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Wildlife Pathology Unit

New York State Department of Environmental Conservation
Wildlife Resources Center
108 Game Farm Road
Delmar, New York 12054
518-478-2203

The Wildlife Pathology Unit (WPU) is responsible for diagnosing and monitoring causes of sickness and death in New York State's amphibians, reptiles, birds and mammals. The WPU also provides forensic wildlife pathology services to DEC's law enforcement division and other agencies, performs field investigations related to the impact of environmental contamination (oil spills, industrial discharges, pesticide use and misuse, hazardous waste sites and landfills) on wildlife, and conducts original research in the fields of wildlife pathology, physiology and toxicology.

Reporting Wildlife Found Dead

Wildlife found dead without obvious cause of death may be of interest to the WPU or other programs within DEC. Also of interest regardless, even if the cause of death appears obvious and ordinary, are cases involving species of special interest or marked specimens (research study animals). Mass mortality or recurring mortality may be especially important. In all cases DEC's Regional Wildlife Offices should be notified to determine what actions, if any, are necessary for submission or disposal of the wildlife in question. If assistance from the Regional Wildlife Offices is not available, call the WPU directly at 518-478-2203 for advice.

  • Exception: Mammals suspected of being rabid (including all bats found indoors where human contact may have occurred), and for which a significant exposure (bite, scratch, contact with saliva or nervous tissue) to humans has occurred, should be reported to local county or municipal health departments (LINK needed).

Submission of Animals for Examination

In most cases, if it is determined that examination of the dead wildlife by the WPU is desirable, Regional DEC staff will collect the animal(s) and arrange for the delivery to the WPU. If for some reason Regional staff is unable to assist in the submission process, direct submission to the WPU may be an option. Call 518-478-2203 between 8:30 AM and 5:00 PM for advice.

  • Exception: In some DEC Regions, persons reporting dead birds may be directed to contact their local County Health Department (LCD) when West Nile virus surveillance is a concern. In such cases the LCD will assist in submission of the birds to the WPU.

Submitting Specimens-Documentation Requirements

It is important that documentation accompany all submissions. Print and use the submission form or provide the information requested on that form on your own paper. Completing the form is recommended even if you have obtained assistance from DEC personnel (who will ask you the same information).

Handling Dead Animals

Dead wildlife can be a health threat to people and other animals. If professional assistance is unavailable or delayed, the following general guidance is offered:

  • Be sure the animal is dead before you touch it or get too close.
  • Avoid direct contact with the carcass or carcass fluids. Be careful of teeth, claws, bone splinters or porcupine quills.
  • Prevent exposure to pets or farm animals.
  • If packaging is necessary, enclose in multiple plastic bags. Small animals (squirrel or crow-sized and smaller) can be packaged simply by inserting one or both hands in a bag, grasping the carcass, and enfolding the bag around it. For larger animals, or for carcasses that have been compromised by extensive trauma, decay or maggot infestation, insert the bag into a can/pail/bucket, then use a shovel to deposit the animal into the bag-lined container. Close all bags securely.
  • If examination by the WPU is likely, place the bagged carcass in a cool location.
  • Disinfect implements used in moving carcasses with a bleach solution (see below).
  • Contact us directly at 518-478-2203 if substantial delays are expected, or if you have additional questions.

Carcass Disposal

If there is no reason for submission and it is desirable to dispose of a carcass for sanitary or esthetic reasons, two options exist:

  • Burial in a location that will protect both surface water and ground water from contamination. Keep at least 200 feet away from wells used to supply drinking water. Be sure the carcass is covered with at least 2 feet of soil.
  • Disposal at a landfill. Carcasses should be triple-bagged in all cases.

Disinfection Procedures

In case of exposure or contamination:

  • Skin: Wash skin thoroughly with hot water and soap. Consult your physician if you have sustained an injury (a bite, scratch or puncture).
  • Tools, Instruments, Hard Surfaces: Immerse or flood items with a 10% chlorine bleach solution (1 part household bleach, 9 parts water). Let stand for 10 minutes. Scrub and rinse thoroughly.
  • Clothing: Pre-soak clothing in a 5% chlorine bleach solutions (1 part bleach, 19 parts water) for 10 minutes and then wash with hot water and laundry detergent. To avoid damage to colors or fabrics, other household disinfectant products may be used, although many of these are less effective than chlorine bleach.

Note: Many pathogens are inactivated by heat, drying, and sunlight.

More Information

Some common or important wildlife diseases, parasites, toxicants and related topics.

House Finch Conjunctivitis

House finch conjunctivitis (HFC) is an extremely important cause of morbidity in House Finches. It is caused by the bacterium Mycoplasma gallisepticum, well-known for causing chronic respiratory tract disease in domestic poultry and gamebirds. It was not recognized as a potentially important pathogen of wild birds until it began to decimate House Finch populations in the eastern United States in the mid-1990s. HFC has also been confirmed infrequently in other finches and allies, particularly goldfinches.

The chief clinical signs in House Finches are swollen reddened eyelids usually accompanied by a clear discharge that often mats the feathers around the eye. One or both eyes may be involved. Sick birds may linger around bird feeders for extended periods, not following the comings and goings of other House Finches. Although mortality has been shown to be low in experimental infection of captive birds, mortality of free-living birds is apparently high no doubt in part due to predation and added stress of exposure to challenging weather.

The observed ocular signs are caused by infection of the conjunctiva (the transparent membrane comprising the inner lining of the eyelid and adjoining surfaces of the eyeball) by M. gallisepticum. Infection of the nasal sinuses is also common in House Finches. M. gallisepticum is spread by direct contact with infected birds at feeding stations and roosts. Transmission also probably occurs by contact with contaminated surfaces. Tube-type bird feeders are suspected as likely to facilitate this latter means of infection.

A tentative diagnosis of HFC can be readily made from the gross appearance of the eyes in most cases. Should more definitive confirmation be desired, M. gallisepticum DNA can be detected by polymerase chain reaction testing. Culture attempts, even from fresh specimens, are frequently unsuccessful.

Sick birds are easily captured once vision is seriously impaired and can potentially be treated with ocular antibiotic ointments and tetracycline in drinking water. The value of such treatment is controversial as treated birds may still harbor the organism after overt disease is no longer apparent. Treated birds may therefore continue to be a source of infection on release.

The recommended course of action once an outbreak is detected is to suspend bird feeding operations for a minimum of two weeks. All feeders should be cleaned with a 10% solution of household bleach (1 part bleach: 9 parts water). Clean-up of seed hulls and spilled seed under feeders is also recommended.

Currently HFC remains largely a disease of House Finches and has been confirmed in most if not all of the species' eastern range. As this eastern population originated from a small release of birds on Long Island in 1940, it has been speculated that lack of genetic diversity may have contributed to the vulnerability of this population to disease challenge. Recently, however, HFC has been detected in House Finches in the Northwest United States and its spread will be closely monitored. HFC poses no threat to human health or non-avian pets.

Trichomoniasis

Trichomoniasis is caused by the flagellate protozoan Trichomonas gallinae. It is the most common disease finding in mourning doves, occasionally causing mortality over sizeable geographic areas. Other dove species are variably susceptible. It is thought that T. gallinae came to North America with Rock (Common) Pigeons accompanying European settlers. Trichomoniasis is occasionally diagnosed in raptors that consume infected doves. Falconers have historically referred to this disease in their birds as frounce.

T gallinae is a parasite of the upper alimentary canal, most commonly the mouth and upper esophagus. Virulent strains produce cheesy necrotic lesions that may block passage of food and impair breathing. Sick doves appear depressed and oral lesions may show externally as bulges beneath the head.

Adult doves may transmit the parasite directly to their young via crop milk (doves produce a milk-like substance in their crops which they feed to their young). Transmission via food and water contaminated by sick birds may be important.

Trichomoniasis is tentatively diagnosed from the gross lesions. Observation of the live flagellated trichomonad in saliva or lesion scrapings is confirmatory. Fresh unfrozen specimens are required for confirmation in this manner.

Trichomoniasis is by far the most important disease of mourning doves. Despite some initial concerns, trichomoniasis did not prove to be a significant problem during the reintroduction of Peregrine Falcons to large cities where Rock Doves were the principal prey. T. gallinae poses no threat to human health.

Salmonellosis

Salmonellosis refers to disease caused by bacteria in the genus Salmonella. There are many species and strains of Salmonella and a large number of them are at least potentially pathogenic to a variety of vertebrates. In many instances, however, salmonellae may inhabit the alimentary canal without causing overt disease; note, for example, the frequent reports of Salmonella in pet turtles. The following discussion will focus on salmonellosis in songbirds caused by Salmonella enterica serovar typhimurium, by far the most frequently recognized problem with regard to Salmonella and wildlife in New York.

In recent times salmonellosis has generally emerged in mid-to-late winter in flocks of redpolls and pine siskins that have fled boreal forests to the north. During outbreaks, salmonellosis is sometimes confirmed in other species such as goldfinches and evening grosbeaks, but such so-called spillover has to date remained a very minor feature of these episodes. Note: all of the aforementioned species typically feed in long bouts at feeding stations (as opposed to the come and go habits of chickadees and nuthatches). The disease is transmitted through fecal contamination of food. How outbreaks begin is poorly known. Possible mechanisms include the presence of carrier birds in either affected or unaffected species, and the possibility of low levels of contamination in commercially packaged birdseed. In addition to outbreaks in redpolls and siskins, salmonellosis is sporadically confirmed in house sparrows without any noticeable seasonal component. Predators and scavengers of diseased songbirds may be susceptible to infection but there is little evidence of significant morbidity in those species beyond an occasional diagnosis in house cats.

S. enterica sv typhimurium principally infects parts of the alimentary canal. In the avian species mentioned above, the most severe lesions are usually in the esophagus. These lesions are sites of thickening and necrosis that appear as relatively firm yellowish masses that can often be palpated and visualized through the skin. Sick birds may appear weak, and they may tend to sit around feeding stations with fluffed-up plumage. At death most individuals are thin despite evidence of continued feeding.

Diagnosis is tentatively made from the characteristic esophageal lesions in the esophagus. If further confirmation is desired, the organism can be cultured and identified in alimentary canal samples (contents, lesion fragments).

When an outbreak of salmonellosis is detected at a bird feeding station, the traditional recommendation is to halt feeding for a minimum of two weeks. Spilled seed and seed husk debris should be cleaned up, and the feeders disinfected with 10% household chlorine bleach (1 part bleach/ 9 parts water) before redeployment. This strategy will disburse the birds, separating uninfected susceptible birds from sick birds and the contaminated feeder environment.

Outbreaks of salmonellosis in redpolls and pine siskins tend to occur in those winters in which there are large winter movements of these species into the northern United States.

Many outbreaks may be recorded over broad geographic regions and the total mortality by winter's end may be large. It seems plausible that any benefit these species gain by access to bird feeders may be cancelled by losses to salmonellosis.

Aspergillosis

Aspergillosis is a disease affecting the respiratory tract of birds and mammals. In regards to wildlife, aspergillosis is almost entirely confined to birds. It is caused by fungi in the genus Aspergillus, most commonly A. fumigatus. These fungi are ubiquitous in the environment and are especially common in soil and decaying plant matter. Birds are constantly exposed to the spores of Aspergillus. Under normal circumstances a bird's immune system will prevent infections from developing. If the immune system has been compromised, or if the bird has been exposed to an overwhelming number of spores, chronic or acute forms of the disease may develop.

The chronic form of the aspergillosis generally occurs in birds that have been weakened and stressed by malnutrition, injury, other disease, or exposure to toxicants. In the wild in New York, chronic aspergillosis is most often seen in gulls, common loons and raptors. It is a fairly common complication in wild birds that are held captive for rehabilitation. Chronic aspergillosis typically starts as small plaques on air sac walls. Plaques may grow, coalesce and completely cover the interior lining of air sacs. They may also form large rubbery masses that envelope blood vessels, particularly in the vicinity of the heart. Mature lesions often include sites of spore production, manifested by a dusty-looking, grey-blue/green surface; i.e. looks like fruiting mold on spoiled food. Despite, the fairly long-term growth in parts of the respiratory tract, actual lung involvement seems to occur only in the terminal phase of disease progression. Clinically, birds with chronic aspergillosis are thin (especially breast muscle), and are often reluctant to fly or are incapable of sustained flight.

The acute form of the disease is triggered by inhalation exposure to massive numbers of spores. In New York outbreaks are occasionally seen in potentially granivorous waterfowl (mallard ducks, Canada geese) feeding on moldy silage. Acute aspergillosis directly affects the lungs and is characterized by the development of small (1-3 mm diameter), yellow-white nodules throughout the lungs. The disease progresses rapidly over a period of several days and the birds typically die without noticeable weight loss.

People who feed birds have been traditionally warned about feeding birds moldy birdseed or bakery products. This directive has a sound basis and may in part account for the fact that we rarely see aspergillosis in songbirds, including those found sick or dead near bird feeders (see Salmonellosis, House Finch Conjunctivitis). Live or dead birds with aspergillosis pose no significant threat to human health.