equis - Articles
Sarcoidosis
Synonym(s): Equine idiopathic Granulomatous disease, Equine generalized granulomatous disease, Equine systemic granulomatous disease, Equine histiocytic disease, Equine histiocytic dermatitis
Introduction
- A rare idiopathic systemic granulomatous disease, which has been reported in horses, cattle and human beings, which is characterized by perivascular granulomatous and lymphoplasmacytic inflammation in many organ systems.
- Equine granulomatous disease appears to be comparable to human sarcoidosis.
- Cause: unknown; it is hypothesized that this disease represents an immunologic reaction to an antigenic stimulus.
- Signs: exfoliative dermatitis, wasting disease affecting multiple organs.
- Diagnosis: based on clinical signs and histopathology.
- Treatment: immunosuppressive doses of glucocorticoids may provide benefit.
- Prognosis: in rare cases spontaneous remission has been reported. Prognosis depends on the extend and chronicity of the disease.
Acute presentation
- Rare.
Age predisposition
- No age predilection.
- Disease can develop in young adults and in older horses.
Gender predisposition
- Some authors report higher prevalence in mares compared to male horses.
- Two reports describe a predisposition in geldings.
Breed/Species predisposition
- The disease has been described in many different breeds.
- Thoroughbreds Thoroughbred were reported as more predisposed in two studies.
Cost considerations
- Leads to loss of use of the animal.
Special risks
- Depends on affected organs and severity of the disease.
Pathogenesis
Etiology
- Unknown.
Predisposing factors
General
- Any antigenic stimulation.
Specific
- Bacteria, eg Mycobacterium spp Mycobacterium spp, toxins (ingestion of hairy vetch - Vicia spp) and Borrelia burgdorferi Borrelia burgdorferi and equine herpesvirus 2 Equine herpesvirus have all been associated with generalized granulomatous disease.
Pathophysiology
- It is proposed that aberrant cell mediated response develops against antigenic stimulation → accumulation of lymphocytes (T helper, CD4+), and macrophages.
- This inflammatory response may affect multiple organs besides the skin.
- In the skin it → alopecia, crusting, scaling and plaque formation.
- Three forms of the disease are described:
- Localized: tends to be confined to the skin without systemic involvement.
- Partly generalized: generally evolve to generalized.
- Generalized: may start with exfoliative dermatitis or granulomatous nodules in multiple organs. Clinical signs reflect the multiorgan involvement with progressive wasting disease
.
Timecourse
- Usually chronic progressive disease that develops over several months.
Diagnosis
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Treatment
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Prevention
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Outcomes
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Further Reading
Publications
Refereed papers
- Recent references from PubMed and VetMedResource.
- Nolte LC, Rosiak M et al (2020) Equine idiopathic systemic granulomatous disease with manifestation in the cerebellum associated with equid gammaherpesvirus 2. J Equine Vet Sci 94, 103225 PubMed.
- Sloet van Oldruitenborgh-Oosterbaan M M & Grinwis G C (2013) Equine sarcoidosis. Vet Clin Equine 29, 615-627 PubMed.
- Sloet van Oldruitenborgh-Oosterbaan M M & Grinwis G C (2013) Equine sarcoidosis: clinical signs, diagnosis, treatment and outcome of 22 cases. Vet Dermatol 24, 218-e48 PubMed.
- Oliveira-Filho J P, Monteiro L N et al (2012) Mycobacterium DNA detection in liver and skin of a horse qith generalized sarcoidosis. J Vet Diagn Invest 24 (3), 596-600 PubMed.
- White S D, Foley J E, Spiegel I B & Ihrke P J (2009) Lack of detectable equine herpesviruses 1 and 2 in paraffin-embedded specimens of equine sarcoidosis. J Vet Intern Med 23, 623-625 PubMed.
- Sledge D G, Miller D L et al (2006) Equine herpesvirus 2-associated granulomatous dermatitis in a horse. Vet Pathol 43, 548-552 PubMed.
- Spiegel I B, White S D et al (2006) A retrospective study of cutaneous equine sarcoidosis and its potential infectious aetiological agents. Vet Dermatol 17, 51-62 PubMed.
- Abbott B, Stephenson & Fox R I (2004) Concurrent granulomatous dermatitis and malignant granulosa cell tumour in a mare. Equine Vet Educ 16 (5), 255-260 PubMed.
- Sellers R S, Toribio R E & Blomme E A (2001) Idiopathic systemic granulomatous disease and macrophage expression of PTHrP in a miniature pony. J Comp Pathol 125 (2-3), 214-218 PubMed.
- Woods L W, Johnson B, Hietala S K, Galey F D & Gillen D (1992) Systemic granulomatous disease in a horse grazing pasture containing vetch (Viciaspp). J Vet Diagn Invest 4 (3), 356-360 PubMed.
- Heath S E, Bell R J, Clark E G & Haines D M (1990) Idiopathic granulomatous disease involving the skin in a horse. JAVMA 197 (8), 1033-1036 PubMed.
Organisation(s)
- Scott D W & Miller W H (2011) Equine Dermatology 2nd edn. Saunders, USA.
- Knottenbelt D C (2009) Pascoe’s Principles and Practice of Equine Dermatology. 2nd edn. Saunders, USA.