Gastroenteritis is an inflammation of the mucosa in both the stomach and in parts of the small intestines.
The dominant symptoms of gastroenteritis are diarrhea and vomiting. Symptoms may appear spontaneously or after eating. The vomit consists of previously eaten food, or is foamy and yellow. Stool becomes soft or even watery and can contain traces of blood. Affected dogs do not necessarily appear clinically ill, and usually have a normal, healthy appetite. Only in very severe cases do animals become feverish and lethargic. Many cases of gastroenteritis are short-lived and symptoms regress by themselves after a few days. Yet, if left untreated, the condition may become chronic, and symptoms can persist for weeks or even months in the form of ailments such as chronic inflammatory bowel disease.
Smaller episodes of sickness and diarrhea are common in dogs, and are often the result of having ingested spoiled foods or water. Symptoms of gastroenteritis are hard to distinguish from more serious conditions, such as intoxication with a poisonous substance. If vomiting and diarrhea persist for more than two days and/or occur repeatedly in a 24-hour time span, a clinical condition is probably present. Bacterial and viral infections, as well as parasites, are common causes of diarrhea. In rare cases, acute vomiting and diarrhea mark the beginning of intolerance towards certain food ingredients that upset the digestive tract and cause inflammation.
Thorough examination plus clinical history can lead to a possible diagnosis of bowel disease. Treatment is mainly aimed at reducing symptoms. Drugs that stop vomiting and relax the bowels can provide relief. If a bacterial infection is suspected, treatment with antibiotics is usually effective. In viral infections they merely attempt to protect against super infections by other intestinal bacteria while having no direct effect on the virus itself. Viruses reproduce in the host's tissue - in this case the intestinal mucosa. As the intestinal mucosa reproduces itself fully within 5-7 days, viral infections are normally short lived. If fluid loss is high after heavy vomiting and diarrhea, the animal is in danger of becoming dehydrated. In this case, hospitalization and stabilization with intravenous fluids is necessary.
If symptoms are mild and the dog does not appear clinically ill, he may undergo a dietary fast for 24 hours (but NOT LONGER!) in order to settle the stomach and bowels. A fast can also limit further irritation of the inflamed mucosa. WARNING: Water has to be available at all times! You can add some salt and sugar, and sprinkle it over lukewarm water, which will be given to your dog. By adding these minerals, you can help to replace electrolytes and add some extra calories. On the second day, a mild diet of boiled chicken or turkey with soft-boiled rice should be fed. Divide the normal daily ration into 4-6 smaller portions and offer them through the course of the day. If symptoms do not improve within 2-3 days you should consult your vet immediately. As the frequency of vomiting and diarrhea is gradually reduced, you can gradually return the dog to its usual diet. A larger portion of the chicken/rice diet should be replaced with normal dog food until the normal diet is restored. This process takes appx. 1 week.