Hello,
My cat was neutered at 6 months old, he's now 4 and a half, and for the past month or so he's been getting erections.
At first I wasn't really sure what was going on — he was going to his litter tray very frequently and licking his penis a lot. I took him to the vet, who diagnosed an infection and gave him treatment.
Since then, he's been rubbing himself on the sofa, on blankets, pillows, and the duvet constantly, grinding his hips in a strange way and making low, unusual meowing sounds. One day I picked him up to have a look at his penis and noticed he had an erection.
I know neutered cats can still engage in that sort of behaviour, but after 4 years of nothing he's suddenly started doing it... I really don't understand it and honestly it's got me a little worried...