I have used it with my ducks, when I have had spring outbreaks of mycoplasma in my large flock of adult birds. It has bern successful with no observed side effects.
However it is a STRONG oxidiser and in my opinion enough to color drinking water dark purple, or purple at all, is far too much. You only need enoughto color the water a pale lilac, only enough to see a slight colour change.
You also don't want to treat the water for more than a few days at a time, as most studies showing harm from it refer specifically to chronic exposure over a longer term.
With the ducks i put just a few grains in a clean plastic bottle or similar to dissolve in a few hundred ml of water, then put a 1-5 capfuls of the disdolved solution into the ducks water when refilling their plasticponds which hold around 100-110 litres of water. I wait till the pond is mostly full before I add it and i kick out ducks trying to get in early for a swim while the pond is refilling, and keep them out and away while i mix it in thoroughly. I put in enough to get a slight colour change in clean fresh water.
Having used this stuff at uni (chemistry and biochemistry at pre med level) for loads of reactions, trust me it is VERY strong stuff.
I read somewhere the fatal dose for a human is 20 of those small grains it comes in as crystals.
So in my opinion it definitely works and good to use if you have any health/disease issues in your flock, or during spring and warm weather, (and to help reduce any bacteria load from the fact ducks like to shit where they eat, swim and drink, lol), but PLEASE don't put it in so strong its dark purple, you don't need that much!
And only use for a few days at most, in all their drinking water at the pale lilac colour. I dont see any benefit in mixing it stronger, only risk to weaker birds.
For me it saves me hundreds in buying oxytetracycline in amounts large enough to treat my adult flock for respiratory infection and seems to be as effective as using veterinary prescribed oxytetracycline has been in the past (in fact my vet saud they would be interested to hear more about the results i have had with it). So now I keep the Oxytet or Tylosin for prophylactic use in ducklings, particularly those hatched in the warmer weather during later spring.
And on that note has anybody used potassium permangenate in the water for Ducklings?
I cant find any research on it in ducklings, or any personal experience, but this spring am having ducklings with some pasty poop issues (ducklings on no meds at all) which might be fungal so looking for an alternative to antibiotics as a mycoplasma prophylactic, given if any ducklings have any fungal issues, giving oxytetracycline will worsen the fungal infection.
If anyone has given it to chicks or ducklings id love to hear your experience?