Goose with a Sinus Infection

Please can anyone offer any advise? We have an 18 month old pet female goose who has developed several swellings on her head.  Our vet said it was a sinus infection and we injected her with a course of antibiotics.   This didn't work, he wasn't prepared to operate and suggested soluable Tylan may help, so we tried that.  That didn't work either.  She seems ok in herself, but looks very odd now as the swellings are quite large.  She is eating normally too, but the swellings do feel a bit hot.  Would be grateful for any other suggestion of things to try, or if anyone knows a goose-friendly vet in the South West???