I have read that unless you know the health of your feeder fish, [like breeding your own] that it can be an unsafe practice as far as your O's health , and possible diseases.
How about feeder crayfish? my LFS has a tank full of small healthy looking baby cray, but does the same rule apply? if you dont know for shure that they are absolutely healthy, can the feeder cray possibly infect/sicken your oscar?
thanks for any help.

baby crayfish is no difference from grass shrimp so i assume i will be okey.
although grass shrimp is know to be prone to parasitic elements, i never had
problems yet with my fishes.

a quarantine tank with a sensitive fish in it is the key, i dont ever just put feeders in my main tank without letting them spend atleast a week in the other safety tank. i just cant afford to treat these big aquaria for diseases lol. its cheaper insurance to just be patient.

i dunno i dont really like the idea of using scavengers for food for my oscar, theres no telling what they ate before they were shiped from the pond they grew in to the retail store. crayfish will eat ANYTHING.

my fish have got infections from live blood worm, shrimp, plants ( yes plants too i got white spot)and just about every other thing that comes from shops. anything that comes with water can carry infection. white spot seams to be most common. i get frozen now. only live I feed is worms, meal worm and bugs etc. i may add this is was over time (many yrs )and I have also had some with NO problems at all. its hit and miss weigh up its worth.

i just dont give my oscar live feeder fish at all anymore. it seemed every other time i buy them a few days later they are eaten up with ick. its just not worth the hassle to me. crickets and worms do the trick and dont carry the aquatic parasites with them in the process.

Hey yall,
A few years, back i raised two oscars and a butterkoferi in a 20 gal tank . The oscars grew to about 8 inches each and the butter about 6 or so . Anywayz i fed them wild caught crawfish on occasion,which they loved and went crazy for. their diet also consisted of lizards, geckos, grass shrimp, rosy reds, and goldfish and sometimes worms and grasshoppers. Never had any trouble, but i guess i was very fortunate.
I have to say, after joining this forum i will probably never feed the oscars i am currently raising any feeder fish. Currently they are on a mixture diet of freeze dried bloodworms, freeze dried red shrimp and hikari gold mini pellets. I have thought about breeding grass shrimp, but that is still just an idea as of now.

I did want to say that i also caught lizards and geckos and fed them to my oscars and butter quite frequently, maybe more than a few times a week, being their main food source. Does anyone else feed their oscars lizards or geckos or have any knowledge about how healthy or not it is??