It's been impossible (in the last couple years) to find and buy medicated food to save fish with bacterial infections but now there are easy ways to make such food successfully. 

It helps to forge a relationship with a legitimate veterinarian who can prescribe antimicrobials, but that's not always available. Weekend card table shot-clinic-vets are "special" in that they aren't regulated by laws that pertain to brick and mortar vets. For example they don't have to have a license to practice in your town or location. They can legally prescribe drugs for a pet they gave shots to one weekend at a feed store, and will never see again. So they have a lot of privileges granted by the FDA and the local VMA's – – that your regular vet can't compete with. So they can be enlisted. But you can also get antibiotics online as long as it has a picture of a fish on the label –  apparently that makes it legal to sell antibiotics over the counter without a prescription. Resources are listed in the article I'm referencing here. 

How To Make Medicated Food Easily and Successfully

The idea is that you can use edible shellac (confectioner's glaze) and bind the medications to the pellet of the appropriate size and kind. And it doesn't float off in the water the way the old old-binding methods did. 

Fishdoc.co.uk And Microscope Training

Over at fishdoc.co.uk there are about ten pages that take you through how to use a microscope. The detail is great, and the author is good at educating a non-technical person. Frank Prince-Iles wrote these tutorials probably 19 years ago. Not much has changed, but the articles were updated with some newer microscope parts. 

You learn about the parts of the microscope, what you can see and learn with a microscope, how to use the different parts and abilities of a microscope and even a suggestion on what to look for in a reasonable student scope. 

Nothing is left out. There are even movies of all the different parasites you could see. 

It's only going to get a LITTLE better when drjohnson.com uses some of that detail, and couples it with video using a SPECIFIC microscope that everyone should own, at least, anyone thinking about buying a microscope. 

https://fishdoc.co.uk/category/the-lab-microscope/

Treating Infections and Ulcers in Koi and Goldfish

Besides discovering and correcting environmental problems with the situation, attacking bacterial infections in Koi and Goldfish is a large undertaking. Especially if the infection is impacting the ability of the fish to breathe: The GILLS. 

The facilities can be very large as in the case of ponds. In fact, so large you can't actually HOLD the fish for treatment. 

The following article discusses how to treat bacterial infections when you CAN hold the fish for treatment, and when you CANNOT hold the fish, also discusses what to do in colder water versus warmer water. 

There are related articles, like how to SHOT GUN parasites in the scenarios with bacterial infections on your goldfish or Koi. 

Always, a microscope is the best way to protect yourself from guessing. 

http://fishtreatments.com/how-to-treat-bacterial-infections-in-ponds-and-goldfish/

We're going to do a video tutorial, step by step using this Celestron LCD microscope. Look for it on drjohnson.com 

Thank you for your kind attention! 

Fish Diseases Fixed By A Good Environment?

It's been said that "If you take care of the water, the fish take care of themselves" and I believe there's a BIG grain of truth in that. 

So much so, that I honestly believe that if you provided 90% of species of aquarium or pond fish with the following conditions, they could survive almost anything:

1. 78 DF temperatures
2. High aeration
3. Sponge filtration properly cycled and 
4. Tested to prove supported pH and nitrogen
5. Buffered pH and 
6. Plenty of space 

And so an article pulls all that together from "soup to nuts" with complete instructions and where to find the best deals on the best gear. 

How To Provide A Perfect Place For FIsh To Quarantine or Recover

Written by fish veterinarian Dr Erik Johnson and recommending ONLY things he has bought and tested in his own home, or fish room. 

If you were to follow this advice, and then treat your fish for their actual illness, I think you could hardly ever lose. 

Resources when facing fish health diseases, symptoms of illness like white spot, and parasite treatments.

There is a lot of information on the internet but it can come from inexperienced sources, and in many cases now, may be a 'bad-translation' of stolen content. It's a "thing" these days. 
"Change enough words and it's not plagiarism!" so they say. And when non-English speakers are 'changing words' I've seen some amazing errors.

The best fish health information can be found on DrJohnson.com because it's coming from ONE person and not a panel of self proclaimed experts. (Forums) 
Other sites in the same family include: Fishdoc.co.uk and Koivet.com 

But, sometimes you don't want a computer near the pond, and prefer details in a written paperback format so, perhaps your best bet is Dr Erik Johnson's textbook "Koi Health & Disease" 2. 
It's written in a cookbook "How to" format that almost anyone could understand. It's been well reviewed. In fact, the ONLY criticism of the book on Amazon.com is that the images inside the book are black-and-white greyscale. You don't lose any information with that, but people expect full color these days. 
Another resource is Fishtreatments.com (A sister site to drjohnson.com) Things are different on that site. 
At that Fishtreatments web site, which calls itself a "What To Buy For That Bug" web site, you get the symptom, plus a brief description and then HOW TO TREAT IT. 
You'll see an emphasis on improving water quality but you're not left wondering how to do that. Everything is spelled out from lighting to filtration, medications and resources on how to use them – 
The site focuses on Amazon.com-availability because they have Prime shipping, which allows virtually overnight delivery of most things. 
You're just LUCKIER when your local pond supplies store has everything in stock. 
Many times they do. 

https://drjohnson.com/thebook/
https://fishtreatments.com
https://amzn.to/2wTqgGR  The Book via Prime

Veterinarian Dr Erik Johnson (koivet) illustrates and explains his housecall kit. From the space saving microscope to the kinds of test kits brought to bear. Everything fits into a Pelican 1500 box. 

The page will be presented live in March, 2020 in North Carolina to a group of hobbyists, vets and retailers along with a Wet Lab and a seminar on "What Really Matters" in Water Quality. 

Here's the Pond Call Kit