The uropygial gland, also referred to as the preen gland or oil gland, is located at the base of the chicken's tail on their lower back, just in front of the tail feathers. This gland is responsible for secreting a thick, transparent oil which the bird spreads over their feathers (through the act of 'preening'). This oil consists of a combination of extruded cells, ester waxes, fatty acids, fat and sudanophilic secretory granules. It performs several important functions in birds, including:
- 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.
Many uropygial gland abnormalities in chickens occur secondary to vitamin A deficiency, resulting in enlargement of the gland, glandular metaplasia, and hyperkeratosis.
Treatment of Uropygial Gland Infections
Treatment will depend on the cause. Most early cases of uropygial gland infections in chickens can be corrected by gently massaging or milking the gland after a moist hot compresses has been applied, in conjunction with diet changes. Sometimes an injection of parenteral vitamin A may be needed. Based on culture and sensitivity results, systemic antibiotic or antifungal therapy may be beneficial. Suspected tumors may require surgical excision.