The first time I walked the Rottie about a week ago, she wasn't high energy but she was at least enthusiastic when she saw me approach her kennel and she was more than happy to go out for a walk. She even pulled on her leash a bit, eager to get going.
This afternoon, when I approached her kennel, she was lying on her blanket and she looked up but did not move. Even when I opened the kennel door and put the leash on her, she didn't seem to want to get up. I knew she hadn't been out in while, otherwise I would have just left her, so I tugged on the leash gently and encouraged her to follow. She obliged but slowly. As we reached the elevator, she slowed down again and then stopped just as she was stepping across the elevator threshold so that the door banged into her as it tried to close. I pushed her into the elevator.
By the time the elevator reached the ground floor and the door opened again, she seemed a little more enthusiastic and we made our way to the exit. As soon as I opened the door, though, and she got a whiff of the sleet and the wind, she stopped in her tracks again. Again, I encouraged her to follow me out and she did slowly. Outside now, we ambled along for a few minutes and she did her business and then we walked back into the building.
Back inside, I talked to one of the staff who said that the Rottie had lost a lot of weight in the last few days and that it might the cancer. I dried her off and then spent some time with her in the upstairs foyer and by the time I brought her back to her kennel, she walked in without complaint and lay back down on her blanket.

When I took the sister Dobie out, she seemed as excited as usual but her breathing had definitely taken a turn for the worse. That first day, she sounded raspy whenever she exerted herself but now she was raspy all the time.
She did the same thing as the Rottie when she first stuck her head outside and felt the sleet and wind. She immediately backed up. But she too hadn't been out in a while so I gently pulled her outside and we went for our short walk.
Her breathing was really giving her a hard time, though. Every minute or so she would stop and sit and tilt her head up and back to get her breath back it seemed. Five minutes later, she decided she really didn't want to be outside at all so we headed back in. The Dobie wasn't housetrained, having come from a puppy mill, but tonight wasn't going to be the night to learn anything different.
After a towel dry, I sat on a bench and massaged her neck and back a bit. Her breathing was bad the whole time. Even when calm, she was struggling with it.
The vet will be coming by on Monday. She'll assess these two dogs and give her recommendations. If anyone feels they can do anything for either of these two, now would be the time to step up. If not, then save a few words for them in your prayers.