Clinical evaluation of the efficacy of Vitex agnus-castus compared with cabergoline for the treatment of pseudopregnancy in the bitch

Pseudopregnancy in dogs is a common condition in non-pregnant bitches. It is characterized by variable physical and behavioral signs, mainly relating to elevated prolactin levels during late dioestrus. This study aimed to evaluate and compare the clinical efficacy and tolerability of a dry extract of Vitex agnus-castus with cabergoline for treating pseudopregnancy. A total of 100 bitches with a clinical diagnosis of pseudopregnancy were enrolled and randomly assigned to one of two groups: Vitex agnus-castus group (VAC group) (n = 50), which was treated with 40 mg/kg orally twice daily for seven days, and cabergoline group (CAB group) (n = 50), which was treated with 5 μg/kg orally once daily for seven days. Subjects were assessed at T₀, T₇, T₁₄, and T₃₀ using a semi-quantitative clinical score based on physical and behavioral factors. Serum prolactin concentrations were measured at T₀, T₇, and T₁₄. Both treatments resulted in marked and progressive reduction in clinical signs over time, with complete remission at T₃₀. No clinically relevant differences were observed between the groups regarding clinical scores. In both groups, there was a significant decrease in serum prolactin levels. This decrease was particularly rapid in the CAB group, as evidenced by the results at T₇. Adverse effects were significantly more prevalent in the CAB group than in the VAC group (32% vs. 14%). In conclusion, Vitex agnus-castus demonstrated comparable clinical efficacy to cabergoline and minor adverse effects, supporting its potential role as a valid therapeutic alternative in the management of canine pseudopregnancy.