Yes, in the feral groups I follow, fishmox is frequently recommended. Its difficult to gets meds for feral cats and its even more difficult to take them to the vet.

Sadly there is a rapidly growing sector of people in the U.S. who do not have and cannot afford insurance, and who also cannot afford the doctor visit to get a presription.

Back in the day when I had a 30 gal aquarium, I had occasion to use antibiotics sold by a pet store.

If you think about it for half a second, what would the alternative be? You could probably hold a convention of all the US vets with a fish specialty in the seating area of a Taco Bell. The vast majority of them likely work at public aquariums, zoos, and maybe some Sea World type places.

A reputable vet in general practice won't prescribe meds for a patient they haven't seen. Would you prefer a house call or instead to take your sick fish on a car ride?

I had no idea this was even a thing. Wow. I guess this is yet another reason to be incredibly thankful for my health insurance coverage.

I presume there must be dosing information online? I can't imagine a tablet designed to melt in water and treat tiny aquatic critters is the same dosage and whatnot as what a human needs?

Today I learned!

I presume there must be dosing information online?

There is, but many times the exact same tablet or capsule is sent that you would get at a pharmacy, you could look it up at drugs.com with the capsule/pill description and number.

I strongly suggest that if one has insurance and /or a way to see a doctor that is vastly preferable, but some people are uninsured, sometimes homeless, without transportation, and don't have access to medical help. Unfortunately under present policies that number of people is increasing.

When we used to take care of a feral colony, they all got an upper respiratory infection. The vet said we would have to bring all of them in. We used the fish antibiotics from the feed store. It came with a flyer for correct dosages for cats, so I'm guessing I wasn't the only one.

I won't give a moral lecture because I'm sure everyone who provides any care for animals not living in a domestic environment does so out of love and sincere concern and compassion for the animals. Unless the care provided included capture for veterinary neutering/spaying, and vaccinations, anyone so engaged may want to do some checking into the recommendations of animal welfare experts. Or, it can even be a good idea to call or visit your local animal shelter or welfare agency.

When I rehabbed, I used Fish Mox, and when I lived on the bayou, I took in two feral cat colonies that had to be relocated. Good stuff. Never had a problem with it, and I was grateful to have it.