That statement about multiple forms in the earlier post is incorrect. You have only one <form...> tag
You have a typo in the tag, but still only one form tag that I am able to locate.
<form name="the_form" form method="POST"
The typo is highlighted in red above.
The real problem is related to your naming scheme.
You are trying to relate the image in the new code to the old code without regards to the overlaps. Also, you changed the new code in the correctly submitting program to not match the new code in the image correct script. It can be fixed, but you need to rethink your naming scheme to be more consistant. When you first posted the problem, you left out some critical information about the extra 'Breed - Name - stuff'. Took me awhile to figure it out because your naming of variables is not very informative.
Look carefully at the original image changing script sent earlier and compare it to your two versions and then to the attached script. In particular look at what is being referenced for the image changes and the 'p1' - 'p3' and 't1' - 't3' names and ID values.
Some of the changes are subtle, so look carefully. Personally, I would create a page with only the selection and submission for say 3 to 6 breeds. Leave out all the banners, information, pricing, etc until you have a working script. Then put all the pretty stuff back in around the important working code. Note the validation message information and expand upon that as you add further elements.
In the code attached file I took out the <form...> submission for testing purposes and put in some alert() debugging code into your confirm_p1() function. I assume this will be a validate function for all entries in the future, but for now it only checks the one 'Add To Cart' button.
Take a look at the following code. If you make changes, comment out the section instead of deleting it. If your changes don't work, then at least you can uncomment the working code if necessary for continued debugging. If your changes work to your satisfaction, then you can delete the un-necessary old code.
Make back-up frequently as you will have a lot of error at first. Send a PM if the above is too confusing to decipher.