There are imjections both dogs and bitches can have.

Tardak is the drug used for chemical castration and It will tell you what effects castration will have on your dog.

Not sure of the one used on bitches.
You may want to consider having a chat with your vet,we currently have an in season bitch and an entire male who is driving us mad whinge,whine,crying,drooling,slobber,scratching at the door,he's forgotton his name,he's going to think it's shut up!Swap them around he won't come in out the garden,when he comes in he wants to go out again.It's not fun I can assure you and it's hard work keeping them apart.

So I would definatly say consider having one of them neutered.