Risk factors associated with Cryptosporidium infection on dairy farms in a New York State watershed.

A cross-sectional study was carried out to determine the prevalence of Cryptosporidium parvum-like oocyst shedding on dairy farms in a watershed in New York State and to identify the factors that put animals at risk. A proportional sample of dairy herds in the targeted area was obtained, and animals were selected using a stratified sampling design to ensure representation of the population at risk. Fecal samples were collected per rectum and analyzed for the presence of C. parvum-like oocysts using the quantitative centrifugation concentration flotation technique and a proprietary enzyme-linked immunoassay. Additionally, isolates of Cryptosporidium were examined via bidirectional DNA sequencing. Data on putative risk factors were collected at the time of sampling and analyzed for association using logistic regression. The herd prevalence was 42% and the overall animal prevalence was 3.2%. The prevalence among animals less than 60 d of age was 20%. The likelihood of shedding Cryptosporidium decreased with the age of the animal and varied with the type of barn water source. Both the number of unweaned calves present at the time of the study, and whether the calves were tied vs. not tied increased the risk of infection. There was significant agreement between the flotation and PCR techniques. Sequencing revealed that 50% of the isolates were Cryptosporidium bovis, an isolate thought to be nonzoonotic.

Serologic survey of selected viral agents in recently captured wild North American river otters (Lontra canadensis).

Blood samples were collected from 64 wild North American river otters (Lontra [Lutra] canadensis) from northern and eastern New York State and analyzed for serologic evidence of exposure to selected viral agents during a 1995 1996 translocation program. No clinical signs of disease nor lesions suggestive of prior viral exposure were seen. Titers were detected for antibodies against canine distemper virus, canine herpesvirus-1, and canine parvovirus-2 but not for antibodies against canine adenovirus-1, canine coronavirus, canine parainfluenza virus, rabies virus, feline herpesvirus-1, feline calicivirus, or feline coronavirus. This is the first report of titers for antibodies against canine herpesvirus-1 in North American river otters, and it suggests a low prevalence of antibody titers against most canine viruses in otter populations in northern and eastern New York. Confounding variables in this study could include exposure to domestic dogs associated with the project, prolonged time spent in captivity, and concurrent bacterial or parasitic infection. Stress-associated humoral immune suppression could have altered serologic profiles, especially in otters exposed to dogs after trapping but before venipuncture.

Infectious and parasitic diseases and contaminant-related problems of North American river otters (Lontra canadensis): a review.

The aquatic North American river otter (Lontra canadensis), a charismatic nonendangered mustelid, presently occupies a greatly reduced range. The species is common in zoos and has economic value as a furbearer. At least 17 states and one Canadian province have undertaken recent reintroduction programs. Nevertheless, little has been published on nonparasitic diseases of river otters, and little is known of the clinical significance of most of their parasitic infections. Records of environmental contaminant-related diseases and traumatic injuries in free-ranging North American river otters are also rare. This paper reviews present knowledge of North American river otter diseases, especially those with the greatest potential for impacting reintroduction programs.

Exertional myopathy in translocated river otters from New York.

Lesions consistent with exertional myopathy (EM) were documented postmortem in four North American river otters (Lutra canadensis) during translocation for a population restoration project. Clinical signs in these otters included depression, anorexia and shock. Gross lesions in one otter included locally extensive linear, pale areas within the subscapularis, rectus abdominis, quadriceps, and dorsal laryngeal muscles. Microscopic lesions were characterized by acute to subacute myofiber necrosis of varying severity, and occurred in a variety of skeletal muscles as well as cardiac muscle in one otter. Based on these observations, we conducted a retrospective review of records of otters which experienced similar capture, transfer, and holding protocols between 1995 and 1997, but with a successful outcome (n = 69). Significant elevations in serum aspartate aminotransferase (AST) and creatine kinase (CK) were observed in 19 (28%) of the otters, but may have been higher due to delayed sample collection from some otters. However, none of the otters with elevated enzymes exhibited clinical signs suggestive of EM. These findings indicate that river otters may develop EM when translocated, but many cases may be mild or clinically inapparent.