Clinical communication — Kliniese mededeling

Vine (Thelotornis capensis) bite in a dog

J Ottoa and R Blaylockb*

a urinalysis and occult blood examination ABSTRACT of all stool specimens. The laboratory A vine snake bite in a dog is reported. There was continued minor bleeding from the findings are reported in Table 1. Further assumed nose bite site for 4 days. Currently manufactured is not studies were not performed in view of effective against vine snake bites and treatment is supportive. expense. Key words: canine, consumption coagulopathy, dog, Thelotornis spp., vine snake. Otto J, Blaylock R Vine snake (Thelotornis capensis) bite in a dog. Journal of the South African DISCUSSION Veterinary Association (2003) 74(1): 27–28 (En.). Leslie Williams Memorial Hospital, PO Box All the above-mentioned 9 human vine 968, Carltonville, 2500 . snake bites were on the fingers, hand or wrist. Eight patients were handling the snake, while the other was disturbing it with a stick. As these are reluctant INTRODUCTION coagulopathy of similar aetiology is pro- to bite unless handled it would be ex- Vine snakes are a small group of highly duced by (Dispholidus typus) pected that dogs would be bitten mostly specialised arboreal snakes that have very envenomation and there is a report of a on the head while holding the snake in elongated bodies, lance-shaped heads boomslang bite of a dog21. their mouths. This was probably the case and cryptic colouration. The savanna in this instance. vine snake (Thelotornis capensis) can easily CASE HISTORY toxicity is dependent on snake be mistaken for a dead twig or vine, aver- A 2-year-old female pug dog (8 kg) was and the venom volume to prey ages 600–800 mm in length and is distrib- bitten by a 90 cm vine snake during the mass ratio8. All 9 human bites involved uted KwaZulu-Natal, Mpumalanga and afternoon of 18 March 2002. The follow- adults, while dogs are smaller and would the Limpopo Province, South Africa, and ing day the owners noted that the dog be expected to be more severely enven- Swaziland, , northern , bled persistently from its nose. The dead omed. However, it is well known that Angola, Zimbabwe, Zambia and Mozam- snake (identified by a herpetologist), venom sensitivity is dependent on bique, and extends along the east coast of assumed to have bitten the dog, was species17. Africa to Kenya and Somalia19. A venom found in the garden and both were taken It is assumed that the persistent unilat- enzyme with a molecular weight of to a veterinary practitioner. Examination eral nose bleed was due to a combination 56 000 D is procoagulant by activating showed an alert and excitable dog with of fang trauma and a bleeding diathesis. prothrombin and factor X2, and dissemi- continuous unilateral nose bleeding The haematological abnormalities are nated intravascular coagulation (DIC) (exacerbated by sneezing) assumed to be compatible with what occurs in humans. occurs. the bite site, and no other abnormalities. Early platelet sparing may occur as Venomhas no direct fibrinolytic activity, Particular attention was paid to signs venom-induced thrombin is different to but accelerates fibrinolysis by activating of internal and external bleeding and physiological thrombin22 and does not plasminogen. Active bleeding occurs if disseminated intravascular coagulation, easily aggregate platelets, while circulat- venom haemorrhagins cause loss of including organ failure. Coagulation ing fibrin degradation products tend to capillary integrity and leaks22. studies showed a haemostatic disturbance prevent aggregation13. It is known that The snake is reluctant to bite. Of 9 (Table 1). Supportive treatment was not DIC per se rapidly leads to multiple organ reported human bites, mild, local, pain- necessary and the dog was observed for 3 failure and has a poor prognosis. If associ- less swelling was noted in 5, 3 did not days until the nasal bleeding stopped. ated with fibrinolysis which dissolves the bleed (although 1 had incoagulable blood), There were never any other clinical signs widespread organ thrombi, the prognosis and the onset of bleeding, in 4 cases, was of internal or external bleeding, including is improved. Consequently, fibrinolysis immediate (from fang punctures) and did not stop, soon, 1 hour 30 min, and 15 Table 1: Haematology results. hours, respectively2,4,5,10,12,14,15,18,20.Inthe same 4 cases bleeding improved at 40 Test Normal values 19/3/2002 22/3/2002 25/3/2002 hours, day 10, 30 hours and 40 hours. Two Haemoglobin 12.0–18.0 g/d 16.5 14.5 patients died, one at 36 hours from inter- Haematocrit 0.37–0.55 0.473 0.434 nal bleeding and the other at 18 days from White cell count 6.0–17.0 × 109/ 14.91 15.88 12,15 multiple organ failure . There are no Platelets 200–900 × 109/ 251 204 reported vine snake bites in . A Reticulocytes 0.0–1.5 % 0.4 0.2 INR 0.8–1.20 2.6 Failed to clot 0.9 aArboretum Animal Clinic, PO Box 21456, Richards Bay, 3900 South Africa. APTT 11.0 –9.0 sec >120 14.4 bLeslie Williams Memorial Hospital, PO Box 968, Urea 3.6–8.9 mmol/ 9.1 Carltonville, 2500 South Africa. E-mail: [email protected] Serum creatinine, alkaline phosphatase and alanine transaminase were normal on 22 March 2002. INR, *Author for correspondence. International Normalised Ratio: an internationally accepted way of expressing the ratio of the patients Received: October 2002. Accepted: January 2003 prothrombin time to that of the control. APPT, activated partial thromboplastin time.

0038-2809 Jl S.Afr.vet.Ass. (2003) 74(1): 27–28 27 should not be prevented with fibrin- ring only after the coagulopathy is well (Abstract). Toxicon 31: 938 22 8 stabilising drugs . Heparin is of no value established . Fibrin monomers, fibrin 12. Fitzsimons D C, Smith H M 1958 Another in preventing thrombin formation2,3 degradation products and D-dimmers rear fanged South African snake lethal to which suggests that antihrombin III are positive. Thrombo-elastography is a humans. Herpetologica 14: 198–202 administration would probably be of no useful aid in diagnosis and management1. 13. Hutton R A, Warrell D A 1993 Action of benefit, although the latter potentiated components on the haemo- static system. Blood Reviews 7: 176–189 the effectiveness of antivenom given to REFERENCES 14. Isemonger R M 1955 The price of experi- 1. Aitchison J M 1990 Boomslang bite – Thai Russell’s viper and Malayan pit viper ence. In Isemonger R M (ed.) Snakes and 11,16 diagnosis and management. 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