My father has two beautiful German Shepherds named Buck and Lady, but I think they weigh too much. Buck weighs 150 lbs and Lady weighs 110 lbs. They both appear to be big boned, but I feel they should weigh less. They are very well behaved, but they don't get any exercise. They are either in the house or chained up outside. What is the ideal weight for both?
Take them to the vet.
This depends so much on the individual dog. The "standard" weight may not be appropriate for your dogs because they might be smaller or larger than the standard.
An easy way to gauge if the dog is overweight is to check their ribs and waist. To check the ribs, run your hands across their chest, in the head-to-tail direction. You should be able to feel the dog's ribs, but you shouldn't be able to see them sticking up out of the skin (that would be too thin). If you can't feel the ribs easily, the dog is likely too fat.
To ckeck the waist, you might need to wet the dog down first if it has long hair like yours do. Stand over the dog, and look straight down at it. You should notice a "waist" at the equivalent place that a human's waist is, between the lowest ribs and the top of the hip bones. If there is no waist or if the waist is actually bulging outward, then you are probably safe in assuming that the dog is overweight.
These are just guidlines, not set-in-concrete ruies.
Of course, the best way to make sure that the dogs are (and stay) healthy is to get them some exercise! I don't mean to presume, but why does your dad keep such strong, energetic dogs like German Shepherds, if he doesn't want to exercise them? It's very unfair to the dogs. All dogs need exercise, but breeds like German Shepherds are bred to be working dogs and really need to move. If your dad is disabled and can't exercise them himself, could he possibly hire a dog walker? If they are well-behaved, as you say, there would probably be some young people in the neighborhood who would like the job.
this is a very late response. Did you ask your vet what to do? German Shepherds are herding dogs and need exercise whether it's a walk around the block or playing and running in a fenced in area. If your dogs aren't getting any exercise, they may be over weight and this will become a health problem.
See your vet, tell them what's going on and they will give you the advise you need. Your dogs need to be on a healthy diet of really good dog food like Eukanuba or IAMS. Go easy on treats. You can get low fat doggie treats at your local pet store. Unless you are dedicated to making your own dog food from raw vegatables and raw meats, don't feed your dogs people food. Left over steak, fish or boneless chicken with no sauce and no bones are fine to give but mix it in the food. Are you aware that German Shepherds have a genetic stomach issue and dry dog food should be soaked in warm water before serving? Once your dogs start getting the proper exercise that involves running, soaking the food is essential. The stomach of a German Shepherd can literally flip over causing it to twist and if not treated immediately, the dog can die. The soaked dog food expands the stomach so the stomach can't flip over. Look it up on the internet. Our two year old shepherd weighs 140 pounds but he is all muscle and is very active. He runs and plays in our fenced in back yard and he has a healthy diet and a shiney coat. Please see your vet.
I keep my German Shep on adult large breed weight control food (Purina One). It's mostly protein and she's nice and trim. I have had German Sheps for many years, and they need mucho exercise. They will get hip dysplasia and other problems if they are overweight. If they don't get enough exercise they will get into trouble and cause problems, etc., etc. My girl is big and she weight approx. 83 lbs. She gets at least 2 hours of exercise at the dog park every day or a very long walk for about one hour.
If one is a couch potato, they should have a couch potato dog, not a large working breed.