Abstract
Sinus‐like dilatations of the mammary duct are recognisable in the mammary gland of pregnant and lactating wild European rabbits. These dilatations exhibit a bilaminar epithelial lining, with luminal epithelial cells expressing basal and lateral E‐cadherin. Occasional binucleated mammary epithelial cells are present in the luminal layer. Underlying the luminal epithelial cells is a basal layer of cytokeratin 14‐positive cells, supported by a thin layer of fibrous tissue. Multi‐segmental epithelial proliferation, as indicated by Ki67 expression, is apparent in the luminal epithelial cells, suggesting a capacity for division during pregnancy and lactation. CD3‐positive T lymphocytes are present both intraepithelially, suggesting exocytosis, and in foci subjacent to the ductular epithelium. We consider that sinus‐like dilatations of the mammary duct may have the potential to give rise to a subset of the mammary gland neoplasms classified as ductal in origin. Milk accumulation in these sinus‐like dilatations is likely to provide a niche for bacterial replication in cases of mastitis in rabbits. These structures are an important component of the innate immune system of the mammary gland, both as a physical barrier and as an interface between the milk and mammary immune cells.
Highlights
Over the last 25 years, diverse sources have indicated that rabbits are an increasingly popular pet species in many parts of the world (Grant et al 2017)
The mean Æ SD and median number of mammary duct cross-sections per teat were 6.7 Æ 0.76 and 7, respectively, which was similar to previous reports suggesting that the rabbit commonly has six galactophores (Cowie, 1974) (Fig. 1A)
The human literature underlines the benefit of ultrasonographic assessment of the anatomy of the lactating breast (Ramsay et al 2005) and we highlight in this study that identification of patent galactophores vs. smaller diameter ducts is subjective and open to interpretation
Summary
Over the last 25 years, diverse sources have indicated that rabbits are an increasingly popular pet species in many parts of the world (Grant et al 2017). From 1994 to 2003 rabbits were the most frequently presented species at the Clinic of Zoo Animals, Exotic Pets and Wildlife at the University of Zurich, with the number of rabbits increasing significantly during that time (Langenecker et al 2009). In the USA, the number of pet rabbits increased between 2001 and 2006 (Shepherd, 2008). In Andalusia, Spain, where traditionally rabbits are considered an important meat-producing species, it has been suggested that young people’s perceptions of the Accepted for publication 18 April 2018 Article published online 7 May 2018 rabbit may be shifting from viewing it as a livestock species to a pet (Gonzalez-Redondo & Contreras-Chacon, 2012). Whereas rabbits are growing in prominence as pets, in many countries they instead, or in addition, constitute an important farm animal species (Kylie et al 2017)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
