Allergic conjunctivitis and conjunctival provocation tests in atopic dogs

Abstract

Introduction Canine atopic dermatitis (cAD) is a very common disease, but little is known about eye involvement. The conjunctival provocation test (CPT) is used in human to study the ocular response to allergenic stimuli and to evaluate anti-allergic therapy. To our knowledge it has not been used in dogs. Objectives To evaluate the prevalence of ocular signs in a population of atopic dogs and relate these with clinical cAD scores; and the usefulness of CPT for dust mites in atopic dogs with itchy eyes. Procedures Sixty cAD patients were evaluated for (i) ocular signs of allergic conjunctivitis including conjunctival hyperemia, chemosis, epiphora, ocular discharge, pruritus and corneal involvement, graded 0 to 3 according to severity, and (2) cAD Extent and Severity Index (CADESI-03). Additionally, CPTs for Dermatophagoides farinae (n = 12) and Dermatophagoides pteronyssinus (n = 12) were performed in sensitized atopic dogs and 24 control dogs. Results Periocular and ocular signs of allergy were present in 60% (36/60) of cases. Conjunctival hyperemia (90%) was the most common sign. Severity of ocular signs was significantly correlated with eye pruritus (r s = 0.690, P = <0.001) and skin lesions score for head region (r s = 0.261, P = 0.04). A highly significant difference (P < 0.001, Fisher test) was found in CPTs between the test and the control groups. Conclusion Allergic conjunctivitis signs associated with cAD seem under valuated so these patients would benefit from an ophthalmologic evaluation. Furthermore, we found CPT to be a reliable, easy to perform and safe test for the etiologic diagnosis of allergic conjunctivitis in the dog.

Comparison of demographic data, disease severity and response to treatment, between dogs with atopic dermatitis and atopic‐like dermatitis: a retrospective study

“…26 In another study, the frequency of allergic conjunctivitis in atopic dogs was 60%, suggesting that conjunctivitis could in fact be underdiagnosed in this disease. 27 Studies evaluating breed predisposition to AD show marked regional variations, [28][29][30][31][32][33][34] yet the Labrador retriever has been frequently reported in various studies from different locations, 28,[32][33][34] so our results are in accordance with previous studies. The other overrepresented breeds in our study were the soft-coated wheaten terrier, English bulldog and American Staffordshire terrier.…”

“…Conjunctivitis was observed in 18.6% of all enrolled dogs and similar results have been reported elsewhere . In another study, the frequency of allergic conjunctivitis in atopic dogs was 60%, suggesting that conjunctivitis could in fact be underdiagnosed in this disease …”

Review: Clinical and histological manifestations of canine atopic dermatitis

“…Concurrent signs of conjunctivitis were reported in 21–30% of dogs with AD, while rhinitis was recorded in ~7% of included dogs . This prevalence of atopic conjunctivitis was lower than previously reported, and it was also lower than that reported in an ophthalmology study . The latter investigators detected ~60% prevalence of an allergic conjunctivitis in dogs with AD .…”

Prevalence of Disorders Recorded in Dogs Attending Primary-Care Veterinary Practices in England

“…The most prevalent disorders identified in dogs within the current study were complex disorders that have multiple interacting environmental and genetic casual factors [90]: otitis externa [91], periodontal disease [92], anal sac disorders [93], nail disorders [94], [95], degenerative joint disease [96], diarrhoea [97], [98], obesity [99], traumatic injury [100], conjunctivitis [101], vomiting [101], [102] and heart murmur [103], [104]. It may be useful for canine health research to move away from viewing individual disorders as necessarily either inherited or non-inherited [105] and towards an acknowledgement of relevant roles for both genetic and environmental components in the majority of canine disorders [106], [107], [108].…”