Yes, ulcer disease (gatenziekte in Dutch) can be treated!
This past year ulcer disease with carp spread like a fire through our region. It probably all started at a well known local canal stretch, contaminating other, mostly private places and syndicates through birdlife and probably carp angler's carp care items like nets, mats, slings, etc.
Personally I am the only one who fished the canal at the same time as our own Monkey Climber syndicate and though being careful (letting nets nets, etc. fully dry out, treat with salt, etc.) unfortunately we had an outbreak of ulcer disease too. Most of the fish in the early Spring were infected, with a few bad wounds already.
That's where an ex colleague over at Aquatic Engineers came to help, together with a well known koi doctor. A three week no fishing ban was imposed and we fed the fish with a mix of Coppens pellets with specific antibiotics against ulcer disease.
Months later now the results are outstanding. Any spots of ulcer disease are completely gone and our precious carp are healthier than ever.
If you own a syndicate and need help, contact us or the above mentioned Aquatic Engineers.
The fish below was heavily infected in Spring, now completely gone!