neuter contract legality?

I have a little spaniel whomst I adore and he just turned 1 year old. The vet has been pressing me to neuter him for ages now but the breeder insisted he not be neutered until 24 months of age or that it would void contract and I would be banned from getting his registration papers if they did not see an original signed document of neuter at the proper age…

This was okay until my life circumstances changed and I found out I’m having to move into an apartment situation where doggy daycare is starting to feel necessary :/ I’ve obviously had to avoid using any services like that thus far and thankfully have been working from home, but the more issues that pop up where I really just need him watched for a day or two, the more this neuter thing weighs on me… also, other dogs have started to be aggressive towards him, which scares me! He’s not a tough guy, very submissive, and I don’t want him to get hurt. I really want him to finally get it over with and be neutered but the legalities are making me uncomfortable.

Is it true they can outright take him back from me if they find out? The vet seems very blasé that these contracts aren’t ever enforceable but I’m still worried.