AIBU to be annoyed neighbour put spikes on the fence?

Cats are protected by law as free roaming animals. The op has done nothing wrong.

Tell that to the places where the only way to keep them safe from predators is to cat proof the garden or keep them in.

They need enrichment much like dogs and other animals they don’t need freedom to shut in peoples veg beds.

That’s very difficult unless you cage them outside, it’s not an experience they need it’s the ability to roam

I’m pretty sure you’re not allowed to do this.

You caused the problem when you got a cat & let it into other people's gardens.

Why should the neighbour come to you to negotiate? Maybe she doesn't feel comfortable. She's taken a tion to stop the problem affecting her. You don't need to change anything.

You could have spoken to her when you got the car and asked her to let you know if there were any problems.

No sympathy for the neighbour who has had three years to speak about the cat, and has not done so.

Be thankful your NDN is only blanking you.

A less scrupulous neighbour would be putting down rat poison to rid themselves of their ‘rodent infestation’.

I agree, plastic spikes don't tend to bother cats. My last next door neighbour detested all cats (mine literally never went into her garden - they crap in the woods and fields beside our house) and she nailed these spikes all the way around the top of her wall. She'd barely finished doing this and had gone inside when I went to put the bin out and spotted my cat jumping up onto her wall to see what she'd done, and proceeded to settle down on top of the spikes! I grabbed him off and took him inside (I haven't seen him do that again) but he definitely wasn't hurt or bothered by them.

OP, you might find it makes no difference to your cat going in her garden at all, so if you can find a way of encouraging your cat to crap elsewhere it might improve relations...

But you did know. You said it in your first post. "admittedly it's probably going into her garden"

You can cat proof your own garden so they can still experience the outside.

That’s ridiculous, people can own a pet & cats absolutely should not be kept inside it’s cruel

That's what I thought. The best you can do is plant a spiky bush or tree, I believe.

I’ve got cats and have for many years and I’ve watched one of my own happily drop one and wonder off no burying it.

"...DP thinks I should go speak to her and just ask what’s going on but my parents think I should just ignore it. Aibu if I say something?..."

No need to ask her what's going on OP, it's obvious.
The time to speak to her would have been when you were thinking about getting a cat that would be likely to shit in her garden.

It's very unlikely to be a shared fence. A fence usually belongs to one property or the other. If it's her fence then it's not really any of your business.

One reason dogs are far superior to cats is the fact dogs very rarely kill birds. It makes me furious the number of beautiful wild birds that get killed by domestic cats round here. You have to appreciate that anyone who is not you will likely see your cat only as a misanthropic shitting and killing machine...

Given your neighbour's age, it's possible she's become more anxious, or may even have some neurological changes due to Alzheimers. It's not unknown for the elderly to become more wary of confrontation, and change in character quite a bit, often quite fast. This could be a factor.

Not have cats, or keep them inside.

Well then if you haven't experienced it, it can't possibly happen.

😂 She isn’t coming across that way at all. She wants to sort the issue out and for her neighbour not to be upset. Stop making things up.

I think quite a lot of people in these comments are quite hard of thinking.

The OP didn't KNOW there was an issue, because no one told her. If she'd been told, she could have taken her own, safe measures to stop whatever issues there are. Cat owners aren't able to telepathically tell where their cats are choosing to shit.

You're all assuming that the cat shitting in the neighbour's garden is the source of the issue. You don't actually know that, because no one has mentioned anything.

The OP has said the neighbour liked the cat when she first got it, so she was clearly aware of the purchase of the cat.

If this was me, I'd be furious. I will never, ever understand people who want to harm people's pets. Find out first of all whose fence it is. If it's yours, remove the spikes.

If it's not your fence, I'd be writing her a strongly worded letter informing her that if your cat is harmed as a result of the spikes you will be holding her liable for any vet bills. I'd also mention that if she had approached you to let you know there was an issue, you would have taken your own, humane, preventative measures.

Totally lack of communication from the neighbour, ignoring you when greeting you isnt going to help you understand whats wrong.

if she cant tell you whats wrong, its hardly your fault you cant read her mind.

what is wrong is putting spikes in a fence without warning https://www.securefencingco.co.uk/can-you-put-spikes-on-your-fence-in-the-uk

I’ve watched them shit in my garden. On the lawn.

In 40 odd years of owning cats, have never found a cat poo in or around my garden! Not sure where all these comments about cats toileting in the open is coming from. They traditionally dig a hole tucked away, poo and cover it up.
Know some just don't like cats in their gardens but that's slightly different.....
She just sounds like she's taken against you and I wouldn't be over happy about spikes going up on a fence....

Maybe she is struggling too.

Do you know for a fact that she is not neurodivergent herself - or have other difficulties or disabilities.

You are coming across as very self absorbed & entitled.

if she put them on your fence, tell her to get them off immediately or you will seek legal advice.

The simple answer will be no, leading to costly legal action which is unlikely to be successful.