PHARMACOKINETICS OF A SINGLE DOSE OF FLURALANER ADMINISTERED ORALLY TO AMERICAN BLACK BEARS (URSUS AMERICANUS)

Sarcoptic mange continues to impact free-ranging mammal populations, including the American black bear (Ursus americanus). Administration of a single oral dose of fluralaner may be a viable treatment option for captive and free-ranging black bears affected by mange. This novel ectoparasitic in the isoxazoline class acts as an inhibitor of γ-aminobutyric acid (GABA)-gated chloride channels and l-glutamate–gated chloride channels (GluCls) and is commercially available in the United States as a flea and tick preventative medication for domestic dogs and cats. Pharmacokinetic parameters of fluralaner were evaluated in clinically healthy American black bear cubs (n = 10) administered a single oral dose of fluralaner at a targeted minimum dose of 25 mg/kg. Blood was collected at 24 hr and 7, 14, 21, 28, 35, 42, 49, 56, 63, and 70 days, and harvested plasma was analyzed for drug concentration using high-performance liquid chromatography. The average half-life (Ke t1/2) was determined to be 4.9 days, which is shorter than that published in domestic dogs. It was estimated that the average drug withdrawal time is approximately 64–72 days in this species.