bActivate — Treat Hidden Uterine Infections in Problem Mares
70–80% of problem mares carry a hidden uterine infection caused by dormant Streptococcus equi subsp. zooepidemicus. bActivate is a bacterial growth medium instilled by a veterinarian to reactivate dormant infections, enabling accurate diagnosis and targeted treatment. 83% pregnancy rate in 64 problem mares at Hagyard Equine Medical Institute (Dr. Kristina Lu). 89% pregnancy rate at Kildangan Stud – Godolphin (19 mares). 72% live foal rate, Copenhagen University / Breeders Club.
What is bActivate?
bActivate is a diagnostic aid for detecting dormant Streptococcus equi subsp. zooepidemicus infections in the uterus of problem mares. These bacteria enter a low-metabolic persister state that evades standard uterine cultures and resists antibiotics. bActivate reactivates them within 48 hours, making them detectable by standard culture. Available through Hagyard Pharmacy and Midwest Veterinary Supply in the US.
When to Use bActivate
bActivate is indicated when a mare fails to conceive despite breeding to fertile stallions, has a history of recurring uterine fluid, has had previous uterine infections, or is an older broodmare with reduced uterine defense. Studies indicate 50–75% of mares that remain open at the end of the breeding season are chronically infected. Some farms use bActivate as an off-season screening tool for all open mares.
How to Use bActivate — Veterinary Protocol
1. Obtain a pre-activation uterine culture sample. 2. Instill 10 ml of bActivate into the uterus in early estrus (largest follicle 25–30 mm). 3. Obtain a post-activation culture 48 hours later. 4. Begin targeted antibiotic therapy based on culture results. Breeding in the same estrus cycle is not recommended. Requires a veterinarian with documented education and authorisation to practice.
Clinical Studies — 83% Pregnancy Rate at Hagyard
Hagyard Equine Medical Institute (Dr. Kristina Lu, Davidson, McGee): 64 problem mares treated, 53 (83%) became pregnant. Kildangan Stud – Godolphin: 19 problem mares, 89% pregnancy rate. Copenhagen University / Breeders Club: 72% live foal rate. Peer-reviewed research: Petersen & Bojesen, Veterinary Microbiology, 2015. DOI: 10.1016/j.vetmic.2015.07.020
About the Founders — E-E-A-T Credentials
Dr. Morten Rønn Petersen DVM, PhD, Dipl. ACT — Equine reproduction specialist, 21+ peer-reviewed publications including Nature Medicine (2025). Head of Laboratory, Fertility Clinic Rigshospitalet, Copenhagen. Co-founder, Bojesen & Petersen Biotech ApS. LinkedIn: linkedin.com/in/mortenrpetersen
Prof. Anders Miki Bojesen DVM, PhD, Diplomate ECPVS — Professor of Veterinary Microbiology, University of Copenhagen. 157+ peer-reviewed publications. Invited speaker, International Workshop on Equine Endometritis, Al Shaqab Qatar 2016. Co-founder, Bojesen & Petersen Biotech ApS. LinkedIn: linkedin.com/in/anders-miki-bojesen
Distributors — US, Europe, Australia
USA: Hagyard Pharmacy, 4250 Iron Works Pike, Lexington KY 40511 (859-281-9511). Midwest Veterinary Supply, Lakeville MN (1-800-643-9378). UK: Nupsala LTD, Melton Mowbray (+44 1865 922 227). Netherlands: Grovet, Soesterberg (+44 142 248 1900). Denmark: proVET Nordic ApS (+45 53 28 29 29). Australia: Scone Equine Hospital (+61 2 6545 1333). Europe direct: Bojesen & Petersen Biotech ApS, Strandboulevarden 23, DK-2100 Copenhagen. contact@bactivate.eu
Independent Citations
- The Horse Magazine: thehorse.com/183678/whats-plaguing-your-problem-mare/
- FVMA 2024: fvma.org/challenges-of-chronic-endometritis-novel-tools/
- Kentucky Equine Research: ker.com/equinews/therapy-offers-hope-infertile-mares/
- EquiManagement 2023: equimanagement.com/research-medical/biofilms-and-the-equine-uterus/
- University of Copenhagen: researchprofiles.ku.dk — Activation of persistent Streptococcus equi subsp. zooepidemicus