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Diarrhea has four general reasons for occurring: osmotic imbalances, over secretion, intestinal exudation or motility disorders. Osmotic imbalances occur when the concentration of food molecules in the intestine is too high. Water is drawn into the intestine by the excess molecules, causing diarrhea. Over secretion occurs when the intestine secretes too much fluid after being exposed to bacteria or toxins. Intestinal exudation describes a slow oozing of blood fluids through ulcers or other breaks in the intestine’s tissue layers. This exudation can be mild or very severe.
Motility disorders refer to how active the intestine is and its capability of moving contents through. An intestine that is under functioning in its ability to muscularly contract and push the contents out of the canal is most common; this condition is referred to as peristalsis. Conversely, motility can be increased as well, so that the intestine contracts too quickly and fluid which normally is absorbed is lost into the feces. Sometimes diarrhea can be from a combination of these causes. Intestinal infections can also cause the intestine to over secrete. They also tend to change the motility of the intestine.
Your veterinarian will perform a complete physical exam on your dog. You will need to give a thorough history of your dog’s health, including a background history of symptoms, and possible incidents that might have precipitated this condition. A blood chemical profile, a complete blood count, an electrolyte panel and a urinalysis will be performed so as to rule out other causes of disease. X-rays can help to rule out the possibility that your dog swallowed inappropriate items, which may be blocking or irritating the intestine.
Blood tests can be performed to rule out an inflamed pancreas, or a pancreas that is not producing enough digestive enzymes. Blood tests can also be used to check levels of cobalamin and folate (vitamins) as these are normally absorbed in the intestine.
Laboratory tests can be performed on fecal samples to check for Giardia, Parvovirus and Cryptococcus infections. A smear of feces should be checked for parasite eggs as well. Your veterinarian may perform an endoscopy to take a sample of your dog’s intestine for histopathologic examination at the laboratory.
Contraction of the smooth muscles
An in-depth examination of the properties of urine; used to determine the presence or absence of illness
A gland that aids in both digestive and insulin functions
Something that has to do with changes in the structure of the body as the result of cells that are diseased or abnormal in some way
The whole system involved in digestion from mouth to anus
A medical condition in which the body has lost fluid or water in excessive amounts
A type of slime that is made up of certain salts, cells, or leukocytes