It appears from this pic that the tortoise body itself may have been also injured, not the shell alone...there is alot of open wet wound there.....I would be sure that this tort is restricted to an entirely sterile environment (no substrate, no dirt material at all) I would use a really thick soft layering of clean white paper towels or white cotton t shirt folded over until soft...I would place the tortoise in an area that you can keep quiet, out of foot traffic and in a place that you can kinda keep in dim lighting (I would obtain a che and or black heat light, no bright lights right now) and be sure that you can maintain a constant heat of no less than 85 degrees...I would not soak the tort, but I would flush the wound sites with tepid water (you can do this with either a spray bottle mist setting or a squeeze bottle)...I would plan to do this about 4 to five times per day for a week to begin with...be slow and gentle and slow slow slow movement around this little one...remember, he literally was in the jaws of death and he knows it....
Do you have a well known tortoise specific vet near you? If you do, then I would try to contact that office and see if their doctor can accept emailed pics of the damage (I would hesitate to cause additional stress to the tort by tossing him into a box then into the car) to see if you can get their instruction and to also get a high grade antibiotic that a doctor can prescribe....
Where are you located in the world? Perhaps a versed Forum member will be near you to offer you hands on aid?
Do you have a well known tortoise specific vet near you? If you do, then I would try to contact that office and see if their doctor can accept emailed pics of the damage (I would hesitate to cause additional stress to the tort by tossing him into a box then into the car) to see if you can get their instruction and to also get a high grade antibiotic that a doctor can prescribe....
Where are you located in the world? Perhaps a versed Forum member will be near you to offer you hands on aid?
Definitely call the vet asap!
