Same sex aggression is a very real thing, I was going to mention it but didn’t want to throw too much at you at one time. This usually happens around the time your dog reaches sexual maturity. It doesn’t always happen but it can be life altering if it does, constant crate and rotate....hopefully since your Boston sounds like he’s submissive it won’t happen, but do your best to make sure he doesn’t get bullied by your Doberman.
Dobermans are not like most dogs, they are extremely smart and a true working breed. If they don’t get enough mental and physical stimulation they get bored and will act out. You mentioned that he doesn’t seem easy to train, I’d be willing to bet he’s actually bored. For example, he knows sit if you make him sit over and over he’s going to be like WTF mom I got this, why do you keep making me do the same thing over and over. Start working on harder more complex things. Here are some ideas to help you keep him stimulated, also keep in mind training should be fun, don’t correct him for something he doesn’t know and always end on a positive note, before he is mentally tapped. You want him to end the game wanting more and make sure you use high value treats for the super hard stuff. Also, I suggest taking a basic obedience class, find an actual training center, not PetSmart or sit means sit.
-puppy sit ups, sit down sit, sit down stand sit etc.
-tricks, turn in a circle, crawl, bow, shake , roll over, high five, shake (careful with these you could end up with a very paw friendly dog) really anything you can think of
-sit and wait for meals...I use get in your spots (which for us is just outside the kitchen), and wait until I release you for dinner. This also helps train them to leave us be while we’re eating.
-stays, slowly increase the time and add distractions like turning your back, walking around your dog Etc.
-incorporate OB into your walks, start with easy stuff like stopping and doing some sits, downs, stays and then start actively looking for distractions, kids playing basketball, great! Work on your OB right in front of them.
-obedience at the pet store, same as above, I also love to stand near the entrance and work on stays while people are coming and going
-name attention, say his name and lure him to look at you with a treat, when he makes eye contact mark it and treat.
-come, this is my favorite thing to teach and games are a great way. You and your husband go outside with a handful of treats one person has the dog and then the other calls him when he comes through a party and give him a treat ( don’t worry if your neighbors are judging you then you’re doing it right), always reach for his collar before treating. Later you can include a sit when he gets to you. You can also play hide and seek in the house, same concept.
That’s all I can think of at the moment, sorry if I’m a little detailed, it’s not to insult you just want to make sure I didn’t leave anything out. I know you said you’ve trained dogs before and read a lot of literature, but I swear some Dobermans are smarter than most people....some use it against us
. Take me for example, I’ve also trained several dogs, ALL Dobermans,my current pup is 14 months old and a heathen! Not really but she can be real obnoxious when she’s bored. She’s been in training classes since she was 10 weeks old and is currently in AKC OB and agility and I work with a private trainer. A few weeks ago she’s being a **** in class and refusing to sit and then jumping on me, instructor comes over and tells me she’s bullying me.....huh? You to,d her to sit she doesn’t, then she jumps on you. Essentially she’s saying no I will not do what you ask me to and eff you give me my treat.....****! Your right! I know better but yet she still got me. They will also test you to see what they can get away with, just like a toddler who doesn’t want to eat his dinner but miraculously 20 min later he’s hungry and wants a snack.
Puppies especially Doberman puppies are ALOT of work, but trust me, put the work in now and you’ll be rewarded ten fold later. You got this!