Oh boy, I've had several but never had any issues like that. I did have them overly hyperactive when I wanted to get the lead on them in and out of the house, and the only way I found that worked was to have them go through the sit routine.

Started out by having them learn the command "sit" and "stay" outside (treats after they succeed every time), and then graduated to putting the leash on them after do sit/stay and THEN giving them the treat. So they associate it with something that isn't harmful, but something to get a treat for.

Some dogs react poorly to being on a tie out (which is what I think you're talking about when you say "lead"). They'd do okay on a leash being walked because the environment changes, but being on a tie out in the yard can make them either feel like they're vulnerable (because they can't get out of the yard) or frustrated (because they see something they can't get to). If you've got her on a tie-out, is it possible to take her for a half hour walk instead? The different sights and smells might make her feel a little more mentally stimulated. A lot of behavioral issues are due to boredom (and lack of exercise).

I have a three year old english setter. I adopted him from a shelter when he was 7 months. At that time, schedules with me and my ex worked so that we were actually able to take him out on 3 or 4 short walks per day. Now he runs 3 - 4 miles with me in the mornings, and walks anywhere from 1 - 3 miles at night. He also goes to doggie daycare once a week. In the house, he is the calmest, laziest lump of fur you'd ever meet. And super sweet. But outside and at daycare, the dog is a total spaz.

Working on the sit/stay/lead progression is a great idea as well. I will admit I'm not as consistent as I should be with making him "work" for things and I need to be better about it. He's getting a little spoiled.

Beagles and Rotts are very strong willed breeds, the beagle especially. I grew up raising Rotts and they take a Very strong willed person to train them. When I met my DH, he had a beagle and I have never encountered such a hard breed to train. I have a Bea-Tzu now (Beagle and Shitzu mix) and he is absolutely the hardest lil' thing I ever had to train. You must be stern with them and let them know that YOU are the alpha. Let them know that it is unacceptable to bite by either very, very firmly telling them "NO!" or actually tapping their nose when they bite and tell them "NO!"

15 weeks old is still very young and it could be that he/she is just very very excited to see his person and he is just worked up and wants to play when you come to take the lead off But, either way, biting is not okay and you Must train him now, while he is young or it will get worse as he gets older and more dominant.

Hope this helps some

Rescues are always fun! I rescued my first 3 years ago and what a treat he is. Hands down my favorite dog ever but as a result of some aggressive behavior, he's taught me a lot about dogs. By the way - mine acts funny when it's nice out and I want him to come in too. It's like they are telling us they want to stay outside and are not ready to come in! Just like a kid! I am sure others will pipe in with some good advice. Here's mine - she needs some distraction while you are removing her from the leash. Eventually, it won't be an issue at all - she just needs to be trained. Does she like playing with tennis balls? Maybe bring one of her toys with you when you go to get her off the leash. Then she'll think - "OK, so I am being taken off the leash but look at the fun game we are about to have!" Talk to her, put her at ease. If she knows what "treats" are (my dog and I have a really ridiculous language and if someone was to hear me talking to him, they would commit me immediately!) tell her you are going to give her one. Or for the first couple of times, bring one with you - then after a while she is going to see that you are not "threatening" her. I don't mean threaten in a violent way. Also, don't be afraid to let her know who's boss and that it is not acceptable to you. Low, booming voice helps if she acts up. As you approach her though, be upbeat, happy and talk to her in a gentle way. Puppies take a lot of work... but with training and love - these behaviors can be eradicated. Have you done a training class with her? My pups and I did and it was so rewarding. It bonded us. He trusts me and I trust him. Of course, he can be a boy at times and not listen - but I am used to that!!!

We broke the 'chewing on the hand' habit in our lab with lemon juice. Get one of those lemon shaped lemon juice bottles, and when she puts her mouth on you, squirt some in her mouth. She will learn real quick not to put her teeth on you. Also works for when they chew on their leash on walks.... Squirtt some lemon juice on the lower foot of the leash and they won't put their mouths on it again.

As for the jumping and scratching. Call her to the edge of her area and make her sit. If she gets up and starts to jump on you, just step back out of her range and wait. Only approach her again when shes calm and sitting. You will have to repeat quite a few times for her to get it, but she will make the connection that they only way she will get your attention/get off her tie is to sit calmly.

Definitely curb the nipping/biting now. She might be a cute little puppy now, but soon she'll be a bigger dog and the biting will get you in big trouble. I hate when I see people letting their puppies bite them because they are cute and it doesn't hurt yet. A dog needs to learn from the very beginning that they are to NEVER put their teeth on a human. EVER. At least not a dog meant as a family pet.

I have a rescue dog as well (chocolate lab) and got him when he was about a year old. He was already a big dog, and tried the nipping thing a few times with me too. I put a stop to it real quick. I grabbed his snout and held his mouth closed, and firmly said, "NO BITE. NO!". Then I made him lie down on his bed and I wouldn't even look at him for about 5 minutes. Dogs love attention and ignoring is a good training technique. After the 5 minutes, I'd call him over and pet him and we would just continue with or day like nothing happened. I probably only had to do that 5-8 times before he got it and stopped. Never bit/nipped again since.

Work on the biting and also bring a treat out with you. Make her sit, and then lay down, and "stay". If she stays, take her off the tie out and give her the treat. If she gets up, start over. Sit, lie down, stay, treat. Work on that all time. When you are feeding her dinner, in the house, outside, on walks, for toys, etc.

I believe it is either fear aggression or aggressive playfulness brought on by over-excitement. I used to be a Veterinary Technician in a former life.

Work on training the puppy to not bite or nip but also work to train the puppy in other basic commands. Once a dog knows what its owner wants, it will usually be a calmer dog. Can you imagine being stuck in a foreign land, not speaking the language and have HUGE people babbling at you and getting mad when you did certain things?

Also, be patient. Beagles are known to be a little stubborn but rotties are easily trained. It's hard to say which end of the spectrum your puppy is going to land on!

Biting/Nipping = finger in the back of the throat. My dog didn't have much of a nip or bite thing when she was a baby but I've dealt with many who have. A dog goes to chew on your hand or bite/nip at you and you dive into it by shoving your finger/wrist/whatever it's going for into their mouth. Natural reaction is to recoil. My pup, now 8, will play now and put her mouth around my arm or wrist or hand but never, ever bite down because she knows it hurts. She knows from when she was little that when she chewed on mom, it hurt cause mom either pushed into it or bit back (yes, I also bit-gently-her ear if she'd come at me too hard). She's the most gentle dog I know and knows the limits. Granted, I have a smart and docile girl for the most part but it's worked on my friend's labs, Aussie's and Pits. The finger or arm into their mouth, I wouldn't bite anyone else's dog