Tuesday, November 13, 2012

Diagnosing dog vision loss: How do you know when your dog can't see?

Liam the pug in the sun
Liam basking in the sun.
My new workroom features two glass doors that point right down the driveway to the street. Liam's favorite new spot (not surprisingly) is right in front of those doors. Here, he can rest in the sun almost all day long, and he can keep an eye out for intruders who might be tempted to walk up the driveway unannounced. I keep telling him that pug barks are far from menacing, but he doesn't seem to get the message.

He's been delivering more and more of those pug barks, and unfortunately, I think his vision might be to blame. When our outdoor cats are about 10 to 15 feet away, sauntering down the driveway, Liam will bark and bark and bark, stopping only when the cats are about 2 feet away and he can recognize them. He also barks at my husband at the 8-foot mark, stopping only when the distance between dog and man closes to about 1 foot. Liam has also become more apt to shy away from garbage bags, lawn ornaments and people as we're on our walks, and he only seems to get comfortable when he's nearly standing on top of the things that once caused him fear.

Liam still motors around the house just fine, and he has no difficulty finding his toys, his food or his water dish. Since I live with a blind cat, I'm also not worried about living with a blind dog. Should he totally lose his vision, we would all figure out a way to adjust. But I am a little worried about what's going on here, and what can be done about it.

Liam's eyes are completely clear, free of any blurring or hazing, so I'm not sure cataracts are the issue. His eyes are also not full of tears or unusually dry or red. They look just as they always do, and the pupils are completely responsive to light. I would think a standard exam wouldn't show anything at all, since his eyes do seem to be so remarkably normal.

Canine ophthalmologists often set up elaborate mazes for dogs, asking them to walk through an unfamiliar collection of obstacles to measure vision. These are apparently pretty effective tests, but I would think a dog could use other senses, including smell and hearing, to manipulate those results. But if this vision loss continues, I may have to sign up Liam for something like this. I may try a test at home, in fact, just to see how well he can actually see. If he's just being protective, I won't worry. But if he really can't see, we might need to make some plans for the future.