Owners of a brachycephalic (i.e., flat-faced) pet need to be aware of certain ocular conditions and eye disorders that commonly develop in these breeds. Shih tzus in particular are prone to eye problems, because of their shallow, less protective, eye sockets. With these protruding eyes comes the potential for a condition called retinal detachment. If you are a proud shih tzu owner, read on to learn more about this condition.
What is retinal detachment in shih tzus?
First, let’s learn about the eye parts. The retina is a layer of thin, light-sensitive tissue that lines the back of your dog’s eyeball. When your pet looks at an object, light rays enter the eye and are focused onto the retina through the cornea, pupil, and lens. The retina then converts the light rays into impulses that travel through the optic nerve to the brain, which interprets them as images.
When the retina detaches from the back of the eyeball, the problem must be treated promptly, or permanent blindness can result. Typically, retinal detachment is associated with an underlying medical condition, so the medical condition must also be treated.
What are retinal detachment signs in shih tzus?
Retinal detachment signs can vary, based on the detachment cause. A shih tzu suffering from a detached retina may exhibit:
- Impaired vision or total blindness
- Dilated pupils
- Visible retinal vessels
- Orb swelling
You may see other signs, depending on your pet’s underlying medical condition. If they have a primary viral or bacterial infection, fever, lethargy, and anorexia may be present. If trauma caused your shih tzu’s retinal detachment, you may see facial lacerations and other injuries.
Keep in mind that detecting retinal detachment in your shih tzu can be difficult. Dogs tend to hide vision impairment well and can compensate quickly for vision loss, especially if they lose vision in only one eye. And, since shih tzus already have bulging eyes, distinguishing whether or not the orb is swollen can be difficult.
What causes retinal detachment in shih tzus?
Hereditary ocular conditions can cause retinal detachment in shih tzus of any age. For example, in one condition called vitreoretinal dysplasia—the vitreous gel is found in the back of the eye, closely adhered to the retina—abnormal development occurs, and the retina comes loose, leading to blindness.
Other retinal detachment causes can include:
- Face or eye injuries
- Diabetes, leading to cataract formation
- Viral or bacterial infections
- Kidney disease
- Poor blood clotting
- Toxin exposure
- Cataracts or cataract surgery
How is retinal detachment diagnosed in shih tzus?
Diagnosing a retinal detachment is seldom easy, and your primary care veterinarian may refer you to a veterinary ophthalmologist for a specialized evaluation. When retinal detachment is diagnosed, the underlying cause must be identified, and the following diagnostic tests may be recommended:
- Blood work — Blood chemistry panels evaluate kidney, liver, and pancreatic function, and measure blood sugar and electrolyte levels.
- A complete blood count will screen your pet for infection, inflammation, and anemia.
- A thyroid test will determine if your dog’s thyroid gland is producing too little thyroid hormone.
- Additional blood testing can detect other endocrine disorders or possible toxin exposure, and point toward potential causes.
- Infectious disease testing — Certain bacterial and viral pathogens can cause ocular issues that can lead to retinal detachment. Testing will vary, based on the suspected cause.
- Blood pressure — Your pet’s blood pressure will be checked to ensure your pet is in the normal range, and hypertension is not contributing to a retinal detachment.
How is retinal detachment treated in shih tzus?
Most retinal detachments in shih tzus can be successfully treated, depending on the cause, but congenital detachments and detachments associated with retinal degeneration cannot. Partial detachments that arise after intraocular surgery or retinal tears can be treated surgically. Many methods, including laser retinopexy, titanium tacking, expandable gasses, vitrectomy, silicone oil, scleral buckling, and cryoretinopexy, can be used to repair retinal holes and detachments.
In addition to—or in lieu of—surgery, medication may resolve the underlying medical condition. For an eye infection, systemic antibiotics are necessary so the medication can reach structures deep inside the eye. If the primary problem is inflammation, oral anti-inflammatory medications can help. Fluid removal from behind the retina may require a diuretic. If the front portion of the eye is infected or inflamed, topical medications may be indicated.
Generally, your shih tzu who is suffering from a retinal detachment may keep their vision in the affected eye. However, prompt diagnosis and treatment is essential for a good prognosis, so monitor your dog closely to ensure their eyes remain healthy. At the first hint of an eye abnormality or problem, contact our Veterinary Vision Center team.