After having owned and kept three horses at home for most of my life,the inevitable has happened ,we all grew old and now we are down to only one.I am spending a lot of time with him ,a 16 year old TB who ,like most racehorses ,grew up being more around people rather than other horses .he is visibly enjoying the renewed attention since for the last few years,most of my time went to keeping the old mare happy and comfortable.i am contemplating getting another horse since conventional horse knowledge says that one horse will be unhappy and i have held that opinion myself .lately i am questioning this since he shows no signs of stress or anything resembling sadness .we have become quite close actually and getting another horse will mean dividing up my time once again.i want to do right by him and wish he could talk 
- interested in other people s thoughts and experiences
it’s one of those “it depends” questions in experience. I would say most horses are happier with a friend of some sort, doesn’t have to be another horse - a donkey, goat or sheep seem to be acceptable to most, but I do have several clients with only horses, usually the last man standing old horse that is retired as a lawn mower and kept in the yard sort of thing and gets lots of human attention that seems perfectly content.
I have known several horses that much to the surprise of the humans were quite happy living alone.
If he seems content, why rock the boat.
Every horse and situation is different, but I too ended up with just one oldster.
I thought he would be happier with a friend and tried for several years to find him a friend.
Some were a good match but he really was happier alone.
If friend/s went off, he laid down and took long naps, never nickered or worried about them being gone or acted interested in them when they came back.
A couple he disliked greatly.
We have others come ride in the evenings and he would hide under the barn until everyone was gone.
Never came out to see who came in those trailers, who nickered, etc.
Once it was obvious he liked it best alone, I quit trying to find him a friend.
I know of other horses that also like it alone best.
If that is the way yours likes it, don’t worry to find him a friend.
If he changes and starts looking around and wanting horse company, look then for another horse?
Depends on the horse 100%.
Many times if you have other animals that they can see that is all they really need. If you have one who is unhappy, restless and just not settled then they need a companion.
If the horse is content then count your blessings!! You will not deal with herd bound issues unless you trailer somewhere with a friend( its a possibility).
I was in the same situation a few years ago. My little herd, originally three horses, got down to one pony. He was relieved when we euthanized the mare he’d been living with for about 15 years–she had gotten very weird suddenly, being very mean to him, not recognizing her humans any more, and it was time to let her go. So there we were, with one pony.
He seemed so much happier for several months. Then he started making the wrong sort of friends. It was fine when he hung out along the fence line with my neighbor’s alpacas–they’d always gotten along well. But then he started inviting the deer in for sleepovers, sharing his food with them. The day I found him with five deer sharing the shed, I knew it was time to get him some better friends.
I boarded him where he was the only boarded horse; the BO had two horses and just wanted one boarder to help pay her horse bills. She was wonderful and the horses got along well. She wanted a retiree, which he had recently become due to cataracts. The timing worked out well as we wanted to sell the horse property and significantlty downsize.
Rebecca
If he’s content to be by himself, I wouldn’t worry about getting him a friend. Like you said, he’s getting all the attention from you now, and if you get another horse, that’ll be split.
When my older two were laid to rest, I had my (then) 12yo gelding left on my farm. He was visibly upset, calling and searching, and spent his days standing at the fence nearest the neighbor’s horses. It was sad, but he’d lived with those two geldings for 11 of his 12 years, and he was very attached to them. Both were rather sudden deaths too, so it wasn’t like he saw them aging and withdrawing from him. They were alive and well one day and gone the next. He handled the first okay because he still had the other, but when that one broke his leg and was euthanized two years later, it really took a toll on my boy (and me for that matter).
Sold the farm, started boarding. He never clicked with anyone very well at the first barn and was kind of a hot mess the entire two years he was there (I think ulcers were probably present too). Second barn, he got along fine with the gelding he was turned out with at first, but he was an old fella too and my guy started bullying him a little, so he got separated and turned out alone. He was fine with that too. Now he’s out with the love of his life, a retired OTTB mare. They get along great and he loves her (sometimes too much).
I think my guy would be okay to live by himself though, if push came to shove. He likes being an “only horse” and getting all of the human attention. All the treats and scratches and pampering are his now. He seems to love it.
If your fella is loving being an only horse, let him. Give him all the love!
i am responding to this last message but really,i am responding to all who have commented so far ! so great to read all your thoughts and stories,this is very helpful to me !
we had said good bye to my almost 40 year old pony last year,while his death was sudden ,at this age it was not unexpected and the other two ,had bonded very closely anyway so all was well .the next to go was the 36 year old mare who he was best friend with right from the get go ( he never bonded closely to the pony ) and they were two peas in a pod,towards the end he was like her body guard ,always close by and *reminding * her gently when it was time to get up ( she would sleep for hours on the pasture some days ) and generally guiding her around as if he knew that movement was good for her old arthritic bones.never pushed or shoved her.but when she started to fail and we had to keep her in the barn more often,he slowly but surely got used to going out to pature by himself ,still coming back to barn once in a while to check up on her.we had to put her to sleep after she quite suddenly suffered a stroke which in a way was a blessing as we could see her time was near but making the final decision is always so difficult.in this case,it was crystal clear.we buried her the next day and i expected him to be complety heartbroken . he did call for her a full day and stayed very close to the house ,almost slept next to my bedroom window for a couple of weeks and did not venture out to the far pasture for a good while.i started to work with him in the ring every day and took him for walks through the woods,gave him massages and carrot stretches and extra TCL and he soaked that up.as mentioned earlier,we have a very close bond now because of that - we did get along fine before as he is a very sweet natured gelding but having just one horse allows for a deeper connection as we both are very focused on each other now…things might change when winter comes as i likely will not be able to do as much as i do now and he will spend more time in the barn by himself - i am keeping an open mind as to what we will do then.
Perhaps your attention during the mourning period/transition helped him get over the loss. He’s adjusted now, and may not need you (or any companions) anywhere near as much in the future. He sounds like a mature, well-adjusted low-energy horse that may be just fine by himself.
I’ve always thought that the minimum number of horses to keep was three, as two get so strongly bonded. With three, they seem to be much more independent and able to be alone happily.
This really made me laugh!
Horses are herd animals and generally seem happier and less stressed with other horses around- but of course horses are individuals and what works for one or even most isn’t always the right answer for another.
And just wanted to clear up any confusion about racehorses - they are actually always around other horses - almost always go out to the track and work in company, spend most of their day in stalls with the door open just a guard on so they can see the other horses, and usually are turned out in large groups as youngsters. It is not uncommon for ottbs to get buddy sour or anxious alone, because they are definitely not used to it.
I had to help my old guy over the Rainbow Bridge this week 
; leaving my homebred alone here on my wee farm. He’s settled fairly quickly (the first day or two about broke my heart) and doesn’t appear distressed in the least. Eating, grazing, laying down to sleep, responding to training / handling like normal, utilizing the barn like normal etc. However, he looks pretty darn bored. So not upset but not perfectly content either. While I would far rather only have the one horse to pay for and take care of, for my boy getting another horse is in his best interest. Eventually. I just don’t have the heart to find another horse right now.
YMMV
so sorry for your loss ! it is so hard to let them go even when we know it is for the best…you bring up an interesting point about the horse looking bored.most horse people will look at a single horse on a pasture and think * poor horse ,it looks lonely*.when researchng this i found sort of a check list : is horse eating ,responding as usual ,changes in behaviour,taking an interest in its surroundings and other things that can be observed.but - a horse is always reflecting our present state of mind and i have had people looking at a horse and giving different impressions about the same animal.so tricky to be sure sometimes.glad you can see it clearly - i am still wondering.
Interestingly, horses that are less dominant in the herd are more likely to be okay alone. The dominant ones are the ones that get anxious when separated from the herd. (The dominant one is usually the one at the gate first to come in at dinner time and will kick or snake his or her neck at whoever challenges their position.)
If your horse is not acting depressed or anxious and it sounds like he is not, then he is probably okay alone, even if he might like some company. Less dominant horses are sometimes happier not being pushed around. I think that makes sense.
Makes sense - this one is relaxed and easy going by nature,non confrontational in a herd ( where he was before i got him) .loves food and sleep 
and being fussed over ,his daily work out .still ,he did love his mare and was glued to the hip to her.but never minded being taken out alone .i do believe he would prefer the same set up we have now where he gets all the love and attention but at the same time ,also have equine company .the perfect world,right … 
Not necessarily and that can be a different situation than a horse completely alone.
We turned a new gelding in with the other three amigos and he seemed to fit fine, there was not an ear pinned, not a hair out of place.
Slowly he gained confidence and started gently driving them around here and there to graze and then back to the pens to drink or eat, then back out to graze, still no ugly faces or snaking head.
Their pasture was a mile long and he spent all day and night slowly driving them back and forth.
After a while, the two older horses were getting sorefooted, so we took new horse away and he was pastured right across the panel fence by them close by and more separated further out from the barn.
Guess what, that horse didn’t care at all, he went out to graze on his own, ignored the others.
The other three?
Silly boys stood by the fence, waiting on their new boss to tell them how to spend their time, when to go graze where, when to go drink, to be fed, etc.
They would watch him come and go from their fence line, stood there all day, took naps there, walked along the fence with him to the pens for water and to be fed, him ignoring them.
I tell you, horses sure live to their own drummer, when we think we have figured how is best for us to manage them, they show us how wrong we can be and what we think we know may change next day, next horse. 
ON POINT !!!
For many years my riding horse had a donkey companion. They got along well, but I always thought he would be happier with another horse. When the donkey died, I adopted a horse to be his new pasture mate, and it has worked out just as I had hoped. Those two horses get along, but not so well that they can’t stand to be apart. And it does seem to me that my riding horse is happier with another horse as a companion. It’s a very subtle difference and hard to put into words, but I see it when I watch them racing around the fields together, bucking and farting. It’s the difference between being just content with life and being joyful.
@buzul, if you do decide to get another horse consider adopting one from a reputable organization. That way you would not only have a companion for your horse; you would also be providing a home for a horse that otherwise might not have one. My adoptee came from the Humane Society, and they provided me with his medical records, accurate assessments of his personality, and as much information as they knew about his background. He has kissing spine which was causing enough pain to make him buck under saddle, so he was adopted out as a pasture pet only. He is completely comfortable in the pasture and doesn’t need any special care (other than he has to have his butt scratched every day), so he really doesn’t add much to my workload. It’s a win for all of us–my riding horse has a buddy, adopted horse has a home, and I have two horses that I love.
Thank you.
Some of the changes in behavior that I’ve noted in my single horse since his buddy passed: he changed where he sleeps laying down, increased whinnying at me and there is something slightly different about his posture when he’s taking standing up naps. Again I don’t think he’s terribly disturbed or anything but ideally I think he would like some company. Since we are still adjusting I’m keeping a close eye on him bc I accept his behavior could change.
Of course, I think my dog would ideally like another dog to play with and that’s a hard no from me.
If he seems healthy and happy I’d leave him by himself but keep an eye out for any changes. Especially if you don’t intend on ever having more horses after this one - you can end up with a situation where you only have the buddy left, then you have to get a buddy for that one, and on and on.
Another option might be to foster, especially if OP intends her one remaining horse to be her last horse. Then the foster has somewhere to return to in the end.
