Species Specifics

Abstract

As difficult as clinical pathology interpretation may be for humans, it is far more complex when numerous other species are considered. Clinical pathology diagnosis is generally similar across species but there are many species-specific differences that must be considered to avoid erroneous diagnosis. For example, birds have nucleated red blood cells but mammals do not. It is normal for red blood cells to resemble a stack of coins (rouleaux) in cats, dogs, guinea pigs, and rabbits, but this is a sign of disease in other species. Mouse leukocyte, lymphocyte, and eosinophil counts can be threefold higher in the morning than in the evening. Alkaline phosphatase is a good indicator of cholestasis except in cats. Manual restraint of rats during sampling can cause increases in plasma protein, calcium, and magnesium; and decreases in blood pH and glucose. The urine of healthy cats tends to be cloudy. Rabbit urine tends to be basic and turbid and it is high in volume because rabbits do not concentrate their urine as well as other animals. Only by understanding peculiarities for a given species can one avoid calling adverse what is actually a normal finding. This chapter provides specific information for the species most commonly encountered in toxicology studies.