Just like humans, dogs can contract a number of viruses that infect the stomach or intestines. While dogs often overcome many of these viruses on their own, some viruses are deadly. Accordingly, you should consult your veterinarian anytime your dog exhibits vomiting or diarrhea that lasts more than a day or two.
Vomiting, which is a different symptom than regurgitation, is one of the most common symptoms of stomach or intestinal viruses in dogs. Whereas vomiting is the forceful expulsion of digested food from the intestines, regurgitation is the passive expulsion of undigested food. Dogs often vomit because they have simply eaten something that disagrees with them, but it can also indicate viruses, such as parvovirus.
A number of serious viruses can cause diarrhea in dogs. Distemper, for example, can cause vomiting and diarrhea, although the first symptoms are usually high fever, red eyes and a runny nose. Another dangerous virus is parvovirus, which causes bloody diarrhea and severe vomiting, both of which contribute to rapid dehydration in afflicted dogs. Vaccines are available that prevent dogs from acquiring both distemper and parvovirus, so be sure your dog has been properly vaccinated. In addition to these serious illnesses, several other less serious viruses can cause diarrhea, such as coronavirus and rotavirus -- the most common cause of intestinal upset.
Bloating and Stomach Pain
Dogs with stomach viruses may suffer from bloating and abdominal pain. Dogs who adopt the "praying" position -- with their head down and hind parts elevated -- may be suffering from abdominal pain. It is important to see your veterinarian if your dog exhibits signs of severe bloating -- particularly if it appears suddenly -- as it can signal a life-threatening problem, in which your dog's stomach twists along its axis.
While many intestinal viruses only cause relatively minor illness and usually resolve in short order, some viruses are deadly if not treated promptly. For example, canine circovirus -- a disease whose primary symptoms are intestinal disturbances -- can be fatal to dogs, as it causes internal bleeding. Additionally, parvovirus, distemper virus and several other viruses that infect the stomach or intestinal tract of dogs can be fatal.
At the Vet: What to Expect
Your veterinarian usually will treat your dog by administering fluids and electrolytes. Additionally, he will examine your dog and take samples to perform diagnostic tests to determine the cause of the illness. Upon arriving at a diagnosis, the vet may prescribe additional medications to treat the virus, or simply provide further supportive care, until your dog's immune system fights off the illness.