Comparison of the healing process in hot and cold brands applied to harbour seal pups (Phoca vitulina)
Pierre-Yves Daoust A C , G. Mark Fowler B and Wayne T. Stobo BA Canadian Cooperative Wildlife Health Centre, Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, 550 University Avenue, Charlottetown, PE C1A 4P3, Canada.
B Department of Fisheries and Oceans Canada, Bedford Institute of Oceanography, 1 Challenger Drive, Dartmouth, NS B2Y 4A2, Canada.
C Corresponding author. Email: daoust@upei.ca
Wildlife Research 33(5) 361-372 https://doi.org/10.1071/WR05024
Submitted: 8 March 2005 Accepted: 27 June 2006 Published: 14 August 2006
Abstract
Hot branding has been used for many years by researchers to identify seals from a long distance. In livestock, cold branding has been proposed as an alternative because it is thought to be less painful. The purpose of this study was to compare the healing process of hot and cold brands applied to harbour seal pups (Phoca vitulina). A total of 306 animals was branded with a unique set of four characters: three applied for 3–5 s with an iron heated to 500°C, and one applied for either 10 or 20 s with an iron frozen to –175°C. At three subsequent times over 10 weeks, 43, 41 and 51 animals, respectively, were recaptured, the macroscopic appearance of their brands recorded, and biopsies taken for microscopic examination. Cold brands had a faster healing rate than hot brands. However, they resulted in less destruction of hair follicles, and cold brands applied for 20 s caused more depigmentation. Regrowth of hair follicles could subsequently obscure brands, while depigmentation reduces the contrast between the brand and the surrounding fur. Cold brands applied for 20 s also caused more extensive deep vascular damage, which subsequently may have resulted in deeper wounds in some of these brands. Yet, macroscopically, other cold brands, or portions thereof, were almost invisible. On the basis of this short-term study, the technique of cold branding that we used in harbour seals does not appear to be as reliable as that of hot branding to provide permanent legible brands.
Acknowledgments
We thank Brian Beck for his assistance in the field component of this study, including the application of both hot and cold brands. We also thank Gerry Forbes and the staff of the Environment Canada Atmospheric Environment Service on Sable Island for assistance throughout the study. The help of Shelley Ebbett was essential in the preparation of the figures.
Bushby, P. A. , Hoff, E. S. , and Hankes, G. H. (1978). Microscopic tissue alterations following cryosurgery of canine skin. Journal of the American Veterinary Medical Association 173, 177–181.
Härkönen, T. , Hårding, K. C. , and Lunneryd, S. G. (1999). Age- and sex-specific behaviour in harbour seals Phoca vitulina leads to biased estimates of vital population parameters. Journal of Applied Ecology 36, 825–841.
| Crossref | GoogleScholarGoogle Scholar |
Schwartzkopf-Genswein, K. S. , and Stookey, J. M. (1997). The use of infrared thermography to assess inflammation associated with hot-iron and freeze branding in cattle. Canadian Journal of Animal Science 77, 577–583.
van den Hoff, J. , Sumner, M. D. , Field, I. C. , Bradshaw, C. J. A. , Burton, H. R. , and McMahon, C. R. (2004). Temporal changes in the quality of hot-iron brands on elephant seal (Mirounga leonina L.) pups. Wildlife Research 31, 619–629.
| Crossref | GoogleScholarGoogle Scholar |
