ABSTRACT
The dog is also a commonly used animal in drug metabolism and disposition studies since most research facilities are equipped to maintain and handle this species. Upon reaching maturity (7-9 months), the body weight of the dog is sufficiently stable over time to allow repeated studies in the same animal, i.e., studies using a crossover design. The large body size of the dog, however, also presents certain disadvantages such as the need for larger housing facilities and cages, greater amounts of test compounds, and somewhat greater difficulties in handling the animal. In contrast to smaller species, relatively large blood samples can be frequently collected from the dog without altering its normal physiology. Commercially available dog cages are usually suitable for the quantitative collection of urine and feces. The gratelike design of the cage floor coupled with the tilted collection pan underneath permits reasonably good separation of urine and feces.
