Heck...read some of my posts...now THOSE are long...welcome lol sorry about your tortWARNING-WARNING-NOT A SHORT STORY.......
(not a bad one either)
My 100lb sulcata - Herman - recently had an encounter with a dog or coyote (I don't know which) this winter, at night. If it hadn't been winter he would have been in his underground den and this wouldn't have happened.
In the winter he has a hot house but the opening can be accessed, indirectly, from the sunny side of the enclosure. The tortoise area is fenced but not high enough to keep out larger four legged critters. He has been good in that area for 12 years now... but as the saying goes,, "you never know".
The result was chew marks all the way around his shell but it held up to the abuse. The attacker was able to put a little "road rash" on his forearms and back of his thighs. These tortoises did evolve in the African Sahara after all. I screwed up and left a gate to the property open over night. I'm still kicking myself for that one.
Anyway, my retired vet buddy recommended some Chlorhexidine Solution ( 2% ) and Furacin Dressing I got at the local Feed, Grain and horse supply store. This worked well to clean and dress the lesions with. Hydrogen Peroxide and Neosporin would probably have done the job. It has scarred over now and you can hardly tell it happened. Tortoises heal very slowly.
My rottenpit (Rottweiler-Pit Bull cross) Buddy got along great with him for the 9 years I had Buddy. Herman would even let Buddy lick pumpkin off his face without even flinching but I didn't let them interact without supervision. Dogs can have ancient instincts that are not something you see coming.
I agree that you should not let dogs have full time access to your tortoises. Herman is big enough that I don't worry about birds. When he pulls everything in, nothing is getting to him. His tail does still seem like it could be a little vulnerable though.