What's the best and safest way to neuter a 3-6 month old pygmy goat?

This is a method called banding, and it is still pretty widely used amongst farmers. Usually it goes without issue or complication, but does have the potential to cause some pain and inflammation. This sounds like once of those cases. Jackson likely could benefit from some pain meds and anti-inflammatory medications. Also, if blood supply was cut off for long enough that there are now just a pair of dead or dying testicles on Jackson, the testicles will need to be removed surgically. I would contact your local veterinarian sometime tomorrow to address this issue and at minimum get him on some pain management.

Banding is cruel and not the correct way to castrate a dog. You mustg take Pip to a vet for the testicle to be removed and the wound to be closed. Pip will also need antibiotics and pain medicine. You can put a cloth around Pip in the area of the testicle so the testicle and wound do not get dirty until you take him to a vet. You need to take him to a vet now.

Generally after a rabbit is six years old, the anesthetic and surgery become more risky, so I wouldn't do it then. If Gwieth Gray is over two years old, I'd recommend having a health check and blood work done before having neutering done. He should be neutered around 3.5 months of age, when his testicles have descended.

Neutering is safe and is very highly recommended. Simba likely is cryptorchid, which means one testicle is retained in the body and hasn't descended. Leaving it leads to a higher incidence of cancer and testicular torsion later in later. You can wait until he is a year old to neuter him.

Although elderly, if he is fit and well and testicular issues are confirmed then yes, castration would be recommended. You should contact your vet to discuss gabis options in light of previous and current issues

It is possible to have your rat neutered. Find a veterinarian who treats exotics/rats regularly and this should be no problem. Here is some good info: https://vcahospitals.com/know-your-pet/neutering-in-rats

There is still a debate on whether or not spaying / castrating animals at a later age is beneficial. For now, until more research is done, it is still recommended to spay female animals around 6 months of age. Some veterinarians will recommend spaying at a later age (12 months or more) due to the effects of removing hormones on the body causing stunted growth and other changes later in life. Castrating is recommended around 6 months of age as well. However, in my opinion, it is ok to wait on castrating a male animal until an older age. In female animals, there is enough research that has been done that shows spaying reduces the risk of developing mammary cancer and also eliminates the chance of getting a uterine infection (pyometra) which can be fatal. In my honest opinion, if the stunted growth theory were true, I would take a decrease in growth rate over mammary cancer. I have spayed and neutered hundreds of animals and I have not seen any complications (other than urinary incontinence in female dogs) from getting spayed or castrated. If you want to wait on castrating Red, I would be comfortable in saying that this should be fine but to consider castrating him in the future due to reducing the risk of testicular tumors and prostate issues. I hope this helps! Please let me know if you have any other questions or concerns and I would be more than happy to help you further!