Gastro-enteritis means inflammation of the stomach and intestines. We see cases where the stomach alone is involved (gastritis), where the intestines alone are involved (enteritis) and where both the stomach and intestines are involved (gastro-enteritis).
This syndrome can have a number of possible causes. The majority of cases are caused by viruses. Other possible causes include bacteria, irritant substances that the animal has eaten, for example rotten food, and malfunctions of the animal’s immune system.
The most obvious signs of this syndrome are vomiting and diarrhoea. In some cases the lining of the intestine is destroyed and the diarrhoea is bloody. This is commonly, but incorrectly, referred to as cat-flu in dogs.
Gastro-enteritis is particularly dangerous in young and very old animals.
The most common complication of gastro-enteritis is dehydration. The animal may drink water, but vomits before the fluid can be absorbed into the body. Fluid is drawn out of the body into the intestines, due to the diarrhoea.
Another complication in viral gastro-enteritis is that, as the animal’s immune system destroys the virus, the virus releases toxins that cause the animal to go into circulatory collapse (technically known as shock).
The most important part of treatment for gastro-enteritis is to prevent or correct dehydration and circulatory collapse. In mild cases a drug to control vomiting may be all that is necessary. In more severe cases the animal has to be put on an intra-venous drip until it is re-hydrated and able to drink water without vomiting. These animals obviously need to be hospitalized, as the drip has to be continuously monitored to ensure that it keeps flowing, and does not flow too fast or too slowly. If the animal moves around too much, the drip may be pulled from the vein and has to be replaced, and it is for this reason that we do not encourage owners to visit animals that are on a drip.
These animals are also given antibiotics and drugs to control vomiting. Once able to eat and drink, they are given electrolytes in their drinking water and fed a special diet that is non-irritant to the healing stomach and intestines.
It is important to note that antibiotics are effective against bacteria, but not against viruses. Animals with viral gastro-enteritis are given antibiotics to prevent bacteria from causing complications in the tissue that is damaged by the viruses, but it is up to the animal’s immune system to recognize and destroy the virus and end the disease. It is thus very difficult for us to give an indication of how long it will take for the animal to recover.
Gastro-enteritis is a serious and potentially fatal syndrome. A bad case of gastro-enteritis in an animal is similar to Cholera in a human.