Clippers are superior to scissors in the collection of hair for chemical analysis in companion dogs: a Dog Aging Project preliminary study

Abstract

Objective: To identify the safest, most efficient method for hair sample collection from companion dogs among clippers, scissors, and razors and to validate obtained samples with cortisol concentration analysis.

Animals: 25 healthy, privately owned dogs.

Methods: 2 hair samples were collected from each dog's ischiatic region with different implements (scissors, razors, or clippers). The collecting clinician completed a Hair Collection Questionnaire (HCQ) for each sample that compared subjective sample quality, time of collection, restraint needed, and patient experience. Each sample was evaluated by cortisol enzyme immunoassay.

Results: Clippers had higher overall HCQ scores than scissors, and scissors had higher HCQ scores than razors. Collection was faster for clippers than scissors, and scissors were faster than razors. There were no differences in sample quality between scissors and clippers, and sample quality was lower with razors. There was no difference in restraint needed or patient experience. Collection of long hair had higher HCQ scores than collection of medium and short hair. Collection of hair from dogs with an undercoat had higher HCQ scores than collection of hair from dogs without an undercoat. Dog size had no effect on HCQ score. Hair cortisol concentration did not vary between scissors or clippers (P = .111). Hair color and age did not affect hair cortisol concentration (P = .966 and P = .676, respectively).

Clinical relevance: Clippers are recommended for hair sample collection from companion dogs. Scissors are an adequate alternative.

Keywords: clippers; cortisol; dog; hair collection; scissors.

Figure 1.

Hair sample usage and allocation for cortisol analysis and the average coefficient of variation (CV) from 25 companion dogs. Each hair sample (n=37) was subjected to cortisol extract to yield two extracts. Two hair samples only provided sufficient material for one extraction (n=37 and n=35 for extract one and two respectively). Each extract was split into two plates and tested with different dilution factors. Each plate was split into two wells for duplicate testing, therefore producing eight cortisol concentration results per sample. The average CV from each sample is listed across all levels of analysis (extracts, plates, and wells) for scissors, clippers, and scissors and clippers combined into the overall CV.

Figure 2.

Hair samples obtained from 25 companion dogs. Participants, pairwise tool comparison, subjective data and samples collected in the study of hair collection methods from companion dogs.

Figure 3.

Hair collection questionnaire for 25 companion dogs. Results are displayed for the time needed for hair collection (>120 sec=1, 30-120 sec=2, or <30 sec=3), restraint required during collection (substantial=1, moderate=2 or none/minimal=3), the overall subjective patient experience (substantial discomfort or anxiety=1, mild to moderate discomfort or anxiety=2, or minimal to no discomfort or anxiety=3) and the quality of sample produced (no sample obtained=0, poor=1, or good=3).