Slug bait - metaldehyde poisoning

1st February 2017


Slug bait poisoning occurs when pets eat slug or snail bait that contains the drug metaldehyde. At Bollington Veterinary Centre it’s a relatively common poisoning we see, and can have some devastating consequences.

All animals are susceptible and just a small quantity of pellets can be fatal.


Why do animals eat slug bait?

  • It looks edible - it is often in a pellet form, which many animals find attractive due to its close resemblance to dry food.
  • It's mixed with food - slug bait is often mixed with other food products, such as soybeans, rice and oats. These additives are designed to attract slugs but unfortunately lure many unsuspecting pets as well.
  • The granules are licked – slug bait can also be found in a granule form. Whilst granules are more difficult to eat, they can stick to their paws and get licked off when grooming.
  • The gardeners weapon – keen gardeners are plagued by slugs in the spring. They are desperate to get young seedling to grow, only to be thwarted by the emerging slugs at night. The garden is also a popular place for pets to wander or roam, and are susceptible to being exposed to large quantities of metaldehyde. Be aware, it might not be you using the slug bait, but your neighbours may be keen on the product and your pet may gain access to their plot.


What are the signs of metaldehyde poisoning?

Once eaten the clinical signs of metaldehyde poisoning develop rapidly, sometimes within an hour of ingestion.

  • Mild twitching – this is usually seen in the early stages. You might see twitching of the eyelids or lips
  • Unsteady gait – this develops within a short period of time, and can look as if your pet is drunk
  • Salivation – look for drooling saliva or frothing at the mouth
  • Vomiting – don’t ignore this. You might initially see just a small pool of saliva, but food may be brought up as well. You wont necessarily see the slug bait, but if you spot anything blue, be suspicious. If left untreated, an affected pet will begin to show more serious signs.
  • Tremors and seizures - these tremors and convulsions significantly raise the body temperature, which can lead to permanent brain damage and death. The twitching becomes more exaggerated and you’ll find an animal starting to go into a full fit.


How do we diagnose slug bait poisoning?

There are many conditions that could present with these signs so we have to look carefully.

  • History - often an owner will have seen their pet eating the slug bait.
  • Clinical signs – if we see several of the above signs we are usually very suspicious of metaldehyde poisoning.
  • Laboratory tests – if we can obtain stomach contents and blood we can arrange for these to be analysed at one of our external laboratories. Unfortunately it takes a few days to get the results, so in an emergency situation this may not help.


What treatment is available?

Unfortunately there is no ‘antidote’ for metaldehyde poisoning. All we can do is minimise further drug absorption and suppress the signs until they wear off. If we know that the poison has been eaten within an hour of being seen, we can sometimes induce vomiting to remove as much of the slug bait from the stomach as possible. This has been done at Bollington Veterinary Centre many times over the years and we’ve saved many lives this way.

In cases where the clinical signs have already started it is often better to anaesthetise the patient. If possible we will empty and flush the stomach. When the animal wakes and is recovering, we can offer activated charcoal to limit further absorption of metaldehyde from the small intestine.

There are many factors that influence the outcome as it depends on how much was eaten and how quickly the treatment is started.

If ever you are suspicious that your pet has eaten any slug bait, don’t delay - ring us immediately and ask for some advice.

Don't delay, contact us immediately