Читать книгу Infectious Disease Management in Animal Shelters - Группа авторов - Страница 141

Consider the following case history:

There is an outbreak of diarrhea, with a concurrent increase in mortality, in cats and kittens in a large, municipal shelter. Several cats and kittens have been found dead within the past few weeks. The bodies were disposed of and the cages cleaned thoroughly but even with isolation procedures in place, the number of affected animals appears to be increasing. The shelter manager and part‐time veterinarian at the shelter both suspect that the feline panleukopenia virus is the culprit. Animals are vaccinated at intake and every two weeks during their stay, but the disease presentation seems more aggressive than they have seen in the past, and several older cats have been affected. A fecal antigen test was performed on two affected animals, but the result was negative for viral antigen on the first and weakly positive on the second animal. Although apparently well yesterday, a cat and a three‐month old kitten were found dead at morning rounds. They believe both animals are part of this outbreak, although diarrhea was seen in the cat's cage but not in the kitten's cage. What is the best way for staff to establish the cause of gastrointestinal disease in their feline population?

This scenario is not at all uncommon in shelters. If accurate (sensitive and specific) pre‐mortem tests are available and results are consistent in affected animals, a cause for increased morbidity and mortality is comfortably determined. However, there are many reasons (e.g. less sensitive test, unusual presentation for a disease, unusual behavior of the disease in a population, non‐responsive to treatment for that disease) a shelter might seek additional information about a disease. In this case, although feces from one cat was positive for the presence of feline panleukopenia virus, the disease seemed to be occurring in the face of vaccination and isolation and was occurring in animals less commonly associated with the suspected disease (older animals).

What should they do? Staff are understandably very busy and need to efficiently diagnose the problem. The tests have been somewhat equivocal and doing full necropsies on each of these animals would likely be very time‐consuming; moreover, they are not sure the gross exam will be helpful since they are not exactly sure what they are seeing.

In a shelter (herd) situation, it is sometimes practical, sufficient, and time‐efficient to ask a more specific (limited) question about disease or death of an animal. Gastrointestinal and respiratory diseases, in particular, are frequent problems in shelters. To ask a more limited question of a necropsy means that the necropsy itself can be simplified. Necropsy samples can be the best samples to definitively diagnose a cause of disease, and proper necropsy sampling in a sentinel case or an infectious outbreak will save other animals.