Lame duck..need ideas

[qwackers9]

So my duck started off with a very obvious left leg limp in early December. After no improvement on it's own, I put her on doxycycline for 2 weeks. She began putting more weight on her leg during second week but then had a very exaggerated wobble. She also began laying around more often. Another week or so later she started to walk with her tail down. I took her to a very good exotic/avian vet. Because of covid, I could not go in to the appt with her: I could only relay info then vet called me himself after exam. Now he thought limp was more in right leg. We decided didn't matter which leg, she is not normal. He tried an anti-inflammatory injection with no improvement, which then he had me start her on aspirin. Also no difference with or without. Vet & I spoke of x-rays but at that time, not even sure where to focus them. It's been another 2 weeks and now she is even sitting with tail pointing downwards. I'm not sure about egg laying because I have 4 females but have only been getting 1-3 eggs/day since molting & colder weather so I don't know who is laying what, but I think she is laying...I just can't be positive.
The other day I was giving her an Epsom salt warm bath. I was cleaning her tail for her (it is exceptionally dirty from dragging it) and I noticed this spot. Location is on lower back almost at base of tail. It felt sorta scaly, somewhat raised. I was looking at different duck-anatomy diagrams but see nothing, at least that should be seen from outside the body. Does anyone know what this is, could she have a possible back injury?
I will be taking her back to vet, probably go ahead and do x-rays of something but I was wondering if anyone has had anything similar.

 

[sourland]

Hard to tell - is that her oil gland?

 

[Isaac 0]

The oil gland (uropygial) is located near the backside of the bird (pygostyle), so from what I'm observing that would be the approximate locations where you've shown in the picture. A healthy oil gland should be smooth, and oily when rubbed.

Given the treatment you've done so far, I think radiographs may be a good next step. If there are no apparent abnormalities in the radiographs, you may ask about "fine-needle aspiration". Doxycycline is not antibiotic frequently indicated for bone infections, more common, and effective antibiotics suggested for bone infection include those of the fluoroquinolone class (Enrofloxacin (Baytril), Ciprofloxacin).

 

[qwackers9]

The oil gland (uropygial) is located near the backside of the bird (pygostyle), so from what I'm observing that would be the approximate locations where you've shown in the picture. A healthy oil gland should be smooth, and oily when rubbed.

Given the treatment you've done so far, I think radiographs may be a good next step. If there are no apparent abnormalities in the radiographs, you may ask about "fine-needle aspiration". Doxycycline is not antibiotic frequently indicated for bone infections, more common, and effective antibiotics suggested for bone infection include those of the fluoroquinolone class (Enrofloxacin (Baytril), Ciprofloxacin).

Agree. When I gave her the doxycycline, I really thought I was dealing with a possible early bumblefoot. She had some spots on her foot that were questionable. Fast forward to her vet appt., those spots were gone.
I had a young male in 2019 & he had infection that seem to start respiratory but spread to bone. Extremely difficult to treat! Under vet care entire time, about 4 months, he was on a total of 6 different antibiotics. Antibiotic-resistant to Baytril & maybe others before we landed on one that was working. He had 3 surgeries & aspirations just about every other day. Vet really went to great lengths to save this poor guy; some treatments & diagnostics were even covered $$ by him. Finally he did get better.
Back to my girl now, tho, oil gland does sound very likely. But it is not at all smooth & oily. I would say at least inflamed. I will definitely have vet check it out. Before, it just seemed that we were dealing with a foot or leg issue because of her limp but with tail down constantly and no real obvious limp anymore, there must be something else going on.
Thanks so much for your input!