How can a GSD become obese? - Page 1

There is some pomposity in this question, but not entirely.

First, the high limit of the amount of food a dog eats is what you give it.

Second. my GSDs are not gluttons. They seem to be satiated very quickly and remain slim even if I try to feed them more.

My female will eat til she explodes LOL. She is not at all picky and would be overweight in a short time if I allowed her to eat as much as she wanted.

Free feeding. Stupidity. Not doing anything with your dogs. I don't get it either...

I had to neuter my 5 year old GSD for health reasons, all else remained the same and he ballooned at an alarming rate.  I now have to severely limit his food to maintain his weight and I also have to deal with a dog that is constantly hungry and begging for food.

I have seen GSD so fat they looked like hippos. Some were thryiod, some were cheap crappy food. Most were lazy owners. Only the police dogs that came in were well balenced. Because they were crazy hiper, bouncing off teh wall, barking non stop- nut bags.
Any breed can be made fat. We use ot groom a St Beanard and a hugely fat whippet. I didn't even know a whippet could be fat until i met that one.

Of my dogs, Jenzi can eat for England and puts on weight very easily. I have to keep a very close eye on her as she has severe HD too.

Zane is just right for his age, height etc and Yiannis for some is on the skinny side of slim. He eats more than Zane and Jenzi put together but never puts on weight.

If a dog is obese it's certainly down to uneducated or ignorant owners. I accept that a dog may put on a littel weight initially without an owner noticing. But to get to the point where they're obese without an owner visiting the vet (assuming they'r enot eating any more or getting ess exercise etc) imo just doesn't happen.

Crap food, large amounts of food, treats (one milk bone is the same amount of calories as a can of beer), not enough exercise, or health issues, mostly thyroid issues. Same as people.

some diseases, like Cushings, cause obesity.  Junk food diets, free feeding, excess treats and table scraps, lack of exercize, age, neuter/spaying, genetics......all of these will contribute to weight gain. 
Every single GSD I've had were lean at a young age (and some were very hard to keep weight on) but sometime around 6-7 years old their metabolisms slowed down and suddenly I have to cut their food way down so they don't get overweight.  I'm struggling to keep the weight off of my oldest dog right now, he gets 3 miles of walking/running everyday plus romping around in the backyard with the other dogs and frequent games of fetch, yet I'm feeding him half the amount of food as my other GSDs. 
I know an obedience trainer/instructer who has a bunch of GSDs, they free-feed their dogs (they think it's good food, I think it's crap food...) and all but one of them are obese, they all have health problems, some of them have a boatload of health problems.  Yet the owner just doesn't accept that free-feeding their crappy kibble is the root of most of their problems, nor do they think their dogs are obese (except for their one lean dog who they think is terribly skinny.)  

Having run a 'pack', all of which were fed in the same way ie 2 meals per day, (no 'free' feeding / food left down 24 hrs) and lots of chews and training treats but very little else extra - and NO human foods - I feel confident in saying that yes, dogs are like people in that their metabolisms vary a little, so some individuals put on fat even though they are only getting the same food and same exercise as their kennel-mates.  And getting on in years can make this happen.  But the thing is to notice those differences and adjust size of meals or particulars of diet accordingly, and if it's getting out of hand take veterinary advice.  Unfortunately far too many pet owners do not pay enough attention to this / do not understand the concept and the necessity of maintaining healthy weights in dogs.  And any  dog can be made obese, not just those who are inclined to be so - although obviously they  will get there worse, and quicker - if you keep giving them bits of ham every time you make yourself a sandwich, for example.  It will matter.

Too much food, not enough exercise. 

Less commonly, thyroid issues.