Stanley L. Marks – Dipl ACVIM (Internal Medicine, Oncology), Dipl ACVN, California, USA
Summary taken from the 59th International Congress SCIVAC (2008) – by the Scientific Director of NBF-Lanes
During the 59th Congress A.N.M.V.I., famous international speakers stressed the importance of diet in the treatment of intestinal disorders.
INTRODUCTION
The therapeutic approach, in most of the gastro enteric pathologies, involves the joint use of pharmacologists and nutritional treatments.
However, limitations or a change in the diet of the individual subject is the most important factor in the treatment of gastrointestinal disorders.
Despite the importance of these recommendations, there is still a lack of information about the nutritional needs for dogs and cats suffering from gastrointestinal disorders.
CHRONIC DISEASES OF SMALL INTESTINE
The dietary changes are essential for the treatment of most patients with chronic pathology of the small intestine. Dogs with diarrhea and diseases of the small intestine should receive a highly digestible diet, moderately fat-free, lactose-free, gluten-free and hypoallergenic. Regarding the fibers, their gelling properties and ligands may be useful in some pathologies of the small intestine.
Lipids in the Diet
The presence of fat slows gastric emptying; diets with limited lipid content are better tolerated in the majority of gastrointestinal conditions. The assimilation of fats is an elaborate process and not absorbed fatty acids are hydroxylated by the bacteria of the bowel of the colon. These hydroxyl acids stimulate water secretion of the colon and worsen diarrhea resulting in the loss of fluids.
Lactose and gluten
Frequently, the intestinal pathologies destroy or decrease the total intestinal villi and related enzymatic activities; in particular that of lactase which is the most superficial enzyme; therefore, the milk or other substances containing lactose should be avoided by patients with intestinal disease.
The inability to digest lactose involves the degradation of this sugar into volatile fatty acids which, in turn cause a type of osmotic diarrhea.
As regards the gluten, this protein is a component of wheat, oats, barley and rye: a valid reason to eliminate all these foods from the diet of patients with inflammatory bowel diseases (IBD inflammatory bowel disease) and diarrhea due to intolerance to gluten.
Protein in the Diet
Adverse reactions to industrial food are common in dogs and cats with chronic gastrointestinal diseases, and often managed to be successfully treated by administering selected proteins. As the determinants unhygienic proteins are referred to as the triggers, it is recommended to administer an elimination diet:
- free of additives and preservatives
- mono-protein, but with proteins of innovative sources
- highly digestible hypoallergenic or formulated in a way.
Since there are not totally hypoallergenic protein sources, the protein component must be highly digestible, as intact proteins are much more unhygienic respect to polypeptides and amino acids.
INFLAMMATORY BOWEL DISEASES (IBD)
Inflammatory bowel diseases (Inflammatory Bowel Diseases – IBD) are the main causes of vomiting and “chronic” diarrhea in dogs, and are attributable to a group of gastrointestinal disorders:
- idiopathic
- with chronically
- characterized by a ‘infiltration of their work to the lamina of lymphocytes, plasma cells, eosinophils, macrophages, neutrophils, or a set of these cells.
The diagnosis of IBD requires the gradual exclusion of all potential causes of gastrointestinal inflammation, including intestinal parasites, bacterial pollution of the small intestine, bacterial enterocolitis, intolerance or food allergies and cancer. An “oversight” in the process of eliminating known causes of gastrointestinal inflammation (able to simulate the IBD) can lead to poor animal’s response to dietary treatment and / or medication, creating the conditions for a frustrating condition for both the owner and the Vet.
From clinical observations, carried out in animal models, there was a significant responsibility of normal intraluminal bacteria (or their metabolites) as causative agents in canine IBD.
The clinical response to hypoallergenic diets or exclusion suggests that dietary factors may influence the pathogenesis of IBD in dogs. The “hypoallergenic” definition refers to those foods that, generally free of additives and preservatives, containing hydrolyzed protein sources.
The food concept of “protein source expendable” in the initial phase of therapy is still under development; according to this protocol, the first innovative protein that is offered to the animal takes the name of “expendable” protein: this protein source, being placed in contact with a more permeable intestinal mucosa abnormally, it runs the risk that the patient develops an allergy against him. The expendable protein is administered for about six weeks, after which it is replaced with a second innovative protein, with real curative intent.
CHRONIC DISEASES OF THE COLON
The dietary recommendations for treating diarrhea, being diseases of the large intestine are still cause for debate. The response to diet therapy can vary dramatically from one patient to another:
- some animals show an improvement when treated with low-residue diets and elimination
- other subjects show positive signs due to the ingestion of very digestible foods containing soluble or insoluble fibers
Protein in the Diet
It is recognized that some forms of colitis are associated with a food sensitivity, in comparable manner to the case for the small intestine: proteins, lipoproteins, glycoproteins, lipopolysaccharides and carbohydrates are able to induce an immune or inflammatory response.
For patients suffering from colitis can hypothesize improvements through the reduction of the digestive stress, minimizing the antigens that reach the colon, or reducing the possibility of an immune reaction.
Several studies in the Veterinarian field suggested that some patients may benefit from the administration of innovative and highly digestible protein sources. However, in the treatment of diarrhea of the large intestine, also the administration of commercial diets high digestibility, without recourse to innovative sources of protein, has shown the same beneficial effects.
A recent study has been devoted to identify the prevalence of adverse reactions to food in cats with chronic gastrointestinal problems: The most common allergens are beef, wheat and gluten.
Cats with diarrhea of the large intestine, much more common than the one from the small intestine, have considerable lost weight. The most important clinical signs in this hypersensitivity to food are gastrointestinal problems and skin manifestations.
These observations suggest that, also in cats, administration of proteins based on selected diets is an important element in the treatment of chronic idiopathic gastrointestinal disorders.
Fiber in the Diet
Frequently, for the treatment of chronic colitis, are recommended diets with high content of soluble, insoluble or mixed fibers.
Sometimes soluble fibers (fermentable) are preferred to insoluble ones (un-fermentable) as the first generate butyrate, the main source of energy for colonocytes. Together with the butyrate are produced also to short chain fatty acids which, by lowering the pH intraluminal colon, prevent the growth of pathogenic bacteria.
To this group of substances belongs fruit oligosaccharides (FOS), carbohydrates that are resistant to enzymatic digestion of the gastrointestinal tract and are metabolized by bacteria that colonize the distal small intestine and the large intestine. The addition of FOS to the feline diets, at a rate of 0.75% (dry weight) does not change the duodenal flora but increases the number of lactobacilli and reduces that of E. coli in fecal bacterial flora.
Polyunsaturated fatty acids
The modifications of the ratio of polyunsaturated fatty acids (polyunsaturated fatty acids – PUFA) omega-6 / omega-3 are able to reduce the inflammatory response in human patients suffering from ulcerative colitis and Crohn’s disease. The n-3 fatty acid enriched diets determine the incorporation of the same in biological membranes, thus decreasing the concentration of pro-inflammatory n-6 fatty acids as arachidonic acid (20: 4, n-6).
In the therapy of ulcerative colitis, immune modulation of extracts nutritional precursors from fish oil (n-3) fatty acids, such as eicosapentaenoic acid (EPA-C 20: 5, n-3) and docosahexaenoic acid (DHA – C 22: 6 n-3) gave positive results through a reduction of 35% – 50% of the production of inflammatory leukotrienes (LTB 4) the neutrophils.
From these studies (Hawthorne AB, T. Edwards, Filopowicz B et al., Gut A738; Scheurlen M, W Dais, Steinhilber D et al., Scand J. Gastroenterol Suppl. 158, 100-101) has reported a significant improvement in the symptomatology and histological characteristics of the rectal mucosa, in patients with Crohn’s disease and ulcerative colitis, to which the daily dose of 3-4 grams of fish oil for a period had been administered between 2 and 6 months.
It is worth to underline that the anti-inflammatory action of fish oil, in addition to the inhibition of LTB4 includes the suppression of IL-1 and the synthesis of PAF (Platelet Activating Factor – platelet activating factor).
At the present time, in the Veterinarian field, has already been established that dogs fed with fatty acids in the ratio n-6 / n-3 optimal (between 5: 1 and 10: 1) exhibit reduced LTB4 concentrations in plasma and neutrophils, as well as in the skin (DM Vaughn, Reinhart GA, Swaim SF et al., Vet Derm 5: 163; Reinhart GA, Vaughn DM, Proceedings of the 13th ACVIM Forum, Lake Buena Vista, FL, 466-469).
Also confirmed in the Human Field!
Fish Oil Effectiveness in the Treatment of Crohn’s Disease
The administration of capsules containing fish oil is able to limit the frequency of relapses in patients with Crohn’s disease, in agreement with what reported by “The New England Journal of Medicine”. Some researchers, led by Dr. Andrea Belluzzi University of Bologna, conducted a double-blind clinical trial, placebo-controlled, which involved 78 patients suffering from Crohn’s disease and prone to relapses.
The daily dose of fish oil was 2.7 grams.Dr. Belluzzi reports that:
- only 28% of patients in the group treated with fish oil has relapsed, compared with 69% of patients enrolled in the control group
- after one year, 59% of patients treated with fish oil remained free of clinical manifestations, against 26% of those in the control group
The Italian team hypothesizes that the fish oil:
- is able to inhibit both the leukotriene (LTB4) and the thromboxane (TXA2) inflammatory, present in high quantities in inflamed intestine of patients with Crohn’s disease
- can inhibit the synthesis of Tumor Necrosis Factor (TNF) or interleukin-1beta
- induces hyperplasia of the enterocytes which, in turn, increases the surface of the mucosa and allows a greater absorption of food. N Engl J Med 334: 1557-160, 1599-1600
