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While spaying is traditionally recommended for kitties between 4 and 6 months of age, spaying as young as 8 weeks old is considered safe, according to Cat Channel. Many animal shelters actually spay kitties prior to adopting them out at this age.
Kittens as young as nine weeks can be neutered. Nursing females can be spayed when their kittens are eating solid food. If you trap a pregnant cat it is generally best to spay her anyway. If you trap a nursing female and you are unsure about the kittens, then use your best judgement after talking to your vet. The first step is making arrangements with a local veterinarian. For help in finding a vet or low-cost spay/neuter program contact SPAY/USA at 1-800- 248-SPAY. The next stage is the trapping. Your local humane society or animal control agency may be able to loan you the traps, or you may prefer to buy a humane trap. You can successfully neuter a colony with just one or two traps.