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Rodenticides are hazardous to pets

Publication date 19.11.2020 8.39 | Published in English on 19.11.2020 at 10.18
Press release

This autumn, the Finnish Safety and Chemicals Agency (Tukes) has received many reports on cat poisoning due to rodenticides entered in the organ system of cats after having eaten poisoned mice. Tukes points out that instructions for use must be followed when using rodenticides. Neighbours must be warned of the use of rodenticides so that they can keep their pets leashed during the use of rodenticides. Primarily, Tukes recommends the use of mechanical mousetraps.

Rodent control is a hot topic as people are making their cottages ready for winter and rodents try to find their way indoors. However, rodenticides that contain alphachloralose also harm animals other than mice, for which the poison is intended. During November, reports on cat poisoning have clearly increased. Poisoned mice are also hazardous to wild animals that eat mice.

–    “In the cat poisoning cases, a cat has been moving freely outdoors, hunting mice. In some cases, rodenticides have been used by a neighbour, but it is not usually known where a cat has consumed poison. In a typical case of dog poisoning, a dog has had access to poison in a cupboard or poison has been spread outdoors, unlike what is defined in instructions for use”, says Sanna Koivisto, senior adviser at Tukes. 

A poisoned cat starts to show symptoms in approximately 30 minutes after eating a mouse. The cat’s body temperature will drop, and it will experience balance disorders, cramps and unconsciousness. A poisoned cat must be kept warm and taken to a veterinarian. Tell the vet if you know where and when the cat has eaten mice and what rodenticide has been used. 

Pauliina Koponen, municipal veterinarian in Kokemäki, says that poisoning caused by alphachloralose can usually be suspected already based on a telephone conversation. 

“Typically, the patient experiences balance disorders, hyperesthesia and muscle twitches. Sometimes, a cat is unconscious and experiences hypothermia when brought to the clinic. In the cases I have treated, owners have not used any rodenticides to poison mice, but cats have probably caught poisoned mice from somewhere close to their home.” 

“Cats are treated according to their symptoms, they are hydrated and their condition is monitored. If a cat is conscious, it can be made to vomit. When vomiting, cats usually regurgitate an undigested mouse. As there is no antidote for alphachloralose, it is more difficult to treat animals. Luckily, most cat patients have recovered one to three days after poisoning, while some have been put to death due to a poor prognosis”, Koponen says.

There are options for rodenticides

Rodenticides must not be used in households that have cats or dogs. There are options available for rodenticides. Primarily, Tukes recommends the use of mechanical mousetraps. One of their advantages is that dead mice do not remain inside structures to rot. The incidence of mice can be prevented by keeping everything clean, by covering any gaps of 5 mm and larger and by ensuring that no nutrition consumed by mice is available. 

Rodenticides that do not contain any alphachloralose are less hazardous to cats and dogs. As there are antidotes for these rodenticides, it is easier to treat any poisoning cases.  The active substance of a rodenticide is indicated on the packaging.

Follow instructions for use and warn your neighbours

If you still decide to use rodenticides for mouse control, follow the instructions given on the packaging. Rodenticides can only be used inside buildings. Keep any poison away from children and animals. Notify your neighbours who have cats or dogs of the use of rodenticides to indicate that their pets are at a risk of being poisoned. Find and remove any dead mice and dispose of them as mixed waste.

Measures have been taken to prevent poisoning cases: rodenticides can only be sold in pre-filled bait stations and the aforementioned instructions for use have been printed on packaging. According to the Chemicals Act, users of rodenticides are obligated to follow the instructions of use given on the packaging. 

Tukes requests reports on suspected poisoning cases. Tukes will use the reported information in considering means to prevent poisoning cases.

Further information: Sanna Koivisto, senior adviser, tel. +358 29 5052 030
Email format: [email protected]

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