Atopy/Sensitive
Efficacy
Food hypersensitivity
Chopping proteins into smaller peptide fragments decreases their antigenicity.
This principle extends to dogs with food hypersensitivity. Dogs with hypersensitivity
towards soy protein developed pruritis upon ingesting the intact protein, but
did not do so with hydrolysed soy protein (Jackson et al., 2003; Puigdemont et
al., 2006).
Commercial hypoallergenic diets containing either hydrolysed chicken protein
and corn starch (Loeffler et al., 2004; 2006) or hydrolysed soy protein and rice
(Biourge et al., 2004) have been used as elimination diet. So far elimination diets
with hydrolysed and parent proteins have not been compared directly, but based
on data for elimination diets with intact (Chesney, 2002; Tapp et al., 2002) and
hydrolysed proteins (Loeffler et al., 2004; 2006; Biourge et al., 2004), it could be
suggested that hypoallergenic diets with hydrolysed proteins are more effective
than those with intact proteins in the management of food hypersensitivity (Cave,
2006; Verlinden et al.,2006).
Atopy
Atopy and food hypersensitivity often go hand in hand and have similar clinical
signs (Biourge et al., 2004; Chesney, 2002), but skin disorders caused by inhaled
allergens will not react to hypoallergenic protein sources. The treatment of atopic
dermatitis involves the suppression of chronic inflammatory reactions in the skin.
Eicosanoids formed from di-homo-gamma linolenic acid and from eicosapentaenoic
acid (EPA) have an anti-inflammatory properties.
Double blind, placebo-controlled experiments in dogs with atopic dermatitis have
shown that supplements of both borage oil, which is rich in gamma-linolenic acid
(GLA) and fish oil, which is rich in EPA, lower the severity of pruritis, erythema and
self-trauma (Logas and Kunkle, 1994; Harvey, 1999). Good results have been obtained with a diet rich in both fish oil and borage oil. The dry diet contained about
0.5% borage oil and 5% fish oil. The efficacy of the diet was tested in four clinics
using a double blind, placebo-controlled design (Baddaky-Taugbøl et al., 2005).
After 10 weeks on the diet, the scores for pruritis and erythema had decreased to
about half, while the control treatment had no influence. According to the owners
the diet had improved skin condition in 60 % of the dogs. Clearly, a substantial
number of the patients with atopic dermatitis will improve after feeding a diet
enriched with suitable amounts of fish oil and borage oil. However, there will be
great differences in individual responsiveness.
Colitis
In dogs with idiopathic chronic colitis or inflammatory bowel disease, the feeding
of a hypoallergenic diet based on a hydrolysed protein source caused a significant
decrease in clinical signs (Nelson et al., 1988; Marks et al., 2002; Cave, 2006;
Münster et al., 2006). Ingestion of fish oil may be expected to further improve the
clinical condition through its anti-inflammatory activity. In humans with ulcerative
colitis such a positive effect has been demonstrated (Aslan et al., 1992).