I bought a harness and lead for my young cat. The idea was to take him outside safely. He changed when I put it on. He is normally very active in the morning. I put the harness on him and he calms down. It is like someone gave him an injection. I don’t know what is happening.
The harness is a bit like a coat but not as big. I like it because it makes him calmer. In the morning he runs around a lot. I am not sure I like it. He could get hurt. He could damage something.
I am not sure he should wear it as it changes him so much. The change is a bit of a shock to me and strange to see.
Do you know why a harness for a lead changes him so much?
Response from Michael: I hope people comment on this. You have probably heard of the Thundershirt. This a product mainly for dogs but also cats. It calms them down. It is usually bought by dog owners whose dog has anxiety problems or becomes overexcited under certain situations. The general opinion is that is works but not always and, here’s the 64,000 dollar question: How does it work?
It seems to me that the harness you have bought works like a Thundershirt. It wasn’t designed to but it does. So it is triggering something inside your cat.
You say it is as if he has been given an injection. This may indicate that wearing the harness triggers the production of a hormone or a brain chemical of some sort in the cat. It may trigger the production of a certain type of neurotransmitter in the brain.
The manufacturers say the pressure calms the animal. Why? It may trigger an emotional connection to the time when the cat was a kitten being nursed by his mother. The pressure of the harness may create a reassurance in the cat for that reason. It may also cause some confusion because it is a created feeling and not real. In other words it puts the cat out of character for his age.
I also wonder if this reaction will continue or will it wear off? It may. I have not read that the Thundershirt stops working after a while but it might become less effective during long usage.
I’d be interested to know what anyone else has to say on this phenomenon. Update: I believe the cause for the change in personality is a partial kitten response. This is the response cats/kittens make when picked up by the scruff of the neck. This is strange because the harness does not put pressure on the back of the neck.

Cats were never meant to be led around! Why should they get used to something alien and unnatural to them.
When we were preparing to move to Florida from New York, since one of our kitties would be flying in the cabin with me and my husband would be driving the cats to our new home it was strongly suggested that we get our cats accustomed to wearing collars with identifying information attached to them JUST for their protection- as well as becoming acclimated to a leash.
We started very slowly. They did get accustomed to the collar (in retrospect a harness would have been safer) but when we attached the leash they went limp.
I don’t think that there going limp was an indication of calmness. In fact quite the opposite.
We introduced our cats to these aids simply for their safey during travel- and never used them to take them for a walk.
This said Jackson Galaxy has often recommends taking cats for walks using a halter and leash- and slowly getting them accustomed to these aids. Some cats that Jackson has worked with really enjoy taking walks with their guardians- as here in the USA in city areas with the huge amount of traffic it just isn’t safe for cats to freely roam unsupervised.
From the behavior you described of your kitty going “calm” when you put the harness on him, it sounds more like he is frightened and doesn’t understand what is now on his body. Perhaps start very slowly- use treats and lots of verbal praise- using the harness for only a few minutes at a time and slowly increasing his exposure to it as he gets more accustomed to wearing it. Then procede with the leash, again very slowly.
Hope this helps.
A young cat needs to run around, it’s against his Nature to stop him, it’s not right for a young cat to be forced to be calm, he needs to use his energy. I hope that person allows that cat to enjoy his youth, if someone likes a calm pet, then they shouldn’t have a kitten.
I expect it’s the pressure on the cats nape that causes him to go calm, like giving an injection, hold the scruff and the cat usually ‘freezes’ into immobility. I’ve heard of some vets putting clothes pegs on a cat’s scruff to immobilise him, I don’t agree with that of course but again it’s the pressure causing the cat to ‘freeze’
It’s not natural for a cat to be fettered and I worry it’s going too far as people are treating them like dogs, they are not dogs and it’s not right to treat them like dogs.
Thanks Ruth, but do you have any ideas why this happens? Sometimes it is not possible to allow cats to roam freely and neither is it possible to build an enclosure. Harnesses are compromises, yes, but they are a decent compromise under certain circumstances.
What is it with people trying to turn cats into dogs! If anyone wants a pet to take out on a leash then they should get a dog! We’ve taken enough from cats, let them be cats, if it’s not safe to let them have their freedom, then build a run!