Hi Emma
A proper ear exam is needed to also look for ear mites....and the lymph nodes in neck and armpit need to be checked for any swelling.
I had exactly this same symptom with some rescue pigs I took in temporarily. Some also had slight intermittant head tilt and/or nasal discharge from one nostril....difficult to spot unless you were extremely observant. One had severe head tilt - it was looking in his ear that first alerted me to the spots - and one developed respiratory problems. Ear mites weren't found and there was no visible pus in the ears, just the cream "pustules"
The first culture from the actual spots in the ears came back negative. However a subsequent nasal culture from one showed a mixed staph/strep infection that was resistant to both baytril and septrin so doxycycline was prescribed.
Many vets will prescribe baytril for piggies without suggesting a culture first. It wouldn't surprise me if that is what your vet may choose to do.
However increasingly bugs are becoming resistant to baytril and other antibiotics and if a culture is to show meaningful results it needs to be taken either before antibiotics are prescribed or at least a week after the last dose of antibiotics As the last 3 "grumbly" infections tested have all turned out to be "superbugs", my vet and I both agree that, providing the piggie is not seriously unwell, a culture is always done first and we wait for the results before antibiotics are prescribed. And just to qualify the last sentence....if a piggie had a serious URI or pneumonia, he would take the swab and prescribe immediately but baytril would not necessarily be first choice.
It therefore might be worth asking your vet if there would be any benefit of doing a nasal swab and also prick one of the spots inside the ears and try to swab from that before giving Sweep any antibiotics? This could be regarded by your vet as a rather excessive/expensive approach when a simple round of baytril would be their preference, especially if Sweep is showing no other symptoms, is eating well and not losing weight.
There's no right or wrong approach - but at least you have some additional information/case history to make an informed decision
HTH
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