I have a 8 month old 70 lb. mixed breed, and since the weather started getting cold she has developed a limp. It will start a few minutes after going into the cold and then stop a few minutes later. It was on the right side for a few days, now it is only on the left side.only on the hind legs. The vet examined her, and said it could be arthritis, but the symptoms seem different than the ones I've read about. Does anyone have a clue?

It could be any one of a number of things really.
It could be nothing, it could just be that her feet are sensitive and she doesn't like the cold ground or it could be a damaged ligament that acts up in the cold or arthritis

Give the breeder a call and let them know what is happening, they might have had it happen to one of their dogs in the past.
I have a dog that suffers from incontinence, she went to the vets to be checked out and they wanted to do thousands of dollars worth of tests on her.
We called the breeder and found out it was a hereditary problem and was told what to do about it from there

Ours sometimes limps just to get attention. She found out that limping can get her an all over pet as we check to see if she's injured.

I was going to say ligament - this was my first sign there was a problem when my Rott tore her cruciate ligament. She limped all winter when she got cold, Vet wasn't sure, it tore in the Spring.

Are you still feeding her puppy chow?
A lot big dogs need to have puppy formual until they are up to a year old. Their bones will grow too fast and cause like every one else has mentioned torn ligaments, which can lead to arthritus, and will probably never heal completley.

My dogs do this in the early mornings when the ground is still frozen. It could simply be that your dog doesn't like the cold.

Are you still feeding her puppy chow?
A lot big dogs need to have puppy formual untill they are up to a year old. Their bones will grow too fast and cause like every one else has mentioned torn ligaments, which can lead to arthritus, and will probablly never heal completley.

It's the opposite actually :)

Large to giant breed dogs shouldn't be fed regular puppy chow as it has too much protein and causes them to grow too fast. Puppy food generally has around 27% protein or higher, whereas large/giant breeds need 23% to 24% protein.
If their bones grow too fast it can cause big, often irreversible problems.

In saying that though 70lbs at 8 months is more medium/large on my scale.
My parents dane is 176lb, he would have been about 100lb or more at 8 months.

Oh really? That's weird. When slash had a torn lig, the vet said I should put him back on puppy formula, because he was growing too fast for his joints. Yes though she said I needed to find puppy chow for large breeds. He was about 100 lbs at 7-8 months.

Oh really? That's weird. When slash had a torn lig, the vet said I should put him back on puppy formula, becasue he was growing too fast for his joints. Yes tho she said I needed to find puppy chow for large breeds. He was about 100 lbs at 7-8 months.

Did your vet mention protein content? Large breed formulas are different from generic puppy chows. Dietary needs while healing also change from normal requirements.

Yes,I was feeding Slash Hollistick food. But she also said that it was a good idea to keep any large breed on large breed puppy formula until they were a year old.
I definitely should have mentioned that in my above post.
While feeding Slash the Hollistick food, I also gave him fruit and veggie cookies for dogs that contained wheats and rice as well.