Shar-Pei Recurrent Fever Syndrome: Causes & Treatment

Understanding Shar-Pei Recurrent Fever Syndrome

Shar-Pei Recurrent Fever Syndrome, also known as Familial Shar-Pei Fever (FSF) or Shar-Pei Autoinflammatory Disease (SPAID), is a genetically inherited inflammatory condition that affects Chinese Shar-Pei dogs. This syndrome is characterized by unpredictable episodes of high fever, joint pain and swelling, and various systemic inflammatory symptoms. The condition occurs as a result of genetic mutations that affect the dog’s immune system regulation, leading to a constant state of inflammation and periodic fever episodes. While the fevers themselves can be uncomfortable and potentially dangerous if they exceed 106°F, the most serious concern associated with this syndrome is the accompanying kidney damage that develops over time.

Genetic Basis and Causes

The root cause of Shar-Pei Recurrent Fever Syndrome lies in a genetic mutation affecting the HAS2 gene, which regulates hyaluronan production. Researchers from Uppsala University and the Broad Institute discovered that a duplicated DNA segment near the HAS2 gene increases the risk for this condition. This duplication leads to overproduction of hyaluronan, a substance that not only causes the breed’s signature wrinkles but also triggers the immune system to produce excessive inflammatory chemicals.

The more copies of the duplicated genetic segment a dog inherits, the higher the risk of developing the disorder. In the United States, approximately 23% of Shar-Peis carry this mutation and possess large quantities of hyaluronic acid in their skin, resulting in extensive skin folding. Dogs with highly wrinkled skin are more susceptible to developing fever episodes, as the excess hyaluronan acts as a danger signal to the immune system.

When hyaluronan escapes into the bloodstream, it stimulates macrophages to produce excessive amounts of inflammatory cytokines, particularly IL-1beta and IL-6. These cytokines trigger the brain to initiate a fever response and stimulate hepatocytes to produce acute phase proteins such as serum amyloid A (SAA). This cascade of inflammatory events leads to the characteristic fever episodes that define the condition.

Clinical Signs and Symptoms

Dogs affected by Shar-Pei Recurrent Fever Syndrome experience distinctive symptoms during acute fever episodes. These episodes typically last 12 to 48 hours and may occur as frequently as every few weeks. The severity and frequency of episodes can vary significantly among affected dogs.

Primary symptoms include:

• Recurrent high fevers, typically ranging from 103°F to 107°F (39.4°C to 41.7°C)
• Swelling and pain in the tibiotarsal joints (hocks), which is the most common location
• Swollen, painful muzzle, sometimes referred to as a “meatmouth” appearance
• Swelling in wrists and lips that may feel hot to the touch
• Reluctance to move or obvious discomfort, such as an arched back
• Abdominal pain
• Vomiting and diarrhea
• Shallow breathing
• Increased thirst and frequent urination
• Loss of appetite
• Halitosis or bad breath

Between fever episodes, affected dogs may appear relatively normal, though they typically experience some residual inflammation and discomfort. Fever episodes exceeding 106°F constitute a medical emergency and require immediate veterinary attention.

Long-Term Complications: Amyloidosis

The most serious consequence of Shar-Pei Recurrent Fever Syndrome is the development of amyloidosis, a condition in which abnormal protein deposits accumulate in vital organs. High concentrations of serum amyloid A (SAA) remain elevated even between fever episodes, leading to the deposition of insoluble amyloid in tissues.

Amyloid primarily accumulates in the kidneys, but can also deposit in the liver, spleen, gastrointestinal tract, and myocardium. In the kidneys, amyloid interferes with the organ’s ability to filter proteins properly, leading to protein loss in the urine. This protein loss creates a cascade of serious complications:

• Progressive kidney damage and potential kidney failure
• High blood pressure
• Loss of body weight due to protein loss
• Abnormal blood clotting due to loss of proteins that prevent clot formation
• Liver damage and potential liver failure
• Early death if kidney disease progresses unchecked

These long-term complications make early diagnosis and appropriate management crucial for extending the quality and length of life in affected Shar-Peis.

Diagnostic Approach

Diagnosing Shar-Pei Recurrent Fever Syndrome requires a comprehensive veterinary evaluation, as fever itself is not specific to this condition. A complete physical examination and blood testing are necessary to rule out other potential causes of fever, such as infections or wounds. This is known as a diagnosis of exclusion, where other conditions must be ruled out before confirming FSF.

Diagnostic findings typically include:

• Elevated white blood cell counts (neutrophilia and monocytosis)
• High cholesterol levels (hypercholesterolemia)
• Low magnesium levels (hypomagnesemia)
• Elevated gamma globulins (hyperglobulinemia)
• High blood platelet count
• Protein in the urine (proteinuria)
• Low albumin in the blood
• Fluid retention
• Serum amyloid A elevation

X-ray and ultrasound imaging may reveal abnormalities of the kidneys and liver, particularly in dogs with advanced amyloidosis. Additionally, genetic testing can identify dogs carrying the HAS2 gene duplication, which helps confirm the diagnosis and can be used for breeding decisions.

Treatment and Management

While there is no cure for Shar-Pei Recurrent Fever Syndrome, various treatment approaches can help manage symptoms and reduce inflammation during acute episodes and over the long term.

Acute Episode Management:

During fever episodes, treatment focuses on reducing inflammation and managing pain. Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used to decrease inflammation and fever. The duration of treatment depends on the severity and duration of the fever episode, typically lasting until symptoms resolve.

Long-Term Management:

Colchicine is the most commonly recommended long-term medication for Shar-Pei fever management. This drug works by reducing inflammation and has been shown to decrease the frequency and severity of fever episodes. In some cases, veterinarians may recommend corticosteroids for additional inflammation control, though their use must be carefully monitored due to potential side effects.

Other supportive care measures include:

• Regular monitoring of kidney and liver function through blood work and urinalysis
• Dietary management to support kidney health
• Maintaining appropriate hydration
• Limiting strenuous exercise during or immediately after fever episodes
• Providing a comfortable, stress-free environment

Potential drug interactions must be carefully considered when prescribing colchicine or other medications, particularly in dogs with kidney or liver compromise.

Prognosis and Quality of Life

The prognosis for dogs with Shar-Pei Recurrent Fever Syndrome varies depending on the severity of the condition, the frequency of fever episodes, and the presence or progression of amyloidosis. Dogs with less severe disease and infrequent fever episodes may have relatively normal lifespans with appropriate management. However, dogs with severe recurrent episodes and progressive kidney disease may have shortened lifespans.

Early diagnosis and aggressive management of inflammation can help slow the progression of amyloidosis and preserve kidney function. Regular veterinary monitoring, including periodic blood work and urinalysis, is essential to track disease progression and adjust treatment protocols as needed.

Prevention and Breeding Considerations

As Shar-Pei Recurrent Fever Syndrome is an inherited genetic condition, responsible breeding practices are important for reducing its prevalence in the breed. Genetic testing for the HAS2 gene duplication is available and can help breeders identify carriers and affected dogs. Breeding decisions should consider the genetic status of both parents to minimize the transmission of this condition to offspring.

Prospective Shar-Pei owners should be aware of this condition’s prevalence in the breed and should inquire about genetic testing and health screening of parents before acquiring a puppy. Some reputable breeders may selectively breed for reduced skin folding, which correlates with lower risk of FSF.

Living with a Shar-Pei with Fever Syndrome

Owners of Shar-Peis with recurrent fever syndrome must be prepared to recognize the signs of an acute episode and provide prompt veterinary care when needed. Maintaining detailed records of fever episodes, including dates, temperatures, duration, and associated symptoms, can help veterinarians optimize treatment strategies. Building a strong relationship with a veterinarian experienced in managing this condition is invaluable for providing the best possible care.

With appropriate medical management, supportive care, and regular monitoring, many Shar-Peis with this syndrome can maintain good quality of life and enjoy many happy years with their families.

Frequently Asked Questions

Q: At what age does Shar-Pei fever typically develop?

A: Fever episodes usually begin before 18 months of age, though they can occur at any point in a Shar-Pei’s life. Some dogs may not have their first episode until later in life.

Q: How often do fever episodes occur?

A: Episodes may occur as often as every few weeks, though frequency varies considerably among affected dogs. Some dogs may have episodes several times per year, while others may experience them more or less frequently.

Q: Can Shar-Pei fever be cured?

A: There is no cure for Shar-Pei Recurrent Fever Syndrome, but symptoms and inflammation can be effectively managed with appropriate medications and supportive care to improve quality of life.

Q: Is genetic testing available for this condition?

A: Yes, genetic testing for the HAS2 gene duplication is available through veterinary diagnostic laboratories and can help identify affected dogs and carriers for breeding purposes.

Q: What temperature is considered a medical emergency?

A: A fever exceeding 106°F (41.1°C) is considered a medical emergency and requires immediate veterinary attention to prevent organ damage.

Q: Can affected dogs still live long, happy lives?

A: Yes, with appropriate medical management, regular veterinary monitoring, and supportive care, many Shar-Peis with this condition can enjoy good quality of life and normal lifespans, depending on disease severity.