Stormy,

There are a few test that can be done before resulting to exploritory surgery. There are a couple of different blood test that can be done to test for testosterone. I would have them done first. Depending on the results will let you know if exploritory is even needed. The results should come back either positive or negative. If it comes back gray so to speak then surgery would be a good choice. Had a client that rescued a young horse that acted very studly (to the point of jumping fences) his test would come back inconclusive and they performed surgery, he ended up having a retained testicle, high up in the abdomin.

I also had a 20 year old gelding that came on to my place that would tease my mare something awful to the point of keeping her in heat. We caught him once and he had even mounted and penitrated her. He was gelded correctly but still carried the stallion traits. I had to have my friend find another place to keep him for both of the horses safety.

Some geldings no matter at what age they are gelded can still act like stallions. But to put your mind at ease I would do the blood test. I believe there are 2-3 test if I remember correctly.

Hope this helps.