Allergic conjunctivitis and conjunctival provocation tests in atopic dogs

Area of Science:

• Veterinary Ophthalmology
• Canine Dermatology
• Allergology

Background:

• Canine atopic dermatitis (cAD) is prevalent, yet ocular manifestations are understudied.
• The conjunctival provocation test (CPT), used in humans, has not been previously applied to dogs for allergy assessment.
• Understanding eye involvement in cAD is crucial for comprehensive patient care.

Purpose of the Study:

• To determine the frequency of ocular signs in atopic dogs and correlate them with cAD severity.
• To assess the utility of the conjunctival provocation test (CPT) for diagnosing dust mite allergies in dogs with itchy eyes.
• To investigate the relationship between ocular signs and clinical cAD scores.

Main Methods:

• Sixty cAD patients were evaluated for ocular signs (hyperemia, chemosis, discharge, pruritus, corneal issues) and skin lesions (CADESI-03).
• Conjunctival provocation tests (CPTs) for Dermatophagoides mites were conducted on 24 sensitized dogs and 24 controls.
• Ocular signs were graded for severity, and correlations with clinical scores were analyzed.

Main Results:

• Ocular allergy signs were present in 60% of cAD dogs, with conjunctival hyperemia being the most frequent (90%).
• Severity of ocular signs strongly correlated with eye pruritus and head region skin lesions.
• CPTs showed a highly significant difference between atopic dogs and controls, indicating test reliability.

Conclusions:

• Allergic conjunctivitis signs are likely underestimated in cAD cases and warrant ophthalmologic evaluation.
• The conjunctival provocation test (CPT) is a reliable, safe, and easily performed method for diagnosing allergic conjunctivitis in dogs.
• Integrating ophthalmologic assessment can improve the management of canine atopic dermatitis.