@eliefig Not always easy to tell when a bitch is coming into heat. My Teddy can sense a female coming into heat before her handler sees any signs. As an example, one day in class he began to get agitated, air sniffing, and totally distracted. I asked my classmates if any of their females were in heat. Oh no they all said. The next day one friend said her dog just started to show signs that day. Males can tell sooner than we!
Assuming you have eliminated a health issue ...
Teach him the "Look At Me" trick. If you have a training center nearby (maybe one that is hosting an agility trial or obedience trial or one that will let you watch a class) go and just sit with him, away from the other participants, and watch the other dog students. The second he looks at another dog, toss a treat in front of his face. If he is very aggressive you will need to start with him in a crate. Keep him in the crate and toss the treat in whenever another dog comes near or when he notices another dog. Do this several times; pretty soon he will start glancing at the other dog and then looking at you for more treats on his own. This is what you want; reward it. Soon you will stop rewarding for looking at the other dog and only reward when he looks back at you. He will catch on that it's okay to look at another dog but he must focus on you if he wants a treat and you must treat him generously for this.
I have a male that was attacked several times and became very "my space" protective/aggressive. It took awhile (and the Fenzi classes I mentioned previously) but he is now fairly calm after working through this.
Finding the right trainer with the right philosophy is important (regardless of the breed). With a situation as yours, you need a trainer who is schooled in BAT (behavior adjustment training) not just an obedience trainer; and of course someone who follows positive reinforcement training. Ask for references from their students if necessary.
I once had a trainer who billed herself as a behaviorist but really she was just an obedience person and believed in yanking on prong collars (I quit after half the class).
There is also an excellent online program for reactive dogs at:
Look under Classes, then discipline and behavior. I took the "Dealing with the Bogeyman" class. Even though its all online, it made a BIG difference with my reactive male. I highly recommend it.
My two have been quite successful catching those plant eating rabbits in my yard, as well as a few chipmunks, a squirrel now and then, and several small birds. I try to keep on eye on them, however, as I especially don't want them eating the rabbits (which they would do).
I bathe only when my male's allergies get out of control and then a natural oatmeal based shampoo. I feed both of mine salmon oil every day with their food. This summer (we have had excessive amounts of rain) his allergies caused semi-bare spots to develop on his sides. The vet gave us Gentived spray to use as needed and twice daily vitamin E oil rubbed on his skin. Working wonders. I have also used Dermactin (shea butter based cream) when the allergies cause a rash on his belly. Also wonderful.
My "aging" dogs are fed TasteOfTheWild kibble topped with a bit of wet food (variety of good brands) or a raw medallion (duck or pheasant) and with a fair amount of water so its kind of soupy (vet suggestion). Their weight hasn't changed and my vet is very happy with their condition. He also does a CBC every year on them for monitoring purposes, which I'm happy about.
I'm real skittish now with essential oil usage. A couple of friends who are into that got me started using them on my dogs but mine started having bad reactions (Teddy's allergies went berserk and he scratched off a lot of fur before I got it under control again). I do use a botanical flea/tick spray but even there one has to be very careful - I tried one that had cedar and cinnamon oil in it and it caused weird shedding and scratching.