Fowler's Toad

If you think that, then that's what you should label it as. I base my ID off of the spotting on the chest as that is the only thing you show in the photos. And from the photos, I can tell you it is not a Fowler's toad. Maybe part Fowler's if the other characters are as you say, but not full Fowler's . And the best character to look at to distinguish the two is how the paratoid glands and cranial crests meet, and you didn't mention those. The number of warts in each dark spot isn't the best character to go off of, it's not always reliable.

I believe it is a cross breed of a Fowler's and an American. It has three warts in each of it's black spots, and the warts on it's femur are the same size as the warts on it's lower leg.

Fowler's toads only have a single spot on the chest, whereas your toad has a very mottled chest, indicative of an American toad. Also, please add this to the captive animals mission since you said it is a captive animal. Thanks.