How Spaying Early Can Eliminate Mammary Tumours


One of the many questions we get working in Veterinary Medicine is “at what age should I spay my dog?”.  As Veterinary Professionals, we like to recommend spaying at an early age. This time frame is typically around 5-6 months old, or before the first heat cycle.

By spaying your dog at this time, the risk of them developing a mammary tumour later on in life is 0.5 %! After the first heat, the risk rises to 8%. After the second heat cycle, the risk rises to 25%! These risk percentages vary due to being linked with the female hormones Estrogen and Progesterone which are both present during a heat cycle. Obesity and a high-fat diet during the first year of life can also be a contributing factor to mammary tumour development.

Mammary tumours are common in females who are between the ages of 5-10 years old in which have had many heat cycles in their life. Did you know that 50% of mammary tumours are benign and the other 50% of them are malignant? The only way to find out what nature the tumour is is to have it surgically removed and sent to a Histopathologist for analysis. Every tumour can be of different nature, thus should always be removed and sent for analysis.

A mammary tumour develops directly in the mammary gland tissue. They can develop as a single nodular tumour or they can develop as a large mass. Small single nodular tumours often feel like a smooth marble. They can be freely movable with the skin or fixed to a deeper structure. A female dog typically has 8-10 mammary glands and tumours can develop in a single gland or in multiple glands.

Give us a call today to discuss spaying your dog and how it can eliminate the risk of developing a mammary tumour.

Written by RaeAnne, RVT