Prairie Rattlesnake Envenomation in 27 New World Camelids

Abstract

Background: Morbidity and case fatality from rattlesnake envenomation is regionally specific because of variability in relative toxicity of the species of snake encountered. A previous report of rattlesnake envenomation in New World camelids (NWC) from the western coastal United States documented high case fatality rates and guarded prognosis for survival.Hypothesis/Objectives: To describe clinical findings, treatments, and outcome of NWC with prairie rattlesnake (Crotalus viridis viridis) envenomation in the Rocky Mountain region of the United States.Animals: Twenty-seven NWC admitted to the Colorado State University Veterinary Teaching Hospital for evaluation of acute rattlesnake envenomation between 1992 and 2012.Methods: Medical records of NWC evaluated for rattlesnake envenomation as coded by the attending clinician and identified by a database search were reviewed retrospectively. Month of admission, signalment, area of bite, clinical and clinicopathologic data, treatments, and outcome were recorded.Results: Twenty-five llamas and 2 alpacas were admitted for envenomation. Llamas were overrepresented compared to hospital caseload. The face was the most common site of envenomation, observed in 96% of recorded cases. Presenting clinical signs included fever, tachypnea, tachycardia, and respiratory distress. Nine animals required a tracheotomy. Median hospitalization time was 3 days and overall survival rate was 69%.Conclusions and Clinical Importance: Case fatality rate for prairie rattlesnake envenomation in NWC was lower than that reported in the Western coastal region of the United States and similar to that reported for prairie rattlesnake envenomation in horses.

Rattlesnake Envenomation in Three Dairy Goats

“…Two bites occurred in lower limbs, and one occurred in the face. The most common sites of rattlesnake envenomation in NWC and horses have been reported as primarily the face and secondarily the legs [1][2][3]. Delays in treatment and increased mortality have been noted in horses [1], and it is noteworthy that the two goats in this case report that survived were promptly treated within hours, and the one that died experienced a several-day delay between the bite and treatment, which may be compounded by the concurrent lungworm infestation.…”

“…These patients displayed respiratory distress, fever, tachypnea, tachycardia [3], hyperthermia, and recumbency [2] as reported in NWC and horses [1]. Facial nerve paralysis has also been reported in horses with rattlesnake envenomation [1] and was noted in one of these cases.…”

“…While multiple studies outline the etiology and treatment of rattlesnake envenomation in llamas, alpacas [2,3], horses [1], small animals, and humans [4], to the author's knowledge, there are no studies or reports in current literature of this disease in dairy goats. Rattlesnakes are a common venomous snake species in North America and therefore represent a potential cause for veterinary emergencies.…”

“…Flunixin meglumine is a commonly used anti-inflammatory in both NWC [2,3] and equine [1] envenomation. Corticosteroid treatment for snake envenomation has been linked to increased mortality in dogs [9], but in a recent NWC study, 10 of 27 rattlesnake envenomation cases were treated with corticosteroids (9 dexamethasone and 1 prednisolone) [3]. This study reported that treatment in NWC with either NSAIDS or corticosteroids was not associated with outcome.…”

“…Cases, treatment, and outcomes of rattlesnake envenomation have been reported for horses [1], llamas, and alpacas [2,3] but veterinary literature is lacking in cases of rattlesnake envenomation in dairy goats. The following 3 cases, referred to the University of CaliforniaDavis William R. Pritchard Veterinary Medical Teaching Hospital (VMTH), between the years of 1994 and 2014, represent rattlesnake envenomation, where the rattlesnake was identified as the Northern Pacific Rattlesnake (Crotalus oreganus).…”