Outdoors What causes lumps on a deer’s skin? By Cottage Life Published: May 2, 2011 Updated: April 4, 2025 share Share on Facebook Share on Twitter Share on Pinterest Copy Link Cancel Photo by Alexey Spehalski/Shutterstock What causes lumps on a deer’s skin? Are these lumps dangerous for the deer? Although these lumps look nasty, they’re actually nothing serious. The hump is either a papilloma or a fibroma, benign tumours found mostly on the skin of deer, though they may also occur on other wildlife. In deer, the cause is a virus. The tumours aren’t all that uncommon but they don’t seem to bother the deer unless they get very large. In that case, they can interfere with walking or other movement. Related Story Chronic wasting disease continues to spread throughout Alberta’s deer populations Related Story Ontario government taking steps to protect against fatal deer disease Sign up for our newsletters By submitting your information via this form, you agree to receive electronic communications from Cottage Life Media, a division of Blue Ant Media Solutions Inc., containing news, updates and promotions regarding cottage living and Cottage Life's products. You may withdraw your consent at any time. Dockside Weekly The latest cottage-country news, trending stories, and how-to advice The Key Weekly Need-to-know info about buying, selling, and renting cottage real estate Family Matters Five-part series Untangle the thorny process of cottage succession with expert advice from lawyer, Peter Lillico