Neurological deficits after confirmed adder bite in a cat

Abstract

A domestic shorthair cat presenting with pyrexia and tachycardia was given an antibiotic for suspected infection but 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. Laboratory parameters and urinary and faecal cultures were normal. Five days later the owner reported an adder in the garden, and due to no response to supportive care, antivenom was given. 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. 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.

Zootoxins and Domestic Animals: A European View

“…Their venom contains high molecular weight, complex proteins, with hemo-, myo-, neuro-, and cytotoxicity properties, including towards the endothelium of blood vessels. A specific cardiotoxin was isolated from the venom of V. berus , while V. aspis venom may have greater neurotoxic properties [ 11 , 105 , 108 , 109 , 110 , 111 , 112 ]. The venom may stimulate the release of cytokines.…”

“…Small animal envenomation is most frequently reported in the literature, followed by livestock envenomation, including horses, cattle, and sheep [ 107 ]. Dog envenomation by vipers seems common in some European countries [ 11 , 106 , 109 ], while cat envenomation is considered uncommon [ 111 ]. Snake bites occurred mostly during the warmer months of the year, but, in the UK, some dog and cat envenomations occurred during the cooler months [ 108 ].…”

“…The predilection sites of bites are the muzzle and face in dogs and horses, limbs in cats, or both sites in ruminants [ 11 , 107 ]. Bites on limbs may lead to more severe clinical cases in dogs [ 111 ]. Overall, Vipera bites caused local swelling and inflammation, with or without systemic signs; for e.g., up to 33% of dogs developed only local clinical signs following adder envenomation in a UK report [ 107 , 113 ].…”

“…Overall, Vipera bites caused local swelling and inflammation, with or without systemic signs; for e.g., up to 33% of dogs developed only local clinical signs following adder envenomation in a UK report [ 107 , 113 ]. More specifically, the clinical signs reported in dogs included fang marks, edema, lethargy, pain, vomiting, and diarrhea, which are signs consistent with disseminated intravascular coagulation, tachycardia, hyperthermia, cardiac arrhythmia, and collapse [ 11 , 107 , 109 , 111 ]. In some V. berus envenomed dogs, cardiotoxicity was evident through increased cardiac troponin I and arrhythmia detected on the ECG [ 109 ]; transient liver injuries were detected in some dogs [ 11 ].…”

“…V. aspis envenomation may have a higher mortality rate, such as 6% of envenomed dogs in a particular report [ 106 ]. A final diagnosis of V. berus envenomation, through the confirmation of venom in the blood circulation, was described in a clinical case [ 111 ].…”