Dogs

• Dogs with parvovirus often develop dehydration.Thinkstock/Comstock/Getty Images
  
  Adult dogs that are exposed to the parvo virus often do not show any symptoms. Parvovirus symptoms are most common for dogs younger than 6 months and most severe cases of parvo occur in dogs that are less than 12 weeks old. The early symptoms of parvovirus include severe vomiting, dark or bloody stools, diarrhea and eventual dehydration. Parvo can be fatal for younger dogs or dogs that are not treated quickly. If you suspect parvo in your dog or puppy, you should consult a veterinarian immediately.
  
  

Cats

• Cats with parvovirus can become dangerously ill within two to three days.Martin Poole/Digital Vision/Getty Images
  
  Feline parvovirus is actually different than the parvovirus that dogs get, but infected cats show similar symptoms. The disease is highly contagious and cats can spread it before they show signs of being sick and up to six weeks after recovery. Symptoms of feline parvovirus include diarrhea, lethargy, high fever and severe vomiting. An infected cat's feces are typically yellow, smelly and bloody. If you suspect that your cat or kitten has parvo you should consult a veterinarian as soon as possible.
  
  

Humans

• Children with parvovirus experience fevers and an upset stomach.Jupiterimages/Polka Dot/Getty Images
  
  Parvovirus in humans is not related to the parvo that cats or dogs contract. Parvovirus is also known as fifth disease and its symptoms are typically mild. Symptoms of parvovirus in children include fever, sore throat, upset stomach, fatigue, itching and headache. Children with parvovirus often develop a distinct rash on their cheeks and face near the end of the illness. The rash is bright red or pink and lacy and may come and go for several weeks after the infection passes. Adults who contract parvovirus often experience joint pain but do not necessarily have the distinctive rash.
  
  

General Cautions

• Parvovirus is common in dogs, cats and humans, but it has different causes in each case. In the case of cats and dogs, parvovirus is spread through contact with infected feces or bodily fluids. Vaccines for parvovirus are available for both cats and dogs but not for humans. In most cases, once a person or animal has contracted and recovered from parvovirus they are immune from contracting it again.