Pony XL-based models seem to struggle to generate images depicting breeding mounts, so use this LORA to assist them. It seems to work fine with most Pony model variants, and with anthros, ferals, and taurs (as you can see in the images), but you'll have to tinker with it a bit to make it work for you. This LORA was designed specifically for "furry" content, but it also works with images of humans, and other humanoids.

The original created by (or for) PaleKemono, and posted in their gallery on CivitAI;

https://civitai.com/models/789714?modelVersionId=883106