Determination of a dog's ability to see or the quality of its vision is not always straightforward. There are varying degrees of vision loss and many causes for reduced vision. Some causes may be apparent during the course of a cursory examination, and in other instances may require a detailed exam by a veterinary ophthalmologist or additional diagnostics. 

Owners of pets with acute blindness or that are given a poor prognosis for retaining vision over time are commonly upset. For some a diagnosis of “blind” or “will go blind” can be devastating news. In some instances, a window of opportunity for helping a pet may have passed. They had waited too long to see the specialist or, more commonly, their veterinarian had not referred the case early enough to institute treatment for the condition. Evaluation of a pet with a suspected reduction or loss of vision loss includes a detailed history of the problem as well as an eye exam. Until recently, the gamut of questions to ask or information to consider was arbitrary and unknown. 

In a Pet Health Pearls segment on “Assessing Quality of Vision in Dogs," we discuss a recent publication that describes a new survey instrument - the Canine Visual Function Instrument (CVFI) - a validated and reliable pet owner-directed questionnaire that can be helpful for revealing deteriorating quality of vision in dogs. Although one application for this instrument is to aid in assessing treatment outcomes of therapies researched in clinical trials for various diseases, 12 of the questions in this CVFI are helpful to both pet care professionals and owners for identifying reduced quality of vision in dogs. And as with any disease or condition, early recognition of a problem could benefit the patient by prompting earlier referral and intervention by a specialist.

In this publication the authors shared other interesting findings relating to answers given to other questions in the original survey - specifically related to the vision diagnosis and owners’ feelings about their dog’s vision impairment. The study described in this paper included 136 dog owners - 38% had dogs with normal vision, 31% had dogs with varying degrees of cataract, 20% had moderate vision impairment from other causes, and 11% of dogs had a diagnosis of progressive retinal atrophy (PRA). When asked about their feelings related to the dogs’ quality of vision, 61% of owners did express concern about their dog’s vision worsening and 56% of owners indicated that they were upset about their dog’s quality of vision. The majority of owners (77%) indicated that there was no additional burden to them in caring for their vision impaired pet.

The CVFI provides pet care professionals and owners 12 questions that can be helpful in confirming a suspicion of deteriorating vision in dogs. This information can lend support to a decision to proceed in seeking an evaluation by a veterinary ophthalmologist to determine or confirm the cause. As with any problem, early detection and intervention generally leads to better outcomes compared with a “wait and see” approach. As evidenced in this study - that 56-61% of owners expressed concern or were upset about their dog’s quality of vision - veterinary caregivers should support a client’s concern or request to seek a specialist’s opinion, so as to maximize on the opportunity to intervene and empower them in the care and understanding of the pet's problem. Learn More about the CVFI