Epidemiological and experimental studies on a new incident of transmissible mink encephalopathy.

Epidemiological investigation of a new incident of transmissible mink encephalopathy (TME) in Stetsonville, Wisconsin, U.S.A. in 1985 revealed that the mink rancher had never fed sheep products to his mink but did feed them large amounts of products from fallen or sick dairy cattle. To investigate the possibility that this occurrence of TME may have resulted from exposure to infected cattle, two Holstein bull calves were injected intracerebrally with mink brain from the Stetsonville ranch. Each bull developed a fatal spongiform encephalopathy 18 and 19 months after inoculation, respectively, and both bovine brains passaged back into mink were highly pathogenic by either intracerebral or oral inoculation. These results suggest the presence of a previously unrecognized scrapie-like infection in cattle in the United States.

Detection of coronavirus-like particles from mink with epizootic catarrhal gastroenteritis.

Coronavirus-like particles have been detected by electron microscopy in fecal samples from naturally occurring cases of epizootic catarrhal gastroenteritis (ECG) of mink. Preliminary transmission trials with bacteria-free filtrates from mink with ECG suggested that a coronavirus plays a role in the disease syndrome.

Coccidial infections in ranch mink.

A field study was conducted from April through June of 1976 to determine whether coccidial infections adversely affect the growth and survivability of young mink. Two anticoccidials, lasalocid (62 mg/kg of feed) and an antibiotic-sulfonamide preparation (220 mg/kg of feed), were incorporated into a standard pelleted ration. Comparisons of weight gains, mortality, and oocyst numbers were made between control and treated groups. Treatment reduced mortality (P < 0.001) but did not significantly affect weight gains. The antibiotic-sulfonamide preparation and, to a lesser extent lasalocid, reduced oocyst discharge. Increased oocyst shedding was detected among adult female mink from parturition to weaning of their kits.

Anticoccidial activity of eight compounds in domestic mink.

Eight compounds were tested for anticoccidial activity in 44 domestic mink (Mustela vision). A treatment group consisted of 4 mink exposed to 2 inoculumns of sporulated oocysts on day 0 and day 22 of the experiments. Each inoculum contained 2,000 Isospora laidlawi, 2,000 Eimeria vision, and 2,000 Eimeria sp. One compound was administered to each treatment group; a control of 4 juvenile mink and a control group of 4 adult mink were designated. All treatments were given each day for 30 days after the initial exposure, except lincomycin which was administered for 14 days. In juvenile mink (3 to 4 months old), amprolium at dose level of 0.012% and sulfaquinoxaline at dose level of 0.024% in the water inhibited almost all of the oocyst production when compared with that of the control group. Lincomycin injected at dose level of 5 mg/day/mink was ineffective in suppressing oocyst production. In adult mink (2 to 4 years) monensin sodium at dose level of 0.012% a commercial antiobiotic-sulfonamide mixture at dose level of 0.49%, and lasalocid solium at dose level of 0.01% in the feed inhibited almost 100% oocyst production. Lasalocid sodium at dose level of 0.10% in the feed was lethal to 3 to 4 mink. Sulfamethazine at dose level of 0.014% and sulfathiazole at 0.014% in the feed had limited anticoccidial activities.