Abstract
The aim of this study was to give an overview of the current literature on equine haemothorax, as well as to analyse cases with this problem that were presented to the Equine Internal Medicine Clinic of the Vetsuisse-Faculty of the University of Zurich between 2005 and 2017. 13 cases met the inclusion criteria, which were a clinical diagnosis of the haemothorax by ultrasound alone or by a combination of ultrasound and thoracocentesis. Four mares and nine geldings of a variety of breeds were included in the study. The average age was 19.92 years (standard deviation ± 3.1). The findings of the clinical examination as well as the findings of blood tests, radiographic, ultrasonographic and cytological examinations of the thoracic fluid as well as the performed therapy were analysed in this study. The following case numbers do not always correspond to 13 patients since not all examinations were performed on all horses. The case histories were appearance of clinical signs during free movement, riding or after great exertion (6/13), unspecific anamnesis (4/13), trauma (2/13) and lung biopsy (1/13). The most common clinical signs were tachypnoea (13/13), abnormal lung auscultation (11/11), altered behaviour (12/13), forced breathing or dyspnoea (8/9), tachycardia (11/13), sweaty body surface (5/9), bilateral epistaxis (5/10) and prolonged capillary refill time (5/12). The general condition was classified as moderate to severely impaired (8/13) and mildly impaired (5/13). 8/12 patients showed signs of dehydration. Blood analysis showed leucocytosis (6/9), thrombocytopenia (4/10), anemia (3/13), hyperglycaemia (8/8), hypocalcaemia (7/8), hyponatremia (7/9), hyperlactatemia (6/8), elevated Creatinin (4/8), elevated creatine kinase (4/8) and hypoproteinemia (6/13). Arterial blood gas analysis revealed decreased p02 (8/8). Thoracic radiographs revealed soft-tissue opaque material ventrally in the thorax (10/10) with a variety of lung patterns. Ultrasonographically, free fluid with a hypo- to hyperechogenic corpuscular character was visible in the pleural cavity (13/13). Thoracocentesis was performed in 8/13 cases and the thoracic fluid was diagnosed as blood. The cause of the haemothorax could be identified clinically in three cases (lung biopsy, rib fractures, diaphragmatic hernia). Treatment included fluid therapy with cristalloid (10/13) and colloid (3/13) infusions as well as antimicrobial (11/13) and analgetic (12/13) medication. In some cases, tranexamic acid (6/13), formalin (2/13) and furosemide (1/13) were administered. Whole blood (5/13) and plasma transfusions (1/13) as well as thoracic drainages (4/13) were performed once or repeatedly if necessary. The mean duration of stay at the clinic was 5 (0-9) days. Eight horses were euthanized either because of a sudden rapid deterioration of the general condition (3/8), a lack of response to treatment (3/8) or right after diagnosis because of poor prognosis (2/8), which results in a short-term survival rate (percentage of horses that left the clinic alive) of 38%. The long-term survival rate (surviving horses in July 2016, six months to ten years and eleven months after leaving the clinic) was 75%. Suspected reasons for haemothorax in the surviving patients were idiopathic bleeding (2/5) as well as bleeding after a lung biopsy, great exertion or trauma (each 1/5). The pathologic diagnoses of the euthanized horses were lung rupture (2/7), lung bleeding (2/7), multiple lung lacerations caused by rib fractures, mesenchymal neoplasia of the thorax as well as a diaphragmatic hernia (each 1/7). This retrospective study elucidates clinical signs and causes as well as diagnoses, therapy and outcome in the clinic for equine haemothorax. © 2018 Hippiatrika Verlagsgesellschaf. All rights reserved.
Rickli, Charlotte Isabelle