Our pens are for small to medium breeds weighing up to 40 lbs and all puppies.
With respect to large-breed puppies, there are some concerns.
Our pens are heavy; a medium 36" height weighs 60 lbs and the aluminum frame is rigid. So they are sturdy, however some large-breed pups will be able to jump out by the time they are 6 months old (or even less). We don't make any tops, so this is a limiting factor. Some dogs love their pen and they don't jump out even when they can because it is their bedroom. This is especially true when they grow up with the pen and when they have a larger size (medium or large). Other pups don't want to be in a pen and they will try to jump out even if they are comfortable in the space.
Most importantly, please consider the weight recommendations (40 lb limit). It is understandable to think that the are pens are a good fit for a larger breed since the square footage is large enough for almost any size pup. However, the weight limit is related to the structural strength of the walls. We never want a puppy to get hurt if they jump on the wall and it breaks.
Overall, we love large breeds and would love to tell you that it is a great fit. But since your pup will quickly be big, it is a risk to buy one because it is expensive and not made for large breeds. Our 30 day return policy states that customers are responsible for return shipping cost and pens must be, "unassembled, unused and in original packaging."