Safe times to spay/neuter

I have a litter of puppies and a mother and want to neuter those I am not planning on breeding asap. My concern is the south node/venus in Taurus is sandwiched by his natal sun and jupiter in the 12th house at the time/place of the surgery; the transiting sun will be squaring the natal moon and mars will be opposing the natal neptune and trining the natal sun.

They were born 4/28/12 around 8/8:30p in northport, ny, usa