Gaby Van Galen

History and clinical features of atypical myopathy in horses in Belgium (2000-2005)

BACKGROUND The emergent nature of atypical myopathy or atypical myoglobinuria (AM) necessitates precise description of its clinical and epidemiologic features. PURPOSE To define key features of AM to help practitioners recognize the disease and to advise owners to take preventive measures. ANIMALS Belgian cases of AM confirmed by histology (CC horses; n = 57) from autumn 2000 to spring 2005 were included in the study. Co-grazing horses (Co-G horses; n = 77) that remained free of any abnormal clinical signs constituted a control group. METHODS History, environmental characteristics, clinical signs, and laboratory results associated with AM were determined by a retrospective case series study. RESULTS Young horses in poor or normal body condition were found to be at risk for AM. Pastures were characterized by poor natural drainage and vegetation of low nutritional value. Features of AM were seasonal occurrence, apparent link with weather conditions (ie, lack of solar radiation with no heavy frost and an excess of precipitation or relative humidity), sudden onset of clinical signs, and rapid death. Evaluation of serum creatine kinase activity indicated severe muscle destruction in CC horses and subclinical disease in a few Co-G horses. CONCLUSIONS The association of AM with specific environmental conditions and individual animals suggests that young horses should not be pastured on bare premises subject to humidity when the weather has been very wet and cold for several days. Management of AM outbreaks should include control of Co-G horses who are apparently healthy.

Atypical myopathy in grazing horses: a first exploratory data analysis.

Over the last decade, atypical myopathy (AM) in grazing horses has emerged in several European countries. An exploratory analysis was conducted to determine horse- and pasture-level indicators or factors associated with AM in Belgium. Belgian cases of AM confirmed by histology (n=57) were compared to their healthy co-grazing horses (n=77) and to pastured horses not involved with AM as controls (n=386). The pastures where confirmed cases were grazing (42 pastures; 38 sites; 44 incidences of AM) were compared with those of the controls (216 pastures; 96 sites; no incidence of AM). Statistically significant (P< or =0.05) exploratory variables, identified by means of adjusted odds ratios, suggested that indicators or factors associated with individual horses (young age, inactivity, body condition poor to normal), management practices (permanent pasturing, spreading of manure) and pasture characteristics (humid, sloping pastures, accumulated dead leaves, presence of waterway) may increase the risk of AM. Specific interventions based on these factors might help to reduce the incidence of AM.

Surgical hand antisepsis in veterinary practice: Evaluation of soap scrubs and alcohol based rub techniques

Recent studies have shown that hydro-alcoholic solutions are more efficient than traditional medicated soaps in the pre-surgical hand antisepsis of human surgeons but there is little veterinary literature on the subject. The aim of this study was to compare the efficiency of medicated soaps and a hydro-alcoholic solution prior to surgery using an in-use testing method in a veterinary setting. A preliminary trial was performed that compared the mean log(10) number of bacterial colony forming units (CFU) and the reduction factors (RF) between two 5-min hand-scrubbing sessions using different soaps, namely, povidone iodine (PVP) and chlorhexidine gluconate (CHX), and the 1.5-min application of a hydro-alcoholic rub. A clinical in-use trial was then used to compare the hydro-alcoholic rub and CHX in a surgical setting. Sampling was performed using finger printing on agar plates. The hydro-alcoholic rub and CHX had a similar immediate effect, although the sustained effect was significantly better for the hydro-alcoholic rub, while PVP had a significantly lower immediate and sustained effect. The hydro-alcoholic rub showed good efficiency in the clinical trial and could be considered as a useful alternative method for veterinary surgical hand antisepsis.

European outbreak of atypical myopathy in the autumn 2009.

BACKGROUND Atypical myopathy is an acute, severe rhabdomyolysis occurring in grazing horses. In the beginning of October 2009, a new outbreak occurred in several European countries. Geographic, demographic and clinical data of the reported cases in the month October 2009 are described. KEY FINDINGS The survival rate in this outbreak was 25%. The most frequently observed clinical signs were congested mucous membranes, dyspnea, tachycardia, depression, weakness, stiffness, recumbency, trembling, sweating, and myoglobinuria. Nonsurvivors were significantly more likely to be recumbent than survivors. Prognostic factors, symptomatic treatment, and preventive measures are discussed. SIGNIFICANCE Differences were encountered during the described outbreak of atypical myopathy in October 2009 compared with previous outbreaks reported. Equine practitioners should be aware that previous epidemiological studies have shown that after a high prevalence in the autumn, new cases are likely to occur in the following spring.

The composition of the inflammatory infiltrate in three cases of polyneuritis equi

Polyneuritis equi (PNE) is a rare neurological disease in the horse. Because of the suspicion in PNE of a T-lymphocyte mediated immune response against the myelin, the objective of this study was to determine the composition of the inflammatory infiltrate in the involved nerves of 3 horses with PNE, studied retrospectively. T-lymphocytes were demonstrated in the lesions, which suggests a T-lymphocyte mediated immune response against myelin. In addition, the presence of B-lymphocytes indicated a local production of antibodies. More research, involving a prospective study, is needed to determine whether the T-lymphocytes are cytotoxic or T-helper lymphocytes.

Mandibular osteodistraction for correction of deep bite class II malocclusion in a horse

OBJECTIVE To describe a technique for, and outcome after, mandibular osteodistraction in the horse. STUDY DESIGN Clinical report. ANIMALS Warmblood horse. METHODS A half ring external fixator was applied on both sides of an osteotomy site performed on the mandible of a colt. A bite plate was placed on the upper incisors creating occlusion between lower and upper jaw. After a 5-day latency period, distraction was applied (1 mm/day) until the overjet was judged normal. RESULTS Mandibular elongation and correction of brachygnathia was obtained without major complications. Six months after the procedure the overjet reduction was considered stable. CONCLUSIONS Mandibular osteodistraction can be considered for treatment of severe brachygnathia in yearlings. CLINICAL RELEVANCE Distraction osteogenesis has the advantage of progressive elongation of the mandible, allowing concurrent bone remodeling and soft tissue adaptation. Severe mandibular incisor malocclusion in horses outside the maximal growth phase can be corrected using this technique.

Mitochondrial function is altered in horse atypical myopathy.

Equine atypical myopathy in Europe is a fatal rhabdomyolysis syndrome that results from the ingestion of hypoglycin A contained in seeds and seedlings of Acer pseudoplatanus (sycamore maple). Acylcarnitine concentrations in serum and muscle OXPHOS capacity were determined in 15 atypical myopathy cases. All but one acylcarnitine were out of reference range and mitochondrial respiratory capacity was severely decreased up to 49% as compared to 10 healthy controls. The hallmark of atypical myopathy thus consists of a severe alteration in the energy metabolism including a severe impairment in muscle mitochondrial respiration that could contribute to its high death rate.

Atypical myopathy: New insights into the pathophysiology, prevention and management of the condition

Summary Atypical myopathy (AM) is a frequently fatal seasonal pasture myopathy that has emerged in several European Countries in recent years. Currently, the aetiology of AM is unknown but recent surveys of confirmed cases have led to new insights into the pathophysiology, prevention and management of the condition.

A case of a periarticular abscess and suppurative arthritis of the atlanto-occipital joint

Summary This Case Report describes a periarticular abscess and a suppurative arthritis of the atlanto-occipital joint in an adult horse. The horse showed a painful swelling localised on the atlanto-occipital region and ataxia in all 4 limbs. During hospitalisation, the horse developed recumbency, dysphagia, facial paralysis and seizures. Ultrasonography of the atlanto-occipital region enabled a tentative diagnosis to be made, which was later confirmed at autopsy. Culture of the abscess revealed a Staphylococcus aureus. However, the horse had a history of recurrent fever, hypertrophy and abscessation of the submandibular lymph nodes, neck pain and dyspnoea for 2 months, which was suggestive of strangles.

Acylcarnitines profile best predicts survival in horses with atypical myopathy

Equine atypical myopathy (AM) is caused by hypoglycin A intoxication and is characterized by a high fatality rate. Predictive estimation of survival in AM horses is necessary to prevent unnecessary suffering of animals that are unlikely to survive and to focus supportive therapy on horses with a possible favourable prognosis of survival. We hypothesized that outcome may be predicted early in the course of disease based on the assumption that the acylcarnitine profile reflects the derangement of muscle energetics. We developed a statistical model to prognosticate the risk of death of diseased animals and found that estimation of outcome may be drawn from three acylcarnitines (C2, C10:2 and C18 -carnitines) with a high sensitivity and specificity. The calculation of the prognosis of survival makes it possible to distinguish the horses that will survive from those that will die despite severe signs of acute rhabdomyolysis in both groups.