puppy bit ds and I don't know what to do.

[Icanonlytry]

We have got an 18 week old puppy, training seems to be going well and she is lovely, very giddy but just normal puppy giddiness.
Ds is two and yesterday we were in the garden playing, puppy was playing with her toys on the other side of the garden. She came over to see what we were up to and then just ran at ds and before I could grab him she bit him on the arm .
He was doing nothing to provoke her, don't even think he knew she was coming towards us.
I didn't know what to do so I quickly made sure ds was ok then put puppy in her crate. ds was very upset, the bite had broken his skin but it wasn't bleeding. He calmed down quickly and doesn't seem scared but I am really worried incase she does it again but worse.
I don't know what to do???

If the puppy is only 18 weeks this is not serious as it may seem. If your son made squealed or cried out, this is actually good. It's how young dogs learn, as they would in a litter, that something is not acceptable. Putting the puppy in the crate was also good. I used to squeal or growl at our puppies and then put them in the kitchen if they got above themselves. Another good thing to do is to give lots and lots of praise and attention when they are playing gently.

Lots of puppies this age go through a biting and mouthing stage and most will grow out of it if you make it clear that it is not acceptable and results in being growled at and then put somewhere by themselves with all the fun over. My current dog was very bitey as a pup and is now, at 2, gentle and soft with everyone. And she's a terrier.

She was probably just trying to initiate play, that's what puppies do and because she is young she hasn't yet learnt to moderate her bite on little ones. So in the short term you are just going to have to keep them apart unless you are actively supervising and in the longer term train bite inhibition.

Are you going to any classes? Could your trainer help you with this?

Agreed. Most puppies try and chomp you at some point, it isn't aggression. They just like biting stuff. You have to teach them what is acceptable to bite, like toys, and what isn't, like skin. My pup bit my 8yr old son on the head when he was about that age. His jaws got stuck and I had to lever him off the back of DS's skull. Not cool. However, DS wasn't badly hurt (no blood) and he never did it again. Sometimes puppies just seem to go a bit nuts, out of nowhere, and go on a mad running/chomping/woofing rampage. The crate is the best place for them My dog is now 20 months old and very soft mouthed.

I agree with the others, it's just what puppies do and they have to be taught not to bite and how to use their jaws gently. Teaching bite inhibition is actually one of the most important things for a puppy to learn. There's a great section about it in Ian Dunbar's online training textbook here. You have to register to read it, but it is well worth it (and free).

Also, like chickens said, a crate is your friend for those times when you aren't able to keep a close eye.

There's a great book called Life Skills for Puppies that you might like to take a look at, and puppy classes are very helpful too.

I'm glad your son wasn't hurt and I'm sure the puppy just thought it was play.

Our pup was a terrible biter as a small pup - she just got so over excited when playing. She reduced my DD (aged 15 and 20 years!) to tears on many occasions and we all had puncture wounds and shredded clothes. We used to banish her to her crate when she started the biting and were consistent in giving her chew toys she was allowed rather than our fingers, ankles, arms etc. At 10 months her bite inhibition is much improved and i would agree that the use of her crate has been a sanity saver.

Oh, the joys of puppies! This has reminded me of how bitey our younger dog was as a pup. She was very boisterous and used to jump up and grab body parts or clothes in her jaws. She particularly did this to DD2, a very small for age 10 year old at the time - I suspect because she saw her as a fellow puppy! We all had holes in our clothes and I really got quite to the end of my tether with it.
The thing that worked best was a loud squeal or cry as if it had really hurt, and immediately removing her or us to another room, or the crate. It took a while to sink in (part terrier, very keen on the bitey thing). However, shes's now 2 and would never dream of biting, she's totally soft!
Keep persevering with the training and as your DS is very young, be very vigilant if they are together in the meantime.