I've owned horses for over 20 yrs and counting. I agree with a lot of the comments stated here. Three out of four of my children have ridden and shown horses competitively since they were 5 yrs old... One still does (she's 28 yrs old) and trains them as well. Here's my thoughts -
Horses are absolutely herd animals. They thrive on companionship and may develop mental issues if kept alone. Those mental issues can range from depression and failure to thrive to full blown neurotic behavior and bad habits like separation anxiety, cribbing, and more. If you don't want two horses, you have some options such as allowing someone else to board a horse at your place as a companion or looking at a smaller companion animal such as a donkey or pony. But for the health of the animal, you really do need a companion.
As someone already mentioned, horses are very expensive. I have 4 horses - 2 elderly mares who reside on my property at my house and 2 show horses who are boarded at a training barn. These costs listed below are ONLY for the 2 mares who are healthy so these don't include any emergency costs related to illness.
1. Feed - Feed prices have gone through the roof. I spend $30/bag on Triple Crown Senior and go through a 50# bag/week. You can probably get cheaper feed ($20/bag or less) provided your horse is an easy keeper without health issues. Horses that are ridden often need more calories, just like athletes. Others have a slower metabolism and need less. My daughter's horse only goes through 1 bag/month, for example. I also buy alfalfa pellets, rice bran, and supplements (MDM, Weight Accelerator, Garlic flakes, and Daily Gold), all of which adds about another $175/month.
2. Forage - horses MUST have adequate forage or they will die. Their GI system is built for forage. A good rule of thumb is to have 1 - 2 acres of pasture with grass per horse. If you don't have this much grass pasture, at a minimum, then you must make up the difference with hay. I try to seed my pasture so it grows rye grass in the winter and bermuda in the summer, but in the dead of winter all grass dies so I typically have to provide a bale of hay/day in forage from December - March. I buy my bales right out of the field for $7/bale. This doesn't count buying bales of alfalfa which provides great protein during the winter or as an occasional treat.
I also spray my pasture with a horse-safe weed killer to improve the grass I've seeded so it doesn't have to compete with weeds. I spent around $500 on grass seed and 2 4-d to improve the quality of my pastures. Again, this is a personal choice.
3. Routine care - my horses don't wear shoes because they are retired, are rarely ridden anymore, and I have thick grass pasture without a lot of rocks. However they still must get regular trimming of their hooves every 6 weeks. It's like you needing to trim your toenails regularly. Their hooves continue to grow and failure to trim properly and regularly can make a horse lame or even cause laminitis which can cause them to die in very severe cases. I pay $80 every 6 weeks for the farrier to trim my girls.
Vaccinations - just like your dogs or cats, horses should see a vet once a year and get their shots. Since we show, we also get Coggins blood test because it is required by law. I generally pay about $200/yr for vaccines and checkup.
Dewormer - horses pick up all kinds of worms through their foraging. I use a rotational deworming schedule every other month. Costs me anywhere from $10 - $30 every other month depending on the wormer.
Teeth floating - horses' teeth continue to grow their entire life. They get sharp edges which impacts their ability to eat. Their teeth need to be checked yearly and sharp edges filed down. This costs me about $80/horse.
Other practicalities -
Shelter - horses need a way to get out of bad weather. Be sure they have access to a barn, shed, or run-in to get out of wind, rain, sun, etc. Along with shelter comes bedding. I buy shavings and straw for our stalls. I buy around 20-30 bags per year at a minimum at $7/bag. My horses have free access to their stalls at all times but rarely stay in the barn unless there's bad weather or they are sick/injured and on stall rest.
Protection from cold - I buy horse blankets and sheets for my horses. Some people do not. This is a personal choice. Being in Florida, you can probably get away with just a lightweight sheet.
Protection against bugs - being a horse gets pretty itchy. I easily spend $50/month from May - October on fly spray and tick repellent.
Horse supplies - at a minimum, you'll need -
Halters, lead ropes, grooming supplies, water buckets, feed bowls, salt/mineral blocks, horse-focused first aid kit, hoof picks, and more. Order a magazine from Stateline Tack and it'll give you some ideas of basic needs.
Horse tack - if you want to ride, naturally you'll need saddle, bridle, bits, reins, saddle pads, etc. All of which can be very expensive.
Ebay and Craigslist are your friends here....
