Parvo, officially known as canine parvovirus or CPV, can be a pet parent’s worst nightmare. One day, your puppy is full of life, thriving and playing. Just a few days later, he’s lying on his bed, too sick to move.

Parvo moves quickly and can be fatal, especially in puppies and unvaccinated dogs. Early detection and treatment can make all the difference, so it’s important for pet owners to know the warning signs of parvo.

So how do you know if your dog has parvo?

One of the first symptoms of parvo will often be lethargy and a lack of appetite. Most dogs with parvo will also begin vomiting and having diarrhea. Vomit and feces will often contain blood and may appear red or dark brown like coffee grounds. As the disease progresses, your dog may be unable to keep any food or water down, leading to dehydration, weight loss, and weakness.

Parvo also often spreads from the gastrointestinal tract into other parts of your dog’s body. Parvo can affect the circulatory and respiratory systems, causing heart damage and bacterial pneumonia.

If you notice any of these symptoms in your dog, take him to the vet immediately. To confirm a parvo diagnosis, your vet will use a combination of physical examination and diagnostic testing. Common laboratory tests for parvo will test either feces or blood and include antigen tests, polymerase chain reaction (PCR) tests, and blood count evaluations.

To learn more about how parvo is treated and how you can help prevent your puppy from contracting parvo, read our Education page: What Is Canine Parvovirus, and How Do I Know If My Dog Has Parvo?