Shetland Sheepdog Syndrome

Shetland Sheepdog Syndrome, also known as Shetland Sheepdog Collie Eye Anomaly, is a genetic disorder that affects the eyes of Shetland Sheepdogs and other breeds, including the Collie, Border Collie, and Australian Shepherd. This condition is caused by a genetic mutation and is inherited in an autosomal recessive pattern, meaning that a dog must inherit two copies of the mutated gene, one from each parent, to develop the disease.

The main characteristic of Shetland Sheepdog Syndrome is an abnormality in the development of the eye, specifically the retina, choroid, and sclera. The retina is the layer of cells at the back of the eye that is responsible for sensing light and transmitting signals to the brain. The choroid is the layer of blood vessels that provides oxygen and nutrients to the retina. The sclera is the white, outer layer of the eye that helps to protect it.

There are three main types of Shetland Sheepdog Syndrome:

  1. Collie Eye Anomaly (CEA): This is the most common form of Shetland Sheepdog Syndrome and is characterized by an underdevelopment of the choroid, which can lead to a reduced blood supply to the retina. In severe cases, the retina may become detached from the choroid, causing vision loss. Dogs with CEA may also have small, blind spots in their peripheral vision.
  2. Choroidal Hypoplasia: This type of Shetland Sheepdog Syndrome is characterized by a thinning of the choroid, which can lead to a reduced blood supply to the retina. This can cause vision loss, especially in bright light.
  3. Scleral Ectasia: This is the least common form of Shetland Sheepdog Syndrome and is characterized by a thinning of the sclera, which can cause the eye to bulge out. This can lead to increased pressure in the eye, causing pain and vision loss.

Causes

The exact cause of SAB is not known, but there are several theories about what may contribute to the development of this condition.

  1. Genetics: Some studies have suggested that there may be a genetic component to the development of SAB, although the exact genes involved have not been identified. It is thought that individuals with a family history of the condition may have a higher risk of developing SAB.
  2. Infections: SAB has been associated with certain infections, including streptococcal infections, HIV, and hepatitis B and C. It is believed that these infections may trigger an immune response that contributes to the development of the condition.
  3. Immune system dysfunction: Some evidence suggests that SAB may be related to a dysfunction in the immune system, which may result in an overactive immune response. This could lead to the production of excessive amounts of collagen, which contributes to the formation of the fibrous patches seen in SAB.
  4. Hormonal imbalances: Hormonal imbalances, such as those seen in diabetes or thyroid disorders, have been linked to the development of SAB. It is thought that these imbalances may disrupt the normal functioning of the immune system, leading to an overactive immune response and the formation of fibrous patches on the skin.
  5. Medications: Certain medications, such as penicillin and other antibiotics, have been linked to the development of SAB. It is believed that these medications may cause an overactive immune response, leading to the formation of fibrous patches on the skin.
  6. Trauma: Trauma to the skin, such as cuts, bruises, or burns, has been linked to the development of SAB. It is believed that the injury may trigger an immune response, leading to the formation of fibrous patches on the skin.
  7. Other underlying medical conditions: SAB has been associated with a number of other underlying medical conditions, including cancer, liver disease, and kidney disease. It is thought that these conditions may contribute to the development of SAB by disrupting the normal functioning of the immune system.
  8. NSD1 Gene Mutation: Sotos syndrome is primarily caused by mutations in the NSD1 (NuRD complex subunit NSD1) gene, located on chromosome 5. The NSD1 gene provides instructions for making a protein that helps regulate gene activity. When mutations occur in this gene, it can disrupt normal growth and development, leading to the characteristic symptoms of Sotos syndrome.
  9. Chromosomal Abnormalities: In some cases, Sotos syndrome is caused by chromosomal abnormalities, such as deletions or duplications of the NSD1 gene. These structural changes can result in the loss or overproduction of NSD1 protein, leading to abnormal growth and development.
  10. Epigenetic Changes: Epigenetic changes, which affect gene activity without altering the underlying DNA sequence, have also been implicated in the development of Sotos syndrome. For example, changes in the pattern of chemical modifications to the NSD1 gene can result in the overproduction of NSD1 protein and contribute to the symptoms of Sotos syndrome.
  11. Environmental Factors: Environmental factors, such as exposure to certain chemicals or pollutants, may also play a role in the development of Sotos syndrome. For example, exposure to certain toxins or chemicals during pregnancy or early childhood may affect the normal development of the brain and lead to the symptoms of Sotos syndrome.
  12. Inheritance Pattern: Sotos syndrome is an autosomal dominant disorder, which means that an affected person has a 50% chance of passing the condition on to each of their children. In most cases, Sotos syndrome is caused by a new mutation in the NSD1 gene and is not inherited from a person’s parents.
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The exact cause of SAB is not known, and it is likely that a combination of factors, including genetics, infections, immune system dysfunction, hormonal imbalances, medications, trauma, and underlying medical conditions, may contribute to the development of this condition.

Symptoms

It is characterized by the accumulation of fibrous tissue beneath the skin, causing it to become thick and stiff. The cause of SAB is not well understood, but it is thought to be related to a malfunction of the immune system, injury, or an underlying medical condition such as diabetes.

The main symptoms of SAB include:

  1. Skin thickening: The affected skin becomes thick and stiff, with a waxy or leathery texture. The skin may also appear shiny and tight. The thickening is typically symmetrical and affects both sides of the body equally.
  2. Pain and discomfort: The thickened skin may cause discomfort, pain, or itching. The skin may also feel tight, making it difficult to move or flex the affected areas.
  3. Limited range of motion: The thickened skin may limit the range of motion in the affected joints, making it difficult to move or perform certain activities.
  4. Numbness or tingling: Some people with SAB may experience numbness or tingling in the affected areas due to nerve compression.
  5. Swelling: The thickened skin may cause swelling in the affected areas, particularly in the arms and legs.
  6. Discoloration: The affected skin may appear reddish or bluish in color, due to changes in blood flow.
  7. Bruising: The skin may be easily bruised, due to its decreased elasticity.
  8. Fungal infections: The thickened skin may provide a favorable environment for fungal infections to develop, such as athlete’s foot or jock itch.

SAB typically affects the neck, upper back, and arms, but it can also affect the legs, chest, and face. The condition may progress gradually, over a period of several months or years, or it may develop rapidly over a few days.

Diagnosis

Diagnosis of Shetland pony syndrome usually starts with a physical examination of the horse. A veterinarian will look for characteristic signs of the disorder, such as short legs, a rounded belly, and a large head. The vet may also take measurements of the horse’s body to determine if it falls within the normal range for its breed and age.

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In addition to a physical examination, a number of other tests may be used to diagnose Shetland pony syndrome. These tests may include:

  1. Radiographs: X-rays can be used to identify any abnormalities in the bones and joints that may be contributing to the horse’s short stature.
  2. Blood tests: Blood tests can help determine if there is an underlying hormonal or metabolic disorder that may be contributing to the horse’s dwarfism.
  3. Genetic testing: Genetic testing can be used to determine if the horse has a specific genetic mutation that is known to cause Shetland pony syndrome.
  4. Ophthalmic Exam: The first step in diagnosing Sheltie Collie Eye Anomaly is a thorough eye exam. This will involve a visual inspection of the eye and surrounding tissues, as well as an assessment of the pupillary light reflex and the presence of any abnormalities in the retina or optic nerve.
  5. Gonioscopy: This test is performed to assess the angle of the anterior chamber of the eye, which is the space between the cornea and the iris. This test is important in the diagnosis of Sheltie Collie Eye Anomaly because one of the hallmark features of the condition is a narrow anterior chamber angle.
  6. Electroretinography (ERG): This test measures the electrical activity of the retina in response to light stimulation. This test can help determine the degree of retinal function and can aid in the diagnosis of Sheltie Collie Eye Anomaly.
  7. Optical Coherence Tomography (OCT): This non-invasive test uses light waves to create detailed, cross-sectional images of the retina. This test can help identify areas of retinal detachment, as well as other abnormalities in the retina.
  8. Fundus Photography: This test involves taking photographs of the back of the eye, including the retina, optic nerve, and blood vessels. These photos can be used to document any changes in the eye over time and can also be used to track the progression of Sheltie Collie Eye Anomaly.
  9. DNA testing: In some cases, a DNA test may be performed to confirm the diagnosis of Sheltie Collie Eye Anomaly. This test can also be used to determine if a dog is a carrier of the gene for the condition, even if they do not show any symptoms.

Treatment

The treatment of Settlès syndrome depends on the underlying cause, the severity of the deformity, and the individual patient’s goals and preferences.

Here are the main treatments for Sydenham’s Chorea:

  1. Antibiotics: The first line of treatment for Sydenham’s Chorea is antibiotics, which help to prevent the streptococcal infection from spreading and causing further damage. Penicillin is the most commonly used antibiotic, but other antibiotics such as erythromycin, amoxicillin, and azithromycin may also be used.
  2. Corticosteroids: Corticosteroids are a type of anti-inflammatory medication that can help to reduce inflammation and swelling in the affected joints and muscles. They may be given orally or intravenously, depending on the severity of the symptoms.
  3. Intravenous immunoglobulin (IVIG): IVIG is a type of treatment that involves infusing a patient with high levels of immunoglobulin, a type of protein that helps to regulate the immune system. IVIG can help to reduce inflammation and improve symptoms of Sydenham’s Chorea.
  4. Plasmapheresis: Plasmapheresis is a procedure that involves removing a portion of a patient’s blood plasma and replacing it with a substitute, such as saline. This procedure can help to reduce the levels of antibodies that are causing the autoimmune reaction in Sydenham’s Chorea.
  5. Physical therapy: Physical therapy can help to improve muscle strength, coordination, and flexibility in patients with Sydenham’s Chorea. Physical therapy may include exercises to improve range of motion, balance, and stability, as well as assistive devices such as braces or crutches.
  6. Occupational therapy: Occupational therapy can help patients with Sydenham’s Chorea to improve their functional abilities and independence. Occupational therapists may work with patients to improve fine motor skills, such as writing or typing, and to develop strategies for managing daily activities, such as bathing or dressing.
  7. Speech therapy: Speech therapy can be helpful for patients with Sydenham’s Chorea who are experiencing difficulty speaking or swallowing. Speech therapists may work with patients to improve their speech, as well as their ability to swallow safely and effectively.
  8. Medications for symptom management: There are several medications that can be used to manage the symptoms of Sydenham’s Chorea, such as tetrabenazine, which is used to treat involuntary movements, and propranolol, which is used to treat tremors. These medications may have side effects, so it is important to discuss the risks and benefits of these medications with a healthcare provider.
  9. Psychological support: Living with a chronic condition such as Sydenham’s Chorea can be challenging, and patients may benefit from psychological support. Psychologists, counselors, and social workers can provide emotional support and coping strategies to help patients manage their symptoms and improve their quality of life.
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Non-surgical treatments

Non-surgical treatments are usually the first line of treatment for mild cases of Settlès syndrome. They include:

  • Nasal splints: Nasal splints can be used to provide support and help reshape the nose. They can be made of various materials, including silicone, and are worn over the nose to apply gentle pressure and help reshape the nasal bridge.
  • Injectable fillers: Injectable fillers, such as hyaluronic acid and collagen, can be used to augment the nasal bridge and provide temporary improvement in the appearance of the nose.
  • Nasal taping: Nasal taping involves the application of adhesive tape to the nose to provide support and help reshape the nasal bridge.

Surgical treatments

Surgical treatments are typically recommended for more severe cases of Settlès syndrome. They include:

  • Open rhinoplasty: Open rhinoplasty is a surgical procedure that involves making an incision on the columella (the strip of skin separating the nostrils) to access the nasal bones and cartilage. The nasal bones and cartilage are then reshaped to correct the deformity.
  • Endonasal rhinoplasty: Endonasal rhinoplasty is a surgical procedure that involves making incisions inside the nostrils to access the nasal bones and cartilage. The nasal bones and cartilage are then reshaped to correct the deformity.
  • Rib cartilage grafting: In some cases, rib cartilage may be used to augment the nasal bridge and correct the deformity. The rib cartilage is harvested from the patient’s own body and shaped to fit the nose.
  • Autologous costal cartilage grafting: In some cases, autologous costal cartilage (taken from the patien
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