Rosy reds are for the most part as unhealthy as goldfish. In terms of diseases they can pass to your fish (ich and internal parasites predominantly) the risk is the same
Most fish carry thiaminase and it is rare were feeders actually harm the fish.There is a chance thats why most people dont.If u do keep them in a quarentine tank for a week.
List for u of fish with it.Plus feeing fish doesent not remove Thiaminase Species that contain thiaminase Freshwater fish Family Cyprinidae (Minnows or carps):
Common bream (Abramis brama)
Central stoneroller (Campostoma anomalum)
Goldfish (Carassius auratus)
Common carp (Cyprinus carpio)
Emerald shiner (Notropis atherinoides)
Spottail shiner (Notropis hudsonius)
Rosy red, Fathead minnow (Pimephales promelas)
Olive barb (Puntius sarana) Family Salmonidae (Salmonids):
Lake whitefish (Coregonus clupeaformis)
Round whitefish (Prosopium cylindraceum) Family Catostomidae (Suckers):
White sucker (Catostomus commersonii)
Bigmouth buffalo (Ictiobus cyprinellus) Family Ictaluridae (North American freshwater catfishes):
Brown bullhead catfish (Ameiurus nebulosus)
Channel catfish (Ictalurus punctatus) Other families:
Bowfin (Amia calva) - family Amiidae (Bowfins)
Burbot (Lota lota) - family Lotidae (Hakes and burbots)
White bass (Morone chrysops) - family Moronidae (Temperate basses)
Rainbow smelt (Osmerus mordax) - family Osmeridae (Smelts)
Loach, Weatherfish (Misgurnus sp.) - family Cobitidae (Loaches) Brackish (freshwater to marine) fish Family Clupeidae (Herrings):
Alewife (Alosa pseudoharengus)
Gizzard Shad (Dorosoma cepedianum) Other families:
Sea lamprey (Petromyzon marinus) - family Petromyzontidae (Lampreys)
Fourhorn Sculpin (Triglopsis quadricornis) - family Cottidae (Sculpins)
Salmon (sp. indet., processed and salted, probably Oncorhynchus sp.) - family Salmonidae (Salmonids) Marine fish Family Engraulidae (Anchovies):
Broad-striped anchovy (Anchoa hepsetus)
Californian anchovy (Engraulis mordax)
Goldspotted grenadier anchovy (Coilia dussumieri) Family Clupeidae (Herrings):
Atlantic herring (Clupea harrengus)
Atlantik menhaden (Brevoortiatyrannus)
Gulf menhaden (Brevoortiapatronus)
Razor belly sardine (Harengula jaguana)
Sauger (Harengula jaguana) Family Scombridae (Mackerels, tunas, bonitos):
Chub mackerel (Scomber japonicus)
Skipjack tuna (Katsuwonus pelamis)
Yellowfin tuna (Neothunnus macropterus) Family Lutjanidae (Snappers):
Green jobfish (Aprion virescens)
Ruby snapper (Etelis carbunculus)
Crimson jobfish (Pristipomoides filamentosus) Family Carangidae (Jacks):
Giant trevally (Caranx ignobilis)
Doublespotted queenfish (Scomberoides lysan)
Bigeye scad (Selar crumenophthalmus) Family Mullidae (Goatfishes):
Red Sea goatfish (Mulloidichthys auriflamma)
Yellowstripe goatfish (Mulloidichthys samoensis)
Manybar goatfish (Parupeneus multifasciatus) Other families:
American butterfish (Peprilus triacanthus) - family Stromateidae (Butterfishes)
Southern ocellated moray (Gymnothorax ocellatus) - family Muraenidae (Moray eels)
Bonefish (Albula vulpes) - family Albulidae (Bonefishes)
Milkfish (Chanos chanos) - family Chanidae (Milkfish)
Common dolphinfish (Coryphaena hippurus) - family Coryphaenidae (Dolphinfishes)
Hawaiian flagtail (Kuhlia sandvicensis) - family Kuhliidae (Aholeholes)
Black cod (sp. indet.) - family Moridae (Morid cods)
Flathead mullet (Mugil cephalus) - family Mugilidae (Mullets)
Sixfinger threadfin (Polydactylus sexfilis) - family Polynemidae (Threadfins)
Regal parrot (Scarus dubius) - family Scaridae (Parrotfishes)
Swordfish (Xiphias gladius) - family Xiphiidae (Swordfish) Invertebrates Bivalves:
Ocean quahog (Artica islandica)
Clam (Tellina spp.)
Cherrystone, Chowder, Steamer clams (family Veneridae)
Pigtoe mussel (Pleurobema cordatum)
Scallop (Pecten grandis)
Hawaiian clam (sp. indet.; extremely high in thiaminase)
Blue mussel (Mytilus galloprovincialis) Gastropods:
Limpet (Helcioniscus sp.) Cephalopods:
Hawaiian flying squid (Nototodarus hawaiiensis) Crustaceans:
Prawn, Tiger shrimp (Penaeus spp.)
ive always fed feeders either rosies, goldfish, crays, or shiners. i do quarentine for some time and overload with chemicals, and lose probably half, but i know the rest are definately not infected, its nice because i thi k live food keeps fish agressive and strong. and definately not a staple food.