In January of 2017, Hoe Down Dash’s owner William discovered his horse with severe limb, ventral and muzzle edema, a bloody nose and loud respiratory sounds. Hoe Down was very uncomfortable and unwilling to move; William promptly called LBEMC to have him evaluated.
Dr. Emma Deane responded on an emergency basis to assess Hoe Down Dash. He was visibly uncomfortable in his stall with an elevated heart rate and respiratory rate. He was pawing the ground and was unwilling to move. As seen in the images, Hoe Down had severe limb swelling and edema in all 4 limbs, severe ventral and limb edema, and edema around his muzzle and lips. The swellings were painful to the touch and there was serous discharge around his pasterns and coronary bands of each limb. Hoe Down also had serosanguinous (blood tinged) nasal discharge (as seen in the image), loud respiratory sounds and small pinpoint hemorrhages (petechiations) on his mucous membranes.
A full blood panel showed evidence of a chronic infection. His globulins (or antibodies), his white cell count, and his fibrinogen (a marker of inflammation) were all elevated supporting the diagnosis of an ongoing bacterial infection. Hoe Down had a history of an abscess on his ventral abdomen approximately 1 month prior, and coincidentally, another horse on the property had been diagnosed with Pigeon Fever, a bacterial infection caused by Corynebacterium pseudotuberculosis.
Based on Hoe Down’s blood-work, history of an abscess and severe clinical signs, Hoe Down was treated for purpura hemorrhagica, an immune medicated reaction that can occur 3-4 weeks after exposure to certain pathogens, including C.pseudotuberculosis.
His treatment consisted of a long course of IV and oral antibiotics to fight the infection and steroids to suppress his immune response. He was also treated with Banamine, an anti-inflammatory and pain medication. Besides the medications, Hoe Down also required daily nursing care for the skin that sloughed around his pasterns and coronary band. This required daily bandaging to reduce the edema formation and supplying his food in an elevated feeder to prevent muzzle edema.
With aggressive and early medical therapy and nursing care from his owner, Hoe Down made a full recovery and after 4 weeks is back to his normal routine!
WHAT IS PURPURA HEMORRHAGICA?
Purpura Hemorrhagica is an immune mediated disorder resulting in a severe vasultits (inflammation and damage of the blood vessels) which allows fluid to leak into the tissues. This leads to very distinct clinical signs that include head, ventral and limb edema, petechiations of the mucous membranes, and serum leakage and necrosis of the affected skin. Although these clinical signs are visible when associated with the skin, purpura can also cause similar damage to the internal organs such as the kidneys, muscles and lungs.
The outcome or purpura is varied and depends on the severity of clinical signs and time to treatment. Early recognition and treatment is critical for survival.
The syndrome has been classically associated with the bacteria that causes Strangles, Streptococcus equi equi; however, it has also occurred in horses with a history of Pigeon Fever (Corynebacterium psuedotuberculosis), Influenza, Equine Herpes Virus1,and post vaccination with the Strangles vaccine.
Definitive diagnosis of the disease involves clinical signs, standard blood test, a high degree of suspicion based on the presence of predisposing infection and, in some cases, a skin biopsy of the affected skin. Streptococcus equi equi and Corynebacterium psuedotuberculosis titers are often submitted.
Treatment involves dampening down the immune response with a steroid and treating the underlying cause. Horses are often placed on antimicrobials to treat the inciting cause and to protect them against further infection while on immunosuppressive steroids. Supportive care is also important to treat any additional complications and improve patient comfort.
As in Hoe Down Dash’s case, purpura hemorrhagica can have a good prognosis if treated promptly. It is not a common disease but can have serious consequences and we are so pleased that Hoe Down pulled through!