Sales with breeding clauses attached?

Not uncommon for breeders to loan snakes to each other for shared breeding programs etc. I know several guys who do it and I may be doing something similar in the fall breeding season. As for buying snakes and promising not to breed I'm with the others, impossible to enforce. 15 years ago I bought a Maine Coon cat from a breeder with an agreement to never breed him. The way it was enforced was I had to have him neutered and provide the breeder the paperwork proving it was done before she would send me his pedigree papers in case I ever wanted to register him.

Yeah its not uncommon to loan. I know some local breeders who do it, and I've been asked. But I don't trust lending out my snakes, both due to theft and disease.

I've also seen snakes sold as pet only, not for breeding, if that counts.

With dogs and horses it's easier to use "stud" animals. As the owner of the male, my animal never has to leave my sight. Either I bring the animal to the female and observe the mating, or I freeze and send sperm. Even if I wanted all of the mammals I produced to not be bred, that's a valid concern from a dog or horse breeder and can be enforced by contract (the breeder's of my cousins dog were strict about this, because she was the only breeder of that particular breed in that metroplex and the odds of inbreeding if you wanted to get into it were high). In the case of a snake, where locks can occur for up to a day or two at a time and when breeding is basically the only reason you would buy an expensive morph, that just isn't possible or practical. Because of these complications, I can't imagine this kind of thing becoming common. If you need the male for stud purposes, just don't sell it. If you don't want a new morph your sitting on to get out too fast, just don't sell it. Assume that once you sell an animal you will never see it again and plan your sales accordingly.

I haven't seen restrictions aside from "this snake shouldn't be bred because... (kink, severe wobble, fertility issues, history of egg binding, etc.)." While I have seen people enter breeding partnerships, it's risky (not much of a way to enforce terms) and I would imagine the most successful ones are between people who have trust in each other, rather than someone offering a stud or brood lady snake to the public. It's just too risky to lend a snake out to another collection and bring it back into yours, plus all the extra quarantine is a hassle. With dogs or horses you can ship seven and artificially imseminate; having the animals physically mate is optional.

I did have someone once ask me to breed his snakes for him, but I declined for a couple of reasons, some of which are listed above.

What some do are breeder loans in the majority of cases it's a lot more trouble than it is worth.

If you chose to do that have everything on paper.

There is nothing that prevents someone from breeding their animal, no matter how it was sold. There is no spay/neuter procedure for snakes (at least that I'm aware of - and certainly not as a routine procedure).

When it comes to dogs and cats for example, with purebreds, a breeder will sell their puppies on limited registration, which means that no puppies that are produced by those can be registered with the AKC (in regards to dogs). It is a check and balance for the breeder if the puppy buyer decides that they want their dog to have a litter or doesn't neuter or spay per the contract.

We recently acquired a golden retriever, who is not on limited registration, and we do not plan to neuter him. We also don't plan to ever breed him. The decision not to neuter is for health reasons only (UC Davis did a study that suggests that intact goldens (who are have high incidences of cancer) are far less likely to develop certain cancers - or at least delay onset significantly by keeping them intact, or delaying neuter/spay until their growth plates close at 18-24 months). But I say that to say that there is no ball python registration, where someone may agree to never breed, but then changes their mind, that governs said agreement.