I don't quite understand you needing to ask this question.
If Testosterone has to be given to your dog -then I hope that would be under a vet's advice -and if so, then the vet would have already shown you how to do it!
Please do not give your dog Testosterone injections unless it is prescribed and advised by a vet. It could have bad consequences.
... for what reason would you be wanting to inject your dog with Testosterone? Who told you to do that?
What??? You have fighting dogs or what??!!
This thread gives me the chills.
Please -if you are part of a dog-fighting set-up...please think about what you are doing to those dogs. Please choose Compassion and kindness.
There are other ways to set up a business. There are other ways to gamble money. Those don't have to hurt creatures -especially creatures who are capable of such love and loyalty.