Hello there!
Only tip I can give you if you ever want to go big on the breeding is that you'll most likely need to "clean up" the offsprings coats. Just going to expand on that now, I noticed some of your puppies have odd brown markings on them, that is perfectly normal in the game however many breeders stick to realistic animals and you may have a slight problem selling such puppies. What most of us do is going into CAP and modifying the animals to what they might actually have looked like. Whilst in CAP you do want to check which puppies have the right built and which don't as well - the game has a silly glitch where some puppies are born with the basic "Create a Dog" body template and again that can be problematic. What you can do is when in CAP change the age of your puppy to adult and see if it looks right, if yes then you just undo that change and you're good to go. If it doesn't look right then you still undo that change and either adjust the proper sliders manually or you if you have mastercontroller then transfer genetics from a puppy with the right body built. In the latter case do make a note of the puppy's traits and the gender and the name because at times they may change. The coat colour is likely to change to that of the puppy with the right built so if you want to keep the original coat colour then you need to save the coat colour whilst in CAP so you can reapply it after you are done with the transfer. Should you need this explained in a better manner/more detail let me know - I am currently revising so my explanations may be all over the place xD
The same thing will apply to kittens and at times, but much rarer, to foals.
Other than than your site looks great so far :) If you have not already you might want to look into al of the CC markings available out there which will certainly make creation of your animals much easier, certainly with horses :)
Should you have any questions feel free to ask them here or in the FAQ threads (btw, they have some information which you may or may not find helpful depending what you need help with) or just get in touch with any of us admins directly, either through a PM or an email :)
And definitely good luck with all of the breeding and such ;) if you do go into the Great Danes let me know because I breed them and may provide you with a puppy of two to start you off ;) also before I go, what cat and horse breeds are you looking to go into?
Edit: God, this turned out longer than I meant it too o.O