13 Apr Redback Spiders & Your Pet
Redback spiders (Latrodectus hasselti) tend to live in close association with people, but prefer dry, dark areas where they will not be disturbed. This means they are often found lurking in garden sheds and garages. The female redback spiders are most commonly recognised, having slender black legs and a black to brown body the size of a large pea with a distinct red to orange stripe down the centre. Males are less boldly coloured, often light brown, and smaller in size (3-4mm) and are of less medical importance due to their much smaller fang size.
The venom contains α-latrotoxin which affects the nervous system and muscles. Many bites may be ‘dry-bites’ where no venom is injected, however a bite where venom is injected can be life-threatening for a small animal. Early signs in small animals include vomiting, diarrhoea, pain and restlessness. Progressive symptoms may include increasingly severe pain (which typically spreads away from the bite site), muscular cramping, agitation, increase in heart rate and increased blood pressure. Cats are particularly sensitive to the venom, and can then go on to develop paralysis, inability to breath, cardiac failure and death.
To avoid spider bites in pets, keep your shed and garage neat and tidy and avoid stacking items too close together, try to have these areas well-lit with natural light and don’t let your pets into these areas (sheds and garages often have other poisons so this is a good general rule for pet safety). Clean outdoor furniture and building eaves/verandas regularly to remove webs and spider sacs, pack away children’s toys that are not used regularly, take to the tip any items stored in yards that are not needed (e.g., tyres, old wood piles), clean up leaves and sticks and remove them from pet accessible areas. Many of these measures are also good for preventing snake bites too.
If you suspect your pet has been bitten by a spider, please call us on 1300 869 738 (from Australia) or 0800 869 738 (from New Zealand) for advice. Our service is free for all pet owners.