The weight at which penile castration is performed in cats varies according to the body weight of the animal. This depends on individual requirements for application site, pain threshold and efficacy per dose. The minimum accepted age for neutering/spaying in most countries is 6 months. However, there are some exceptions where this may be up to 18 weeks depending on country or region (see below).
Is it safe? You have probably heard that “it’s not just good for cats but also good for kittens” when it comes to neutering your kitty. While this might be true in some cases, you will want to consider factors such as age of kitten, health status etc before making a decision about spaying or neutering your pet cat. Once again I would recommend speaking with your veterinarian before undertaking any form of surgery on your cat(s) if possible!