Animals – Rat bait poisoning

Rat bait poisoning is, unfortunately, a recurring event every winter, and if the symptoms are only detected in the later stages of poisoning, it is a seriously life-threatening issue for your pet. Rat baits are designed to produce delayed onset of symptoms, so that the rodents do not associate the consumption of bait with feeling unwell. The toxin in the bait inhibits blood clotting. This leads to internal bleeding and results in a non-painful death. To what extent the blood clotting is affected is dependent on the amount of bait consumed in relation to the body mass of the poisoned animal. A rat, for example, will need to eat only small amounts of bait to die, whereas for a 35kg dog the consumption of a single bait will be less dramatic. The common symptoms are lethargy, anaemia and increased heart rate.

Treatment of rat bait poisoning is primarily aimed at the re-establishment of normal blood clotting. For this purpose an antidote, vitamin K, is administered for a sufficient period of time. This period is usually quite long.  We are talking weeks here, not just a few days.

To determine the effect of the poison, as well as the antidote, we take blood samples before treatment and three to four days after treatment with vitamin K. We do this to gauge the initial impairment of blood clotting and to decide when stopping vitamin K treatment will be safe. Sometimes symptoms on initial presentation are so severe that we cannot wait for vitamin K to take effect. Your pet will need a blood transfusion to restore clotting factors and it will still need vitamin K after that.

To minimise the chance of this type of stressful experience for you and your four-legged family member, I advise you to keep your bait in a locked cupboard, place your bait only in places inaccessible to your dog and always secure the bait to the spot where it is laid. 

Most baits can be nailed or wired to framing. If you fail to do this, rats will take the bait away and create large storage depots in places your dog can and will find.

As a final word, if you see your dog consuming bait, your vet has got a two-hour window to give your dog a medication that will make it vomit its total stomach content and lengthy treatment could possibly be avoided.

Olaf Klein, Wellsford Vet Clinic
www.vetsonline.co.nz/wellsfordvet