Influence of restricted food intake on estrous cycles and pseudopregnancies in dogs

Objective-To examine effects of restricted food intake on estrous cycle fre quency, interestrus interval, and pseudopregnancy prevalence in dogs. Animals-28 female Labrador Retrievers. Procedure-Dogs were paired by body weight when they were 6 weeks old and fe d so that the limit-fed pair-mate received 75% of the amount of food offere d to its maintenance-fed counterpart. Estrous cycle, interestrus interval, and pseudopregnancy data were recorded. Results-Mean annual frequency of estrous cycles and duration of interestrus intervals did not differ between feeding groups. Prevalence of clinically evident pseudopregnancy was significantly greater among females that were m aintenance fed, although results of endocrinologic testing did not identify a mechanism for this observation. Conclusions and Clinical Relevance-Pseudopregnancy in dogs can be influence d by physiologic factors related to nutrition. Clinicians should consider a variety of physiologic and environmental factors when evaluating reproduct ive function in dogs.