Dr. Marie replied:

There are some dogs who don't have a heat until after two years of age, so don't give up hope! Your girls may yet come into heat on their own.

The GNRH implant is also known as deslorelin or ovuplant. It usually works 90% of the time and produces a heat cycle within 5-7 days. The implant is inserted under the skin inside the vulva of the dog. Usually a dog will need to be sedated in order to do this. Then, when it is time for breeding (i.e. 10-14 days into the heat) it is removed.

You asked about the "fertile rate of success"....really the only thing I can tell you is that it is 90% successful at causing a dog to come into heat. It won't really have any bearing on whether or not she gets pregnant and holds a pregnancy though.

I don't know whether your girls could have a normal heat afterwards, but I really can't see why not.

Regarding safety, I could only find one study on safety and this was done on horses and not dogs. It is considered very safe in horses. A few horses had some mild swelling at the injection site. The fact that I couldn't find any safety issues in dogs is a good thing and likely means that it is safe!

If these were my patients I would definitely recommend waiting at least until they are 2. Most likely they will come into heat on their own!

Hope that helps!

Dr. Marie.

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Dr. Marie replied:

I just realized I didn't answer part of your question. You asked whether a dog had to have already had a heat in order for this to work, and the answer is no. It has been used successfully in dogs as young as 4 months of age, so no prior heat is necessary.

Dr. Marie replied:

No, it's not true. It is used quite often to bring a dog into heat who has never had a heat before.

Dr. Marie replied:

It definitely sounds like that was a heat. It could have been a silent heat where she just didn't display any outward signs that she wanted to breed.

There are other possibilities. If the male was inexperienced, or if he lives with her all the time sometimes they just don't do the right things.