Do you think their should be an "additional service" option for small animals?

I think the majority of Rover sitters only care for typical household pets. It starts to get too complicated the more types of animals you add. Dogs and cats are the most common, and anything above and beyond that will be case by case anyway. Caring for a small reptile or rodent will be much different than caring for poultry will also be much different than caring for livestock.

I think posting in your own profile what 'other' animals you can also care for and the rates you'd associate with that is best. You could even include it in your headline so owners see it on the initial search.

I have sat for chickens and other animals. I simply charge my regular drop-in fee collectively for each additional type (ex.: dogs, cats, critters). Having a separate category for every type of pet would be exhaustive.
As for horses, I don't think many horse owners would look to a dog walking site for their horse. Typically, they find someone in their equestrian community who has the proper experience. And as for boarding, they would most definitely prefer an actual horse boarding facility. Not to mention that the insurance would most likely be a bit different. If you have this type of experience and the proper facilities then I would use Rover for domestic house pets and perhaps advertise your other services within your community or feed stores.

All the best!

I think this makes sense for your "normal" household critters, but not so much for livestock. For someone who's hied to look after the dog(s)/cat(s), it's well within reason that a client might say "hey, could you also feed our hamster/rat/iguana?" But livestock typically require more specialized and more frequent care.

The great thing about Rover, as others noted above, is that you can advertise these other services as you see fit. I'm not a travel sitter, but if I was, I'd post that I have no problem "sitting" snakes (love snakes!). I'd even feed your tarantula if you need it!

I definitely agree. One of my clients was asking if I could take in her pet rabbit along with her dog but since there wasn't an option for "other pet" I apologized and told her I wouldn't be able to.

They may have downvoted due to your there/their grammar error. I didn't, but you asked, and it does drive ME crazy, so maybe it did someone else too. I agree with adding an "other" animal category (small animals, reptiles, fish, birds), but not cattle.

By Rover NOT advertising care for other animals, a google search will not come up. You advertising in your Rover description won’t really matter, unless someone looking by chance clicks yours. I’ve watched chickens and horses but it’s extremely rare.