Chicken Anatomy FAQ

Author: Aussie Chook Supplies  

My chicken has this weird, pimple-like thing on their back, just above their tail feathers. Is this normal, and if so, what is it?

What you have found is commonly referred to as the Uropygial Gland, also known as the ‘preening gland’. All poultry and most birds of flight have a preening gland, is completely normal and will excrete a bit of yellow, oily substance. Your chickens will use their beak to stimulate the gland to produce a thick, transparent oil, which they then rub/spread all over their body using their beak.

PoultryDMV states that the “functions of the preening gland are:

  • Waterproofing
  • Suppression of growth of bacterial organisms on the skin through its antibacterial properties.
  • Manufacturing vitamin D precursors that are spread over the bird’s feathers while they preen. With exposure ultraviolet rays produced by sunlight, the secretions convert to an active form (vitamin D3) which is then ingested with subsequent preening.
  • Maintaining quality of their skin, feathers, and beak.”

Preening oils in healthy chickens help to keep the beak, feathers and scales supple and in good condition. If there are unhealthy changes in these areas, chicken owners are encouraged to investigate the cause by inspecting the chicken for mites/lice infestations, inspect their eating appetite and weight or possible infections at the preening gland.