Edit - don't know about British meds, but anybody who says ich should be left to 'run its course' shuld be regarded as suspect - and DON'T buy fish in his care.
Re-edit - each little critter will produce THOUSANDS of offspring - early treatment saves lives - and treatment should continue past the four day cycle possible ONLY at a higher temp - in unheated tanks, the life cycle can take a month or so to complete.
Heat speeds up the cycle for faster treatment - if heat is increased but no treatment given, it worsens the infestation VERY rapidly.
Re- RE-RE-Edit - hiked temps around 84-86 degrees used to often prevent ich from multiplying, but apparently heat-resistant types are now fairly common - life is just unfair...
Salt is an alternate treatment - personally I'd treat ASAP.
Re-RE EDIT: thought it would be faster to Google than dig through my notes for a sensible link - much not good online
This is good:
[URL="http
/www.aquaticcommunity.com/disease/ich-explained.php"]http
/www.aquaticcommunity.com/disease/ich-explained.php[/URL]
Thanks to you, he has a life where someone can worry about him being spoiled.
I and many others have had the odd reluctant eater started on bloodworms who has later accepted other things - sometimes it's a question of triggering the appetite, once it's been 'turned off', as you know.
Tibby has a very valid point regarding at least the various fish she, I, and various others have rescued, not that I've rescued anything near the numbers she has, or could afford/bear to, or have her expertise in dealing with these.
Once fish (or any of us) get run down, they become susceptible to illnesses, and, apart from exposures at large fish farming facilities, even bettas kept separately in containers in pet stores may have water added from a communal supply, such as a plant tank in which other fish have been kept.
Not only infections but parasites may be present and have gained ascendency in any rescue fish - I recently lost two once-greatly improved little bettas (bought because of very obvious health issues, which turned out to be secondary) after 9 months, to encysted parasites which were unaffected by medicated foods.
And I was so sure the by-then-beautiful little male was all right, after several months of symptomless improvement in colour, finnage regrowth and other respects, that I exposed my precious rare-find giant otos in a tank shuffle and later watched two of them die in convulsions as parasites ate their way out of their bodies.
By this time, my lovely little male had suffered a sudden, rapid weight loss and partial paralysis and the same-source, evidently related female developed large, fast-growing lumps - all at the same time, within days - and they were all lost at once.
The stricter quarantine procedures observed in Britain may well spare pet-owners there the worst effects, but not all effects are immediately noticeable, although they may be sudden in onset, triggered, perhaps, by lengthening days as I suspect occurred in the example given.
Where symptoms are present, as Tibby points out, intuition must come into play - and some diseases often considered less prevalent simply tend to go unrecognized, especially when imported into areas where they previously did not exist.
The more aware we are of such possibilities, the more likely we are to deal with problems before it's too late for our pets.
Hopefully, the little betta you're aiding will make a complete recovery and have a long and healthy life.
But it's always best to be aware and sometimes better (where symptoms are present) to try something rather than nothing because of uncertainty in what is usually anyway an uncertain situation.