Changes characteristic of the cycle of the bitch include, growth and proliferation of the mammary gland with each cycle even if the bitch does not conceive. Frequent proliferation and subsequent [[Lactation - Anatomy & Physiology#Involution|involution]] predisposes the bitch to [[Neoplasia - Pathology#Examples of Tumour Types|mammary tumours]]. | Changes characteristic of the cycle of the bitch include, growth and proliferation of the mammary gland with each cycle even if the bitch does not conceive. Frequent proliferation and subsequent [[Lactation - Anatomy & Physiology#Involution|involution]] predisposes the bitch to [[Neoplasia - Pathology#Examples of Tumour Types|mammary tumours]]. |