I drew the short straw and took our dog, Katy, to the vet for yet another knee problem. At this point she’d already undergone an ACL rebuilt on one leg and a patella tendon issue repaired on another. We’d adopted her from a shelter a couple of years earlier, and she seemed determined to make up for her initially “free” purchase via a series of four digit transactions at the pet hospital. She was, to her credit, savvy enough to space these events out over the course of eight years.

On this particular day Katy held her back right leg in the air and hopped along on the other three legs. To be clear — none of her legs could be described as “good” so I the absence of that descriptor is deliberate.

The vet tech who checked us in was, as always, very concerned about starting things off with a trip to the scale. Nothing could happen before the animal was weighed on the steel plate that sat just above the floor and I subsequently received the latest declaration of my poor pet stewardship. It didn’t matter what number came up on the scale — it was always too high, and it was always my fault.

I led hopping Katy over to the scale and she grudgingly went along with the process while conveying a look that suggested perhaps she was not the only one in this relationship with a weight problem. I pretended to ignore her gaze, took the high road by not mentioning her proclivity to rummage through the kitchen trash, and nudged her unto the scale. She stood, shakily indignant, her back right leg still in the air.

The vet tech peered over the counter at the display for the scale. “Sir. I’m not going to be able to get an accurate reading if your dog doesn’t have all four feet touching the scale.”

Katy looked at me in disbelief. She didn’t speak English, but even she has a problem with this attempt at physics. I thought through the statement that had just been made to make sure I wasn’t missing anything. No, I wasn’t.

“I kind of think my dog weighs the same regardless of how many of her feet are touching the scale.”

The vet tech sighed deeply. I was definitely adding to her already long day. “No sir, that’s not the way it works.”

Katy dropped her head and stared at the scale in disbelief.

I slowly raised one foot in the air, forced a puzzled expression and then set it back down.

“You got me,” I said. “How does it work?”

Katy and I both stared at the vet tech. With her back right leg still in the air, the scale’s display flickered between 61.1 and 61.3 pounds.

The vet tech’s mouth opened, and then closed. Were she a computer Katy and I likely would have heard a series of clicks and beeps.

The vet tech switched gears, recorded 62 as the official weight and looked back at me with an unfriendly smile. “Your dog is overweight.”