excercising puppy

Question
Hi. This is not so much a question, more need of a reassurance that I have
not, unintentionally, done something bad. And I am going to call the vet first
thing monday morning. But if you have time to get back to me I would be
very grateful.  I have an eight month old female labradoodle that is fixed. I
got Miller when she was 3 months old and my room-mate got a four month
old female goldendoodle the same weekend.  So it has been crazy puppy
madness since august.  My room-mate and I work opposite schedules so one
of us was always with pups and we walked them a lot and they were rambunctious. We live in a town with pretty slack leash laws and lots of dog
friendly trails and woods and beaches.  So they got 2 sometimes 3 outings a
day and they were getting to be longer and longer as the got a little bit older.  
Somewhere we decided to wear them out so they would be mellow and well
behaved at home.  My worry is that I have taken the exercise to far... Last
month I started running with Miller we go almost everyday and we have
worked up to a couple of miles. Some friends suggested that i might be over exercising her so I googled exercise and puppy, and I am almost sick to my
stomach that I have probably caused her horrible arthritis and/or hip
problems.  I also feel so ignorant for not researching this better, before we
started.  We have just been so active from the beginning and I gradually
increased the amounts, and she seems to love it and almost always leads...
But i am sure i have taken it to far.  what are the odds that she won't have
horrible arthritis and is there a supplement I can give her.  Again will call vet
on monday. thank-you. Meredith

Answer
It is really hard to say.  It certainly isn't good to push them once they start to lag.  Running on pavement is bad.  One more definite factor is weight.  

There was an extensive discussion of weight in a recent newsletter from a service dog school.

''Obesity is the number one nutritional disease affecting dogs. It's estimated that 25-45% of dogs in the US are obese. Studies have shown that joint and locomotive problems increase by 57%, circulatory problems by 74%, respiratory problems by 52%, skin problems by 40% and cancer by 50% in animals that are overweight.

Large breed dogs that are overweight also are more prone to developing hip dysplasia. Obesity is especially dangerous for young puppies, as their underdeveloped frame cannot support the extra poundage that it must carry.''

Your dog definitely should be narrower at the waist than the hips and chest.
You should be able to easily feel the ribs, but not see them.  Each dog is
different.  Standard recommendations are a good place to start, but each dog
must have its food adjusted to its individual needs. Here is a link to a good illustrated guide,
http://www.longliveyourdog.com/twoplus/RateYourDog.aspx

Evaluate her using the above link.  Ask the vet if he agrees with your evaluation.  If you have kept her lean, the exercise shouldn't have been nearly as bad.  As for supplements, Usually a good chow doesn't need them.  Go with what the vet says.

None of us are born knowing all about dogs.  I see many questions here from people lacking the very basics.  You can hardly be blamed for enjoying fun times with your puppies.  I do know that allowing them to play together never hurts them.