sad as a hound dog's eye. Sad, pitiful.

This is a simile based on the droopiness of hound's eyes, making them appear, in anthropomorphic terms, sad. The odd quality of the term is that structure of a hound's eye does not actually indicate the emotional state the dog is in. It suggests that this kind of sadness might be inauthentic, like crocodile tears. On the other hand, the implication of pitiful or pathetic may be more to the point. When dogs look sad, they work it.

In Lloyd Lewis' essay “The Holy Spirit at West Point,” he describes a Chickamauga war veteran as “six feet tall, blond-whiskered, his blue eye always sad as a hound-dog's.”

Having hound dog eyes is apparently not a desirable feature. If you have such eyes, you can opt for a Blepharoplasty or eyelid tuck that will “rejuvenate the eyelid and remove eyelid bags and dark circles under the eyes...” Cosmetic surgeon Brooke Seckel informs us that this is the third most common cosmetic...operation performed in the United States.” Run your cursor over Figure 2 to see the “after” image, that is, the result of surgery to “correct” for hound dog eyes.

Figure 2 is a detail from Brooke Seckel's before and after pictures of his blepharoplasty surgery. The main image is the before picture, the roll-over image shows the after.