P‐46 
A placebo‐controlled, double‐blinded study of recombinant IFNγ in dogs with atopic dermatitis

Abstract

Skin physiology in cats has received little attention. The aim of this study was to evaluate the long-term influence of sex, time and the level of dietary fat and energy on the dynamics and qualities of the hair coat. Twenty-four European short-haired laboratory cats were followed over a 1-year period. They were divided into eight groups of three, according to: sex (12 males and 12 females), sexual status (intact or neutered) and diets [(high energy 4300 kcal/kg as fed, 21% fat) vs. (moderate energy 3500 kcal/kg as fed, 10% fat)]. Both diets were fed for 6 months to all cats following a cross-over design. The following parameters were evaluated throughout the study: thickness of hair coat and hair lengths (neck, rump, lateral, flank), hair regrowth (after periodic clippings of 25 cm 2 areas), and telogen/anagen ratio. The thickness of the hair coat initially varied from 1.2-1.7 cm on the neck, 1-1.4 cm on the rump, 1.8-2.5 cm on the flank, and hair shaft lengths were 1.7-2.5, 3.7-3.9 and 2.5-3.2 cm, respectively. Comparison of values revealed few statistical differences: increase of the thickness of hair coat in neutered cats (male and female) during the study, and increase of the length of lateral hairs in all groups during the study. Over all periods and in all groups, the curve of growth was similar (rapid then slower). Some transient variations were attributed to temporary changes in ambient conditions. In conclusion, neither sex, nutrition or season (in housed cats) influenced the general quality of hair coat, in particular hair regrowth. Funding: Royal Canin. P-2Evaluation of the influence of sex, diet and time on skin pH and surface lipids of cats P. BOURDEAU, K. W. TAYLOR, P. NGUYEN and V. BIOURGE National Veterinary School of Nantes, Nantes, France; Royal Canin, Aimargues, France Skin lipids and pH are two factors classically considered of importance in homeostatic characteristics of skin. Skin physiology in cats has received little attention. The aim of this study was to evaluate the long-term influence of sex, sexual status, season, and dietary fat and energy on these parameters. Twenty-four European short-haired laboratory cats, 14 months of age, were followed over a 1-year period. They were divided into 8 groups of three, according to: sex (12 males and 12 females), sexual status (intact or neutered) and diets [(high energy 4300 kcal/kg as fed, 21% fat) vs. (moderate energy 3500 kcal/kg as fed, 10% fat)]. Both diets were fed to all cats for 6 months following a cross-over design. Parameters regularly evaluated were skin pH and hair total lipid content (extraction from samples of 0.6-1.2 g of clipped hairs). The pH of the skin varied from 6.6-6.8 initially to 7.2-7.4 at the end of the study. This increase was significant only in intact animals (male and female). The dietary changes did not affect skin pH. Hair total lipid content was not affected by sex or the diets but slightly increased in all groups over the study period from 1.5-2.4 to 2.4-3.3%. In conclusion, skin pH appeared to be potentially m...

The use of recombinant omega interferon therapy in canine atopic dermatitis: a double‐blind controlled study

“…This corresponded with treatment induction periods (repeated rfeIFN‐ω injections at reduced intervals from 3 days to 4 weeks or daily use of cyclosporin over the first 2 months of the trial). Our results with rfeIFN‐ω are in agreement with marked improvement of clinical signs recorded in studies with IFN‐γ 4,5 . In the randomized comparative study with IFN‐γ, 6 efficacy rates of 72% for pruritus and 61–74% for lesions (excoriation, erythema and alopecia) were recorded on day 28, significantly higher than in the antihistamine group.…”

“…Only glucocorticoids and cyclosporin have demonstrated strong efficacy 16,17 . However, three Japanese studies on IFN‐γ have shown good results: an open study in 10 dogs, 4 a double‐blind placebo‐controlled study in 100 dogs 5 and a randomized comparative study (using a topical antihistamine as control) in 92 dogs 6 . Our previous pilot, open uncontrolled study 11 suggested that rfeIFN‐ω could be considered as a candidate drug for the control of CAD.…”

“…In Iwasaki and Hasegawa’s study, 6 a simplified CADESI was used, and included pruritus. The two earlier studies on IFN‐γ investigated erythema, lichenification and alopecia 4,5 plus pruritus in one of them 4 . Comparisons of clinical results are thus difficult to make between studies.…”

“…immunomodulation by drugs) has been considered as a good therapeutic approach for this chronic disease. In particular, cyclosporin was demonstrated as effective 3 and studies on interferon‐gamma (IFN‐γ) have shown promising results 4–6 …”

“…The mechanism by which IFNs reduce skin inflammation has not been clearly elucidated. Atopic humans exhibit increased levels of IL4 and low levels of IFN‐γ 5 . IFN efficacy in CAD may be explained by a regulatory effect on the imbalance between Th1 and Th2 cytokine levels that has been demonstrated in atopic dogs, which show high levels of IL4 expression at lesion sites and low IFN‐γ expression in peripheral mononuclear blood cells and skin lesions 6 .…”