Vivariums house a number of animals, typically test animals, such as mice or other rodents, in a number of cages, often a large number. The test animals are frequently used to test drugs, genetics, animal strains, husbandry experiments, methods of treatment, procedures, diagnostics, and the like. We refer to all such uses of a vivarium as a study.
The prior art of vivariums is labor-intensive. The animals must be monitored for behavior and health. This is typically done by direct observation, or by removing an animal from its cage for more careful inspection and tests.
Such manual observations and measurements are inherently infrequent, such as once per day per animal. This infrequency creates three weakness of the prior art. First, problems such as sickness may not be discovered until after an unacceptable delay. Second, subtle health changes will be missed. Third, such observation and out-of-cage testing require light for the observer. For the convenience of the vivarium operation, most animal tests are done in light, during the day. The natural activity period of mice is at night, in the dark. This timing not only misses health issues that happen during their normal activity period, but also puts stress on the animals, as the light interferes with and alters their normal behavior and health, and thus alters the results of the study compared with animals in their natural lighting regimen.
Prior art includes urine test strips. A typical paper strip comprises ten to twelve small treated squares, or patches. When the strip is saturated with urine, each square changes color based on one particular attribute of the urine. The colors of the patches are read manually, comparing each square against a set of reference colors to determine the best match. The patches on the strip must be read at a specified time from saturation, such as one minute. Often, different patches require a different read time.
Such strips are not well suited for measuring mice urine in a cage. A puddle of urine is likely not fresh, and may well be contaminated. In addition, if there are multiple mice in a cage, which is common, it is unlikely that a determination can be made of which mouse produced the urine. Alternatively, placing a mouse in a clean sanitary enclosure to collect its urine, separate from its home cage, is very labor intensive and stresses the mouse, as discussed above.
Prior art does not include any method of fully automated urine analysis of multiple mice in a home cage on a continual basis.