B. Schwarz

Keratoconjunctivitis sicca attributable to parasympathetic facial nerve dysfunction associated with hypothyroidism in a horse

CASE DESCRIPTION A 6-year-old 680-kg (1,496-lb) German Warmblood gelding was evaluated because of bilateral blepharospasm and head shaking. CLINICAL FINDINGS Moderate blepharospasm was evident bilaterally, and both eyes had hyperemic and edematous conjunctivas and lusterless corneas. For each eye, the Schirmer tear test value was only 7 mm/min. The horses nasal mucosa was dry. Abnormal behaviors included mild repetitive vertical movement of the head, snorting, and flehmen response (classic signs of head shaking). Touching the horses nostrils and face revealed paresthesia and dysesthesia with slight nasolabial muscle hypertrophy bilaterally. Cranial nerve examination revealed no other abnormalities. Serum thyroxine concentration was low, and results of thyrotropin-releasing hormone and thyroid-stimulating hormone stimulation tests were negative, indicating that the horse had hypothyroidism. The diagnoses included keratoconjunctivitis sicca and dry nares attributable to parasympathetic facial nerve dysfunction, head-shaking syndrome with paresthesia and dysesthesia of the face attributable to sensory trigeminal nerve disorder, and hypothyroidism. The 2 nerve dysfunctions were considered peripheral neuropathies that were most likely caused by hypothyroidism. TREATMENT AND OUTCOME Treatment of both eyes was initiated with topical applications of cyclosporine, 0.5% sodium hyaluronate, and vitamin A ointment. Levothyroxine (20 microg/kg [9.1 microg/lb], PO, q 24 h) was administered. Within 3 weeks to 4 months, serum thyroxine concentration was within reference range, and clinical signs and Schirmer tear test values improved. CLINICAL RELEVANCE Hypothyroidism should be considered as a differential diagnosis in horses with peripheral neuropathy or keratoconjunctivitis sicca. In affected horses, administration of levothyroxine may lead to resolution of neurologic signs.

Diagnostic value of the neutrophil myeloperoxidase index in horses with systemic inflammation.

The myeloperoxidase index (MPXI) was investigated as a diagnostic indicator of systemic inflammation in a retrospective study using data from 859 hospitalised horses. A reference interval of 8.5-10.4 for the MPXI was established. In horses with systemic inflammatory response syndrome (SIRS), the MPXI was significantly lower than in healthy horses, those with localised inflammation and those with sepsis. The MPXI in horses with sepsis was also significantly lower than in healthy animals and those with localised inflammation. Horses in the SIRS group with leucopenia, white blood cell (WBC) count within the reference interval (WRI) or leucocytosis had significantly lower MPXIs than healthy horses, those with localised inflammation and those with sepsis in the same WBC count subgroups. In horses with sepsis and WBC count WRI, the MPXI was significantly lower than in healthy horses or those with localised inflammation. MPXI is a useful complementary tool to identify horses with systemic inflammation, especially if they have WBC counts WRI.

Estimated prevalence of the GYS-1 mutation in healthy Austrian Haflingers

The aim of this study was to determine the occurrence and frequency of a mutation in the gene coding for skeletal muscle glycogen synthase type 1 (GYS-1), which is the cause of equine polysaccharide storage myopathy (PSSM) type 1 in a population of 50 Haflingers. GYS-1 genotyping of 50 Haflingers was performed with a validated restriction fragment length polymorphism (RFLP) assay. The second aim was to compare resting and post-exercise muscle enzyme activities as well as parameters of glucose metabolism in blood between horses with and without the mutation. Nine of the 50 Haflingers were identified to be heterozygous for the mutation (HR). None was homozygous (HH). The estimated HR prevalence was 18 per cent in this herd. Mean aspartate aminotransferase (AST) activity at rest and mean creatine kinase and AST activity after exercise were significantly higher in HR compared with RR (homozygote normal) horses. No significant differences could be found in the other parameters.

Equine multinodular pulmonary fibrosis (EMPF): Five case reports.

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.

Cutaneous fungal granuloma in a horse

This case report describes a 4-year-old-horse with two cutaneous masses on the right crest of the neck. Biopsy revealed chronic nodular pyogranulomatous dermatitis and panniculitis. Giemsa and periodic acid-Schiff stains showed focal spherical, yeast-like organisms. A diagnosis of cutaneous fungal granuloma was made. The size of the masses decreased after oral treatment with fluconazole for 10 days combined with potassium iodide for 30 days, and the remaining masses were excised by laser. Lesions did not recur at the site. Fungal granuloma should be considered as a differential diagnosis in horses with cutaneous or subcutaneous nodules. A definitive diagnosis can only be achieved by histopathological examination or by culture of the affected tissue.

Outbreaks of equine grass sickness in Hungary

Equine grass sickness (EGS) occurs mainly in Great Britain, but has once been reported in Hungary. The stud which was affected by EGS in 2001 had no new cases until 2009/10, when 11 of 60 and five of 12 one- to three-year-old colts died or were euthanased due to EGS. Following a few hours in the high-risk field during the winter of 2010/11 further four cases of acute EGS were noted among these horses. The affected horses showed somewhat different clinical signs compared with the cases reported in Great Britain. Histopathological findings in these horses were consistent with EGS. In most examined cases carbofuran, a carbamate was found in the liver by toxicological examination, and it is postulated that carbofuran may influence the immune system and therefore predispose the horses to develop EGS. Carbamates are thought to cause a delayed neurotoxicity in human beings. Further studies are needed to clarify the potential role of carbamates in EGS.

Paroxysmal atrial fibrillation and clinically reversible cor pulmonale in a horse with complicated recurrent airway obstruction

Cor pulmonale is considered an uncommon complication in horses with recurrent airway obstruction (RAO). This case report describes the history, clinical and further examination findings, treatment, progression and outcome of a horse diagnosed with cor pulmonale and paroxysmal atrial fibrillation of 2 days duration due to a severe exacerbation of RAO. To our best knowledge, this is the first report of RAO induced pulmonary hypertension in a horse causing atrial fibrillation. However, even severe cardiac changes due to respiratory dysfunction seem to be largely reversible in horses.

Equine grass sickness: what's new?

WRITING a science editorial regarding new aspects of equine grass sickness (EGS) is challenging at a time when we are eagerly awaiting results from vaccination trials and ongoing research, trying to identify the cause of EGS and factors involved in aetiopathogenesis. Britain has remained the country most affected by this often fatal neurodegenerative disease, with EGS being one of the most important threats to equine health in some areas. To collate details of clinical cases in Great Britain, a nationwide surveillance scheme has been instituted (Wylie and others 2011). Similar to the Alert group for atypical myopathy, a European epidemiosurveillance network could be initiated for EGS, because the disease has also been reported in other countries, including Cyprus, Hungary and the Czech Republic (Protopapas and others 2012, Schwarz and others 2012; personal communication, B. Bezdekova). In north eastern Hungary, young horses (two to three years old) have been affected in outbreaks (Schwarz and others 2012) and the disease has now also occurred in west Hungary and the south of the Czech Republic, similar to the disease pattern that occurred when EGS was first described in the east of Scotland, with isolated ‘mini outbreaks’ occurring at distant locations, rather than a gradual spread (Wylie and others 2011; personal communication, S. Pirie). Larger numbers of EGS cases have also occurred in the Swiss Jura range (personal communication, L. Unger). Since the excellent review on EGS by Newton and others (2010), quite a few …