Clinical efficacy of sublingual allergen‐specific immunotherapy in 22 cats with atopic dermatitis

BACKGROUND: Sublingual immunotherapy (SLIT) has been deployed in humans and dogs; to the best of the authors’ knowledge, there are no published studies about the use of SLIT in cats. OBJECTIVES: Evaluate the clinical efficacy of SLIT in atopic cats sensitized to dust and storage mites, assessing immunological changes associated with SLIT treatment. ANIMALS: Twenty‐two client‐owned cats with clinical signs compatible with feline atopic dermatitis (fAD) and serum allergen‐specific immunoglobulin (Ig)E against house dust and storage mites. METHODS AND MATERIALS: Prospective, multicentre, open‐label clinical trial. Individualized mite‐specific SLIT was administered orally for 12 months. All cats underwent clinical examination to record SCORing feline allergic dermatitis (SCORFAD), pruritus Visual Analog Scale (pVAS) and serum allergen‐specific IgE and IgG, every three months for 12 months. RESULTS: Sixteen of 22 cats (73%) completed the study and three of six cats withdrawn from the study were included in an intention‐to‐treat analysis. SCORFAD and pVAS values decreased significantly from baseline (T0) to the third month of treatment (P = 0.0004 and P = 0.0013, respectively), with median total values ranging from 19 (6–44) (T0) to 2.5 (0–17) (T12) (P = 0.0001), and from 8 (6–10) (T0) to 2.3 (0–8) (T12) (P = 0.0001), respectively. Allergen‐specific IgE values decreased significantly from the ninth month (T9) of treatment (P = 0.0032), with median scores decreasing from 56 (12–729) (T0) to 34 (0–158) (T12) (P = 0.0208). No significant differences in allergen‐specific IgG values were observed throughout the study. No adverse effects related to the use of SLIT were reported. CONCLUSIONS AND CLINICAL IMPORTANCE: Sublingual immunotherapy should be considered a rapid, effective, safe and well‐tolerated treatment in cats with feline atopic dermatitis fAD.