Minimally invasive approach to lumbosacral decompression in a cadaveric canine model

AIMS : To determine efficacy of a minimally invasive (MI) surgical approach using a human MI lumbar retractor for canine lumbosacral dorsal laminectomy and partial discectomy and to compare this technique to the standard open surgical (OS) approach. METHODS : Lumbosacral dorsal laminectomy and partial discectomy was performed on 16 largebreed canine cadavers using either a standard OS (n=8) or MI (n=8) approach. Skin and fascial incision length, procedure time, and intraoperative complications were recorded. Postoperatively specimens were evaluated for laminectomy and discectomy dimensions, and visible damage to the cauda equina and exiting nerve roots. RESULTS : Median length of skin and fascial incisions in the OS group were longer than in the MI group (p<0.001). Median laminectomy length was similar between both approaches (p=0.234) but width was greater for the MI than OS approach (p=0.002). Both approaches achieved similar partial discectomy width (p=0.279). Overall surgical time was longer for MI approaches compared to OS, with a median of 18.5 (min 15.5, max 21.8) minutes for MI compared to 14.6 (min 13.1, max 16.9) minutes for OS (p=0.001). CONCLUSIONS : The MI approach reduced incision lengths while retaining comparable laminectomy and discectomy dimensions. For this in vitro model the MI approach required more time to complete, but this difference may not be relevant in clinical cases. CLINICAL RELEVANCE : Dogs undergoing lumbosacral dorsal laminectomy are commonly large-breed dogs. The traditional open approach requires a large skin incision and soft tissue dissection, especially in overweight animals. A MI approach accomplishing the same surgical result while minimising soft tissue trauma could reduce post-operative pain and recovery time, and may lower wound-related complications. Clinical studies are needed to confirm postoperative benefit and assess operating times in vivo.http://www.tandfonline.com/loi/tnzv202017-03-31hb2016Production Animal Studie

Sensitivity and specificity of a hand-held milk electrical conductivity meter compared to the California mastitis test for mastitis in dairy cattle

Screening tests for mastitis can play an important role in proactive mastitis control programs. The primary objective of this study was to compare the sensitivity and specificity of milk electrical conductivity (EC) to the California mastitis test (CMT) in commercial dairy cattle in South Africa using Bayesian methods without a perfect reference test. A total of 1848 quarter milk specimens were collected from 173 cows sampled during six sequential farm visits. Of these samples, 25.8% yielded pathogenic bacterial isolates. The most frequently isolated species were coagulase negative Staphylococci (n = 346), Streptococcus agalactiae (n = 54), and Staphylococcus aureus (n = 42). The overall cow-level prevalence of mastitis was 54% based on the Bayesian latent class (BLC) analysis. The CMT was more accurate than EC for classification of cows having somatic cell counts >200,000/mL and for isolation of a bacterial pathogen. BLC analysis also suggested an overall benefit of CMT over EC but the statistical evidence was not strong (P = 0.257). The Bayesian model estimated the sensitivity and specificity of EC (measured via resistance) at a cut-point of >25 mO/cm to be 89.9% and 86.8%, respectively. The CMT had a sensitivity and specificity of 94.5% and 77.7%, respectively, when evaluated at the weak positive cut-point. EC was useful for identifying milk specimens harbouring pathogens but was not able to differentiate among evaluated bacterial isolates. Screening tests can be used to improve udder health as part of a proactive management plan.http://www.elsevier.com/ locate/tvjlhb2013ab201

Pancreatic lipase immunoreactivity in serum of dogs with diabetic ketoacidosis

BACKGROUND : Diabetic ketoacidosis (DKA) is a relatively common endocrine disorder in dogs and is routinely associated with concurrent pancreatic injury. OBJECTIVES : The aims of this study were to determine the prevalence of pancreatic injury in dogs with DKA based on measurement of pancreatic lipase immunoreactivity in serum (PLI); compare demographic, clinicopathologic, and ultrasonographic findings in dogs with and without evidence of concurrent pancreatic injury; determine the impact of pancreatic injury on duration of hospitalization and short-term outcome. ANIMALS : One hundred and nineteen dogs with DKA with or without concurrent pancreatic injury. METHODS : Retrospective study. Dogs with DKA were divided into three groups on the basis of PLI results: positive for pancreatic injury (PLIpos), negative for pancreatic injury (PLIneg), and not tested (PLIna). Demographics, clinicopathologic test results, findings on abdominal ultrasonography (AUS), duration of hospitalization, and short-term outcome were compared between the three groups. RESULTS : Based on serum PLI activity, 45 dogs (73%) with DKA had evidence of concurrent pancreatic injury. Median total carbon dioxide was significantly lower in the PLIpos dogs compared to the PLIneg dogs. There was fair agreement (j = 0.26) between serum PLI activity and AUS. Evidence of pancreatic injury was not associated with significantly longer periods of hospitalization (PLIpos median 6 days, range 4–7 days, PLIneg median 4 days, range 3–6 days) and did not influence short-term outcome (PLIpos failure to survive to discharge 11/45, 24%, PLIneg failure to survive to discharge 2/17, 12%). CLINICAL IMPORTANCE : Concurrent pancreatic injury is common in dogs with DKA, but did not affect prognosis in this population of dogs.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1939-1676hb2017Production Animal Studie

Hunting performance of captive-born South China tigers (Panthera tigris amoyensis) on free-ranging prey and implications for their reintroduction

The South China tiger (Panthera tigrisamoyensis), although listed by the IUCNas critically endangered, is probably extinct in the wild. This leaves captive-born animals as the only stock available for reintroductions. Because reintroduced tigers will not survive in the wild unless they hunt proficiently, we aimed to determine whether captive-born tigers were able to hunt free-ranging prey and to evaluate their hunting performance as a criterion for reintroduction. The effect of other variables on subsequent hunting success, such as the availability of stalking cover and the upbringing history of tigers while they were cubs were also explored, given their relevance in reintroduction programs. Twelve tigers over two years of agewere fittedwith GPS collars and placed individually in 100 ha enclosures to determine their kill rate of blesbuck (Damaliscus pygargus), as a measure of their hunting performance. All tigers but one successfully hunted blesbuck, although kill rate varied substantially amongst individuals, ranging from one blesbuck every 3.14 days to no blesbuck. Tigers also killed other species indicating plasticity in their hunting behavior, and showed higher kill rates in the enclosure where cover was more abundant, confirming the importance of stalking cover in hunting success for this species. Results showed that the presence of the mother during cub development was not necessary for cubs to hunt later in life, although it had a positive effect on kill rate. Our study represents the first empirical evidence that captive-born tigers can successfully hunt free-ranging prey adequately to meet their energetic demands, validating the use of captive animals to recover wild populations, should other reintroduction criteria be met. Moreover, that tigers adapted to the African veld ecoregion suggests they should be able to adapt back to southern China where opportunities for stalking and ambush are more numerous.University of Pretoria.http://www.elsevier.com/locate/bioc2016-12-31hb201

Eradication of transboundary animal diseases : can the rinderpest success story be repeated?

A matrix system was developed to aid in the evaluation of the technical amenability to eradication, through mass vaccination, of transboundary animal diseases (TADs). The system involved evaluation of three basic criteria - disease management efficiency, surveillance and epidemiological factors - each in turn comprised of a number of elements (17 in all). On that basis, 25 TADs that have occurred or do occur in southern Africa and for which vaccines are available, in addition to rinderpest (incorporated as a yardstick because it has been eradicated worldwide), were ranked. Cluster analysis was also applied using the same criteria to the 26 diseases, creating division into three groups. One cluster contained only diseases transmitted by arthropods (e.g. African horse sickness and Rift Valley fever) and considered difficult to eradicate because technologies for managing parasitic arthropods on a large scale are unavailable, while a second cluster contained diseases that have been widely considered to be eradicable [rinderpest, canine rabies, the Eurasian serotypes of foot and mouth disease virus (O, A, C & Asia 1) and peste des petits ruminants] as well classical swine fever, Newcastle disease and lumpy skin disease. The third cluster contained all the other TADs evaluated with the implication that these constitute TADs that would be more difficult to eradicate. However, it is acknowledged that the scores assigned in the course of this study may be biased. The point is that the system proposed offers an objective method for assessment of the technical eradicability of TADs; the rankings and groupings derived during this study are less important than the provision of a systematic approach for further development and evaluation.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1865-16822016-06-23hb201

Frequency and number of ultrasound lung rockets ( B-lines ) using a regionally based lung ultrasound examination named Vet BLUE ( veterinary bedside lung ultrasound exsam ) in dogs with radiographicallynormal lung findings

Lung ultrasound is superior to lung auscultation and supine chest radiography for many respiratory conditions in human patients. Ultrasound diagnoses are based on easily learned patterns of sonographic findings and artifacts in standardized images. By applying the wet lung (ultrasound lung rockets or B-lines, representing interstitial edema) versus dry lung (A-lines with a glide sign) concept many respiratory conditions can be diagnosed or excluded. The ultrasound probe can be used as a visual stethoscope for the evaluation of human lungs because dry artifacts (A-lines with a glide sign) predominate over wet artifacts (ultrasound lung rockets or B-lines). However, the frequency and number of wet lung ultrasound artifacts in dogs with radiographically normal lungs is unknown. Thus, the primary objective was to determine the baseline frequency and number of ultrasound lung rockets in dogs without clinical signs of respiratory disease and with radiographically normal lung findings using an 8-view novel regionally based lung ultrasound examination called Vet BLUE. Frequency of ultrasound lung rockets were statistically compared based on signalment, body condition score, investigator, and reasons for radiography. Ten left-sided heart failure dogs were similarly enrolled. Overall frequency of ultrasound lung rockets was 11% (95% confidence interval, 6–19%) in dogs without respiratory disease versus 100% (95% confidence interval, 74–100%) in those with left-sided heart failure. The low frequency and number of ultrasound lung rockets observed in dogs without respiratory disease and with radiographically normal lungs suggests that Vet BLUE will be clinically useful for the identification of canine respiratory conditions.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1740-8261hb201

Brucellosis in domestic water bufallo (Bubalus bubalis) of Trinidad and Tobago with comparative epidemiology to cattle

The water buffalo is an important domestic animal worldwide and the local Buffalypso variety was developed in Trinidad to have improved beef qualities. Brucellosis was diagnosed in Trinidad and Tobago during 1998 in both cattle and domestic water buffalo (Bubalus bubalis) populations. Brucellosis in the latter species is caused by infection with Brucella abortus, similar to bovine brucellosis. Control of brucellosis is of paramount importance to preservation of the genetic diversity of these animals in Trinidad, and this has been complicated by differences in the epidemiology of water buffalo and bovine brucellosis. Some diagnostic tests do not have comparable accuracy between the two species, and the RB51 vaccine does not adequately protect against infection in water buffalo. The water buffalo in Trinidad may also be more resistant to infection than cattle. Development of effective vaccination protocols is key to control disease in Buffalypso in Trinidad, and prohibitions on import of virulent B. abortus strains for vaccine efficacy studies has impeded progress in this area. These Trinidadian strains are of variable virulence; some might be effective for challenge in vaccine efficacy studies, while other, of lower virulence, may be vaccine candidates for use in water buffalo.The Campus Research Funds Committee, St. Augustine.http://www.springerlink.com/content/0049-4747ab201

Lesions and cellular tropism of natural Rift Valley fever virus infection in adult sheep

Rift Valley fever (RVF) is a mosquito-borne disease that affects both ruminants and humans, with epidemics occurring more frequently in recent years in Africa and the Middle East, probably as a result of climate change and intensified livestock trade. Sheep necropsied during the 2010 RVF outbreak in South Africa were examined by histopathology and immunohistochemistry (IHC). A total of 124 sheep were available for study, of which 99 cases were positive for RVF. Multifocal-random, necrotizing hepatitis was confirmed as the most distinctive lesion of RVF cases in adult sheep. Of cases where liver, spleen, and kidney tissues were available, 45 of 70 had foci of acute renal tubular epithelial injury in addition to necrosis in both the liver and spleen. In some cases, acute renal injury was the most significant RVF lesion. Immunolabeling for RVFV was most consistent and unequivocal in liver, followed by spleen, kidney, lung, and skin. RVFV antigen-positive cells included hepatocytes, adrenocortical epithelial cells, renal tubular epithelial cells, macrophages, neutrophils, epidermal keratinocytes, microvascular endothelial cells, and vascular smooth muscle. The minimum set of specimens to be submitted for histopathology and IHC to confirm or exclude a diagnosis of RVFV are liver, spleen, and kidney. Skin from areas with visible crusts and lung could be useful additional samples. In endemic areas, cases of acute renal tubular injury should be investigated further if other more common causes of renal lesions have already been excluded. RVFV can also cause an acute infection in the testis, which requires further investigation.http://journals.sagepub.com/home/vethj2019Paraclinical SciencesProduction Animal Studie

Ovine fetal and placental lesions and cellular tropism in natural Rift Valley fever virus infections

Infection with Rift Valley fever phlebovirus (RVFV) causes abortion storms and a wide variety of outcomes for both ewes and fetuses. Sheep fetuses and placenta specimens were examined during the 2010–2011 River Valley fever (RVF) outbreak in South Africa. A total of 72 fetuses were studied of which 58 were confirmed positive for RVF. Placenta specimens were available for 35 cases. Macroscopic lesions in fetuses were nonspecific and included marked edema and occasional hemorrhages in visceral organs. Microscopically, multifocal hepatic necrosis was present in 48 of 58 cases, and apoptotic bodies, foci of liquefactive hepatic necrosis (primary foci), and eosinophilic intranuclear inclusions in hepatocytes were useful diagnostic features. Lymphocytolysis was present in all lymphoid organs examined with the exception of thymus and Peyer’s patches, and pyknosis or karyorrhexis was often present in renal glomeruli. The most significant histologic lesion in the placenta was necrosis of trophoblasts and endothelial cells in the cotyledonary and intercotyledonary chorioallantois. Immunolabeling for RVFV was most consistent in trophoblasts of the cotyledon or caruncle. Other antigen-positive cells included hepatocytes, renal tubular epithelial, juxtaglomerular and extraglomerular mesangial cells, vascular smooth muscle, endothelial and adrenocortical cells, cardiomyocytes, Purkinje fibers, and macrophages. Fetal organ samples for diagnosis must minimally include liver, kidney, and spleen. From the placenta, the minimum recommended specimens for histopathology include the cotyledonary units and caruncles from the endometrium, if available. The diagnostic investigation of abortion in endemic areas should always include routine testing for RVFV, and a diagnosis during interepidemic periods might be missed if only limited specimens are available for examination.The Agricultural Sector Education Training Authority of South Africa. Publication of this study was funded by the Department of Paraclinical Sciences of the Faculty of Veterinary Science, University of Pretoria, and the Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University.http://journals.sagepub.com/home/vethj2020Paraclinical Science

Coagulation, oncotic and haemodilutional effects of a third-generation hydroxyethyl starch (130/0.4) solution in horses

REASONS FOR PERFORMING STUDY : Clinical indications for hydroxyethyl starches (HES) in horses include rapid plasma volume expansion and oncotic support during periods of hypoproteinaemia. Side effects such as coagulopathies associated with HES administration pose limitations to their use in veterinary medicine. In humans, tetrastarch [hydroxyethyl starch (130/0.4)] has demonstrated less profound effects on coagulation compared to 1st and 2nd generation HES. OBJECTIVES : To evaluate the haemostatic and oncotic effects of tetrastarch (130/0.4) administered at 10, 20 and 40 ml/kg bwt in healthy horses. Study design: Randomised crossover study design. METHODS : Tetrastarch (130/0.4) was administered to 6 healthy pony mares at 10, 20 and 40 ml/kg bwt with a 2-week washout period. Packed cell volume (PCV), total solids (TS), plasma colloid oncotic pressure (pCOP), platelet count and thromboelastography (TEG) was measured at baseline, immediately after infusion (0 h), 1, 6, 12, 24, 48, and 96 h after tetrastarch infusion. RESULTS : All TEG variables remained within normal reference ranges in all 3 treatment groups. Administration of tetrastarch at 40 ml/kg bwt resulted in a prolonged K-time (P=0.049) at 6 h post-infusion, and decreased maximum amplitude at 0 (P<0.001), 1 (P=0.022), 6 (P=0.006), 24 (P<0.001) and 48 h (P=0.013) postinfusion compared to baseline. Administration of tetrastarch increased mean pCOP values above baseline in all 3 treatment groups, persisting to 24, 6 and 48 h for the 10, 20 and 40 ml/kg bwt dose respectively. CONCLUSION : Although still within established reference ranges, compared to lower dosages, the administration of 40 ml/kg bwt tetrastarch (130/0.4) is more likely to induce changes in coagu lation as measured by TEG. Tetrastarch increased pCOP at all dosages evaluated in healthy horses.Faculty of Veterinary Science Research Fund ; Department of Companion Animal Clinical Studies, University of Pretoria ; and the Abe Bailey Trust.http://onlinelibrary.wiley.com/journal/10.1001/(ISSN)2042-33062015-11-30hb201