My baby chicken has a throat infection

[nmchickenloverhyatt]

I have a baby chicken who I got on December 5th, 2019 (2.5 months old).
Two weeks back from today (February 22, 20), I noticed her opening her beak quite weirdly and then closing it again, upon close examination I noticed that her beak was filled with strings of mucus (clear in colour). I also felt a small tender lump under her beak. She was also lethargic (very active and playful otherwise) and was not able to eat anything at all. Her poop was watery, slightly green in colour (picture attached). I took her to a Local Pharmacy that specialises in Birds Medicines and ailments etc. They told me it was canker and gave me 4 tablets of Ronidazole for 4 days (given by mouth). I paired this treatment with a Mucolytic agent, and gave her semi solid food and water with a syringe as she couldn’t swallow at all. After the 3rd day, I felt that she was getting better but the infection wasn’t completely gone (the mucus was still there but she could pick up her treats now still wasn’t able to swallow easily). So after day 4, I went back to the vet and told them I had seen little improvement, so they gave me 5 more tablets of Ronidazole that I continued to give her for 5 more days. On the 6th day of her being on this tablet, I noticed some blood in her beak and got super worried. So I grabbed my phone and recorded a video of the inside of her mouth. I saw that her tongue had some whitish yellow substance on it. After 9 days of giving her Ronidazole and noticing no significant change, I took her back to the vet and showed them what I had seen on her tongue. They told me it was a fungal infection (oral thrush). So they told me to give her Nystatin syrup (3 drops daily) for 7 days and told me to discontinue Ronidazole.
We are currently on Day 3 of Nystatin Syrup, discontinued the mucolytics and I examined her mouth, saw a yellowish membrane under her tongue. I am super worried now, don’t know what this is.
She doesn’t have fever, isn’t lethargic, is eating alright, but her mouth gets filled with mucus, no respiratory difficulties or sounds, the lump can still be felt under her beak.
I dont know what I should do, should I continue with Nystatin? Or go back to Ronidazole?
What does this look like?
Please relate the pictures according to the timeline described above, also do notice the lump under her beak.

 

[azygous]

Is your pharmacist also a vet? There are certain risks with the protozoa drug the pharmacist gave you. There are some meds that cannot be used along with it, and it has the potential of causing cancer in humans when your skin comes into contact with it. So you need to use gloves when handling the drug.

Nystatin is not one of the drugs that interact dangerously with Ronidazole, so I see no danger in using them concurrently.

The bleeding your chicken experienced was likely associated with the canker as it breaks away from affected tissue, it can cause minor bleeding. You may need to consult with your pharmacist on dosage. It may be necessary to increase it to effect a cure.

 

[dawg53]

If it's canker, cull the bird. Canker is contagious via waterers/feeders and birds remain carriers for life.