Zuma 5yr old (today) GSD has had patches on the lower part of his nose since May, 1st vet gave him Synolox - made no difference, 2nd vet took swabs, results showed it was pseudomonas and only effective antibiotic was marbofloxacin.
He had 14 days which improved things, back to vet, another 10 days of same, spoke to vet today and will get another 5 days tabs, total of 29 days on meds.

Vet is talking about needing to do a biopsy - she did suggest this initially but I declined at that stage. the vet seems reluctant to give more Marbofloxacin after we finish day 29 but they were the only effective treatment and the data sheet states 'in skin and soft tissue infections, treatment duration is at least 5 days.  Depending on the course of the disease, it may be extended up to 40 days'

I am wondering if it is time to ask for a referral -and if so where to - i am in Suffolk and Animal Health Trust and Dick White are both quite close and Z is insured
any advice or thoughts  please
Chris

It is obvious this infection is resistant to that antibiotic so no point in continuing with it. Has the vet sent any more swabs for culture and sensitivity, it is unusual that results come back suggesting only one antibiotic, the bug may have become resistant if this is a frequently used antibiotic in vet meds.

This is the problem,  the tests showed that this IS the only antibiotic which will work on the strain of pseudomonas that he has, and it is used as a 'last resort'  compared to the more usual ones. It has worked in that he now has pink patches instead of the 'sometimes raw' patches that were there originally but it is still not completely cleared and I am worried that he will run out of allowed doses befor it heals completely.
This is why I am wondering about asking for a referral to a specialist practice but who or where.
My usual vets are good and do a mixed small/large/zoo practice.

You can't get better than Dick White, I would always ask to see him or one of his vets if at all concerned. He has worked miracles for my dogs in the past