can puppy teething cause diarrhea
June 2, 2009. Teething puppies can develop digestive issues with diarrhea and sometimes vomiting. Puppy teething begins around 3 months of age and can last until the puppy is 9 to 12 months old. A young puppy with diarrhea should visit the vet, because puppies can dehydrate quickly. credit: cynoclub/iStock/Getty Images.