Staphylococcus bacteria are ubiquitous in the environment and are part of the normal flora of the skin and other mucous membranes of poultry and other animals. Skin wounds, minor procedures (i.e., beak, toenail or comb trimming), injections, and compromised intestinal mucosa can introduce the bacteria into tissue or the bloodstream. Infection can also occur in newly hatched chicks through contamination of an open navel. Systemic infections include septicemia or gangrene, or more commonly through localized lesions. S. aureus can invade joints, leading to arthritis and osteomyelitis (infection in the bones). It can also cause disease in immunocompromised birds.
Case Study: Staphylococcus Lump
“My husband and I are first time chicken parents and one of our girls looked in rough shape.
At first we thought she was having a bad moult, but then her situation looked more serious. She lost almost all of her neck, and some on her belly, feathers. The most concerning thing was a very hard, dry, dark, scaly lump on her back that had continued to get bigger. At first we thought it was stuck on poop and tried scraping it, which didn’t please her. When we saw little feather quills poking out we assumed it might be a bad molt, or a feather follicle cyst, and decided to keep an eye on it.
Week 3: In the course of three weeks the lump continued to grow. She didn’t peck at it nor did it appear to bother her. The only time she got flustered was when we touched it.
Throughout this time she was in normal spirits, still active and laying healthy looking eggs; normal poops; no signs of mites on her skin or remaining feathers or worms in her poop; normal weight. None of the other flock members picked on, or bullied, her. In fact, the rest of the flock were all so sweet to her and the dominant hen was more snuggly with her at night to keep her warm.
Week 4: I have a friend whose wife is a zoo veterinarian who offered to do a virtual consultation because we couldn’t find a local vet that would see her. The vet looked at the lump over Face Time and thought it could be a staphylococcus infection, similar to bumblefoot, but just in an odd location. We think she got a small cut on her back, probably when she dug under our pasture fence, that got infected and spread.
We got supplies together to do a mini-surgery the next day.
The vet recommended we soak her and then cut into the lump. Our hen was a good patient: once her face was covered she just chilled. My husband cut into the lump and sent a photo to the vet who confirmed it appeared to be a staph infection, as she expected. She directed him to cut at the base and gently tug it until the whole lump came off. He then squeezed around the site to get the rest of the infection out and then disinfected the wound.
I wasn’t home when the surgery was done otherwise I would have taken a video. I’m a biology teacher and former zookeeper so I love this stuff. I know about wearing gloves. My husband was scolded already because he removed it when I wasn’t home.”
Her post-op care included Vetericyn spray and antibiotic cream applied to the wound. She was returned to her flock and they are treating her well and not picking on her.
Many thanks to Lauren Hamory for her story and photos.
Credit: Merck Veterinary Manual