Diagnostic pathology of selected diseases in wildlife.

The prompt detection and effective management of infectious disease in wildlife rely greatly on field diagnosis. Although clinical work is sometimes of value, the cornerstone of diagnosis is pathological examination (gross necropsy with supporting laboratory investigations). The approach and rationale to gross post-mortem examination are common to all species, despite possible significant differences in technique. Likewise, the principles of sampling are usually comparable, with emphasis on standardisation, the correct use of equipment, and consistency in methods of storage and transportation of specimens. However, the type of sample taken and the laboratory tests required differ, depending upon the circumstances and possible diagnosis. Retention of material is always important. The principles of diagnostic pathology are discussed, with reference to selected diseases, namely: mycobacteriosis, Rift Valley fever, rabies, spongiform encephalopathies, morbillivirus and poxvirus infections, viral encephalitides, West Nile virus infection and chytridiomycosis. The importance of being able to perform certain investigations in the field, efficiently and safely, is emphasised.