Litter box size and litter type preference and their associated behavioral changes in cats.

House-soiling is the most common problem faced by cat owners and is the main reason for owners surrendering cats to animal shelters. Although many studies have reported on inappropriate cat excretion in relation to the toilet environment, few reports have explored the preferences of cats kept indoors when multiple litter boxes are presented. In this study, we investigated the effect of litter box size and litter types on the excretion behavior of cats and whether a litter environment that combines their preferred elements would change their excretion behavior. Our findings indicated that cats preferred litter boxes measuring ≥50 cm as well as clumping clay litter. Moreover, a comfortable litter environment combining these two elements promoted normal urination behavior while improving house-soiling (both urination and defecation) as well as three dissatisfied behaviors during excretion. The results of the present may be beneficial for cat owners and cats exhibiting house-soiling, and they could facilitate the reduction of the number of cats being abandoned owing to house-soiling.