# Shih Tzu Health Problems: Brachycephalic Eye Disease and Kidney Stones ## Key Takeaways - Brachycephalic Eye Disease (BED) in Shih Tzus stems from anatomical conformation, leading to exposure keratitis due to incomplete eyelid closure (lagophthalmos) and shallow orbits, increasing corneal trauma risk. - Diagnostic tools for BED include Schirmer tear tests for tear production, fluorescein staining to detect corneal ulcers, and slit-lamp biomicroscopy for detailed ocular examination. - Management of BED involves medical therapy (antibiotics, lubricants, immunosuppressants for KCS), surgical correction (e.g., blepharoplasty, medial canthoplasty), and environmental modifications to protect the prominent eyes. - Kidney stones (nephrolithiasis) in Shih Tzus are linked to mineral crystallization in urine, with common types including calcium oxalate, struvite (often secondary to UTIs), and urate stones. - Diagnosis of kidney stones relies on urinalysis to detect crystals and infection, bloodwork to assess kidney function, and abdominal radiography or ultrasound to visualize stones. - Treatment for kidney stones varies by type, encompassing dietary management, medical dissolution (for struvite), and surgical removal for obstructive or non-dissolvable stones, with increased water intake being a crucial preventative measure. --- If you own a Shih Tzu, you are likely familiar with their distinctive flat face and large, expressive eyes. However, these beloved physical traits come with significant health risks. This article provides a definitive, source-grounded overview of two major health concerns in the breed: brachycephalic eye disease and kidney stones. We will explain the anatomical reasons behind these conditions, how they are diagnosed, and the most effective management strategies. **Owner Triage Summary:** If your Shih Tzu is squinting, has a cloudy eye, or is pawing at its face, this is an emergency. Ocular ulcers and corneal damage can progress rapidly. If your [dog](/knowledge/veterinary-medicine/clinical-methods/dog) is straining to urinate, producing bloody urine, or crying out in pain, seek immediate veterinary care. These signs can indicate a life-threatening urethral obstruction from a kidney stone. Do not wait to see if symptoms improve. ## At a Glance: Comparing the Two Conditions This table provides a quick clinical comparison for owners. It is not a substitute for professional diagnosis. | Feature | Brachycephalic Eye Disease (BED) | Kidney Stones (Nephrolithiasis) | | :--- | :--- | :--- | | **Primary System** | Ophthalmic (Eye) | Urinary (Renal/Ureteral/Bladder) | | **Core Problem** | Anatomical conformation leads to corneal exposure, poor tear distribution, and increased trauma risk. | Crystallization of minerals in urine forms stones in the kidneys or urinary tract. | | **Common Clinical Signs** | Squinting, excessive tearing, corneal cloudiness, visible third eyelid, pawing at eyes. | Blood in urine, straining to urinate, frequent small urinations, abdominal pain, vomiting. | | **Diagnostic Tools** | Schirmer tear test, fluorescein stain, slit-lamp exam, ocular ultrasound. | Urinalysis, bloodwork, abdominal radiographs (X-rays), abdominal ultrasound. | | **Emergency Threshold** | Any squinting or corneal opacity is an emergency. | Inability to urinate or severe straining is an emergency. | | **Management Focus** | Medical therapy (lubricants, antibiotics), surgical correction (e.g., eyelid surgery), and environmental modification. | Dietary management, increased water intake, medical dissolution (for certain stone types), or surgical removal (e.g., ureterotomy). | | **Prognosis** | Good for acute ulcers with prompt treatment; guarded for chronic exposure keratitis. | Good for single, small stones; guarded for recurrent or obstructive stones. | ## Understanding Brachycephalic Eye Disease in Shih Tzus Brachycephalic eye disease is a cluster of ocular problems that arise from the flat facial conformation of breeds like the Shih Tzu. The term "brachycephalic" refers to animals with a shortened skull. While this gives the breed its characteristic appearance, it creates a shallow orbit (eye socket) and a large, prominent eye. This combination leads to a range of secondary issues. ### Anatomy and Pathophysiology of the Shih Tzu Eye The primary anatomical defects are macroblepharon (an abnormally large eyelid opening) and a shallow orbit. Because the eye is so prominent, the eyelids often cannot close completely. This leads to two critical problems: 1. **Exposure Keratopathy:** The central cornea is constantly exposed to the air. This leads to drying, which can cause chronic irritation, corneal vascularization (blood vessel growth into the cornea), and pigmentation. This is a painful condition that reduces vision over time. 2. **Lagophthalmos:** The inability to fully close the eyelids means the tear film is not spread evenly across the eye. The tear film has three layers (oily, watery, and mucous), and proper blinking is essential for its maintenance. In brachycephalic dogs, the tear film is often unstable, leading to dry spots and irritation. Additionally, the prominent eye is more susceptible to trauma. A simple scratch from a bush or a play-fight with another dog can cause a corneal ulcer. The nasal folds, which are the heavy skin folds on the nose, can also rub against the cornea, causing chronic irritation and ulcers. This is termed "nasal fold keratitis." ### Common Manifestations of BED Owners may see one or more of the following conditions, which are all part of the BED complex: - **Corneal Ulcers:** These are erosions or full-thickness defects in the cornea. They are intensely painful. Signs include squinting (blepharospasm), excessive tearing (epiphora), and pawing at the eye. In the UK study, ophthalmological disorders were among the most prevalent grouped-level disorders in Shih Tzus, with a prevalence of 11.9%. This highlights that eye problems are a major reason for veterinary visits in this breed. - **Corneal Sequestrum:** This is a specific type of corneal ulcer where a piece of dead corneal tissue becomes a brown or black plaque. It is more common in brachycephalic breeds and requires surgical removal. - **Keratoconjunctivitis Sicca (KCS or Dry Eye):** While not exclusively caused by conformation, the abnormal blink and tear film distribution can contribute to or exacerbate dry eye. This condition involves a deficiency in the aqueous (watery) portion of the tear film. - **Entropion:** This is a condition where the eyelid rolls inward, causing the eyelashes and hair to rub against the cornea. It is a common conformational issue in Shih Tzus and causes significant irritation. - **Proptosis:** This is a severe emergency where the eye is displaced from the socket, usually due to trauma. The prominent eyes of the Shih Tzu are at higher risk for this. ### Veterinary Examination and Diagnostics for Eye Disease If you notice any eye issues, a prompt veterinary examination is critical. The veterinarian will perform a series of tests: 1. **Schirmer Tear Test (STT):** This measures tear production. A small strip of paper is placed in the lower eyelid for one minute to measure the amount of tears produced. This helps diagnose KCS. 2. **Fluorescein Stain Test:** This is a crucial test. A green dye is applied to the eye, and a blue light is used to look for any corneal ulcers. The dye will adhere to areas where the corneal surface is damaged, making them visible. 3. **Tonometry:** This measures the intraocular pressure (IOP) to rule out glaucoma, which can also cause a red, painful eye. 4. **Slit-Lamp Biomicroscopy:** This is a specialized microscope that allows the veterinarian to examine the anterior segment of the eye in detail, including the cornea, iris, and lens. 5. **Ocular Ultrasound:** If the cornea is too cloudy to see the inside of the eye, an ultrasound can be used to evaluate the lens and retina. ### Evidence-Based Management of BED Management depends on the specific condition and its severity. - **Medical Management:** For mild ulcers, antibiotic eye drops are prescribed to prevent infection. Atropine may be used to relieve the pain of ciliary muscle spasms. Artificial tear supplements are used to lubricate the eye and protect the cornea. For KCS, immunosuppressive drugs like cyclosporine or tacrolimus are often used to stimulate tear production. - **Surgical Management:** For conformational issues like entropion or macroblepharon, surgery is often the definitive treatment. Procedures like eyelid shortening (blepharoplasty) can reduce the eyelid opening, providing better corneal coverage and protection. Medial canthoplasty is a common procedure that narrows the eyelid opening at the inner corner of the eye. Corneal sequestrums require surgical removal. - **Environmental Management:** Owners can help by using a harness instead of a collar to reduce pressure on the neck, which can exacerbate eye protrusion. Keeping the facial hair trimmed and clean is also important. Using a humidifier in dry climates can help maintain tear film stability. ## Kidney Stones (Nephrolithiasis) in Shih Tzus Kidney stones, also known as nephroliths, are solid concretions that form in the kidneys. While they can occur in any breed, the Shih Tzu is considered a breed predisposed to certain types of urinary stones. It is important to distinguish between stones in the kidney (nephroliths) and stones in the bladder (cystoliths). While related, they are different conditions. ### Pathophysiology of Stone Formation Kidney stones form when the urine becomes supersaturated with certain minerals. This means there is a higher concentration of the mineral than the urine can hold in a dissolved state. When this happens, the minerals can crystallize and aggregate, forming a stone. Factors that contribute to this include: - **Genetics:** Certain breeds have a genetic predisposition to produce specific types of stones. - **Diet:** High levels of certain minerals in the diet can increase the risk. - **Urinary Tract Infections (UTIs):** Some bacteria produce the enzyme urease, which breaks down urea into ammonia. This alkalinizes the urine and promotes the formation of struvite stones. - **Dehydration:** Concentrated urine is more likely to become supersaturated. - **Urine pH:** The acidity or alkalinity of the urine can influence which types of crystals form. For example, struvite stones form in alkaline urine, while urate and cystine stones form in acidic urine. ### Types of Kidney Stones in Shih Tzus While a definitive breed-specific breakdown of stone types in Shih Tzus is not available in the provided source, the breed is known to be at risk for several types. The most common types seen in small breed dogs include: - **Calcium Oxalate Stones:** These are common in small breeds. They tend to form in acidic urine and are often associated with high levels of calcium and oxalate in the diet. They are not typically caused by infection. - **Struvite Stones:** These are composed of magnesium ammonium phosphate. They are almost always secondary to a urinary tract infection with urease-producing bacteria, most commonly *Staphylococcus* or *Proteus* species. - **Urate Stones:** These are associated with a defect in purine metabolism, which can lead to high levels of uric acid in the urine. The Dalmatian is the classic breed for this, but it can occur in other breeds, including the Shih Tzu. They form in acidic urine. ### Clinical Signs and Diagnosis of Kidney Stones Many dogs with kidney stones show no clinical signs, and the stones are found incidentally during an examination for another issue. However, when signs do occur, they can include: - **Hematuria:** Blood in the urine. - **Stranguria:** Straining to urinate. - **Pollakiuria:** Urinating frequently in small amounts. - **Abdominal Pain:** Pain in the flank or abdomen. - **Systemic Signs:** If a stone causes a ureteral obstruction (blockage of the tube from the kidney to the bladder), it can lead to vomiting, lethargy, and inappetence. This is a life-threatening emergency. **Diagnostics:** The veterinarian will use several methods to diagnose kidney stones: 1. **Urinalysis:** This is essential. It can detect blood, crystals, and infection in the urine. The urine pH is also measured, which can give clues about the stone type. 2. **Bloodwork:** A biochemistry panel and complete blood count (CBC) are important to assess kidney function (BUN, creatinine) and check for signs of infection or inflammation. 3. **Abdominal Radiographs (X-rays):** Some stones, like calcium oxalate and struvite, are radiopaque and will show up on X-rays. However, urate and cystine stones are radiolucent and may not be visible. 4. **Abdominal Ultrasound:** This is a more sensitive imaging modality that can detect stones in the kidneys, ureters, and bladder, including those that are not visible on X-rays. It also allows the veterinarian to assess the overall health of the kidneys. ### Management and Prevention of Kidney Stones The treatment plan depends on the type, size, and location of the stone, as well as the overall health of the dog. - **Medical Dissolution:** For struvite stones, medical dissolution is often possible. This involves a specific therapeutic diet that is low in protein, magnesium, and phosphorus, and promotes the production of acidic urine. Antibiotics are also given to treat the underlying infection. This approach is not effective for calcium oxalate or urate stones. - **Surgical Removal:** For stones that are causing an obstruction, are very large, or are not amenable to medical dissolution, surgery is required. A ureterotomy is a surgical incision into the ureter to remove a stone. A nephrotomy involves an incision into the kidney itself. These are major surgeries that require specialized care. - **Dietary Management:** For calcium oxalate stones, the goal is to reduce the risk of recurrence. This involves feeding a diet that is low in oxalate and sodium, and that promotes the production of less concentrated, more dilute urine. Increasing water intake is crucial. This can be achieved by feeding wet food or adding water to dry food. It is important to discuss specific dietary recommendations with your veterinarian, as commercial "urinary health" diets are formulated for specific stone types. - **Prevention:** The most important preventative measure is to encourage water consumption. Providing fresh, clean water at all times is essential. Regular veterinary check-ups with routine urinalysis can help detect early signs of crystal formation or infection before they become a major problem. ## The Connection Between Breed and Health The study from the UK VetCompass Programme provides valuable data on the health of Shih Tzus under primary veterinary care. It found that the most prevalent disorders were periodontal disease, anal sac impaction, and ear disorders. While this study did not specifically highlight kidney stones or eye disease as the most common issues, it did show that ophthalmological disorders were a major grouped-level condition, affecting 11.9% of the studied dogs. This confirms that eye problems are a significant health concern for the breed. The study also reported a median age of 4.1 years and a mean adult bodyweight of 7.9 kg. This information is useful for owners to understand the typical profile of the breed. The study's findings on demography and common disorders help veterinarians and owners prioritize health screening and preventative care. ## Limitations and When to Contact a Veterinarian This article provides a comprehensive overview of two significant health problems in the Shih Tzu breed. However, it is crucial to understand its limitations. Breed-level information cannot predict what will happen to your individual dog. Many Shih Tzus live long, healthy lives without developing severe eye disease or kidney stones. The information here is a guide to help you understand the risks, recognize the signs, and know when to seek professional help. **When to contact a veterinarian immediately:** - **Eye:** If your dog is squinting, has a red or cloudy eye, is pawing at the eye, or has visible discharge, contact your veterinarian immediately. Corneal ulcers can deepen and even rupture within 24 hours. - **Urinary:** If your dog is straining to urinate without producing urine, is crying out in pain, has blood in the urine, or is vomiting, this is an emergency. A urethral obstruction is a fatal condition if not treated promptly. Do not attempt any home remedies for these conditions. For eye issues, do not use over-the-counter eye drops without veterinary guidance, as some can be harmful. For urinary issues, do not give any medication. The safest course of action is always to seek professional veterinary care. ## The Clinical Reality of Brachycephalic Eye Disease: Why Early Recognition Matters Brachycephalic eye disease is not a single diagnosis but a constellation of interrelated problems that stem from the same underlying anatomical blueprint. For Shih Tzu owners, understanding this clinical reality is the first step toward protecting their dog's vision and comfort. The flat face that makes the breed so endearing also creates a cascade of ocular vulnerabilities that require lifelong vigilance. ### The Anatomy of Vulnerability The Shih Tzu skull is characterized by a shortened muzzle and a relatively large orbit relative to the facial skeleton. This creates a situation where the eyeball is proportionally too large for the socket that houses it. The result is a globe that protrudes forward, leaving it exposed and vulnerable. This is not merely a cosmetic concern; it fundamentally alters how the eye functions. The eyelids of a Shih Tzu are often unable to achieve complete closure, a condition known as lagophthalmos. When your dog blinks, the eyelids may only partially cover the corneal surface. This means that a portion of the cornea remains exposed to the environment at all times. Over hours, days, and years, this chronic exposure leads to desiccation of the corneal epithelium, the outermost protective layer of the eye. The cornea becomes dry, irritated, and more susceptible to injury. The tear film itself is also compromised. A healthy tear film has three layers: an outer oily layer that prevents evaporation, a middle watery layer that provides moisture and nutrients, and an inner mucous layer that helps the tears adhere to the cornea. Proper blinking is essential for spreading these layers evenly across the eye. In a Shih Tzu with incomplete blinking, the tear film becomes unstable, breaking apart between blinks and leaving dry spots on the cornea. This instability contributes to the chronic irritation that many affected dogs experience. The nasal folds, those charming wrinkles on the nose, can also play a role in ocular disease. In some individuals, the nasal fold is prominent enough to rub against the corneal surface with every blink or facial movement. This constant friction, known as nasal fold keratitis, can cause chronic irritation, corneal scarring, and even ulceration. The hair on the nasal fold can also act like a brush, depositing debris and bacteria onto the already compromised corneal surface. ### The Spectrum of Ocular Disease The clinical manifestations of brachycephalic eye disease are diverse, and an individual Shih Tzu may experience one or several of these conditions over its lifetime. **Corneal ulceration** is perhaps the most common and most urgent manifestation. An ulcer is a break in the corneal epithelium that exposes the underlying stroma. This is intensely painful because the cornea is densely innervated with nerve endings. A dog with a corneal ulcer will typically squint, tear excessively, and may paw at the affected eye. The eye may appear red and cloudy. Without prompt treatment, a superficial ulcer can deepen into a descemetocele, where the deepest layer of the cornea is exposed, or even rupture, leading to loss of the eye. **Corneal sequestrum** is a unique and serious condition that is more common in brachycephalic breeds. In this condition, a portion of the corneal stroma undergoes necrosis and becomes a brown or black plaque. The sequestrum acts as a foreign body, causing chronic inflammation and pain. It will not resolve on its own and typically requires surgical removal. The underlying cause is often chronic corneal exposure and irritation, which leads to cell death and pigment deposition. **Keratoconjunctivitis sicca (KCS)**, commonly known as dry eye, is a deficiency in the aqueous (watery) portion of the tear film. While KCS can occur in any breed, the conformational abnormalities of the Shih Tzu eye can contribute to its development or worsen its severity. The abnormal blink dynamics and tear film instability seen in brachycephalic dogs can exacerbate the effects of reduced tear production. KCS is a progressive condition that, if untreated, leads to chronic corneal inflammation, pigmentation, and vision loss. **Entropion** is a conformational abnormality where the eyelid margin rolls inward, causing the eyelashes and facial hair to rub against the cornea. This is a painful condition that causes chronic irritation and can lead to corneal ulcers and scarring. In Shih Tzus, entropion can affect the lower eyelids, upper eyelids, or both. The condition may be present from a young age or may develop as the dog matures and facial conformation changes. **Distichiasis** is another eyelid abnormality seen in the breed. In this condition, extra eyelashes grow from an abnormal location on the eyelid margin, often rubbing against the cornea. This can cause chronic irritation, tearing, and corneal ulcers. Distichiasis may be present in young dogs and can be managed with various treatments, including electrolysis, cryotherapy, or surgical removal. **Proptosis** is the most dramatic and severe ocular emergency. This occurs when the eye is displaced from the socket, usually due to trauma such as a dog fight, a fall, or even excessive pressure on the neck from a collar. The prominent eyes of the Shih Tzu are at significantly higher risk for proptosis than the eyes of other breeds. This is a true emergency that requires immediate veterinary intervention. The prognosis for saving the eye depends on the severity of the trauma and how quickly treatment is initiated. ### The Diagnostic Workup: What to Expect at the Veterinary Hospital When you bring your Shih Tzu to the veterinarian with an eye concern, the examination will be systematic and thorough. Understanding what to expect can help you prepare and reduce anxiety about the visit. The veterinarian will begin with a general observation of your dog, noting any squinting, discharge, or asymmetry between the two eyes. They will then perform a series of specific tests, often in a darkened room to facilitate examination. The **Schirmer tear test** is typically performed first, as it requires the eye to be relatively undisturbed. A small, sterile strip of filter paper is placed in the lower conjunctival sac, and the amount of tears absorbed in one minute is measured. This test is essential for diagnosing KCS. Normal tear production is typically greater than 15 mm per minute, though this can vary slightly between laboratories and individual dogs. Next, the veterinarian will apply a **fluorescein stain** to the eye. This is a vital diagnostic step. A drop of orange dye is applied to the corneal surface, and then the eye is examined under a cobalt blue light. The dye will adhere to any areas where the corneal epithelium is damaged, revealing the presence and extent of any ulcers. The depth of the ulcer can also be assessed by observing how the dye penetrates the corneal layers. This test is critical for identifying corneal ulcers that may not be visible to the naked eye. **Tonometry** is used to measure the intraocular pressure (IOP). This test is important for ruling out glaucoma, which can also cause a red, painful eye. A small device called a tonometer is gently placed against the cornea to measure the pressure. Normal IOP in dogs is typically between 10 and 25 mmHg. Elevated pressure can indicate glaucoma, which requires immediate treatment to prevent vision loss. **Slit-lamp biomicroscopy** is a specialized examination that allows the veterinarian to view the structures of the eye in detail. The slit lamp provides a magnified, three-dimensional view of the cornea, anterior chamber, iris, and lens. This examination can reveal subtle abnormalities that are not visible with the naked eye, such as early corneal edema, anterior uveitis, or lens changes. If the cornea is too cloudy or opaque to visualize the internal structures of the eye, an **ocular ultrasound** may be recommended. This imaging modality uses sound waves to create a picture of the eye's interior. It can be used to evaluate the lens, vitreous, and retina, and to rule out conditions such as retinal detachment or intraocular masses. ### Treatment Strategies: From Medical Management to Surgical Correction The treatment of brachycephalic eye disease is tailored to the specific condition and its severity. Some conditions can be managed medically, while others require surgical intervention. **Medical management** is the mainstay of treatment for many acute and chronic ocular conditions. For corneal ulcers, topical antibiotics are prescribed to prevent or treat bacterial infection. The frequency of application depends on the severity of the ulcer; some ulcers require antibiotic drops every two to four hours. Atropine is often used to relieve the pain associated with ciliary muscle spasms, which occur when the eye is inflamed. Atropine dilates the pupil and paralyzes the ciliary muscle, providing significant pain relief. However, it can cause photosensitivity, so dogs on atropine should be kept out of bright light. Artificial tear supplements are used to lubricate the eye and protect the cornea. These are available as drops, gels, and ointments. Gels and ointments provide longer-lasting lubrication and are often recommended for overnight use. For dogs with KCS, immunosuppressive medications such as cyclosporine or tacrolimus are the mainstay of treatment. These drugs stimulate tear production and reduce corneal inflammation. They are typically administered twice daily and may take several weeks to achieve their full effect. **Surgical management** is often necessary for conformational abnormalities and for conditions that do not respond to medical therapy. **Blepharoplasty** is a group of surgical procedures designed to correct eyelid conformational abnormalities. **Medial canthoplasty** is a common procedure that narrows the eyelid opening at the inner corner of the eye. This reduces the exposed corneal surface and improves corneal coverage. It is often performed in brachycephalic breeds to address macroblepharon and lagophthalmos. **Entropion repair** involves surgically everting the eyelid margin to its normal position. The specific technique depends on the location and severity of the entropion. **Distichiasis** can be treated with electrolysis, which destroys the hair follicle, or with surgical removal of the affected eyelid margin. **Corneal sequestrum** requires surgical removal. The necrotic tissue is carefully dissected from the cornea, and the resulting defect is allowed to heal or is covered with a conjunctival graft. The prognosis after surgery is generally good, but recurrence is possible if the underlying conformational abnormalities are not addressed. **Proptosis** is a surgical emergency. The eye is replaced into the socket under general anesthesia, and the eyelids are temporarily sutured closed to protect the eye during healing. The prognosis for vision depends on the severity of the trauma and the condition of the optic nerve and blood vessels at the time of presentation. ### The Role of the Owner in Managing Ocular Health Owners play a crucial role in the management of brachycephalic eye disease. Daily observation and proactive care can significantly reduce the risk of complications. **Daily eye inspection** should be part of your routine. Look for any signs of redness, cloudiness, discharge, or squinting. Check the hair around the eyes for matting or debris that could irritate the cornea. If you notice any changes, contact your veterinarian promptly. **Facial hair maintenance** is essential. The hair around the eyes should be kept trimmed to prevent it from rubbing against the cornea. Many owners learn to trim this hair at home, but your groomer or veterinarian can also do it. Keeping the nasal folds clean and dry is also important, as moisture and debris in the folds can contribute to skin infections and ocular irritation. **Environmental modifications** can reduce the risk of ocular trauma and irritation. Use a harness instead of a collar to reduce pressure on the neck, which can exacerbate eye protrusion. Be cautious during play with other dogs, as the prominent eyes of the Shih Tzu are vulnerable to injury. Keep your dog away from bushes, branches, and other potential eye hazards. **Lubrication** may be recommended by your veterinarian, even if your dog does not currently have eye problems. Prophylactic use of artificial tears can help maintain tear film stability and protect the cornea, especially in dry or windy environments. Your veterinarian can recommend an appropriate product and frequency of use. ## Kidney Stones in Shih Tzus: A Deeper Dive into Pathophysiology and Management Kidney stones, or nephroliths, are a significant health concern for Shih Tzus. While the breed is perhaps best known for its ocular issues, urinary tract disease is also an important consideration. Understanding the underlying mechanisms of stone formation, the diagnostic process, and the available treatment options is essential for owners who want to provide the best possible care for their dogs. ### The Biochemistry of Stone Formation Kidney stones form when the urine becomes supersaturated with specific minerals. Supersaturation occurs when the concentration of a mineral exceeds the point at which it can remain dissolved in the urine. When this threshold is exceeded, the minerals begin to crystallize, and these crystals can aggregate to form stones. Several factors influence the risk of stone formation: **Urine pH** is a critical determinant of which types of stones form. Struvite stones (magnesium ammonium phosphate) form in alkaline urine, typically with a pH above 7.0. Calcium oxalate stones, in contrast, tend to form in acidic urine, typically with a pH below 6.5. Urate stones also form in acidic urine. The pH of the urine is influenced by diet, hydration status, and the presence of urinary tract infections. **Urine concentration** is another key factor. Concentrated urine, which occurs with dehydration, has a higher concentration of minerals and is more likely to become supersaturated. Encouraging water intake is therefore a cornerstone of stone prevention. **Dietary factors** can influence the types and amounts of minerals in the urine. Diets high in protein, sodium, calcium, or oxalate can increase the risk of stone formation. However, the relationship between diet and stone formation is complex and varies depending on the type of stone. **Urinary tract infections** play a significant role in the formation of struvite stones. Certain bacteria, particularly *Staphylococcus* and *Proteus* species, produce the enzyme urease. Urease breaks down urea in the urine into ammonia and carbon dioxide. The ammonia alkalinizes the urine, creating an environment that is favorable for struvite crystal formation. The bacteria also serve as a nidus, or starting point, for stone formation. **Genetics** also plays a role. Certain breeds, including the Shih Tzu, are predisposed to specific types of stones. This predisposition is likely due to inherited differences in metabolism, urinary excretion of minerals, or other factors that are not yet fully understood. ### Types of Stones and Their Clinical Significance The most common types of stones seen in small breed dogs, including Shih Tzus, are calcium oxalate, struvite, and urate stones. **Calcium oxalate stones** are composed of calcium and oxalate. They are the most common type of stone in dogs and are particularly prevalent in small breeds. These stones are hard and radiopaque, meaning they are visible on X-rays. They tend to form in acidic urine and are not typically associated with urinary tract infections. Calcium oxalate stones cannot be dissolved medically and must be removed surgically or managed with dietary changes to prevent growth and recurrence. **Struvite stones** are composed of magnesium ammonium phosphate. They are almost always secondary to a urinary tract infection with urease-producing bacteria. Struvite stones can vary in size and number, and they are radiopaque. Unlike calcium oxalate stones, struvite stones can often be dissolved medically with a combination of a therapeutic diet and antibiotics. The diet is designed to acidify the urine and reduce the concentration of the minerals that form struvite, while the antibiotics eliminate the underlying infection. **Urate stones** are composed of uric acid and its salts. They are associated with a defect in purine metabolism that leads to elevated levels of uric acid in the urine. The Dalmatian is the classic breed for this condition, but it can occur in other breeds, including the Shih Tzu. Urate stones are radiolucent, meaning they are not visible on standard X-rays. They require ultrasound or contrast studies for detection. Urate stones can sometimes be dissolved medically with a low-purine diet and medications that alkalinize the urine, but surgical removal may be necessary in some cases. ### The Diagnostic Journey: From Clinical Signs to Definitive Diagnosis The clinical signs of kidney stones can be subtle or dramatic, depending on the size, location, and number of stones. Many dogs with kidney stones show no clinical signs at all, and the stones are discovered incidentally during an abdominal ultrasound or X-ray performed for another reason. When clinical signs do occur, they are often related to the presence of the stone in the urinary tract. **Hematuria** (blood in the urine) is a common sign and may be visible as pink or red urine or may only be detected on a urinalysis. **Stranguria** (straining to urinate) and **pollakiuria** (urinating frequently in small amounts) can occur if the stone is irritating the bladder or urethra. **Abdominal pain** may be present, particularly if the stone is in the kidney or ureter. If a stone causes a **ureteral obstruction**, the clinical signs are more severe. The dog may vomit, become lethargic, and lose its appetite. This is a life-threatening emergency that requires immediate veterinary intervention. The obstruction prevents urine from flowing from the kidney to the bladder, leading to a buildup of pressure in the kidney and a rapid decline in kidney function. The diagnostic workup for suspected kidney stones begins with a thorough history and physical examination. The veterinarian will palpate the abdomen to check for pain, enlarged kidneys, or a distended bladder. **Urinalysis** is an essential first step. It can detect blood, crystals, and infection in the urine. The urine pH is also measured, which can provide clues about the type of stone. The presence of specific crystals in the urine can be suggestive of the stone type, but it is not definitive. Some dogs with stones do not have crystals in their urine, and some dogs with crystals do not have stones. **Bloodwork** is important to assess kidney function. A biochemistry panel will measure blood urea nitrogen (BUN) and creatinine, which are waste products that accumulate in the blood when kidney function is impaired. A complete blood count (CBC) can detect signs of infection or inflammation. **Abdominal radiographs (X-rays)** are often the next step. Radiopaque stones, such as calcium oxalate and struvite, will be visible on X-rays. However, radiolucent stones, such as urate and cystine, will not be visible. The sensitivity of X-rays for detecting kidney stones is limited, especially for small stones or stones in the ureters. **Abdominal ultrasound** is a more sensitive imaging modality. It can detect stones in the kidneys, ureters, and bladder, including those that are not visible on X-rays. Ultrasound also allows the veterinarian to assess the overall health of the kidneys, including the size, shape, and architecture of the renal parenchyma. Hydronephrosis, a dilation of the renal pelvis due to obstruction, can also be detected on ultrasound. In some cases, additional imaging may be needed. **Contrast studies**, such as an intravenous pyelogram (IVP), involve injecting a contrast agent into the bloodstream and taking X-rays to visualize the urinary tract. This can help identify the location and severity of a ureteral obstruction. **CT scans** provide the most detailed imaging of the urinary tract and can be helpful in complex cases. ### Treatment Options: A Multifaceted Approach The treatment of kidney stones depends on the type, size, and location of the stone, as well as the overall health of the dog. **Medical dissolution** is an option for struvite stones and, in some cases, urate stones. For struvite stones, the treatment involves a therapeutic diet that is low in protein, magnesium, and phosphorus, and that promotes the production of acidic urine. Antibiotics are also given to treat the underlying urinary tract infection. This approach can be highly effective, with dissolution occurring over a period of weeks to months. Regular monitoring with urinalysis and imaging is necessary to assess progress. For urate stones, medical dissolution may be attempted with a low-purine diet and medications that alkalinize the urine. Allopurinol, a medication that reduces uric acid production, may also be used. However, this approach is not always successful, and surgical removal may be necessary. **Surgical removal** is indicated for stones that are causing an obstruction, are very large, or are not amenable to medical dissolution. The specific surgical procedure depends on the location of the stone. A **ureterotomy** is a surgical incision into the ureter to remove a stone. A **nephrotomy** involves an incision into the kidney itself. These are major surgeries that require specialized equipment and expertise. In some cases, a **ureteral stent** may be placed to bypass an obstructing stone and allow urine to flow. **Extracorporeal shock wave lithotripsy (ESWL)** is a non-invasive procedure that uses shock waves to break stones into smaller fragments that can be passed in the urine. This technique is more commonly used in human medicine but is available at some veterinary referral centers. It is most effective for small stones in the kidney or upper ureter. **Dietary management** is a cornerstone of both treatment and prevention. The goal is to reduce the concentration of stone-forming minerals in the urine and to promote the production of dilute urine. For calcium oxalate stones, the diet should be low in oxalate and sodium, and should promote a neutral to slightly alkaline urine pH. For struvite stones, the diet should be low in protein, magnesium, and phosphorus, and should promote acidic urine. For urate stones, the diet should be low in purines. **Increasing water intake** is perhaps the most important preventative measure. Dilute urine is less likely to become supersaturated with minerals. Owners can encourage water intake by providing fresh, clean water at all times, using a water fountain, and adding water or broth to the dog's food. Feeding wet food instead of dry food can also significantly increase water intake. ### Prevention and Long-Term Monitoring Prevention of kidney stones is a lifelong endeavor for dogs that are predisposed to them. The specific preventative measures depend on the type of stone the dog has formed. For dogs with a history of calcium oxalate stones, the focus is on reducing dietary oxalate and sodium, promoting dilute urine, and maintaining a neutral urine pH. Regular monitoring with urinalysis and imaging is essential to detect early signs of recurrence. For dogs with a history of struvite stones, the focus is on preventing urinary tract infections and maintaining acidic urine. Regular urinalysis can detect early signs of infection, allowing for prompt treatment. For dogs with a history of urate stones, the focus is on reducing dietary purines and maintaining alkaline urine. Medications such as allopurinol may be needed to control uric acid production. Regardless of the stone type, regular veterinary check-ups are essential. A urinalysis should be performed at least annually, and more frequently for dogs with a history of stones. Abdominal imaging may be recommended periodically to monitor for the presence of new stones. ## The Evidence Base: What the Literature Tells Us About Shih Tzu Health The UK VetCompass study provides valuable epidemiological data on the health of Shih Tzus under primary veterinary care. This study analyzed the records of a large population of Shih Tzus to determine the most common disorders and the demographic characteristics of the breed. The study found that the most prevalent disorders were periodontal disease, anal sac impaction, and ear disorders. This is consistent with the general understanding of breed-specific health issues in small, brachycephalic dogs. Dental disease is a common problem in small breeds due to crowding of the teeth and a predisposition to plaque and tartar accumulation. Anal sac impaction is also common in small breeds, likely due to the anatomy of the anal sacs and the consistency of the feces. Ear disorders are common in breeds with heavy, pendulous ears, which can trap moisture and debris. The study also found that ophthalmological disorders were a major grouped-level condition, affecting 11.9% of the studied dogs. This confirms that eye problems are a significant health concern for the breed. The specific types of ophthalmological disorders were not detailed in the study, but they likely include the conditions described in this article, such as corneal ulcers, KCS, and entropion. The study reported a median age of 4.1 years and a mean adult bodyweight of 7.9 kg. This information is useful for owners to understand the typical profile of the breed. The relatively young median age suggests that the study population was skewed toward younger dogs, which may reflect the popularity of the breed in recent years. The study's findings on demography and common disorders help veterinarians and owners prioritize health screening and preventative care. For example, the high prevalence of dental disease suggests that regular dental cleanings should be a priority for Shih Tzu owners. The high prevalence of ophthalmological disorders suggests that regular eye examinations should also be a priority. It is important to note that this study was conducted in the UK and may not be fully representative of Shih Tzu populations in other countries. Additionally, the study only included dogs under primary veterinary care, so it may not capture the full spectrum of health issues in the breed. However, it provides a valuable baseline for understanding the health challenges that Shih Tzus face. ## Special Considerations for Puppies and Senior Shih Tzus The health concerns discussed in this article can affect Shih Tzus of any age, but there are special considerations for puppies and senior dogs. ### Puppies and Young Shih Tzus Brachycephalic eye disease can manifest in puppies as young as a few months of age. Entropion and distichiasis are often present from a young age and may require surgical correction. Corneal ulcers can occur at any age, but puppies may be more prone to trauma due to their playful and energetic nature. Kidney stones are less common in puppies, but they can occur. If a puppy is diagnosed with kidney stones, a thorough diagnostic workup is essential to identify any underlying metabolic or genetic abnormalities. Early intervention is critical to prevent complications and to establish a long-term management plan. For puppies, it is important to establish good habits early. Regular eye examinations, dental care, and a balanced diet can help prevent or delay the onset of breed-related health issues. Owners should also be educated about the signs of ocular and urinary emergencies so that they can seek prompt veterinary care if needed. ### Senior Shih Tzus As Shih Tzus age, the risk of both ocular and urinary disease increases. Chronic exposure keratopathy can progress over time, leading to corneal pigmentation and vision loss. KCS may develop or worsen with age. Cataracts and other age-related ocular changes can also occur. Kidney function naturally declines with age, and this can increase the risk of stone formation. Additionally, older dogs may have other health issues, such as kidney disease or diabetes, that can affect urinary health. For senior Shih Tzus, more frequent veterinary check-ups are recommended. A comprehensive geriatric screening, including bloodwork, urinalysis, and blood pressure measurement, can help detect early signs of disease. Regular eye examinations are also important to monitor for age-related changes. Owners of senior Shih Tzus should be particularly vigilant about monitoring for signs of ocular and urinary disease. Changes in vision, increased tearing, or squinting should be evaluated promptly. Changes in urination habits, such as increased frequency or straining, should also be evaluated. ## The Importance of a Partnership with Your Veterinarian Managing the health of a Shih Tzu requires a partnership between the owner and the veterinarian. The breed's predisposition to ocular and urinary disease means that proactive care is essential. Your veterinarian can provide guidance on the specific risks for your individual dog, based on its age, sex, and health history. They can recommend appropriate screening tests and preventative measures. They can also provide education on the signs of emergencies and what to do if they occur. It is important to establish a relationship with a veterinarian who is familiar with the breed and its specific health concerns. A veterinarian with experience in brachycephalic breeds will be better equipped to recognize the subtle signs of ocular disease and to recommend appropriate treatment. In some cases, referral to a veterinary specialist may be recommended. A veterinary ophthalmologist has advanced training and equipment for diagnosing and treating complex ocular conditions. A veterinary internist or urologist may be recommended for complex urinary tract issues. ## Practical Tips for Daily Care In addition to the specific medical and surgical treatments described above, there are several practical steps that owners can take to support the health of their Shih Tzu. **Eye care:** Clean the area around the eyes ## Frequently Asked Questions ### 1. What are the first signs of brachycephalic eye disease in a Shih Tzu? The first signs are often squinting, excessive tearing, and a slight cloudiness or redness of the eye. You may also notice your dog rubbing its face on the carpet or furniture. ### 2. Can kidney stones in Shih Tzus be dissolved with medication? Only certain types of stones can be dissolved with medication. Struvite stones can often be dissolved with a special diet and antibiotics. Calcium oxalate and urate stones cannot be dissolved and typically require surgical removal or other interventions. ### 3. How can I prevent my Shih Tzu from getting dry eye? While you cannot change your dog's conformation, you can help manage tear film stability. Keeping the hair around the eyes trimmed, using a humidifier, and using veterinary-approved lubricating eye drops can help. Regular veterinary check-ups are essential for early diagnosis and management of KCS. ### 4. Is surgery always necessary for kidney stones? No, surgery is not always necessary. Small, non-obstructive stones that are not causing clinical signs may be managed with dietary changes and monitoring. Surgery is indicated for stones that cause obstruction, pain, or recurrent urinary tract infections. ### 5. What is the prognosis for a Shih Tzu with a corneal ulcer? The prognosis is generally good if the ulcer is treated promptly and aggressively. However, it depends on the depth and cause of the ulcer. Deep or infected ulcers can be more challenging to treat and may require surgery. Chronic ulcers due to conformational issues may have a more guarded prognosis for complete resolution without surgical correction. ### 6. Are kidney stones more common in male or female Shih Tzus? The provided source does not specify a sex predisposition for kidney stones in Shih Tzus. However, in general canine medicine, certain stone types are more common in females (struvite) and others in males (calcium oxalate). Your veterinarian can provide breed and sex-specific risk information. ### 7. What should I feed my Shih Tzu to prevent kidney stones? There is no single "best" diet for all dogs. The ideal diet depends on the type of stone your dog is prone to. A diet that promotes dilute urine and is balanced in minerals is generally recommended. Your veterinarian can recommend a specific therapeutic diet based on your dog's urinalysis and stone type. ### 8. How often should my Shih Tzu have its eyes checked? As a brachycephalic breed, Shih Tzus should have an ophthalmic examination at least once a year as part of their routine wellness check. If your dog has a history of eye problems, more frequent checks may be recommended by your veterinarian. ## Veterinary Disclaimer This article is educational and is not a substitute for veterinary diagnosis or treatment. Always consult with a qualified veterinarian regarding any questions you have about your pet's health. ## Sources 1. [Demography, common disorders and mortality of Shih Tzu dogs under primary veterinary care in the UK.](https://pubmed.ncbi.nlm.nih.gov/38263229/) ## Related Clinical & Scientific Guides * [Birman Health Problems: Inherited Conditions and Cardiac Screenings](/knowledge/veterinary-medicine/breed-specific-health/birman-health-problems-inherited-conditions-and-cardiac-screenings) * [Singapura Cat Health Problems: Inherited Conditions and Cardiac Screenings](/knowledge/veterinary-medicine/breed-specific-health/singapura-cat-health-problems-inherited-conditions-and-cardiac-screenings) * [Siberian Cat Health Problems: Inherited Conditions and Cardiac Screenings](/knowledge/veterinary-medicine/breed-specific-health/siberian-cat-health-problems-inherited-conditions-and-cardiac-screenings)