills).
  • Horse hoof parings.  Dogs find these very tasty and generally they are well chewed up by the dog and do no harm.  However, occasionally a dog swallows a chunk that can perforate the intestine.
  • Some collies and collie crosses can be poisoned by the anthelmintics ivermectin and abamectin.
  • Some materials that are swallowed can cause intestine blockage, eg corn cobs or other chunks of indigestible vegetables from the compost heap and plastic wrap (especially if it has held food such as dog sausage).