How does Egalitte® work?

How long does Egalitte® last?

Egalitte® is marketed as a “reversible” contraceptive and requires ongoing application to maintain infertility.

Initial Dose – Achieving Efficacy:

To be effective, Egalitte® requires 2 initial injections administered by a veterinarian 3-4 weeks apart. In conversation with ACC&D, Egalitte® reported that infertility is achieved about 15 days after the second injection and lasts for an average of 8 months in healthy dogs.

However, according to the data in their peer reviewed journal article published in 2020, “Reproductive and Behavioral Evaluation of a New Immunocastration Dog Vaccine", (Siel et al.), initial treatment was reported as effective for an average of 5 months in a study sample of 32 owned dogs of different age, size, and breeds. Egalitte® plans to publish further research demonstrating the product’s efficacy.

Booster shots – Maintaining Efficacy After Initial Period of 2 Injections:

Egalitte® requires ongoing booster injections to maintain effectiveness, which reportedly cause antibody levels to increase and remain stable for an average of 12 months per treatment.

Treatment Considerations

Age Restrictions

Egalitte® should only be administered to post-pubertal dogs (~6 months of age or older).

Male vs. Female dogs

Egalitte® reports that in male dogs, treatment can be given at any time. However, vaccination in females should begin in diestrus, the stage following estrus when the female is no longer receptive to the male.

Where is Egalitte® available, and when will it be available elsewhere?

Egalitte® is currently approved for use in only Chile. The product is patented (but not yet approved) in 40 countries, including Europe, the United States of America, Brazil, and Argentina.

Currently, a timetable is not available for when Egalitte® might be available outside of Chile, but ACC&D will update this page when more is known.

Are there any side effects of Egalitte®?

Estrus may still initially occur after administration if given in proestrus or late anestrus. Additionally, ~2% of animals have experienced an inflammatory reaction at the injection site, which has been identified as being associated with a specific formulation component, which Egalitte® is working to eliminate.

What is ACC&D’s outlook on Egalitte®?

Overall, ACC&D is excited about the promising results reported by Egalitte®. We are eager to read and review future publications reporting on larger field studies with female and male dogs.

Assuming future data confirms initial results, Egalitte® appears to provide an effective non-surgical fertility control option for both male and female owned dogs with owners capable of ensuring ongoing treatment. It offers potential for dogs who are not good candidates for surgery, or for owners who wish to spare their dogs surgery or are not ready to commit to surgical sterilization.

However, based on the need for 2 shots delivered 3-4 weeks apart to initiate efficacy, and the need for ongoing boosters, ACC&D does not anticipate this product playing a significant role in managing unowned, free-roaming dog populations (although it should be noted that in some situations a temporary dog contraceptive like Suprelorin® has proven useful, for instance in the efforts of Winnipeg Humane Society to address logistical challenges and resistance to surgery on First Nation land in northern Manitoba).