• Open Access

The Effect of an Oral Probiotic Containing Lactobacillus, Bifidobacterium, and Bacillus Species on the Vaginal Microbiota of Spayed Female Dogs


  • This work was performed at the College of Veterinary Medicine, North Carolina State University, Raleigh, NC.



Recurrent urinary tract infections (UTIs) are often difficult to treat. Vaginal colonization with lactic acid-producing bacteria (LAB) is associated with reduced frequency of recurrent UTIs in women. Oral probiotics might help increase the prevalence of vaginal LAB and decrease the frequency of recurrent UTIs in dogs.


Administration of an oral probiotic supplement containing Lactobacillus, Bifidobacterium, and Bacillus species will increase the prevalence of LAB in the vagina of dogs.


Thirty-five healthy, spayed female dogs without history of recurrent UTIs.


Prospective, controlled study. Enrolled dogs received an oral probiotic supplement for 14 or 28 days. A vaginal tract culture was obtained from each dog before and after oral probiotic administration. Twenty-three dogs received the oral probiotic supplement daily for a period of 14 days and 12 dogs received the oral probiotic supplement daily for a period of 28 days.


Lactic acid-producing bacteria were isolated from 7 of 35 dogs prior to probiotic administration. After the treatment course, 6 of 35 dogs had LAB isolated. Only one of these dogs had LAB (Enterococcus canintestini) isolated for the first time. Enterococcus canintestini was the most common LAB isolated from all dogs in this study, although it was not included in the probiotic supplement.

Conclusions and Clinical Importance

Lactic acid-producing bacteria are not a common isolate from the vaginal vault of dogs. Administration of this oral probiotic supplement for a 2- or 4-week period did not increase the prevalence of vaginal LAB in dogs.