Nellie Choi1, Heather D Edginton1, Craig E Griffin2, John C Angus1. 1. Animal Dermatology Clinic, 150 N San Gabriel Boulevard #400, Pasadena, CA, 91107, USA. 2. Animal Dermatology Clinic, 5610 Kearny Mesa Road, Suite B-1, San Diego, CA, 92111, USA.
Abstract
BACKGROUND: Canine otitis externa is a common disease. Cytological evaluation of otic exudate is a useful diagnostic test to direct and monitor treatment for otitis externa. One method of collecting ear cytological specimens utilizes a cotton-tipped swab inserted into the vertical ear canal. A proposed alternative method is to aspirate exudate from the deep horizontal canal using a rubber tube. HYPOTHESIS/ OBJECTIVES: To compare cytological findings between two different collection techniques by evaluating the numbers of bacteria, Malassezia yeast and inflammatory cells. ANIMALS: Thirty client-owned dogs with otitis externa. METHODS AND MATERIALS: A prospective, randomized, blinded comparison study. Ear canals from each dog were sampled using cotton swab and rubber tube. Ear cytological preparations were evaluated independently by two investigators for polymorphonuclear leucocytes (PMN), monocytes/lymphocytes, macrophages, yeast, intracellular (IC) cocci, extracellular (EC) cocci, IC bacilli and EC bacilli. RESULTS: A paired Student's t-test was used to compare the two techniques. The inter-investigator reliability for PMN, EC bacilli and yeast was good, and for EC cocci was moderate. There were significantly higher numbers of PMNs obtained by the tube method (P = 0.0024) than by the cotton swab method. There were no statistically significant differences between cotton swab and rubber tube methods for monocytes/lymphocytes (P = 0.7780), macrophages (P = 0.1751), EC cocci (P = 0.1262), EC bacilli (P = 0.1162), yeast (P = 0.5371), IC cocci (P = 0.6606) or IC bacilli (P = 0.6761). The technique was well tolerated. CONCLUSION: An alternative ear cytological collection technique was identified which enables sampling of the deep horizontal canal.
BACKGROUND:Canineotitis externa is a common disease. Cytological evaluation of otic exudate is a useful diagnostic test to direct and monitor treatment for otitis externa. One method of collecting ear cytological specimens utilizes a cotton-tipped swab inserted into the vertical ear canal. A proposed alternative method is to aspirate exudate from the deep horizontal canal using a rubber tube. HYPOTHESIS/ OBJECTIVES: To compare cytological findings between two different collection techniques by evaluating the numbers of bacteria, Malassezia yeast and inflammatory cells. ANIMALS: Thirty client-owned dogs with otitis externa. METHODS AND MATERIALS: A prospective, randomized, blinded comparison study. Ear canals from each dog were sampled using cotton swab and rubber tube. Ear cytological preparations were evaluated independently by two investigators for polymorphonuclear leucocytes (PMN), monocytes/lymphocytes, macrophages, yeast, intracellular (IC) cocci, extracellular (EC) cocci, IC bacilli and EC bacilli. RESULTS: A paired Student's t-test was used to compare the two techniques. The inter-investigator reliability for PMN, EC bacilli and yeast was good, and for EC cocci was moderate. There were significantly higher numbers of PMNs obtained by the tube method (P = 0.0024) than by the cotton swab method. There were no statistically significant differences between cotton swab and rubber tube methods for monocytes/lymphocytes (P = 0.7780), macrophages (P = 0.1751), EC cocci (P = 0.1262), EC bacilli (P = 0.1162), yeast (P = 0.5371), IC cocci (P = 0.6606) or IC bacilli (P = 0.6761). The technique was well tolerated. CONCLUSION: An alternative ear cytological collection technique was identified which enables sampling of the deep horizontal canal.
Authors: Ariadna Flores Ortega; Camilo Romero Núñez; Rafael Heredia Cárdenas; Linda Guiliana Bautista Gómez Journal: Vet Res Forum Date: 2022-06-15 Impact factor: 0.950