For people who are looking for the O.K.Cattery's "debugger", the most important part is the feature to allow you to tweak the emotions, health and age of pets. I've not used the debugger itself, but I do use a small registry key for each of the Petz and Babyz games, and I'm sharing those keys with you here to help hexers who want to see their pet in adult and baby stages, as well as the breeders of Alley catz.
The trouble with Alleys is that they are constantly full of fleas and sickness, which I think was a very mean thing for P.F.Magic to have done to the breed. It makes no difference if you substitute a different breedfile for the base Alley one; the behaviour appears to be written into the petfile.
What you can do to alleviate this and help them to breed is to keep re-setting their flea level to zero; the flea spray helps with this, but doesn't remove the sickness. The best way to get them past this problem is to enable the hidden "sliders" in the game. You can do this with Omar's "debugger" if you can get hold of it, and I believe that some people are now putting it up at their sites, but if you can't find it, this will work (and it's what I do).
Open Notepad. Then click on the link, below, that's for your version of the game, and then copy the stuff that's on the next page.
For Petz 2
For Petz 3
For Petz 4
For Petz 5
Babyz players who don't seem able to make it work, click here for a fuller description and a manual method. Incidentally, the manual method works for the Petz games too.
Save it as "pet.reg" -- the .reg extension is important -- and then double-click on it.
Next time you start up the game and your pets come out, you will have a slider-panel for each pet or baby. On that slider-panel you will see "Sickness" and "Fleas", and they keep popping up to 100% for Alleys. Just keep pulling them down, and keep on with using the love potion. They will breed after a while.
If you want to turn the slider-panel off, replace the line "Show Slider Brain"=hex:01 with "Show Slider Brain"=hex:00