Prevalences and clinical signs of polysaccharide storage myopathy and shivers in Belgian draft horses

OBJECTIVE: To determine prevalences of polysaccharide storage myopathy (PSSM) and shivers in Belgian Draft Horses (BDHs) and determine whether there was an association between these 2 conditions. DESIGN: Prospective cohort study. ANIMALS: 103 BDHs > 1 year old. PROCEDURE: Owners were questioned regarding clinical signs of PSSM, shivers, and hindquarter weakness, defined as poor hindquarter muscling and lack of propulsion. Blood samples were collected for determination of serum creatine kinase and aspartate transferase activities and serum selenium and vitamin E concentrations. A biopsy sample from the gluteus medius muscle was submitted for histologic, histochemical, and biochemical analysis. A diagnosis of PSSM was made if abnormal amylase-resistant polysaccharide inclusions were seen histologically. RESULTS: 37 (36%) horses had PSSM and 19 (18%) had shivers, but only 6 (6%) had both PSSM and shivers, whereas 31 (30%) had PSSM alone, 13 (13%) had shivers alone, and 53 (51%) had neither, and a significant association between PSSM and shivers was not detected. Hindquarter weakness was found in 30 horses. Only 13 of 37 (35%) horses with PSSM and 11 of 19 (58%) horses with shivers had hindquarter weakness. Serum creatine kinase and aspartate transferase activities and serum selenium and vitamin E concentrations were not significantly different between horses with and without PSSM or between horses with and without shivers. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that PSSM and shivers are common but unrelated disorders in BDHs.     

P-80 Clinical aspects of chronic progressive pastern dermatitis in Belgian draft horses

The aim of this study was to evaluate the fungi present on the skin surface in healthy horses with a particular interest in Malassezia on predisposed skin areas. Twenty-five mares were included, each sampled on nine skin areas including those most likely contaminated by Malassezia : nostrils, lips, ear pinnae, base of the mane, pasterns, pectoral areas, lateral thorax, udder and perianal areas. Two sterile carpets were applied to the skin, and then used for inoculation of agar (Sabouraud's plus cycloheximide and chloramphenicol), both with and without lipids for isolation of different species of Malassezia . This method is currently successful in isolating Malassezia in dogs. Cultures were incubated at 32°C, observed on day 5 for Malassezia , and then maintained at 27°C for complementary morphological identifications. From 223 cultures on standard medium, only seven remained sterile. The most common fungi were filamentous (number of positive samples): Scopulariopsis (156), Penicillium (79), Acremonium (67), Aspergillus (53), Paecilomyces spp. (38), and Stachybotrys (33). Interestingly, Microsporum gypseum was also isolated (14 samples from seven areas) from 10 horses. Yeast or yeast-like fungi were Geotrichum (52), Trichosporon (21), and an additional 33 samples being positive for yeast other than Malassezia . Results from the other 223 cultures on lipid-rich agar were similar. Most of the fungi were isolated from the nine areas selected, but Malassezia was never isolated from 446 cultures.
Funding: Self-funded.     

Ataxia and weakness associated with fourth ventricle vascular anomalies in two horses

Two adult horses with progressive neurologic signs were examined clinically and at necropsy. Both horses had signs of progressive ataxia and weakness, clinically diagnosed as spinal cord in origin. Differential diagnoses for cervical spinal ataxia in horses included cervical vertebral malformation, equine degenerative myeloencephalopathy, equine herpes-virus-I myeloencephalopathy, and equine protozoal myeloencephalopathy. Necropsy findings in both horses were similar and consisted of a large hematoma in the fourth ventricle, with upward compression of the cerebellum and downward compression of the pons and rostral portion of the medulla.     

Clinical findings and treatment of shear mouth in two horses associated with ipsilateral painful dental disease

Shear mouth is a rare and poorly described dental condition observed in horses. This report outlines 2 cases of unilateral shear mouth with ipsilateral painful dental disease. Both cases are young horses diagnosed with idiopathic 409 cheek tooth fractures associated with shear angles on the 100 and 400 cheek teeth rows. Corrective odontoplasty was performed in both cases to correct the cheek tooth occlusal surface angle following exodontia of the diseased molars.     

Clinical, histopathological and immunophenotypical findings in five horses with cutaneous malignant lymphoma

This study documents the clinical, histopathological, immunohistochemical and flow-cytometric findings in five horses with cutaneous non-epidermotropic malignant lymphoma (ML). The median survival time after discovery of the first subcutaneous nodules was 3.8 years (range 2-5 years: n=4). Histologically, the cutaneous ML had a pleiomorphic structure and contained a mixture of large reticulo-endothelial cells, medium-large sized lymphoid cells with a rounded nucleus and small nucleoli, many medium sized lymphoid cells with irregular nuclei, and some small lymphoid cells. Immunohistochemically (IHC) the lymphoid cells were positive for the pan-T-lymphocyte marker CD3 but negative for the B-lymphocyte markers CD21 and kappa and lambda immunoglobulin light chains. Although routine haematological examination revealed no abnormalities in the horses with cutaneous ML, changes in the peripheral blood lymphocyte population were apparent flow-cytometrically. Compared to clinically healthy horses, a decreased total percentage of cells was recorded in the lymphocyte gate. In three horses with cutaneous ML, an increase in CD4 positive cells was noticed in the monocyte gate. Flow-cytometric analysis of tumour cells collected by fine needle aspiration (FNA) suggested that the cutaneous MLs consisted primarily of CD4 and CD8 positive T-lymphocytes. The results were compared to those of a monomorphic multicentric T- and a monomorphic multicentric B-cell lymphoma. The results of immunohistochemistry and flow-cytometry were largely but not completely in accordance. In conclusion, the results of this study suggest that cutaneous non-epitheliotropic malignant lymphomas in the horse are of T-cell origin and that, after improvement of its accuracy, flow cytometric analysis of FNAs might become a useful aid to rapid tumour identification.     

Clinical, pathologic, and microbiologic findings of foot abscess in neonatal pigs

A longitudinal study was undertaken in a swine herd with an ever-present problem of foot abscess in suckling pigs reared on a woven-wire floor. Of 3,322 4-day-old pigs, 199 (6%) developed abscess lesions involving claws and accessory digits before weaning. Lesions were first detected in 4-day-old pigs; median and mean ages at onset were 10 and 11.3 days, respectively. At first detection, most pigs had only a single claw affected, but 39 pigs had at least 2 claws with abscesses. Hind limbs had more affected claws (140) than forelimbs (96). In the hind limbs, medial claws were most likely to have lesions, whereas the reverse was true for the forelimbs. Gross and microscopic examinations of affected claws indicated necrotic pododermatitis, with severe osteomyelitis, arthritis, and tenosynovitis. Bacteria isolated from foot abscess lesions included Actinomyces pyogenes, Staphylococcus spp, beta-hemolytic Streptococcus spp, Actinobacillus spp, Escherichia coli, Fusobacterium spp, Bacteroides spp, and Peptostreptococcus spp.     

Methods, applications and limitations of gait analysis in horses

Over the last 30 years, the increase in interest in horses for racing and riding activities has stimulated scientific research in equine locomotion. This paper presents a review of the measurement methods and their applications used to assess equine locomotion. After describing gaits and velocity-related changes in stride variables, the current applications of gait analysis are presented. The economic consequences of lameness justifies the great effort now being put into lameness quantification and prevention. To improve breeding and reduce the costs of training, early performance evaluation tests for each discipline are proposed. After extensive fundamental and methodological research on the various aspects of equine locomotion, the horse industry should benefit from the applications of gait analysis by improving the profitability of racing and riding activities.     

Clinical, radiographic, endoscopic, bronchoalveolar lavage and lung biopsy findings in horses with exercise-induced pulmonary hemorrhage

A clinical study was performed to determine whether clinical, endoscopic, radiographic, bronchoalveolar lavage (BAL) cytological, and pulmonary biopsy findings could be correlated in horses with exercise-induced pulmonary hemorrhage (EIPH) compared with controls. Racing standardbred horses were selected as either EIPH (n = 10) or control (n = 10), based on repeated postexertional endoscopy of the lower airways. Complete physical and respiratory examinations were performed and blood samples were submitted for arterial blood gas analysis, hematologic study, and fibrinogen determination. Bilateral chest radiographs were taken with the horse standing, and a BAL sample was obtained for cytological examination. Lung was biopsied transcutaneously. Weighted scores were calculated for clinical, radiographic, and pulmonary biopsy findings. The conclusion was that only routine physical examination may help the clinician when EIPH is suspected in horses, especially when there are abnormal findings on percussion of the caudodorsal areas of the chest.     

Clinical and pathologic features of oligodendrogliomas in two cats

Two oligodendrogliomas in two domestic cats involved mainly the rostral brain stem, midbrain, fourth ventricle, and cerebellum. Both cats were aged neutered males presenting with clinical neurologic deficits suggestive of a brain stem lesion. Magnetic resonance imaging of both tumors demonstrated lesions with a pattern of heterogeneous contrast enhancement and multifocal lesions in one cat. Routine cerebrospinal fluid analysis was normal in one cat and suggestive of an inflammatory disease in the other. Oligodendroglioma cells were seen in cytospin preparations of cerebrospinal fluid from both cats. In each cat, the tumors occurred intraventricularly in the midbrain and fourth ventricle with aggressive intraparenchymal infiltration. There was extensive growth into the basilar subarachnoid space of the midbrain and brain stem in one cat. One tumor was well differentiated, and the other was an anaplastic subtype. Immunostaining for several myelin- and oligodendroglia-specific antigens was negative with formalin-fixed tumors and with unfixed frozen samples from one cat. In both tumors, component cells of the intratumoral vascular proliferations were positive for human von Willebrand factor VIII antigen or smooth muscle actin. Immunocytochemical reactivity for glial fibrillary acidic protein identified both reactive astrocytes and a subpopulation of minigemistocytes in both tumors. Ultrastructurally, the tumor cells were unremarkable except for their prominent desmosomal junctions and paucity of microtubules.     

Equine odontogenic tumors: Clinical presentation,CT findings,and outcome in 11 horses

Odontogenic tumors present as locally invasive, slow growing, firm swellings on the face. They are rare in all species and are characterized histologically by the degree of differentiation and dental tissue of origin. Radiographic appearance is not pathognomonic for these lesions. Computed tomographic (CT) examination allows exact determination of tumor extension and aggressiveness. The objectives of this retrospective, case series study were to describe the clinical presentation, CT characteristics, and outcome in horses with histologically confirmed odontogenic tumors, and to identify imaging features suggestive of individual types of tumors. Four ameloblastomas, two ameloblastic carcinomas, three ameloblastic fibromas, and two complex odontomas were included. All but one complex odontoma presented as a single mass. All tumors were associated with maxillary or mandibular bone expansion, alveolar and cortical bone lysis, and cortical bone thinning. The majority also had cortical bone thickening and periosteal proliferation. All tumors contained some degree of mineral attenuation, although only the complex odontomas contained enamel attenuation allowing differentiation from other types of odontogenic tumors in this study. Ameloblastomas were found to have variable CT characteristics likely due to the sub‐groups of ameloblastomas. Both ameloblastic carcinomas contained a mixture of mineralized and soft tissue attenuating material whereas ameloblastic fibromas were mainly composed of soft tissue attenuating material. Computed tomographic characteristics of odontogenic tumors generally indicate that they are expansile, aggressive tumors and can occur in a wide range of ages. Further investigation is needed to elucidate differences between each type of equine odontogenic tumor.     

Equine odontoclastic tooth resorption and hypercementosis affecting all cheek teeth in two horses: Clinical and histopathological findings

This report describes the clinical presentation and histopathological findings of two horses with equine odontoclastic tooth resorption and hypercementosis (EOTRH) affecting all cheek teeth. Equine odontoclastic tooth resorption and hypercementosis is a well documented condition known to affect the incisors, canines and occasionally the premolars in horses. At this time there have been no documented cases of EORTH affecting all cheek teeth described in the peer reviewed literature. This paper documents the first reported cases of EOTRH affecting the cheek teeth in one horse in the United States and one from Germany.     

Trigeminal and polyradiculoneuritis in a dog presenting with masticatory muscle atrophy and Horner's syndrome

A 9-year-old, spayed female, Airedale Terrier was euthanatized and necropsied after a progressive clinical course that included Horner's syndrome of the left eye and unilateral atrophy of the masticatory muscles. Although gross lesions were limited, a polyradiculoneuritis and ganglionitis that was most severe in the trigeminal nerves and ganglia were confirmed histologically. The inflammatory infiltrate consisted predominantly of macrophages and B and T lymphocytes that were phenotypically confirmed by immunostaining. Horner's syndrome was the result of damage to postganglionic sympathetic fibers that were incorporated in segments of the inflamed trigeminal nerve and its ophthalmic branch. Histologically, the character and distribution of the inflammation was similar to previously described syndromes of suspected immune-mediated etiology in humans and animals.