One of the first symptoms of parvo that may appear in a puppy after it has contracted the disease includes depression and lethargy. You will notice that the puppy is no longer very active and a considerable reduction in its playfulness. Another thing that you may observe is that it will sleep far more than before. These early symptoms of parvo will typically appear within 5-10 days after the puppy is exposed to the virus that causes the disease.
A puppy with parvo will experience frequent episodes of vomiting. It may also show signs of abdominal pain. You will notice that the puppy has its abdomen tucked in, mainly because of the contraction of the stomach.
If the puppy is really young, you may want to take it to the veterinarian and get it checked for the cardio version of parvo. It is an even deadlier form of the parvo virus that attacks the heart muscle of the newly born puppy, thus causing cardiac arrest and possibly death. The virus passes from the mother to her puppies and can be avoided by determining in advance if the mother is a carrier.
Watery diarrhoea is another common symptom of parvo. If the puppy excretes feces that appears more liquid than solid, then there is a strong chance that it has the deadly viral disease. Keep in mind that watery diarrhoea can cause the puppy to dehydrate very quickly.