Lower urinary tract diseases are among the most common and frustrating issues encountered in feline medicine. Despite their prevalence, these disorders are often diagnosed very late in the course of disease, often due to a lack of owner observation of the early warning signs. Cats are often less likely to urinate with their owner watching, and the presence of multiple cats, multiple litter boxes, and lack of ability to observe cats combines with issues of owner recall to make it difficult to quantify early behaviours of inappropriate urination.
Video recording systems have been used extensively in humans and veterinary medicine to objectively evaluate and monitor factors ranging from classroom behaviour in children to estrus in dairy cattle. In this study, authors applied video recording systems (VRS) of litter boxes to compare the urination behaviours of healthy cats and those with conditions likely associated with lower urinary disease.
11 healthy and 8 abnormal cats were recruited for this study (three additional cats were excluded due to camera malfunction). Video recording systems consisting of up to 4 high definition, motion activated, color and infrared IP cameras were set up for a 14 day period monitoring litter boxes in each of these households. Healthy cats were free of systemic diseases that may influence the urinary system, while unhealthy cats had a combination of CKD, FIC, or subclinical bacteriuria. Healthy cats were younger than unhealthy, however there were no differences in sex, weight, diet (canned vs dry) or other factors.
632 urinations were recorded, the gross majority of which were in the litter box. Owner reports were compared to VRS data, showing that owners reported a median of ~0.5 urinations per day, while VRS detected ~2.5. No difference was seen between the healthy and lower urinary groups for mean urination time, however cats with urinary disease had significantly more urinations per day (2.9 vs 2.1) and a significantly shorter cover-up time (22.7s vs 8.7s).
The increased frequency of urination in cats with a history of lower urinary tract disease is not surprising, and may be due to bladder discomfort, reduced bladder capacity, polyuria, or other factors. It could be expected that in cats (especially male cats) experiencing active lower urinary tract disease, total urination times may be longer (due to struggling to express urine) or shorter (due to lack of ability to urinate). This was not observed in this study, likely due to the lack of active urinary disease. A decrease in cover up time may be due to a history of litter box aversion.
A major drawback of this study was the small sample size, which may lead to errors in interpretation. There were also some concerns for the classification of cats with lower urinary disease, as the inclusion of cats with CKD may lead to alterations in urinary behaviour due to upper, rather than lower urinary signs. Periuria (urination outside of the litter box) was also unable to be detected by this system.
While there may be some limitations to the practical relevance of the techniques in this study (video monitoring systems of litter boxes may not be readily implemented in most households), it raises many good points related to urinary disease. This study suggests that owner reported urinary habits may not be very adequate, and that the presence of clinical disease should not be determined based solely on owner observation. This is especially relevant as the question of subclinical bacteriuria becomes more topical. This study also suggests that while stranguria is a classic clinical sign of lower urinary disease, number of urinations and mean cover-up time are also important indicators. (MRK)