highlights wildlife mortality and morbidity events reported to the
National Wildlife Health Center (NWHC) from April through June,
1996. There were 31 events reported to NWHC this quarter which compares
with 41 events during this quarter in 1995 and 1994, 37 in 1993,
58 in 1992, and 53 in 1991.
was confirmed in several areas this quarter: in Quakerstown, Pennsylvania,
muscovies died on private land; in Chesapeake and Poquoson, Virginia,
muscovies died on small residential ponds. Although free-flying
waterfowl had access to both Virginia areas, no other species were
found sick and all the muscovy ducks died. Duck plague was confirmed
as the cause of another outbreak near Beaver Dam, Wisconsin in which
muscovy and muscovy/mallard hybrids were affected. Also, duck plague
was suspected as the cause of mortality in muscovies from San Marcos,
California. A local breeder had mortality in approximately 100 caged
muscovies and no other action was taken.
swallows was reported from the Nebraska Panhandle and Eastern Wyoming
area. Emaciation was diagnosed as the cause of death and it is thought
that the cold weather in the area may have contributed to decreased
availability of their food source.
was diagnosed as the cause of death for an estimated 100 black crowned
night herons and snowy egrets in Napa, California. Salmonellosis
outbreaks are usually a problem in passerine birds using bird feeders.
There are two salmonellosis outbreaks previously reported in egrets
in California and one outbreak in cattle egrets in Texas. This is
the first outbreak of salmonellosis in black-crowned night herons
reported to NWHC.
Department of Natural Resources, Rose Lake laboratory, has reported
the confirmation of Mycobacterium bovis (bovine tuberculosis) from
a wild deer collected in November 1994, and from lymph nodes of
21 deer collected during a survey of deer collected during the fall
1995 hunting season in four northeastern Michigan counties. The
MIDNR has implemented several on-going surveillance activities in
coordination with five other domestic animal, human health and wildlife
health agencies. To date, no human cases of tuberculosis have been
traced back to exposure to deer and no livestock were found to be
infected with bovine tuberculosis.
Refuges reported the mortality of at least 10,000 common murres.
An estimated 500 birds were found dead but the impact to the colonies
appears to be greater, with colony abandonment between 25-80% in
a population of 750,000 birds. This is the most significant mortality
recorded in adult murres in Oregon in the last 20 years that records
have been kept. Emaciation has been a consistent finding in necropsied
birds. Starvation is a likely cause of the emaciation; however,
there is insufficient data to allow adequate assessment of their
US Fish and
Wildlife Service, Ecological Services reported a small die-off of
Canada geese on a residential pond in Barrington, Illinois. Geese
were observed swimming in circles with their head twisted and extended
over their back. Mallards were present on the area but were unaffected.
Two geese submitted to the NWHC were in good body condition; one
goose had widespread infiltrating lymphocytic masses and the other
goose had distended intestines filled with sloughed epithelium and
blood. No viruses were isolated, no parasites were present in the
intestines, brain cholinesterase levels were normal, and analyses
for lead and anticoagulants were negative. Salmonella sp. was present
in the brain of one goose. No cause of the enteritis could be determined.
The New York
State Department of Environmental Conservation reported three cases
of toxicosis this quarter. A screech owl was found on Long Island
in convulsions and subsequently died after apparently ingesting
food contaminated with chlordane, widely used for termite and turf
insect control. In Fire Island Pines, two red foxes and a raccoon
died from ingesting Brodifacoum, an anticoagulant rodenticide. Four
badly decomposed deer were also found nearby but could not be submitted.
In Mt. Kisco, New York, three skunks found dead below an old landfill
area were poisoned with Bromadiolone, another anticoagulant rodenticide.
For additional information please contact Dr. Scott Wright,
USGS National Wildlife Health Center - Disease Investigations Branch Chief, at 608-270-2460 or
Paul Slota, USGS National Wildlife Health Center - Support Services
Branch Chief at 608-270-2420.