Singleton Syndrome: The Lifelong Consequences of a Lonely Kitten

Singleton Syndrome. Whether you’ve heard this term or not, you’ve likely met a cat or kitten with it! Perhaps you’ve heard the terms “Single kitten syndrome” or “Tarzan Syndrome” instead. Heard stories about kittens being taken away from their mothers or littermates too early? But what does this all mean? Why is it such a big deal, and what can be done about it? This is what we’ll discuss today!

First, let’s get our definition straight. I have adopted the term singleton syndrome. To me, it is the most straightforward and to-the-point label. It says what it is, doesn’t create false impressions and is often accompanied by proper treatment definitions. So, what is singleton syndrome, really? It is a set of behavioral problems that arise when kittens are not socialized with other cats during crucial developmental periods; when they’re learning to “Cat” from their peers.

It is characterized by:

This is a real issue, one that makes up the majority of my consults. We may see cats as independent, we may classify them as selectively social…but early socialization, both with humans and other animals is an absolute necessity for behavioral health throughout their lives if we intend to keep them as household companions.

If this is such a big issue, what’s being done to combat it? It’s tricky. Combatting singleton syndrome in homes often means taking away freedoms from adopters. In this world, it can even limit their housing options! (Looking at you, landlords with single cat policies.) I’m going to discuss what shelters can do and often are doing, as that is the environment I’m most knowledgeable about. In shelters, kittens that come in alone and healthy can be combined with other kittens to provide socialization. Kittens who have needed to be quarantined due to contagious health issues such as ringworm may need to spend some extra time in care as often they will already be showing some behavioral issues by the time treatment has ended. (Ringworm singletons are the worst!) For these little ones, simply combining with other healthy litters or perhaps sending them off to a foster family with another kitten for a while will help.

Many shelters are working hard to avoid singleton syndrome, adopting stricter adoption policies for their kittens. For many of them, all kittens must be adopted in pairs unless there is another cat in the home. For some, there are additional parameters on what that cat at home is like, as a skittish senior is not going to help that kitten one bit, nor is the kitten going to help that senior. If the potential adopter puts up resistance to this policy, there are two different ways I’ve seen for dealing with it. In one instance, the shelter will simply refuse to adopt out the kitten. The other puts the responsibility on that adopter, often making it a fun learning experience at the same time! Many of these shelters have brilliantly designed fun, art-filled pamphlets and contracts that depict why these policies are in place. They are willing to bend on the policy and adopt out that kitten, so long as the guardian thoroughly reads and signs a contract describing the potential behavioral issues they are signing up for by adopting a single kitten. The adopter is acknowledging that they were warned that this may potentially become “Kitten or catzilla” and they were willing to take that on. Many people think this is just some marketing ploy, a way to push kittens or make money…but it’s not. Heck, many shelters do BOGO or BOGHO on kittens just to make it easier. We’re trying to prevent returns, angry calls, behavioral problems, and abandonment.

So…where does that leave the guardian in the prevention game? Adopt two. Or, only adopt a singleton if you have another moderately high energy (or highly tolerant), confident cat in the home. If you insist on having only one cat, you may still be able to raise a well-adjusted kitten, but it will take a lot of work on your part. The primary reasons I hear for not wanting to have two cats are that of time or cost – and honestly, as a guardian of eight cats, neither are very proportionate to the number of cats. Costs for veterinary care and food do mildly increase when you have more than one cat, but it is not exorbitant. There are ways to do things “smarter” and keep costs down while still adequately or even superbly caring for your cats! I can tell you that you will spend a lot more time on one cat than you will on two. I don’t spend any more time on eight than I did on three, aside from maybe scooping the extra litter boxes! If you’re dealing with singleton syndrome, the time taken triples as you’re actively treating behavioral problems. With one cat, you’re their sole source of enrichment, attention, care- You’re their entire world. That’s a lot of responsibility. Just tossing toys on the floor does not keep a cat entertained. You need to be playmate and prey, and even if you aren’t willing you’ll become it, courtesy of tooth & claw. Having two cats takes much of that responsibility off of you. The other cat becomes their playmate and companion, they may be affectionate towards each other. If you’re really crafty, you might be able to schedule veterinary appointments in blocks; have them seen together and save that time, too. (This can be helpful behaviorally as the foreign scent of the veterinary office on only one cat can in some instances make them unfamiliar for a period and seen as a threat – an impostor. This causes extreme, but temporary aggression and unease in the home environment that requires the cats be separated for a period of time. This is called feline non-recognition aggression.)

This is not to say any cat raised alone will always have issues, nor that every kitten adequately socialized with other kittens is going to be an angel. This is simply a "condition" or collection of behavioral problems that has a set cause - and this so happens to be it. These problems often lead to injury and relinquishment, but are easily avoidable! I want people to know about it so that more can be done to combat it.

What does singleton syndrome look like? I feel the best way to demonstrate this is to give you an example of a common behavior call I take:

“I need help with my cat, I don’t understand why but he’s just become so aggressive, he won’t stop attacking me. He’s so sweet most of the time but he just attacks out of nowhere and I don’t know what I’m doing wrong, or what’s wrong with him.”

“Okay, I’d love to see what I can do for you. Can you describe the typical attack for me? What’s usually happening before he attacks you – are you walking by him, petting him, or does it just seem to happen regardless of what you’re doing? Are these attacks seemingly playful in nature by your estimation, or are they aggressive? Does his hair stand up, do his ears pin down? Does he vocalize at all? How often is this happening, and how have you been responding to it?”

“Well, it depends. It’s gotten more severe recently, sometimes it happens when I’m petting him, but it did start when I would walk around the house. He’d run up and grab my leg with his paws and bite. At first, it seemed like play but now he really clamps down. He’s broken skin, I’ve got cuts and bruises all over my calves. When I pet him he’ll be okay for a moment then turn around and start biting my hand really hard, sometimes he just won’t let go. It is getting more frequent, I feel like he’s stalking me. I can be sitting at my desk doing work and he’ll grab onto my leg – I haven’t even done anything. Sometimes I notice his eyes get wide, his ears pin back, and he’ll pounce. Other times it just seems completely unpredictable! I have noticed him having the "zoomies" from time to time. I’ve tried telling him no and bopping him on the nose, just hard enough to let him know, but that wasn't effective. I tried giving him time-outs…but he just screams to be let out and it doesn’t seem to help. I thought about using a spray bottle but someone told me not to. I just don’t know what to do. That’s not even the thick of it, he’s into everything! He’s a real handful…but he can be a wonderful cat when he wants to be. It’s like Jekyll and Hyde. Can cats be bipolar?”

“Goodness, yes, that certainly sounds like you're dealing with a lot. I’m sorry, but I’m sure we can find a solution. That’s a lot of great information to work with. First, no, bipolar is not a thing in cats. This sounds like an energy management problem, but I'd like just a bit more information. Are there any other animals in the home?”

“No. I did think about getting him a playmate, I thought maybe he’s bored and taking it out on me like I’m a peer or something...but I tried having my daughter bring her cat over for a playdate and it went awfully! He hated her. I don’t think he would come around to another cat…I’m not sure I could handle two anyway. What if it made it worse?!”

“That can be the case sometimes. That still may be a potential suggestion, but I will take the additional information you’ve given me into account. There may be alternatives, they just might be a bit more intensive on your part. No matter what path we take in treating this, I’m here to help! What does his daily routine look like? Explain his feeding schedule, playtime? Do you have interactive play sessions, meaning playing with a wand toy, laser, fetch, anything like that?”

“It seems to be worst when I get up in the morning and he’s hungry, he’s all over me then, but he’ll settle down after I fill his bowl. I keep dry out all day but he’s usually emptied it by the next morning. I work from home so he gets riled up again when I’m settled at my desk, I’ve wondered if he’s jealous he’s not getting attention. He’ll bite me or chew on cords, knock things off my desk. Sometimes I’ll try and toss some toys around when I have a moment to distract him, but he’s not interested. I’d lock him out, but he just screams and it’s hard to get work done. Eventually he calms down and takes a nap, but when I go to make dinner he’s after me again, usually for the rest of the night. Sometimes he’ll sit on the couch with me, but I try not to interact with him too much because he seems to want to be near me but not want me touching him since he’ll attack me after a few pets. Sometimes at night he’ll walk around howling, jump up at pictures on the walls, tear through the house like a bat out of hell! He’s also very smart, I’ve woken up to the kitchen cabinets open, Tupperware out on the floor, and him inside! I don’t know what to do about that now! He has a lot of toys, he liked those fuzzy mice but seemed to get bored. He likes milk rings too. Sometimes he’ll play fetch, but lately not as much. He’s destroyed the blinds trying to get at the windows, I don’t know if he just wants to be outside, or what…”

“So, no regular interactive play? Just want to be sure.”

“No, I guess not. Should I be playing with him more?”

You get the gist. A nightmare, right? This is just one example – It comes in many shapes and sizes. This is the “usual.” Sometimes the adults just verge on the aggressive side, without the tenacity or high energy. A ton of skin rolling, hissing, growling – snapping when touched, severe aggression with change, new smells, any animals around or in the home. I’ve seen some cases that were let go for so long, and to a degree where these cats didn’t know any outlets for their emotions or energy other than snapping. I’ve had to train a cat how to play! Seriously! How does that happen, it’s instinct! They truly never learned to cat. I feel so much compassion for these cases, it's almost as if they're neurodivergent like me. They simply don't have the tools to fit in. They’re overwhelmed and have nowhere to put all the “Stuff.” I’ve been there, and I want to help.

So, what do you do when you have a singleton, can’t get another cat, but desperately need them to “get better?” The short answer? Enrichment. Enrichment. Enrichment. Treat this like the Tasmanian devil of high-energy cats. Act like you’ve adopted a savannah or serval, perhaps. Pull out the entire bag of tricks.

First, play. Lots of play. Vigorous, long play sessions. As much as you can get the cat to take. Doesn’t like any toys you’ve gotten? Try some new ones! Get different styles, experiment! If it truly seems like you’ve got a kiddo who doesn’t know how to play, we can work with that. Clicker training or positive reinforcement without a clicker can do the trick. Bring out the wand toy and reward them for approaching it. Reward them for sniffing it, touching it, swing it around a little, if they bop it – even out of annoyance instead of play at first, reward them. (We don’t want them to keep being rewarded for violent smacks, but if that’s what starts making the Paw + toy = treat/pets connection, we can later dampen things down to only gentle or playful touches!) Make the toy a source of good things and something they want to be around. As they progress up this ladder, stop rewarding for the little things like sniffing. Eventually, only touches with the paw are acceptable for a reward. They want the reward, so they should start experimenting to get it more. Once they’re touching it more often, start trying to get them to chase it. So on, so forth. Eventually, that instinct they will start to enjoy play. This is one of the few behaviors in training where you shouldn’t have to reward forever, as it should become rewarding all on its own.

Lasers work, too, if that’s what they like, but lasers come with a warning. We’ve been finding that lasers cause heightened stress in cats due to the lack of a successful hunt; they don’t get to catch anything. This has been found to result in increased play aggression in some cats. (The exact thing we’re trying to combat in singleton syndrome!) So, if you use a laser, always finish it with another toy they CAN catch, bite, and kick, or provide them with a small meal.

Environmental enrichment: Vertical spaces! Scratching area! Window seats! Battery-operated and motion-activated toys! Catios! Anything to make their environment exciting and entertaining – anything to expend energy. Keep them moving, thinking, and reduce stress. Provide fun things to not only entertain them but keep them out of trouble, especially if they’re inquisitive and getting into everything. These kiddos are smart: they’ve got a lot of brainpower and energy and not enough outlets for it. With a friend they might be expending it through wrestling and ambushing throughout the day, play hunts. When they’re alone…the world gets pretty boring. It’s like giving a 5-year old a rubber ball as their only toy and locking them in a room for a year. That ball will lose its appeal in a few hours if not minutes, and that kid will go a little batty before long! Those fuzzy mice are only entertaining for a while, and only when interacted with. They don’t DO anything on their own. Hide treats around the house for them to hunt out, buy puzzle feeders – anything at all. I’ve had guardians who call me to let me know in the middle of our treatment journey that their cat became ENAMOURED with the reflections from their windchimes one summer and they kept him occupied every afternoon, they wanted to know if setting up windchimes or reflective objects like that in the home would be a good idea. If it's working, go for it! I’ve used disco balls in the shelter for enrichment! Just don’t let this passive entertainment take away from other activities.

What else? Clicker training! Train them practical stuff, fun stuff, weird stuff, anything at all! Clicker training is great because it’s mental and physical stimulation, as well as a great bonding experience.

Harness train them! The great outdoors is highly stimulating, mentally invigorating. Walks are physically strenuous. You’re once again burning tons of energy and working through stress. There are so many sights, sounds, and smells. Once they’re used to that harness, taking them out can be wonderful enrichment.

DO NOT respond to their attacks. No spray bottle, no bops or smacks. No time-outs. No “Bad kitty!” No…anything. A sharp, short sound immediately as they bite can be effective – I won’t tell you you can’t do that. Overall, it’s best to go limp and when they release, walk away. Just leave them for a while. They don’t get any gratification for what they’ve done. If you’re consistent with it, they should learn that nothing that could even be construed as positive comes from what they’re doing. No play, no attention. The behavior should lessen – they may become gentler. Once you return from your absence, it might be a good time to start a play session so you’re not immediately a target again – you know they’re wound up, so what do we do about it? We drain it. You just don’t want to play immediately as that would reinforce the biting behavior as a cue for “I want to play!” Consider this a variation of a time-out – it’s just not putting the cat away. Moving the cat would involve handling, maybe talking, and so on. In that time the cat might forget and make several other associations. Handling might be a reward, too! It’s much better to remove yourself as promptly as possible. It’s them chasing you away for several minutes as a direct consequence of their action.

Looking to have cat-cat playdates for your cat? This one is difficult. It takes more than a short visit to acclimate the average cat, and a singleton may take much longer. You can’t just have that animal over and hope everything’s going to be okay, it won’t be. You can start getting items from your friend that smell like their pet, introducing them to the home. Give them items to scent soak if you have to – trade cat beds for a week or two. On the first playdate, they won’t see each other, they'll just smell each other through a door. Next, you might stack baby gates in that doorway and cover with towels - more smells, still no sight. If that goes okay, maybe next time without the towels, still not interacting. So on, so forth. It will be many visits before the cats ever meet. Ultimately, it will need to be gradual, and I cannot guarantee that any occasional interaction like this will be successful; it’s never allowed to become truly familiar. That doesn’t mean you can’t try, though…especially if the cat is young. For another animal staying in the home for a while, this is more likely to work, but will again take time. If it’s a week or two, you may only get them to meet each other by the end of the visit – if at all. This could take months. For a cat like this, unless you’re going to truly bring another animal into the home for good, I honestly recommend just separating them from any visitors, it’s likely not worth the stress. As much as socialization might help them, irregular socialization after the damage is done may do more harm. Especially if you’re already dealing with aggression.

A cat that never learned to communicate properly may not be able to, we may not be able to teach it to give us appropriate cues, but we can learn how to read those they do. Even if they are sending mixed signals, there are usually very subtle cues in there that do fit what they’re actually feeling and can be followed. If you have a cat like this, I'd recommend studying a little feline body language! Learn the subtleties. If your cat goes from purring and trilling to lunging, or maybe hisses and spits in between bunts and flank rubs – you might be missing piloerection, maybe their ears weren’t quite neutral. How was their tail moving? Was their back rolling? There are a lot of pieces to feline communication, and even when stress throws it off, there’s often still a roadmap. In these cats, their communication is also typically very fast, moving from back twitch to bite in seconds – you may miss the cue if you’re not diligent. Knowing what to look for and being fully aware of your cat throughout treatment and management is helpful.

Treating singleton syndrome as a human will likely be a lifelong journey. As they age they may require a little less of you, but they may always need more than the typical cat. They just never got the right tools, it’s not their fault. It doesn’t mean they’re bad cats…and all of that extra time together shouldn’t be seen as a burden, these are opportunities to bond! You could be the talk of the town with your super cool harness-walking, high-five giving, does-backflips-during-fetch cat! How things turn out in these situations really depends on how much you’re willing to put into them. I’ve had clients who thrived and now have amazing relationships with these cats, and I’ve had clients who couldn’t break through and ended up surrendering or rehoming. I’ve seen worse. I’ve treated some singleton adults myself, in-shelter, and sent them home with their recommendations and I’ve seen those recommendations followed and those cats thriving, those recommendations neglected and cats eventually returned. It is all up to you. You’re their world…and these kids, especially, are at a bit of a disadvantage.

That’s singleton syndrome. A complex group of behavioral problems and deficiencies that comes from a lack of inter-species socialization during their early development. My dear friend and devoted kitten foster who voted on this topic for this week might prefer it be called “baby shark syndrome!” because the sudden behavioral change and snapping really is no joke!

Next time you head into a shelter…don’t see them as kitten pushers or moneygrubbers for trying to get you to take two. Heed these warnings…kittens truly do fare better in pairs!

Until Next Time

-Meg