Journal of the South African Veterinary Association最新文献

Abstract: The immobilisation time and cardiopulmonary effects of ketamine-medetomidine (KM) and tiletamine-zolazepam-medetomidine (TZM) were compared in semi-captive cheetahs (Acinonyx jubatus). Seven healthy adult cheetahs were included in a randomised prospective crossover study. Each cheetah was immobilised on two occasions by remote injection, once with a combination of ketamine (4.93 ± 0.75 mg/kg) and medetomidine (0.038 ± 0.003 mg/kg) (KM) and once with tiletamine-zolazepam (1.16 ± 0.12 mg/kg) and medetomidine (0.039 ± 0.002 mg/kg) (TZM). Time to safe approach, characterised by absent responses to an ear flick and tail tug, was recorded as the immobilisation time. Following immobilisation, cardiopulmonary parameters were recorded, and an arterial blood gas sample analysed. Data is reported as mean ± SD and compared using a general linear mixed model (p < 0.05). Immobilisation times were no different between combinations, 11.4 ± 5.7 minutes for KM and 13.2 ± 4.6 minutes for TZM (p = 0.528). Systolic blood pressure was 218 ± 22 mmHg for KM and 210 ± 28 mmHg for TZM (p = 0.594). There was moderate hypoxaemia with both combinations with arterial oxygen partial pressure of 58.4 ± 6.6 mmHg for KM and 61.3 ± 4.2 mmHg for TZM (p = 0.368). Haematocrit was higher with KM (40.7 ± 2.5) than TZM (35.8 ± 2.8, p = 0.007). There were differences in electrolytes, with TZM resulting in higher serum potassium (4.3 ± 0.2 mmol/L, p < 0.001) and glucose (11.8 ± 2.9 mmol/L, p = 0.039) than KM. Both combinations provided acceptable immobilisation for field use, although severe hypertension was a consistent finding. Supplementation with oxygen is recommended with both combinations.

Abstract: Nemaline myopathy - a clinically and genetically complex heterogenous group of disorders - is described uncommonly in humans and rarely in animals, and is characterised by progressive muscle weakness. The diagnosis is confirmed by histological and/or ultrastructural identification of subsarcolemmal, thread-like, rod-shaped structures called nemaline rod bodies within more than 40% of skeletal muscle fibres. These rods contain the Z-line protein, α-actinin, that can be effectively stained in skeletal muscles using Gomori or Masson trichrome and negatively stained with periodic acid-Schiff. Similar rod-like bodies have been found in smaller numbers in dogs with endocrine disorders and occasionally in other conditions in humans. This report is of a six-monthold Pomeranian dog which had progressive exercise intolerance over a two-month period associated with severe disuse muscle atrophy of the thoracic limbs, as well as gradual pelvic limb weakness and regurgitation of food. Baseline diagnostics ruled out endocrinopathies and after histological and ultrastructural evaluation of thoracic limb muscles and nerve biopsies confirmed nemaline myopathy. The clinical course, diagnostic test results, ultrastructure of skeletal muscle and peripheral nerve, gross necropsy findings and histopathology using various stains are described and illustrated.

Abstract: A six-year-old intact male Southern African hedgehog (Atelerix frontalis) presented with a history of chronic mild to moderate weight loss, and sub-acute hind limb ataxia that progressed to complete paralysis, at which point the hedgehog was euthanised. At autopsy, a large multinodular pale mass had completely replaced the left testicle and transcoelomically metastasised to the diaphragm and the peri-renal area, from where it then invaded the vertebral column and spinal cord. Multifocal, irregular to round, well-demarcated, blood-filled, proliferative lesions were also present in the hepatic parenchyma. Histological analysis of both the testis and metastatic lesions revealed diffuse sheets of neoplastic cells with moderate pale cytoplasm, large irregular to round nuclei and mostly one prominent magenta nucleolus, consistent with metastatic seminoma. The neoplastic cells were negative for periodic acid-Schiff (PAS) stain and positive for CD117 by immunohistochemistry (IHC). Taken together with the morphology of the neoplastic cells and the advanced age of the animal, this is suggestive of a spermatocytic seminoma. Histological analysis of the liver revealed multifocal lesions consisting of large anastomosing blood-filled spaces bordered by compressed hepatocytes, consistent with hepatic peliosis. This is the first report of a neoplasm in the Southern African hedgehog (Atelerix frontalis), the first report of a metastatic seminoma in a hedgehog, together with diagnosis of spermatocytic subtype, and the first report of a hedgehog with concomitant hepatic peliosis.

Abstract: Canine parvovirus (CPV) is a common cause of enteritis, immune suppression and systemic inflammation in young dogs. Endothelial markers, such as intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1), and molecules that upregulate their expression, such as high mobility group box 1 protein (HMGB-1), provide insight into the state of the endothelium during inflammation. This study aimed to determine if circulating concentrations of ICAM-1, VCAM-1 and HMGB-1 were altered in CPV enteritis compared to healthy controls, and whether a correlation existed between these molecules and the degree of inflammation. Thirty dogs with naturally occurring CPV enteritis and ten control dogs were included. Physical examinations, complete blood count and C-reactive protein (CRP) measurements were performed on all dogs at presentation. The concentrations of ICAM-1, VCAM-1 and HMGB-1 were measured using commercially available canine-specific enzyme-linked immunosorbent assay (ELISA) kits. In dogs with CPV enteritis, ICAM-1 concentrations were significantly lower (median: 5.9 [IQR: 4.3-8.3]) and CRP higher (134 [IQR: 85-195]) compared to controls (8.0 [IQR: 6.9-10.3], p = 0.008; 1 [IQR: 0-7], p < 0.001). No significant difference was found for VCAM- 1 and HMGB-1. A strong correlation was identified between VCAM-1 and segmented neutrophil count (r = 0.612, p < 0.001). Despite the presence of systemic inflammation in CPV enteritis, evidenced by high CRP concentrations, our results suggest circulating concentrations of ICAM-1, VCAM-1 and HMGB-1 failed to show an increase. Endothelial activation with subsequent leukocyte adhesion and transmigration through the endothelium may be affected in CPV enteritis and these findings require further investigation.

Abstract: The informal poultry and pig sector in the Eastern Cape Province (ECP) of South Africa is of significant socio-economic importance as it sustains livelihoods and ensures food security; yet little is known about the distribution and prevalence of infectious and zoonotic diseases in this region. This paper reviews data published for pig and poultry diseases in the province during the last 20 years (2000-2020). The review included relevant published papers identified by a computerised literature search from Web of Science; provincial animal health reports; the national database from the Department of Agriculture, Land Reform and Rural Development (DALRRD); animal health reports submitted by DALRRD to the World Organisation for Animal Health (OIE) via the World Animal Health Information Database (WAHID) interface and laboratory records. A publication was considered eligible if it included qualitative or quantitative information on any disease affecting pigs and poultry including zoonosis. The search retrieved 174 publications, of which 26 were relevant. The review found that Newcastle disease (ND), coccidiosis and fowl pox (FP) were the most reported avian diseases in the national database, whereas avian infectious bronchitis (AIB), ND and highly pathogenic avian influenza (HPAI) were the most reported diseases in the OIE database. Classical swine fever (CSF) was the most reported pig disease in both databases. The retrieved literature on pig and poultry diseases was scarce and no longer up to date, providing decision makers with little information. The review identified important zoonotic diseases that require further studies yet failed to find information on important neglected diseases like leptospirosis.

Abstract: Staphylococcus pseudintermedius (SP) is an important opportunistic pathogen, frequently associated with pyoderma and otitis in dogs. The emergence and rapid expansion of methicillin-resistant Staphylococcus pseudintermedius (MRSP) is problematic due to multidrug resistance and reduced treatment options. The aim of this study was to determine i) the prevalence of MRSP in dogs with pyoderma or otitis externa, ii) the antimicrobial resistance patterns of MRSP from South African isolates, and iii) the risk factors for MRSP-associated pyoderma or otitis externa in dogs in South Africa (RSA). Sixty-eight presumptive clinical SP isolates (collected from 65 dogs) from five geographically dispersed laboratories in RSA were collected over 2 years. Possible MRSP isolates were flagged when resistance to oxacillin was observed. Thereafter, all isolates were confirmed as SP by polymerase chain reaction (PCR) and further genotyped for the mecA gene. Fifty-seven of 68 isolates were confirmed to be SP (83.8%), while 49/57 (85.9%) carried mecA. Our findings showed that preliminary phenotypic methods supplemented by genotypic methods increased the accuracy of correctly identifying SP. All isolates were resistant to at least one antimicrobial drug. There was a high incidence of amoxicillin (70.1%) and enrofloxacin (65%) resistance. Important risk factors for mecA positive carriage were previous hospital admission, pruritus, and previous antibacterial failure. This study demonstrates a high prevalence of mecA positive carriage (85.9% of samples) in MRSP pyoderma and otitis in dogs in RSA. There is an urgent need for better laboratory diagnosis of MRSP and surveillance of dogs presenting with pyoderma and otitis in South Africa.

Abstract: This study investigated causes of attenuation of cerebrospinal fluid (CSF) signal on heavily T2-weighted (T2W) images in dogs with thoracolumbar disc extrusion. Medical records and magnetic resonance images were retrospectively reviewed. Dogs were classified into the following grades; grade 1, non-ambulatory paraparesis; grade 2, paraplegia with deep pain perception and grade 3, paraplegia without deep pain perception. The length of intramedullary T2W hyperintensity of the spinal cord, cranial/ caudal expansion of extradural compressive materials (ECM), and the CSF signal attenuation were measured. Ratios to the second lumbar vertebra (L2) were calculated for the length of intramedullary T2W hyperintensity (T2W:L2), cranial/caudal expansion of ECM (ECML:L2), and CSF signal attenuation (CSF:L2). The dogs were classified into focal or extended T2W hyperintensity groups according to the length [focal, shorter than length of L2; extended, longer than L2]. The area of EMC and the spinal canal were measured on transverse images at the lesion deriving occupancy ratio. The correlation between CSF:L2 and other data were analysed, and CSF:L2 was compared between the grades. In dogs with intramedullary T2W hyperintensity, the locations of CSF attenuation and the hyperintensity were compared if those locations were matched. Fifty-five dogs were included, 36 of which showed intramedullary T2W hyperintensity. Twenty-two of 36 dogs were considered as match of the location of the CSF attenuation and hyperintensity. CSF:L2 was significantly correlated with T2W:L2 in dogs with extended T2W hyperintensity (p = 0.0002), while CSF:L2 was significantly correlated with ECML:L2 in dogs with focal or no T2W hyperintensity (p = 0.0103 and p = 0.0364, respectively). CSF:L2 in grade 3 was significantly greater than those in patients who were grade 1 or 2 (both p < 0.001). In conclusion, higher CSF:L2, which was frequently seen in grade 3, would be most consistent with a higher T2W:L2 which might indicate spinal cord swelling.

Abstract: West Nile virus (WNV) is a vector-borne virus maintained in nature by a bird-mosquito cycle. However, it can occasionally and accidentally infect horses and human beings, leading to sometimes severe or even fatal outcomes in these species. Therefore, the monitoring of its circulation and disease occurrence is of relevance. Unfortunately, it is underdiagnosed or not diagnosed in several African counties, including Namibia, where no data is currently available for horses. In this study, 98 horses in three different stables in the Windhoek city area were investigated. They were found to have a seroprevalence of approximately 7%. Positive reactions were seen at all three stables, suggesting a greater than expected prevalence of the virus. This is the first report of serological evidence for the presence of the virus in horses in Nambia. Even though clinical signs were not reported in any of the stables from which the sera were derived, the seroprevalence to the virus suggests that horses with high genetic and/or economic value could benefit from vaccination against WNV. Because of the zoonotic potential of the virus, these findings are also of significance to human health authorities.