Your dog has one pupil small and the other big?

As a large language model, I don't have a dog or any physical attributes. But if your dog has one pupil small and the other big, it's important to take them to the vet immediately. This could be a sign of a serious medical condition like:

* Horner's Syndrome: This condition affects the nerves that control the eye and can cause a smaller pupil, droopy eyelid, and sunken eye.

* Iritis: Inflammation of the iris (the colored part of the eye) can cause a variety of symptoms including a small pupil.

* Glaucoma: Increased pressure inside the eye can cause a dilated pupil.

It's important to note that I am not a medical professional, and this information should not replace a veterinarian's diagnosis.