The Domestic Ferret (Mustela putorius furo) as a Lethal Infection Model for 3 Species of Ebolavirus

Cross, Robert W.; Mire, Chad E.; Borisevich, Viktoriya; Geisbert, Joan B.; Fenton, Karla A.; Geisbert, Thomas W.

Fifteen female ferrets weighing 0.75-1 kg were housed 2-3 per cage per study. Ferrets were anesthetized by intramuscular injection with a ketamine-acepromazine-xylazine cocktail prior to all procedures. Prior to challenge, transponder chips (Bio-Medic Data Systems) were subcutaneously implanted for identification and temperature monitoring. Subjects were challenged intranasally with 1000 plaque-forming units (PFU) of ZEBOV strain Kikwit (n = 5), SEBOV strain Gulu (n = 5), and BEBOV (n = 5), respectively. The passage history of challenge viruses can be found in the Supplementary Methods. To account for variations between challenge events, 2 independent studies were completed, with the initial experiment having 3 animals, followed by a repeat confirmatory study with 2 additional ferrets per virus group. Whole-blood, ethylenediaminetetraacetic acid-associated plasma, and citrated plasma samples were collected from the superior vena cava for hematologic, serum biochemical, and coagulation assays and viremia determination on days 0, 2, 4, and 6 and at the time of euthanasia. Clinical signs, weights, and transponder-mediated temperatures were recorded daily up to the point of euthanasia. Clinical scores were determined on a scale of 0-12, based on coat appearance, social behavior, and provoked behavior. Animals scoring ≥9 were euthanized per the University of Texas Medical Branch (UTMB) Institutional Animal Care and Use Committee protocol criteria.