I agree that he/she may need another course of antibiotics or perhaps he/she has another dental issue. I also would like to know how long ago was the last visit and also how thorough the vet check was (x-rays? teeth checked under anesthetic?)
Is he/she eating normally? How is her/his weight?
Degu: Nod (RIP 2022, 7yrs), Jax, Jos, Jet, Florence and Lorraine Departed: Inken (2021, 6.5 yrs), 2019 Ni (8 yrs), Blinken (4yrs); 2018 Peridot (8.75yrs), 2017 Jin (6yrs), Rei (5.5yrs), Makoto (5.5yrs), Ichi (5.5yrs,), Shi (5.5yr), Roku (2016, 4.5yr) 2015: Gi (4yr); Yuu (4yr); Go (4yr); Meiyo (4yr); Sean (5.75yr); Lilac (7.75yr); Chuugi (3.5yr); Azure (2012, 4.5 yrs), San (2011) Budgies: Peppy, Skylar, Lilly & Marshall Tonks: Vesper and Tsuki Assassin snails, Platy Mickey
If you haven't had x-rays carried out already, I would strongly suggest that you get this done by a chinchilla savvy vet. Weight monitoring is also critical as an indicator as to what may be going on. Is your chin still eating pellets and hay? Is there a change in, or lack of droppings? Oxbow Critical Care may help to keep your chin's weight up while tests are being carried out. Is your chin male or female, and what age is he or she? please give as much information as possible. It helps with formulating the most appropriate reply. Also monitor any changes in normal behaviour, however small. please keep us updated, and will help as much as I can.
I'd echo the need for xrays - my chin had similar issues & also had a weepy eye. After months of investigation I took him to a specialist vet who xrayed him & found an abscess inside the gum on the root of the tooth. Would never have picked that up without xrays. Unfortunately there was no surgical option as it was the very back tooth & impossible to get to, antibiotics would help in the short term (as did painkillers) but it never went away. Within days of stopping meds it was back to the same.
Where are you? Maybe we could help you find a specialist vet? I'd also have a chat to your vet about the different antibiotics, maybe you could try a different one? Is he/she on metacam too? Pain will stop them eating so be prepared to help him/her. You'll need critical care,supreme science recovery food & maybe make your own mash from his/her usual food. Some chins will eat it themselves from a bowl, others only from a spoon & some awkward gits only if you syringe feed it to them. Sometimes baby food is good, but make sure it's veggie, no fruit or meat, but only if nothing else works.
How mellow is your chin? can you hold him & feed him, does he take meds well?
3 rescue rabbits - Zak,Janis & Jim 2 rescue cats - Eddie & Nala 2 rescue dogs - Jack Russell Stan, Romanian Terror *cough* terrier Minnie 3 degu - Jelly, Leadbelly & Bo. 3 chinchillas - Sir Ian McKellen & Sir Patrick Stewart & Dame Maggie Smith 3 adopted Guinea Pigs - Aaron, Bea & Heidi
R.I.P my best friends Cat & Bengi, my first & best friends. Never forgotten, always missed.