To the best of my knowledge, there is precisely one person making a comfy living with pet photography as a business right now - see
www.amandajones.com There's a fellow in Northern Chicago who's garnered a similar reputation, but he stays in-studio, not traveling as Jones does...and his biz also caters to corporate and portrait clients.
There's also a fellow who took to his van this past summer, and went coast-to-coast gathering up pet shots on teh cheap, building an immense stock library in the process...but I can't say whether or not that action will lay a foundation for mortgage payments being met over the course of his working life.
I could be wrong, but what I have seen through extensive research on the matter is that there are a few who may also have the generic stock/greeting card market as FAVORING them as a supplier, but too it's likely that these folks also sell much other stock and images to pay the mortgage.
There are not many publications, either, that pay much money for it - most farm the assignemtns to a pool of photographers and take the best of the submissions, the rest of the photographers having spent time and effort for naught. . .and those pubs that do pay a lot (two or three at best), often hire professional/respected portrait photographers to photograph the animal with their celebrity owner.
I've seen many photographers with booths at canine and equine events, shooting pics much like one would at a college football game, and letting the animals' owners buy a $20 print on-the-spot...but can't imagine that's paying mortgage and putting the kids through college.
Back to Amanda Jones - she has a good business hook, and a sturdy business plan. She works referrals out of every city she travels to with $ incentives for shop owners to get her bookings, etc. Her gimmick is a well lit, shallow depth of field photo in large format that gives a fine art feel to the results. The prints are often huge.
Your posted image above is gorgeous, the lighting great, the colors well-managed and the image pleasing to view....but what's going to differentiate it? What's your gimmick?
That's food for thought, along with marketing, incentives, etc. That your project could be well funded is fantastic, and may prove the success.
As a man who doesn't gamble (and no business should be a gamble), I don't think I'd go for it as a source of steady income at all. A photography biz would likely also need other sources of income, pleading for diversity in the business.
Hope I'm not a wet blanket...just sharing what I've learned.