If it is a hingeback (any of the several species), two things apply:
(1) You shouldtake it to a REPTILE vet
immediately.(your general dog/cat cow/horse vet will almost surely not be qualified to treat this species) These turtles are notoriously difficult to care for. They arrrive in pet stores as wild caught animals and they seem to suffer greatly during transit.
They are always riddled with parasaites (or so i am told).
It would be amazing if you could keep it alive a year without competent veterinary intervention if you are not a long time Hingeback keeper.
(2) Keep it as far from your sulcata as possible.
If it is ill you don't want to risk it infecting your sulcata and hingebacks hail from semi -arid to very high humidty environments, not at all like the desert and dry grasslands from where sulcatas live. These would NOT be compatible.
(there is one exception, Bell's Hingeback, Kinixys belliana, which is found in some grassland environments, but even it will require at least some moist area in its enclousre)
Don't expect pet store people to know a whole lot about what they are selling. (they should but in 9 out of 10 stores, they don't)
Don't take my word for it about hingebacks:
Hingebacks (Kinixys) on the web