Dog flea treatments killing cats
The lives of hundreds of pet cats in the UK are being put in danger by well meaning owners using flea products intended only for use on dogs according to The Feline Advisory Bureau (FAB), a cat welfare charity. FAB has joined forces with the Veterinary Poisons Information Service (VPIS), part of the Medical Toxicology Unit at Guy’s and St Thomas’ hospitals, to once again warn owners of the dangers of using dog flea preparations on cats following the publication of a recent report in a feline veterinary journal.
The VPIS report highlighted the lethal risks of permethrin based dog spot-on treatments being inappropriately applied to cats. Toxic effects can also occur from cats coming into close physical contact with dogs in the same house (through sharing beds or grooming) that have been appropriately treated with permethrin. These products are available in pet shops and many supermarkets, and have been mistakenly or unwittingly used on cats, frequently causing severe illness and even death. Cats poisoned with permethrin may need 2-3 days of intensive veterinary treatment to aid recovery.
Permethrin is one of a group of insecticidal compounds called pyrethroids. These have widespread use in pet flea treatments, ant-killers, and other products for control of pest insects. Although pyrethroids are considered to have a low mammalian toxicity, cats are the exception. Pyrethroids are toxic to cats because of metabolic deficiencies found only in felines.
The report is a review of 286 cases reported to VPIS where such canine spot-on permethrin preparations have been used on cats. Of these cases, 97 per cent of the cats had signs of poisoning, 88 per cent had twitching or convulsions and 10.5 per cent of the cats died or were euthanased. Although these data are startling, the VPIS feels that they are an under-representation of the scale of the problem. The veterinary press often receives letters on the topic from vets in practice and the Veterinary Medicines Directorate (VMD) highlighted the problem in 2000 – ‘These spot-on products are sold through UK pet stores or supermarkets and veterinary surgeons should be alert to the possibility of being presented with feline cases’ (Gray, Veterinary Record 147, p556).
There is no need to use permethrin containing products to control fleas on cats. There are many different ‘spot on’ medications formulated specifically for cats, none of which contain permethrin. The active ingredients in these are varied, as are their mechanisms of action. They also have differing availability in that some can be purchased in supermarkets, pet shops and agricultural merchants, others may be obtained only from vets.
FAB and VPIS are urging cat owners to check very carefully when treating their cats with spot-on products. Owners should ensure they do not use ones designed for dogs and especially not ones that contains permethrin. Advice should be sought from a vet or a qualified professional on the most appropriate, safe and effective products to use on cats. FAB and VPIS will also be urging manufacturers to ensure that the warning on dog products is larger and more noticeable and to put them onto the product itself as well as the packaging so that owners are less likely to mistakenly use them on cats.
‘Accidents inevitably occur, but it's not enough for the manufacturers of these products to say there is a warning on the packet. It must be visible, understandable, and printed on both the packet and dispenser if the incidence of these serious poisonings is to be reduced. They have a responsibility to their customers, and both have a duty to the animals under their care’, points out Alex Campbell, Manager of the VPIS.
Cat owners can find more information on the different flea products available and how they work by going to www.fabcats.org/owners/fleas. Copies of the paper (Sutton NM, Bates N and Campbell A (2007) Clinical effects and outcome of feline permethrin spot-on poisonings reported to the Veterinary Poisons Information Service (VPIS) London, JFMS 9 (4), 335 – 340) can be found by clicking on the following link: www.fabcats.org/esfm/permethrin.pdf
The Veterinary Poisons Information Service (VPIS) is part of the Medical Toxicology Unit at Guy’s and St Thomas’ NHS Foundation Trust. The VPIS is a subscription only service available to all vet practices in the United Kingdom. The VPIS provide information and advice on all types of toxic exposures in animals, 24 hours a day.
FAB is a charity dedicated to promoting the health and welfare of cats through improved feline knowledge, to help us all care better for our cats. For more information contact FAB, Taeselbury, High Street, Wiltshire SP3 6LD, telephone 0870 742 2278, or go on-line to www.fabcats.org
Produced by Karen Bessant, FAB Press Officer
August 2, 2007