Nutritional management of small intestinal disease in dogs

Irrespective of the underlying cause, most small intestinal disorders are associated with some degree of malassimilation (maldigestion and/or malabsorption). It is this malassimilation that results in undigested/unabsorbed nutrients within the GI lumen that osmotically attract water and contribute substantially to diarrhoea.

Unabsorbed nutrients can also serve as a substrate for undesirable bacterial growth. Bacterial metabolites stimulate increased GI secretory activity and also contribute to the osmotic diarrhoea. Bacterial fermentation of undigested fats also results in production of hydroxy fatty acids that contribute to fluid retention in the GI lumen, and also result in abnormal intestinal motility.

Fat digestion and absorption is frequently impaired in small intestinal disease:

• Typically 90% of dietary fats are long chain triglycerides (LCTs) whose digestion and absorption is complex.
• Digestion of LCTs involves eight steps and requires both bile acids and pancreatic lipase.
• Fat absorption occurs predominantly via the epithelial cells at the tip of the villi, which are the cells most susceptible to mucosal injury.

Restriction of dietary fat levels in dogs with GI disease can therefore have several benefits such as:

• Avoiding delayed gastric emptying, which could promote vomiting.
• Improved caloric intake by avoiding fat malassimilation.
• Limiting the quantity of malabsorbed fats being fermented to hydroxylated fatty acids.
• Limiting fat malabsorption associated with IBD, EPI, lymphangectasia, etc.

However, restriction of fat intake alone may not be sufficient to manage enteropathies. It is vital that other dietary ingredients are highly and easily digestible. Also, restricting fat may result in higher levels of carbohydrates which, if not fully digested, may also contribute to osmotic diarrhoea and increased bacterial activity.

Dietary management is extremely important in dogs with colitis, and may be used alone or along with appropriate drug therapy where indicated. Dietary therapy should provide a highly digestible diet with fat restriction – this is likely to be beneficial in most cases, and reduces colonic irritation as a result of poorly digested nutrients.

Beyond these recommendations, in colitis a diet containing a combination of both soluble and insoluble fibres is highly beneficial:

• Insoluble fibres modify intestinal motility and transit times. These help motility in the colon by stimulation of both segmental and peristaltic contractions;
• Soluble fibres are fermented with the production of short chain fatty acids (SCFAs) that are preferentially used by colonocytes, and improve both the structure and function of the colon;
• Bacterial fermentation of soluble fibre may also modify the flora in the colon, and help suppress the growth of pathogens such as Clostridia spp that can contribute to colitis.

Key factors provided by Canine EN in the management of enteropathies include:

• A strictly limited LCT concentration in the diet, minimising the risk of fat malassimilation.
• The low LCT concentration also makes Canine EN excellent for management of EPI and hepatic diseases associated with reduced bile acid production.
• Addition of moderate levels of medium chain triglycerides (MCTs) which require only three steps for digestion.
• MCTs can be efficiently utilised even when hepatic, pancreatic or intestinal function is compromised. This not only provides a readily absorbed source of fats, but also avoids an over-reliance on increased carbohydrates in the diet.
• All components of Canine EN are highly digestible and have a high palatability - essential for managing small intestinal disease.
• Added long chain omega-3 fatty acids help to reduce undesirable inflammatory responses.

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