Key takeaways
Sarcoidosis is a rare condition in horses, referring to accumulation of inflammatory cells in one or more areas of the body. Note: sarcoidosis is not the same as “sarcoids,” which is a separate, unrelated equine condition.
- Inflammation associated with sarcoidosis can present as round nodules localized to a particular area of the body, or can be more widespread across multiple systems
- Most horses present with scaly or crusty areas of skin that may have hair loss
- The causes are unknown and diagnostics require biopsies, diagnostic imaging, and a physical examination
- Treatment involves long-term corticosteroids, however the side effects of treatment can be severe
- Prognosis varies depending on localization and progression of symptoms, but is generally considered poor
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A closer look: Equine Sarcoidosis
Sarcoidosis causes inflammation of the affected tissues, which may compromise their function. Most cases of sarcoidosis begin as localized skin nodules or sores, which may progress to affecting the entire body, including the internal organs. Prognosis is generally poor and rapid veterinary intervention is best to have the best chance of recovery.
Risk factors
Symptoms can vary based on the subtype of sarcoidosis, which depends where and how widespread the inflammation is. It can be classified as either cutaneous (localized to the skin) or generalized (affecting internal organs).
Sarcoidosis is rare and the underlying disease process is not well understood, so it is difficult to identify specific risk factors. Prognosis is generally poor even with timely medical intervention.
Possible causes
The causes of sarcoidosis in horses are currently unknown. Immune system dysfunction is a suspected factor, but the disease process is not well understood.
Main symptoms
Most cases of equine sarcoidosis affect the skin, particularly on the lower legs.
The cutaneous form, which only affects the skin, does not usually produce nodules. Nodular inflammation is more common with the generalized form of sarcoidosis.
Testing and diagnosis
After a medical history and physical examination, a number of tests can help to identify equine sarcoidosis and rule out other potential causes, including:
- Skin biopsies
- Diagnostic imaging, including ultrasound of internal organs
- Bloodwork
Steps to Recovery
Treatment primarily involves corticosteroids to suppress the immune system and reduce inflammation. After getting the inflammation under control, steroids are tapered to the lowest effective dose.
The prognosis is varied depending on if it is localized or generalized sarcoidosis, but is generally characterized as poor.
Most cases of localized sarcoidosis respond at least partially to steroid therapy, however long-term steroid use can increase the risk of laminitis, a serious condition that can lead to permanent lameness and poor quality of life. Horses that develop laminitis due to steroid use have a poor prognosis.
Prevention
Since the cause of equine sarcoidosis is unknown, there are no preventive measures. Equine sarcoidosis is not contagious.
Is Equine Sarcoidosis common?
Equine sarcoidosis is rare in horses.
Typical Treatment
- Corticosteroids
