Equine Piroplasmosis

Equine piroplasmosis (EP) is a tick-borne protozoal disease of horses, mules, donkeys, and zebras that is characterized by acute hemolytic anemia. The etiologic agents are two hemoprotozoan parasites, Theileria equi (Laveran, 1901) and Babesia caballi (Nutall and Strickland, 1910) that are transmitted primarily by ixodid ticks. Equine piroplasmosis is found globally where tick vectors are present and is endemic in tropical, subtropical, and some temperate regions. Horses infected with B. equi remain seropositive for life; horses infected with B. caballi are seropositive for several years to life. Economic losses associated with EP are significant and include the cost of treatment, especially in acutely infected horses; abortions; loss of performance; death; and restrictions in meeting international requirements related to exportation or participation in equestrian sporting events. Equine babesiosis–free countries limit the entrance of Babesia-seropositive horses into their countries. In the United States a few sporadic outbreaks have occurred in recent years but have been limited due to implementation of stringent control methods. The cELISA for both T. equi and B. caballi is currently the recommended test for international horse transport. Different therapies for control and sterilization of the parasites are discussed.     

Equine rhabdomyolysis

A 1.5-year-old Quarter Horse gelding with a history of chronic nasal discharge and leukocytosis presented with signs of increased lethargy and muscular pain. The horse quickly became recumbent and unable to rise and was euthanized due to a poor prognosis. At necropsy, severe bilateral guttural pouch empyema was observed, as well as numerous well-demarcated areas of pallor within the skeletal muscles of all major muscle groups. Polymerase chain reaction testing of the guttural pouch exudate confirmed an infection with Streptococcus equi subsp. equi, and an S. equi-associated immune-mediated rhabdomyolysis was initially considered to be the most likely diagnosis. This report briefly discusses the various etiologies that should be considered in cases of equine myopathy, and it demonstrates the complexity of these poorly understood muscular disorders.     

Equine haemothorax

Haemothorax is an uncommon, although clinically important, condition in horses of all ages and has a wide range of aetiologies. Clinical signs can include tachypnoea, dyspnoea, tachycardia, absence of bronchovesicular sounds, haemoptysis, colic and death. The most common aetiologies are associated with trauma, neoplasia, coagulation disorders, iatrogenic causes and vessel rupture. Diagnosis is made if there is evidence of thoracic fluid on ultrasonography and confirmation of haemorrhage by thoracocentesis. The goals of treatment are to address the primary cause and provide supportive care. Prognosis depends on aetiology, severity of active bleeding and volume of blood loss.     

Equine glaucomas

The glaucomas are diseases that lead to the destruction of retinal ganglion cells and their axons via a number of mechanisms such as direct pressure damage, hypoxic and toxic injuries. The aim of this article is to present a review of this condition in horses in order to have a proactive attitude and to enable an early diagnosis to be made in order to determine the most adequate prophylactic (on predisposed individuals) and therapeutic treatment.