6 Months
It depends on how old you are! lol if they arn't fixed they will go into heat and try there hardest to get to each other and the result is normally a pregnant mother dog for 3 months. hello puppies!
Whenever the vet says the dog is old enough.
he should get fixed
If either dog is fixed, no, they can't have babies.
a pug
It depends on how they were raised, but generally Female dogs are calmer. If you happen to get a Male dog its most likely people will tell you that if you get him "fixed" it will make him calmer. This is a myth.
Take your dog to the vet to check up on your dog. Dogs usually get fixed as puppies.
A dog can be fixed at any age but it is best to have it done before the dog is four or five at the latest, because it will heal faster and not be as traumatic to the dog.
The girl's dog was lost
Never, but if they are past there prime they may act a bit wierd after.
If your 7 year old dog is an unneutered male and your four year old dog is an unspayed female, the answer is a definite yes. Getting one of them "fixed" as well as carefully keeping females that are in season away from males that have not been neutered or otherwise made sterile, will prevent a pregnancy.
It is a good job for an 11 year old girl to wash a dog. but if you don't like dogs you shouldn't wash a dog.