title: Cardiotoxicity, inflammation, and immune response after rattlesnake envenomation in the horse.
abstract: BACKGROUND
  Cardiac abnormalities are reported in rattlesnake-bitten horses. The prevalence and cause are unknown.
  
  
  OBJECTIVE
  To detect cardiac damage in rattlesnake-bitten horses by measuring cardiac troponin I (cTnI) and evaluating ECG recordings for presence of arrhythmias, and explore causes of this cardiac damage by measuring venom excretion, anti-venom antibodies, and tumor necrosis factor alpha (TNFα).
  
  
  METHODS
  A total of 20 adult horses with a clinical diagnosis of rattlesnake bite and 6 healthy adult horses.
  
  
  METHODS
  In a prospective clinical study, bite site swabs, blood samples, and urine samples were collected at various time points from 20 horses with a clinical diagnosis of snake bite. Continuous ECG recordings were obtained on the 20 affected horses and 6 normal control horses using 24-hour holter monitors. Plasma samples were assayed for cTnI, serum samples were assayed for TNFα and anti-venom antibodies, and bite site swabs and urine were assayed for venom.
  
  
  RESULTS
  Forty percent of rattlesnake-bitten horses (8/20) experienced myocardial damage (increased cTnI). Seventy percent (14/20) experienced a cardiac arrhythmia. There was a positive correlation between cTnI and TNFα (P < .02). Horses with cTnI ≥ 2 ng/mL were more likely to have antibody titers >5,000 (P < .05). No correlations were found between venom concentration and cTnI, anti-venom antibody titers, TNFα, or presence of arrhythmias.
  
  
  CONCLUSIONS
  Cardiac abnormalities in this population of horses indicate that cardiac damage after rattlesnake bite is common. Rattlesnake-bitten horses should be monitored for signs of cardiac damage and dysfunction. Long-term follow-up should be encouraged to detect delayed cardiac dysfunction.
authors.affiliation: Department of Veterinary Clinical Sciences, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK 74078, USA. l.gilliam@okstate.edu
authors.forename: L L
authors.initials: LL
authors.lastname: Gilliam
authors.forename: T C
authors.initials: TC
authors.lastname: Holbrook
authors.forename: C L
authors.initials: CL
authors.lastname: Ownby
authors.forename: D
authors.initials: D
authors.lastname: McFarlane
authors.forename: M M
authors.initials: MM
authors.lastname: Sleeper
authors.forename: S
authors.initials: S
authors.lastname: Martin
authors.forename: K
authors.initials: K
authors.lastname: Levis
authors.forename: M E
authors.initials: ME
authors.lastname: Payton
mesh_terms: D000818:Animals; D003435:Crotalid Venoms / Q000633:toxicity*; D017839:Crotalus; D004562:Electrocardiography / Q000662:veterinary; D006331:Heart Diseases / Q000209:etiology / Q000662:veterinary*; D006734:Horse Diseases / Q000473:pathology*; D006736:Horses; D007249:Inflammation / Q000209:etiology / Q000662:veterinary*; D012909:Snake Bites / Q000276:immunology / Q000473:pathology / Q000662:veterinary*; D019210:Troponin I / Q000097:blood / Q000378:metabolism
chemical_list: D003435:Crotalid Venoms; D019210:Troponin I