Hi there! I'm sorry to hear about the problems you're having with your old gal. I hope I can help to help you.
First, personally I would take her off of the antibiotics particularly if she's getting 'a little bit'. The type of symptoms you're describing usually aren't treatable with 'mycins and sometimes can be increased with it (due to the fact that it'll kill the good bacteria while doing nothing to decrease the bad bacteria).
What I would do is this: First, thoroughly examine her for lice and mites. This may take a few look-see's at night, off the roost, as mites travel at night. I'd more highly suspect regular lice as she's not really gone down in health.
I very strongly suspect that the sores youo're seeing, and her redness and her swelling at her abdomen below her vent, are due to the droppings clinging. They cause the sort of irritation and spot infections that are like that. I also think there's possibly a yeast infection (fungi actually) both topical and systemic due to three things:
a) her age
b) possibly laying issues (or increased need for some supplements)
c) a bacterial imbalance in her digestive tract; and
d) a lowered immune system either due to worms, to any of the above, or to some other issue.
First, I would treat the immediate problems:
- Give her 1 teaspoon of yogurt daily for 10 days, no less - or - another probiotic like an acidophilis capsule/tablet or Probios probiotic powder for livestock.
- Use organic apple cider vinegar in her water at a rate of 1 tablespoon per gallon as her sole source of water for 10 days.
- Give her a *one-time-only* gentle flush to cleanse her digestive tract and make a 'clean slate' onto which you will then be applying good bacteria through probiotics or yogurt. Ingredients: 1/8th teaspoon molasses, 1 tablespoon applesauce (baby food is the easiest), 1 teaspoon of yogurt or another probiotic powder (1/4t), cooked oatmeal. The applesauce cleanses the digestive tract and makes good bacteria happy. The molasses will flush out lingering paralyzed worms. The yogurt/probiotic replaces good bacteria in the now clean slate. The oatmeal sooths and birds like it.
- I would cleanse her vent area, the sores, with either nolvasan or chlorhexidine cleanser (very diluted in warm water for either). I would think wipe them once with a solution of water and iodine make into a solution the color of very weak iced-tea. Pat that dry and then apply the following, mixed: 50% Neosporin ointment, 50% lotrimin cream.
The neosporin (and the iodine pre-wipe) will kill bacteria, the lotrimin will help with yeast/fungal problems due to moisture and/or a systemic Candida infection.
- Reapply the hybrid ointment/creme daily for 7 to 10 days.
- Give her 3 drops of polyvisol baby vitamins without iron in the beak for 7 days. If she'll eat that on egg yolk, a bite, give it that way for your ease. Just make sure she gets it daily. The vitamin E within will help with inflammation and has anti-oxidant properties. The D might help with some egg issues. The over all vitamin package will help with her immunity while she's going through this.
I have a question - is this hen laying? Is she currently on a diet of laying pellets with oyster shell available? If not, make sure she does. I like the higher protein laying feeds like 18 or 20 if you can get it. (I use game bird breeder for 20%)
You can also put a little honey in a wet treat - a bit of honey, the yogurt, egg, whatever you can get her to eat with the yogurt in it. The honey might give her a little energy.
