Unless this is a young uncoordinated puppy, this could be abnormal, like a neurological problem or problem with the inner ear and balance. Even if it is an uncoordinated puppy, it shouldn't happen frequently. The best plan would be to have the dog checked by a vet, this could be a serious symptom.
That would probably mean your dog has a serious problem if your dog just falls over.
It has probably passed out from illness, dehydration, or stress.
when it falls (hard impact), eats something wrong, or if you just mess with her
only two living things have been sent over a falls safely with out special protection. a dog over the American falls in the1800's and a boy over the horseshoe falls in 1960.
It could be the dog is tired. Is the dog old? You might want to get it checked at a vet.
You dog is very ill, go to the vet.
it can if it had a disability or it was breaded wrong
No. A dog has to do what a dog has to do.
That he is depressed. Or is lonely.
It probably has mites. Consult a pet store for mite cream.
Sounds like anaphylacitc shock
That would be called a seizure, get your dog to the vet IMMEDIATELY!! There is a medical problem wrong
The dog whisperer's method of training a dog is wrong, since a dog gets kicked.
You should take it to the vet right away. It sounds like a seizure or poisoning.