Fel d1 and Fel d4 Fur, Urine and Saliva Levels in Domestic Cats

Abstract

Introduction: Sensitization to cat dander is associated with an increased risk of asthma and rhinitis. The majority of patients with cat allergy have IgE to Fel d1 but recent reports indicate that some react to Fel d4. There is little information about Fel d4 levels in cats. Objectives: The purpose of this study was to evaluate Fel d4 in fur, saliva and urine of cats in comparison with Fel d1. Methods: Cats coming for general surgical procedures at a local animal hospital were recruited for this study. Owners volunteered their cats and signed an informed consent prior to any sample collection. Fur, urine and saliva samples were obtained from male and female cats of various breeds and ages. Commercially available ELISA kits were used to measure Fel d1 and Fel d4. Results: The study included 26 cats, 13 male, 13 female, age 5.6 ± 4.3 years (mean ± SD). Fur was obtained from all cats; urine and saliva from 20 and 17 cats, respectively. Urine Fel d1 (0.02, 0.065-0.071 ug/ml, median, 25-75 percentile) and Fel d4 ( Conclusions: This study demonstrates that, in cats, saliva is the main source of Fel d4 while fur is the main source for Fel d1. It is possible that levels of Fel d4 in fur arise from saliva deposited when grooming rather than from secretion from the sebaceous glands.