CONDITION
Retinal Detachment
Retinal detachment describes the separation of the retina—the light-sensitive layer at the back of the eye—from the tissue beneath it. When this happens, the retina can no longer function normally, and vision is affected. In dogs and cats, this can occur suddenly or develop over time, and may affect one eye or both. Owners often notice changes in how their pet moves through familiar spaces: hesitation, bumping into objects, or reluctance to navigate in dim light. The pupil may appear unusually large, and in some cases the eye itself may look different—cloudy, enlarged, or with visible changes behind the clear front surface. These signs can appear quite suddenly, or they may develop more gradually depending on what is driving the detachment. This page explores what these changes in vision and eye appearance can signal, the range of underlying processes that can lead to retinal detachment, how the condition is investigated through examination and imaging, and the approaches that exist once a detachment has been identified.
Why this matters now
Retinal detachment can occur at any age, but certain patterns tend to emerge in particular groups. Younger animals may experience detachment linked to inherited conditions affecting retinal structure or blood pressure regulation, whilst older dogs and cats more often develop detachment secondary to chronic conditions such as high blood pressure, immune-mediated inflammation within the eye, or changes in the vitreous gel that fills the eye. Some breeds—including Shih Tzus, Labrador Retrievers, and Siamese cats—appear more frequently in clinical reports, reflecting a mix of inherited predispositions and breed-specific health tendencies. In many cases, the detachment itself is not the starting point but rather a consequence of another process that has been unfolding quietly for weeks or months.
The speed at which retinal detachment develops varies considerably depending on what is driving it. In cases linked to sudden blood pressure spikes or acute bleeding within the eye, vision can deteriorate over hours to days. When the underlying cause is a slow-growing mass, gradual inflammation, or progressive degeneration of the vitreous, the detachment may take weeks to become complete, and owners may notice subtle changes in behaviour before the eye itself appears obviously abnormal. Once the retina has separated, the degree of vision loss depends on how much of the retinal surface is affected and how long it has been detached, as the retinal cells begin to lose function when deprived of their normal contact and nutrient supply.
Signals & patterns
Early signals
Hesitation in familiar spaces
An animal that previously moved confidently through the home may begin to slow down, pause before stepping off furniture, or navigate corners more carefully. This often reflects a reduction in depth perception or peripheral vision as the detachment begins to affect how the retina processes visual information.
Reluctance in low light
Owners may notice their pet is less willing to go outside at dusk, or becomes uncertain in rooms with dimmed lighting. Partial retinal detachment can reduce the eye's ability to adapt to changes in brightness, making low-contrast environments more difficult to interpret.
Unusually wide pupils
One or both pupils may appear larger than usual and may not constrict normally when a light is shone towards the eye. This can occur when the detached retina is no longer able to signal the brain effectively, disrupting the normal reflex that controls pupil size.
Misjudging distances
A pet may overshoot when reaching for a toy, hesitate before jumping, or misstep on stairs. These moments can indicate that the brain is receiving incomplete or distorted visual input from the affected eye.
Later signals
Obvious bumping or disorientation
As more of the retinal surface detaches, vision loss becomes more pronounced. Animals may walk into furniture, fail to notice people approaching from one side, or appear confused in previously familiar spaces.
Cloudiness or colour change in the eye
In some cases, fluid accumulates within the eye or inflammation develops, causing the normally clear structures to appear hazy, bluish, or milky. This can be visible when looking directly at the eye and may indicate that the detachment has been present for some time or is accompanied by secondary complications.
Enlargement of the eye
Fluid build-up behind the detached retina or changes in the pressure within the eye can cause the globe itself to appear larger or more prominent. This may be subtle or quite marked, depending on the underlying cause and how long the process has been active.
Click to read about the biological mechanisms
How this is usually investigated
Options & trade-offs
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