As the photographer I will always retain the copyright to my images. Images are sold by default with a personal use license, this means you are free to use your image to share on social media, print (high resolution files), text, breeding ads, etc. I can also provide a commercial usage license on a case by case basis for purposes such as business branding, advertising, magazine covers, packaging, etc.
I do not consider dog breeding commercial usage, so using images for promotion of a litter or for a dog show ad is perfectly acceptable personal usage.