Idiopathic immune‐mediated polysynovitis in three horses

Abstract

This paper describes the clinical, laboratory and histological findings in three horses with immune-mediated polysynovitis; they had lost weight, suffered intermittent fever, were lethargic and stiff, and had effusions in several joints. Laboratory abnormalities included anaemia, leucocytosis, hyperfibrinogenaemia and hyperglobulinaemia. The diagnosis was based on the presence of a suppurative, non-septic inflammation in at least two different joints in each of the horses and the presence of immunoglobulins in the synovial membrane of one of them. The horses were treated with a combination of dexamethasone and azathioprine, and responded well to the initial treatment. Twenty months after its last re-evaluation, the first horse was being maintained on azathioprine because similar clinical signs had recurred after the cytotoxic drug was discontinued; the second horse was finishing a tapering course of prednisolone 15 months after its first examination, and the third horse was euthanased five months after it was first examined as a result of an unrelated injury.

Medical and surgical management of an intra-abdominal abscess of hepatic origin in a horse

“…6,[35][36][37][38][39][40] In most affected horses, similar to the horse in the present report, the nonseptic tenosynovitis resolved with supportive care and resolution of the primary disease. Confirmation of immune-mediated nonseptic polysynovitis necessitates the detection of immune complexes within the synovial membrane of the affected synovial structure, which was not performed for the horse of the present report, leaving the exact etiology unclear.…”

Septic funiculitis caused byStreptococcus equisubspeciesequiinfection with associated immune‐mediated haemolytic anaemia

“…There is limited data on the use of azathioprine for immunosuppressive therapy in the horse; however, this case report adds increasing support for its use to the handful of case reports previously published in the literature. Despite limited oral bioavailabity (White et al 2005), azathioprine has been used successfully to treat IMHA in one horse, immune-mediated thrombocytopenia in 4 horses and immune-mediated polysynovitis in 2 horses (Humber et al 1991;Messer and Arnold 1991;McGuirrin et al 2004;Pusterla et al 2006;Hardefeldt et al 2010). Reasons for its use have been due to failure to respond to corticosteroid treatment or concern over laminitis with corticosteroid treatment, as was the rationale in this case (Messer and Arnold 1991;Hardefeldt et al 2010).…”

Haemolytic anaemia in a pony associated with a perivascular abscess caused by Clostridium perfringens

“…Immune‐mediated polysynovitis in adult horses typically affects synovial structures symmetrically (Pusterla et al. 2006).…”

“…Definitive confirmation requires detection of immune complexes in the synovial membrane that are absent in other causes of arthritis (e.g. septic arthritis or osteochrondritis dissecans) (Pusterla et al. 2006).…”