Department of Natural Resources
One of the functions of the Wildlife Pathology Laboratory is to investigate diseases and mortality factors of wildlife. As a general rule, sick and dead animals and reports of unusual wildlife mortality should be sent to the Wildlife Pathology Laboratory, Rose Lake Wildlife Research Center, 8562 E. Stoll Rd., East Lansing, MI. 48823.
What follows is a general guide to go by in collecting, handling and submitting specimens. On occasion we may send out supplementary memorandums alerting Field personnel to disease situations or epidemics that exist or are anticipated in wild species. Special instructions for procedures differing from the routine as described here will be covered in such memorandums. Questions concerning kind and number of specimens desired, handling procedures, and other technical aspects of the work should be directed to the Wildlife Pathology Laboratory.
Animals and their parts are collected for many purposes and under different conditions, making it impossible to state in a few sentences the best way in which to handle them. However, most specimens are submitted for the purpose of diagnosing the cause of sickness or death. In these instances, examinations are best made on the whole animal whenever possible, rather than its parts. The usual order of preference from the standpoint of the laboratory worker is:
Ordinarily, we are not interested in receiving animals killed on the road or dead from other causes obviously not connected with disease, poison, malnutrition, or other conditions which should be investigated.
Occasionally, the Wildlife Pathology Laboratory will submit program directives asking that certain animals be collected by field personnel. Such program directives include exact instructions for treatment and handling of the specimens involved.
The methods for handling specimens will vary with the type of examination to be made. The specific examples given below will cover most events. Contact the Wildlife Pathology Laboratory if a given situation presenting a special problem is encountered.
Most examinations involve laboratory tests and a complete necropsy of the animal. The entire animal is preferred, alive if possible, fresh if dead. An effort should be made to keep dead animals cold until they are delivered to the laboratory. Usually, an animal will keep in fair condition for a day or two at 45° F, although lower temperatures (but not freezing) are better. Styrofoam coolers are excellent containers for transporting properly iced small specimens in warm weather.
Generally, specimens that must be held longer than two days should be frozen.
Large animals such as elk present a particular problem in handling and transporting. The Laboratory should be notified in those instances in order that special arrangements may be worked out.
All examinations of animals for rabies are made by the Michigan Department of Community Health Laboratory. Specimens may be submitted to them via the Wildlife Pathology Laboratory, a public health officer, a medical doctor, or a veterinarian. Because of their huge workload, the Community Health Laboratory will examine only specimens of immediate public health concern. This would include animals involved in human or domestic animal exposure (bite, scratch, excessive handling). As rabies is principally a wildlife problem, the Department of Community Health will examine animals submitted by the Department of Natural Resources. However, we should use some discretion in submitting animals to them, and do so only where there appears to be due cause. Again, where there is a question of what to do, contact the Wildlife Pathology Laboratory for instructions.
Among wild animals in Michigan, rabies is very prevalent among bats, occurs occasionally among skunks and red foxes, and rarely among raccoons. All mammals are susceptible, however.
The disease is diagnosed by examination of the brain, so consequently do not damage or destroy the head. Decomposition in the earliest stages makes diagnosis impossible. Ice or refrigerate the specimen after putting it in a container that does not leak (can or jar having a tight fitting top, double or triple layers of plastic bags, etc.).
Avoid handling rabies suspects with bare hands and getting saliva from the animal onto your skin. Handle suspects with protective gloves or a shovel. Bury suspects that are not submitted for examination.
These specimens require unique and special handling. In addition to adequate preservation, samples used as evidence must be properly and precisely identified and catalogued, the chain of evidence must be secured with proper receipt and transfer documentation.
Wet or moist material (feces, water, etc.) should be placed in a glass or plastic vial which can be stoppered to prevent leakage. An identifying label or tag should be securely attached to the vial. Wet blood should be absorbed onto a piece of filter paper or paper towel (plain white), and placed in an envelope which should be marked for identification and sealed. Flakes of dried blood should be similarly placed in an envelope. Dry specimens (feathers, hair, dried bone, etc.) may be placed in plastic bags, with proper identification attached. Pieces of flesh, or meat, or small carcasses (pheasant, grouse, rabbit) should be tagged, placed in plastic bags and kept refrigerated or frozen until delivered to the Laboratory. Each piece of evidence should be individually identified.
Plastic bags are generally the best way to package specimens to be submitted to the Laboratory. They are inexpensive, readily available, and watertight. Specimen tags should be attached outside the bags which contain specimens. The tag should include the following information for each specimen:
Tissues and organs collected for structural examination only (for example, tumors, deer ovaries, anatomical specimens) may well be kept in a chemical preservative. Formalin is the preservative we routinely use. It is cheap and may be purchased as formaldehyde at any drug store or will be furnished by the Laboratory upon request. Add nine parts of tap water to one part of formaldehyde to make 10% formalin, the strength used for preserving animal tissues. Put enough of the solution in the specimen jar to make a volume of formalin at least four times that of the material being processed.
Bear in mind that formalin, and most other chemical preservatives, kills bacterial, viral and fungal disease-producing organisms and renders the specimen useless for disease transmission experiments and bacteriological culture.
Specimens, reports, communications, should be directed to the Wildlife Disease lab at 517-336-5030.
In summary, when in doubt about handling a specimen give the Laboratory a call.