Before the WWW (yes, there was a time before the web) I made about $2K-3K a year writing articles and selling photographs (generic kid-with-horse, horse-in-pasture, etc). I freelanced mostly --wrote, then submitted, and occasionally was given a specific topic to create an article. I also wrote short stories which found a small market in magazines.
When the WWW entered the picture, the entire market for magazine writing dried up, and many if not all of the magazines I wrote for consolidated or went out of business or turned entirely to in-house writers.
COTH forum board is the only writing I do these days. I no longer do photography either --instead switched to oil painting and do make a little money at that.
To your question: If I wanted to make money on my writing today, I would set myself up a website (very professional), blog, maybe, with links to my articles and short stories. I would then ask for a “donation” from those who enjoyed the site. I would then spend part of every day promoting my site and enlisting the help of other bloggers to promote my site.
I would go visual, too --making a YouTube commercial to entice people to “click on the link below” to take them to my site to read more . . .Tic Toc, too –
The only other way I can see that someone could make money writing in the horse industry would be for on-line established sites --but that’s a tough market and pays little. The problem is, no one really wants to pay to read something when there is so much for free to read on the same topic.
You might be able to pick up some money writing descriptions of horses for auction catalogues, but most people do that themselves . . .
In all honesty, it’s really tough to make money writing these days –
Interestingly, I still get a check now and then for a photo that’s reused and occasionally I will see an article or short story posted on line that’s one of mine. I always thank the person who posted it for using the material, and ask that they credit me with a by-line. Getting into the whole “you stole my story” thing is a waste of effort --everything is on-line now and too easy to copy and paste . . .my most often reprinted article is “How to Buy a 4-H Horse” --it appears yearly on many 4-H websites --but I actually “stole” the concept from another writer whom I know --I asked him if I could rewrite it for the 4-H handbook --he said sure, just make sure I put in there that he wrote it first and I’d simplified it and shortened it to fit in the printed handbook. It’s been circulating for 25+ years . . .