Bacteria and nematodes in the conjunctiva of mule deer from Wyoming and Utah.

Swabs of conjunctiva were collected from 44 live and 226 hunter-harvested mule deer (Odocoileus hemionus) from Wyoming and Utah (USA). We identified 29 gram negative and 22 gram positive bacterial taxonomic categories, but many isolates from hunter-harvested animals were environmental contaminants. Staphylococcus spp. and Micrococcus spp. were the most common gram positive bacteria isolated, and Enterobacter spp., Escherichia coli, and Pseudomonas spp. were common gram negative bacteria isolated. Thelazia californiensis were found in 15% of hunter-harvested deer in Utah in 1994 and in 8% in 1995. Nematodes were found in 40% of live deer in 1995 and 66% in 1996. Three live animals showed clinical signs of infectious keratoconjunctivitis (IKC) in 1996, but pathogenic bacteria were not isolated from these individuals. Hemolytic, non-piliated Moraxella ovis was isolated from two clinically normal live deer in 1996 and isolates were similar to those cultured from IKC cases from Wyoming and Utah.

Association of Moraxella ovis with keratoconjunctivitis in mule deer and moose in Wyoming.

Six cases of infectious keratoconjunctivitis (IKC) in mule deer (Odocoileus hemionus) and moose (Alces alces) in Wyoming (USA) were investigated during fall and winter of 1995 and 1996. Excessive lacrimation, mucopurulent conjunctivitis, keratitis, and corneal opacity were observed in mule deer. Moose had severe mucopurulent conjunctivitis, keratitis, and corneal ulceration. Hemolytic, non-piliated Moraxella ovis was isolated from two mule deer and two moose. We attempted to reproduce IKC in three mule deer fawns using an isolate of M. ovis from a clinically affected mule deer. These fawns did not develop clinical signs of infection and the bacterium was not reisolated from inoculated deer. Inoculated deer may not have developed clinical signs because deer were not exposed to ultraviolet light or mechanical insult before inoculation. In addition, the isolate used for inoculation may have lost virulence factors through passage, or M. ovis may not have been the primary pathogen responsible for clinical disease in the natural cases of IKC we investigated. The etiology of IKC in free-ranging wild ruminants remains poorly understood.

Infectious keratoconjunctivitis in free-ranging mule deer (Odocoileus hemionus) from Zion National Park, Utah.

An epizootic of infectious keratoconjunctivitis (IK) was studied opportunistically in free-ranging mule deer (Odocoileus hemionus) from Zion National Park, Utah (USA), from November 1992 to March 1994. Moraxella sp. and Chlamydia sp. were isolated from the conjunctiva of two of seven deer. In addition, Thelazia californiensis occurred on the conjunctivas of six of seven deer. Based on field observations, adults appeared to be affected clinically at a higher incidence during both years as opposed to juveniles. Corneal opacity was the most apparent clinical sign from 1992 to 1993. However, in the following year, blepharospasm and epiphora were noted more often. We were also able to document the clinical recovery of three affected deer. In addition, Moraxella sp. was recovered from the eyes of a clinically unaffected deer 1 year after the epizootic occurred.

Plague in a black-footed ferret (Mustela nigripes).

Diagnosis of sylvatic plague in a captive black-footed ferret (Mustela nigripes) was based on gross and microscopic lesions, fluorescent antibody tests, culture of Yersinia pestis, and immunohistochemistry. Gross lesions consisted of acute hemorrhage and necrosis associated with cervical and mesenteric lymph nodes, subcutaneous hemorrhages, and pulmonary edema. Acute edema, hemorrhage, and necrosis with numerous bacteria in blood vessels and sinusoids characterized microscopic lesions. Occurrence of fatal plague in a black-footed ferret potentially has significant implications for recovery of this endangered species due to the widespread distribution of plague in prairie dog colonies throughout historic black-footed ferret range.