One of our previous cases has been published. The cat presented with pyrexia and tachycardia and then returned 48 hours later with inability to defecate or urinate and with tail paralysis. There was swelling and bruising at the tail base but no radiographic evidence of a tail pull injury.
The owner later saw an adder in the garden, and adder envenomation was suspected. Antivenom was given 5 days after the original presentation due to lack of response to other therapies (antibiotics and analgesia). Within two hours clinical signs improved, and by 12 hours the tachycardia and pyrexia had resolved. Laboratory analysis confirmed the presence of adder venom in a blood sample taken prior to antivenom administration. Urination and defecation were normal at five months with regained function in the cranial third of the tail.
It is thought clinical signs were due to direct venom-induced necrosis of nerve tissue rather than venom neurotoxins since neurotoxicity is generally not a feature of envenomation with the European adder (Vipera berus berus).
If you have access to Veterinary Record Case Reports you can read the full article online.
Robinson R, Bates N, Bolton F, Robinson N. Neurological deficits after confirmed adder bite in a cat. Vet Rec Case Rep 2019;7:e000635.