There are a number of spider species in Australia, however the main spider associated with envenomation in small animals is the redback spider. All spider bites can be associated with local pain, redness and swelling but redback spiders can cause severe regional and generalized pain, vomiting and elevations to the heart rate. Cats are particularly sensitive to redback spider venom and can develop early severe signs of paralysis. Guinea pigs are even more sensitive than cats, however are considered less likely to provoke a spider to bite them. All redback spider bites in cats and guinea pigs should be considered as life-threatening. Whilst funnel web spider bites have resulted in death following bites in humans, there are no documented cases of lethal bites in companion animals, however there are limited case reports. Dogs exposed to funnel web spider venom have developed changes to their blood pressure and heart rate. Given the lack of documented cases, if your pet has been bitten by a big black spider they should be assessed by a veterinarian as soon as possible.