Brown snake envenomation in cats: are two antivenom doses better than one?
Pursue your passion for animals and science - help improve survival rate of cats bitten by brown snakes.
Snake envenomation is a common feline emergency seen at our veterinary hospital and at veterinary clinics in many parts of Australia.
Brown snakes (Pseudonaja spp.) are the most common snake species reported to cause envenomation in Australian dogs and cats. Clinical signs of Pseudonaja spp envenomation in cats and dogs are predominantly associated with neurotoxicity manifest as progressive flaccid paralysis, as well as coagulopathy.
Diagnosis of brown snake envenomation is usually based on a supportive history, such as animal witnessed being bitten; playing with live or dead snake; snakes witnessed in the animal’s environment - with or without typical clinical signs and laboratory test results as above.
Intravenous administration of brown snake antivenom is the mainstay of treatment for brown snake envenomation. The survival rate of cats and dogs treated with antivenom is significantly higher than those not treated. Recommendations for how much antivenom to administer to animal or human patients varies. There are no published veterinary studies which have evaluated differences in clinical outcome in animals administered one or multiple vials of brown snake antivenom.
We have developed a severity scoring system for envenomated cats which predicts a strong probability of dying despite standard treatment in our hospital, i.e. a single dose of antivenom.
To follow up, a limited-case number pilot study project will collate and assess ongoing clinical data and monitor implementation of the severity scoring system and recommended treatment.
- To establish a classification scheme for accurately predicting outcome after treatment with one vial of brown snake antivenom and supportive care, to be applied at initial clinical presentation of cats envenomated by brown snakes (Pseudonaja genus).
- To prospectively compare the clinical outcomes of a cohort of envenomated cats with poor prognostic features treated with one vial versus a cohort treated with two vials of snake antivenom
- To better understand the incidence, diagnosis, treatment and outcomes of brown snake envenomated cats in general practice by analysis of electronic clinical records from general practices.
- On the basis of our preliminary data, we hypothesise that cats with initial clinical scores ≥ 7 in our classification system and receiving one vial of antivenom and supportive care treatment for envenomation by brown snakes will have a 50% probability of mortality.
- The mortality rate for cats with initial clinical scores ≥ 7 will be no different between cats that receive one or two vials of antivenom in addition to supportive care for treatment of envenomation by brown snakes.