The aims of this study were to detect physiological changes in blood biochemical parameters throughout gestation, to compare the findings in nonpregnant and pregnant Lipizzaner mares in early-mid and late pregnancy, and to provide reference values for clinical chemistry parameters in this horse breed. A total of 136 venous blood samples were collected from 20 pregnant and 10 nonpregnant (control) asymptomatic Lipizzaner broodmares for biochemical analyses. Twelve parameters (albumin, total protein, urea, triglycerides, glucose, creatinine, alkaline phosphatase, aspartate transaminase, glutamate dehydrogenase, gammaglutamyltransferase, creatine kinase and lactate dehydrogenase) were measured. For the statistical analyses, correlation, analysis of variance and Kruskal–Wallis H-test were used to evaluate the possible associations between parameters. Serum triglyceride levels proved to be significantly different in pregnant mares compared to the control group. Total protein and urea levels significantly decreased, while glucose, triglyceride and glutamate dehydrogenase values increased from approx. the fifth month of gestation until parturition. Four biochemical parameters (albumin, aspartate transaminase, total protein and urea) were lower and three other variables (glucose, alkaline phosphatase and creatinine) were significantly higher in late-term pregnant mares than in mares in early or mid-gestation. It is concluded that reference values not only reflect the species, breed and sex but also the reproductive status of animals.
Temperament has not been taken into account in previous studies evaluating the stress response to exercise in horses. The aim of the present study was to investigate the cortisol response in Thoroughbred racehorses to a single exercise bout, and to analyse the results based on the basic personality of the horse examined. Twenty healthy Thoroughbred horses were selected for the study based on a 25-item rating questionnaire survey used for characterising equine temperament. Eight temperamental and twelve calm horses took part in the experiment. The horses trotted as a warm-up activity, and then galloped on a rounded sand track. Blood sampling was conducted four times for each horse. Horses with a more excitable temperament showed a higher cortisol response to the test (P = 0.036). In conclusion, cortisol levels in response to a mild intensive exercise can be affected by temperament in horses. Serum cortisol may be a relevant marker to quantify individual temperamental differences in racehorses.
This paper presents the embryological and pathological features as well as the terminology and classification of common atrioventricular canal, a type of endocardial cushion defect. The authors give a complete description of an extremely rare congenital cardiac malformation in an equine neonate. The diagnosis of a complete, balanced common atrioventricular canal of type C in Rastelli’s classification scheme was based on two-dimensional, contrast and colour Doppler echocardiography and subsequent postmortem gross pathology. To support our diagnosis and study the pathophysiological effect of the alteration, physical examination, blood gas analysis and other laboratory tests, electrocardiography and thoracic radiography were also performed. Our search of the literature suggests that this type of developmental anomaly might account for a higher percentage of equine congenital cardiac defects than was thought earlier. We suppose that some previously described congenital heart abnormalities were misinterpreted: these anomalies could have actually represented some type of atrioventricular canal defect, resulting from the failure of the endocardial cushions to undergo complete and proper fusion.
West Nile virus (WNV) is a zoonotic arbovirus transmitted by mosquitoes between wild birds (natural hosts) and other vertebrates. Horses and humans are incidental, dead-end hosts, but can develop severe neurological disorders. Owing to the close contact of cerebrospinal fluid (CSF) with the extracellular fluid of the brain, the analysis of CSF composition can reflect central nervous system (CNS) impairments enabling the diagnosis and understanding of various neurodegenerative CNS disorders. Our objective was to compare the findings from the CSF samples of horses with neuroinvasive WNV infection with those of healthy controls. We compared findings from fifteen CSF samples of 13 horses with acute WNV encephalomyelitis with those of 20 healthy controls. Protein, particular enzymes and ions, glucose and lactate showed abnormal levels in a significant number of WNV cases. None of the six horses with elevated glucose concentrations survived. Rather neutrophilic than mononuclear pleocytosis was identified with WNV infection. Neutrophils probably play a role in the development of inflammatory response and brain damage. Although elevated glucose levels reliably predicted the outcome, they might be the consequence of increased plasma levels and reflect general stress rather than CNS pathophysiology. The CSF findings of WNV encephalomyelitis patients are non-specific and variable but facilitate the differential diagnosis.
Equine multinodular pulmonary fibrosis (EMPF), a progressive fibrosing interstitial lung disease has been associated with gammaherpesviruses. This case series describes five horses with EMPF. Three of the horses (two in Hungary, one in the Czech Republic) were diagnosed with EMPF ante mortem. They presented with typical clinical signs of EMPF including dyspnoea and weight loss. Arterial blood gas analysis revealed hypoxaemia. Blood work showed signs of inflammation like neutrophilia and hyperfibrinogenaemia. An endoscopic examination of the respiratory tract including cytology and culture of tracheobronchial secretion and bronchoalveolar lavage were performed, revealing secondary bacterial infection in one case. A suspected diagnosis of EMPF was made on the basis of a positive EHV-5 PCR from bronchoalveolar lavage and the findings of thoracic radiographs and ultrasound examination. In one case the diagnosis was confirmed by lung biopsy. All horses died or had to be euthanised despite treatment. Two horses (from Austria) were diagnosed with EMPF post mortem. They not only had EMPF but also concurrent other diseases which seemed to be associated with immunosuppression. Three horses showed the discrete form and two horses the diffuse form of EMPF. EHV-5 DNA was identified in lung tissue of all horses by PCR.
A severe form of recurrent exertional rhabdomyolysis occurs enzootically in a well-defined region of Transylvania, Harghita county. At the highest lying two settlements (more than 800 m above sea level), the prevalence of equine rhabdomyolysis is between 17 and 23%, while in the neighbouring villages in the valley it is less than 2%. The objective of our study was to clarify the role of selenium and vitamin E in the high prevalence of rhabdomyolysis in that region. Soil and hay samples were collected from each area to evaluate mineral content. Ten horses from the non-affected and 20 horses from the affected area were tested for serum selenium, vitamin E, glutathione peroxidase (GSH-Px), muscle enzymes, lactate and electrolytes. Hay samples collected from the affected area had lower selenium content. Horses in the affected regions had significantly lower serum selenium (P = 0.006) and GSH-Px levels than animals living in the non-affected regions. A good correlation between erythrocyte GSH-Px and serum selenium concentration could be demonstrated (r = 0.777, P < 0.001). Serum vitamin E levels were low independently of the origin of the horse. Based on our results, selenium deficiency possibly has a role in the Transylvanian enzootic equine recurrent rhabdomyolysis syndrome.
Equine grass sickness (also known as dysautonomia) is a life-threatening polyneuropathic disease affecting horses with approx. 80% mortality. Since its first description over a century ago, several factors, such as the phenotype, intestinal microbiome, environment, management and climate, have been supposed to be associated with the increased risk of dysautonomia. In this retrospective study, we examined the possible involvement of genetic factors. Medical and pedigree datasets regarding 1,233 horses with 49 affected animals born during a 23-year period were used in the analysis. Among the descendants of some stallions, the proportion of animals diagnosed with dysautonomia was unexpectedly high. Among males, the odds of dysautonomia were found to be higher, albeit not significantly, than among females. Significant familial clustering (genealogical index of familiality, P = 0.001) was observed among the affected animals. Further subgroups were identified with significant (P < 0.001) aggregation among close relatives using kinship-based methods. Our analysis, along with the slightly higher disease frequency in males, suggests that dysautonomia may have a genetic causal factor with an X-linked recessive inheritance pattern. This is the first study providing ancestry data and suggesting a heritable component in the likely multifactorial aetiology of the disease.