I have 2 kittens, 5 months old. One of them is showing sexual-type behavior and his urine has changed odor recently. How soon do I need to neuter him before he starts ro spray? I was planning to get it done after Jan 1st, but it will be at least 5 days from now - maybe more...I was supposed to go out of town. I really don't want him to start spraying!!! Help!