Diagnostic Pitfall of Gastric Signet-Ring Cells: How to Diagnose a Benign Signet-Ring Cell From a Malignant One

Sometimes non-neoplastic changes of the gastric mucosa mimic diffuse-type gastric carcinoma, specifically signet-ring cell adenocarcinoma. In fact, gastric epithelial cells undergoing signet-ring cell change have a cellular morphology that is almost identical to signet-ring cell adenocarcinoma, often leading to misdiagnosis. Accurate recognition of signet-ring cell change is essential to avoid overdiagnosis and overtreatment of signet-ring cell adenocarcinoma. Research on this topic is limited and clinicians lack formal diagnostic tools when signet-ring cells are detected in biopsy specimens. The aims of this study are 3-fold. Firstly, to increase the awareness of both clinicians and pathologists of this rare but highly significant entity. Secondly, to report 4 additional examples of signet-ring cell change and analyze them alongside signet-ring cell adenocarcinoma to compare their morphological and phenotypic features and their evolution over time. Finally, to highlight the potential utility of endoscopic resection to confirm the diagnosis. Cells in signet-ring cell change strongly express E-cadherin, show a wild-type p53 expression, and have a low Ki67 index. In contrast, cells in signet-ring cell adenocarcinoma strongly express p53, have high proliferation rates, and show either no or weak E-cadherin staining. Genetic analysis may be useful in identifying patients at risk of hereditary early diffuse gastric adenocarcinoma, which can mimic signet-ring cell change.

Pharmacological characterization of GLPG1972/S201086, a potent and selective small-molecule inhibitor of ADAMTS5

OBJECTIVE

A disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS5) is a key enzyme in degradation of cartilage in osteoarthritis (OA). We report the pharmacological characterization of GLPG1972/S201086, a new, potent and selective small-molecule ADAMTS5 inhibitor.

METHODS

Potency and selectivity of GLPG1972/S201086 for ADAMTS5 were determined using fluorescently labeled peptide substrates. Inhibitory effects of GLPG1972/S201086 on interleukin-1α-stimulated glycosaminoglycan release in mouse femoral head cartilage explants and on interleukin-1β-stimulated release of an ADAMTS5-derived aggrecan neoepitope (quantified with ELISA) in human articular cartilage explants were determined. In the destabilization of the medial meniscus (DMM) mouse and menisectomized (MNX) rat models, effects of oral GLPG1972/S201086 on relevant OA histological and histomorphometric parameters were evaluated.

RESULTS

GLPG1972/S201086 inhibited human and rat ADAMTS5 (IC50 ± SD: 19 ± 2 nM and <23 ± 1 nM, respectively), with 8-fold selectivity over ADAMTS4, and 60->5,000-fold selectivity over other related proteases in humans. GLPG1972/S201086 dose-dependently inhibited cytokine-stimulated aggrenolysis in mouse and human cartilage explants (100% at 20 μM and 10 μM, respectively). In DMM mice, GLPG1972/S201086 (30-120 mg/kg b.i.d) vs vehicle reduced femorotibial cartilage proteoglycan loss (23-37%), cartilage structural damage (23-39%) and subchondral bone sclerosis (21-36%). In MNX rats, GLPG1972/S201086 (10-50 mg/kg b.i.d) vs vehicle reduced cartilage damage (OARSI score reduction, 6-23%), and decreased proteoglycan loss (∼27%) and subchondral bone sclerosis (77-110%).

CONCLUSIONS

GLPG1972/S201086 is a potent, selective and orally available ADAMTS5 inhibitor, demonstrating significant protective efficacy on both cartilage and subchondral bone in two relevant in vivo preclinical OA models.

Particulate matter and airborne endotoxin concentration in calf barns and their association with lung consolidation, inflammation, and infection

Agricultural operations are important sources of organic dust containing particulate matter (PM) and endotoxins, which have possible negative health consequences for both humans and animals. Dust concentrations and composition in calf barns, as well as the potential health effects for these animals, are scarcely documented. The objective of this study was to measure PM fractions and endotoxin concentrations in calf barns and study their associations with lung consolidation, respiratory tract inflammation, and infection in group-housed calves. In this cross-sectional study, samples from 24 dairy farms and 23 beef farms were collected in Belgium from January to April 2017. PM_1.0, PM_2.5 and PM₁₀ (defined as particulate matter passing through a size-selective inlet with a 50% efficiency cut-off at a 1.0-μm, 2.5-μm, and 10-μm aerodynamic diameter, respectively) were sampled during a 24-h period using a Grimm aerosol spectrometer (Grimm Aerosol Technik Ainring GmbH & Co. KG). Endotoxin concentration was measured in the PM₁₀ fraction. Thoracic ultrasonography was performed and broncho-alveolar lavage fluid was collected for cytology and bacteriology. Average PM concentrations were 16.3 µg/m³ (standard deviation, SD: 17.1; range: 0.20-771), 25.0 µg/m³ (SD: 25.3; range: 0.50-144.9), and 70.3 µg/m³ (SD: 54.5; range: 1.6-251.2) for PM_1.0, PM_2.5, and PM₁₀, respectively. Mean endotoxin in the PM₁₀ fraction was 4.2 endotoxin units (EU)/µg (SD: 5.50; range: 0.03-30.3). Concentrations in air were 205.7 EU/m³ (SD: 197.5; range: 2.32-901.0). Lung consolidations with a depth of ≥1, ≥3, and ≥6 cm were present in 43.1% (146/339), 27.4% (93/339), and 15.3% (52/339) of the calves, respectively. Exposure to fine (PM_1.0) PM fractions was associated with increased odds of lung consolidations of ≥1 cm (odds ratio, OR: 3.3; confidence interval (CI): 1.5-7.1), ≥3 cm (OR: 2.8; CI: 1.2-7.1), and ≥6 cm (OR: 12.3; CI: 1.2-125.0). The odds of having lung consolidations of ≥1 cm (OR: 13.9; CI: 3.4-58.8) and ≥3 cm (OR: 6.7; 1.7-27.0) were higher when endotoxin concentrations in the dust mass exceeded 8.5 EU/µg. Broncho-alveolar lavage fluid neutrophil percentage was positively associated with PM₁₀ concentration, and epithelial cell percentage was negatively associated with this fraction. Concentration of PM_2.5 was positively associated with epithelial cell percentage and isolation of Pasteurella multocida. Although concentrations of fine dust are lower in calf barns than in poultry and pig housings, in this study they were associated with pneumonia in calves. Dust control strategies for reducing fine dust fractions in calf barns may benefit human and animal respiratory health.

BSGIE survey on COVID-19 and gastrointestinal endoscopy in Belgium : results and recommendations

BACKGROUND AND AIMS

With the first wave of the COVID-19 pandemic declining, activities in the gastrointestinal clinic are being recommenced after a period of stringent measures. Since a second COVID-19 wave is not entirely ruled out health care professionals might remain faced with the need to perform endoscopic procedures in patients with a confirmed positive or unknown COVID-19 status. With this report we aim to provide a practical relevant overview of preparation and protective measures for gastroenterologists based on the currently available guidelines and our local experience and results of a national Belgian survey, to guarantee a fast recall of an adequate infection prevention if COVID-19 reoccurs.

METHODS

From the 23rd of March 2020 and the 13th of May 2020 we performed a Pubmed, Embase and Medline search, resulting in 37 papers on COVID-19 and endoscopy. Additionally, we combined these data with data acquired from the national BSGIE survey amongst Belgian gastroenterologists.

RESULTS

Based on 72 completed surveys in both university and non-university hospitals, the results show (1) a dramatic (<20%) or substantial (<50%) decrease of normal daily endoscopy in 74% and 22% of the units respectively, (2) a difference in screening and protective measures between university and non-university hospitals. These findings were subsequently compared with the current guidelines.

CONCLUSION

Based on new data from the BSGIE survey and current guidelines we tried to realistically represent the current COVID-19 trends in protective measures, screening and indications for endoscopy and to provide a practical overview as preparation for a possible second wave.

Pathogen-specific risk factors in acute outbreaks of respiratory disease in calves

Respiratory tract infections (bovine respiratory disease) are a major concern in calf rearing. The objective of this study was to identify pathogen-specific risk factors associated with epidemic respiratory disease in calves. A cross-sectional study was conducted, involving 128 outbreaks (29 dairy, 58 dairy-mixed, and 41 beef) in Belgium (2016–2018). A semiquantitative PCR for 7 respiratory pathogens was done on a pooled nonendoscopic bronchoalveolar lavage sample for each herd. Potential risk factors were collected by questionnaire and derived from the national cattle registration databank. Most outbreaks occurred between October and March, and single and multiple viral infections were detected in 58.6% (75/128) and 13.3% (17/128), respectively. Bovine coronavirus (BCV) was the most frequently isolated virus (38.4%), followed by bovine respiratory syncytial virus (bRSV; 29.4%) and parainfluenzavirus type 3 (PI-3; 8.1%). Mycoplasma bovis, Mannheimia haemolytica, Pasteurella multocida, and Histophilus somni were detected in 33.3, 41.2, 89.1, and 36.4% of the herds, respectively. Specific risk factors for BCV detection were detection of M. haemolytica [odds ratio (OR) = 2.8 (95% confidence interval = 1.1–7.5)], increasing herd size [OR = 1.3 (1.0–1.8) for each increase with 100 animals] and detection of BCV by antigen ELISA on feces in calves in the last year [OR = 3.6 (1.2–11.1)]. A seasonal effect was shown for bRSV only {more in winter compared with autumn [OR = 10.3 (2.8–37.5)]}. Other factors associated with bRSV were PI-3 detection [OR = 13.4 (2.1–86.0)], prevalence of calves with respiratory disease [OR = 1.02 (1.00–1.04) per 1% increase], and number of days with respiratory signs before sampling [OR = 0.99 (0.98–0.99) per day increase]. Next to its association with BCV, M. haemolytica was more frequently detected in herds with 5 to 10 animals per pen [OR = 8.0 (1.4–46.9)] compared with <5 animals, and in herds with sawdust as bedding [OR = 18.3 (1.8–191.6)]. Also, for H. somni, housing on sawdust was a risk factor [OR = 5.2 (1.2–23.0)]. Purchase of cattle [OR = 2.9 (1.0–8.0)] and housing of recently purchased animals in the same airspace [OR = 5.0 (1.5–16.5)] were risk factors for M. bovis. This study identified pathogen-specific risk factors that might be useful for the development of customized control and prevention and for the design of decision support tools to justify antimicrobial use by predicting the most likely pathogen before sampling results are available.

Short communication: Herd-level analysis of antimicrobial use and mortality in veal calves: Do herds with low usage face higher mortality?

The veal calf sector fears that a too-rapid and large decrease in antimicrobial use (AMU) as demanded by European authorities would increase mortality, causing economic and welfare issues. To determine whether this concern is justified, the relationship between AMU (total and different classes) and mortality in dairy-type white veal calves, managed by 2 large veal companies, was explored. A retrospective cohort study was performed on electronically collected antimicrobial consumption and mortality data from the largest Belgian veal practice during the period 2014 to 2016. Mixed linear [mortality (%) as continuous outcome] and generalized linear mixed models with binary outcome for event and trial approach were built to identify factors associated with mortality. Data consisted of 76 production cycles from 29 farms managed by 2 veal companies (1 and 2) and covering 45,001 calves. Average AMU was 30.1 ± 10.4 defined daily doses for animals per year (± standard deviation) and was higher in veal company 2 than in veal company 1 (35.9 ± 9.3 and 22.4 ± 5.7 defined daily doses for animals per year, respectively). In contrast, mean mortality was lower in veal company 2 (2.3 ± 1.4%) than in veal company 1 (4.1 ± 1.4%). Both models showed a positive association between AMU and mortality in veal company 1 and no association in veal company 2. The final linear model identified increasing herd size and the use of third- or fourth-generation cephalosporins as risk factors for mortality and the use of long-acting macrolides as a protective factor. The final logistic model identified an increased mortality risk with increased use of third- or fourth-generation cephalosporins and sulfonamides-trimethoprim and decreased mortality when using long-acting macrolides. Based on these data, at the current levels of AMU in Belgian veal calves, an increase in mortality when reducing AMU could not be evidenced. Differences in herd size and factors other than AMU likely better explain why one veal company faces almost double the mortality of another one. Abandoning the use of long-acting macrolides might have negative consequences for mortality under the current state of the industry. The most ethical way to further reduce AMU in veal calves is likely simultaneously monitoring AMU and animal welfare parameters, starting with, but not limited to, mortality.

Atrial and ventricular electrical and contractile remodelling and reverse remodelling due to chronic pacing-induced atrial fibrillation in horses: preliminary results

In humans, electrical and contractile reverse remodelling following restoration of sinus rhythm (SR) after a prolonged period of spontaneous atrial fibrillation (AF), requires several weeks. There is little known about this phenomenon in horses. In the present study, six healthy horses were instrumented with a neurostimulator and a pacemaker to maintain AF for four months by intermittent burst pacing and to study atrial and ventricular electrophysiology. AF became persistent in all horses after two to six weeks of burst pacing. Before, during and after the AF period, parameters, such as the atrial fibrillation cycle length, the right atrial and ventricular refractory period and vulnerability, such as inducing atrial arrythmias, atrial tachyarrythmias or maintaining AF, were determined. Two-dimensional echocardiography was used to measure atrial and ventricular contractility expressed as fractional shortening and size expressed as diameter and area. In two of the six horses, the procedure was discontinued due to an increased threshold (1 horse) and due to infection at the level of the pacemaker pocket (1 horse). In the four remaining horses, significant electrical and contractile remodelling compared to baseline values was observed from 48 hours onwards after AF induction. Upon restoration of SR with quindine sulfate, all electrical and contractile values returned to normal within one to two months. No ventricular remodelling was observed. Four months of pacing-induced AF resulted in electrical and contractile remodelling and reverse remodelling. The results suggest that pacing-induced chronic AF does not cause permanent damage and suggest that a resting period of six to eight weeks before returning to training might be beneficial.

Retrospectief onderzoek naar de activiteiten van de Vlaamse gezelschapsdierenpracticus met het oog op aanpassing van het curriculum diergeneeskunde

De literatuur over de activiteiten van de gezelschapsdierenpracticus in Vlaanderen is vrij beperkt. Het doel van dit onderzoek was informatie te verwerven over de samenstelling van de gemiddelde praktijk, de meest uitgevoerde handelingen en het belang van de verschillende klinische disciplines. Er werd hiervoor gebruik gemaakt van logboeken, i. e. documenten geschreven door studenten diergeneeskunde tijdens hun stages. De hond was de meest aangeboden diersoort. De belangrijkste disciplines waren dermatologie, gastro-enterologie, wondzorg, algemene ziekte en orthopedie. De meest frequent uitgevoerde chirurgische ingrepen waren castratie en sterilisatie.Bovendien mag het aandeel preventieve diergeneeskunde niet onderschat worden: tijdens 28% van alle consultaties werd gevaccineerd. Deze informatie kan gebruikt worden om het curriculum van de studenten diergeneeskunde aan te passen zodat deze beter voorbereid worden op het werken in de praktijk.

Diagnostische parameters voor klinische wintercyathostominose bij paarden

Wintercyathostominose is een van de belangrijkste parasitaire aandoeningen bij het grazende paard. Deze studie werd opgezet om de meest significante parameters te identificeren die geassocieerd zijn met klinische wintercyathostominose. Het betreft een retrospectief onderzoek van 307 paarden die tussen 2008 en 2018 aangeboden werden op de Faculteit Diergeneeskunde van de Universiteit Gent. Paarden ouder dan drie maanden die op de faculteit een mestonderzoek ondergingen en diarree hadden, werden opgenomen in de studie. De diagnose van larvale cyathostominose werd gesteld op basis van een positief mestonderzoek, i.e. het aantonen van L4- larven in de feces. De gegevens van paarden met larvale cyathostominose zonder diarree werden niet in de studie opgenomen. Klinische, biochemische, hematologische en parasitaire parameters werden onderzocht. Na statistische analyse van deze retrospectieve gegevens kwam albumine als meest significante parameter naar voor. Een serum-albuminegehalte dat lager was dan 20 g/L, had een hoge gevoeligheid voor het voorspellen van een positief mestonderzoek. De combinatie van het serum-albuminegehalte, het geslacht, de lichaamstemperatuur, het neutrofielenpercentage en het seizoen was volgens het finale statistische model de beste combinatie om de aanwezigheid van wintercyathostominose te voorspellen. Aan de hand van de diagnostische accuraatheid van het finale model werd aangetoond dat hiermee echter geen sluitende diagnose van larvale cyathostominose kan gesteld worden en dat een mestonderzoek nog steeds noodzakelijk is om het vermoeden van larvale cyathostominose te bevestigen.

Equine metabool syndroom

Het equine metabool syndroom wordt omschreven als een verzameling van risicofactoren voor het ontstaan van endocrinologisch veroorzaakte hoefbevangenheid. Een verstoring van de insulineregulatie ligt aan de basis van het probleem. Voeding, voedingstoestand en genetische factoren zijn belangrijke risicofactoren voor het ontstaan van deze verstoorde insulineregulatie. Er is een groot aantal diagnostische methoden beschreven, elk met hun voor- en nadelen. Behandeling en management van paarden en pony’s met het equine metabool syndroom bestaan vooral in het aanpakken van een aantal risicofactoren, waarbij diëtaire maatregelen de belangrijkste rol spelen.

Risk factors for antimicrobial use in veal calves and the association with mortality

The intensive use of antimicrobials in the veal industry is heavily criticized, but drivers for antimicrobial usage (AMU) are still poorly understood. The industry fears that a drastic reduction in AMU would increase mortality, creating an unacceptable welfare issue. The objectives of the present study were to identify risk factors for AMU and to explore the relationship between AMU and mortality. A retrospective cohort study was performed on the antimicrobial registration data from the largest Belgian veterinary veal practice. The data set contained 295 production cycles from 78 farms, representing 146,014 calves and 8 veal companies (also called integrations). The average AMU was 32.3 defined daily dose animal per year (standard deviation: 11.04), of which 76.2% was administered orally and 23.8% parentally. The AMU remained stable between 2014 and 2016 with only a slight, but significant increase in total AMU between 2015 (31.0 defined daily dose animal per year, standard deviation: 10.5) and 2016 (35.1, 10.8). Use of almost all antimicrobial classes decreased over 2014 to 2016; however, use of long-acting macrolides, doxycycline, and aminosides increased significantly. Analysis identified breed (higher use in beef calves compared with dairy and crossbreeds), month of arrival (lower use when arrived in April or May compared with winter months), and veal company as risk factors. The veal company not only significantly affected total AMU, but also affected the majority of the antimicrobial classes. Additionally, breed differences were present for oxytetracycline, colistin, and classic macrolides, and a month effect was present for doxycycline only. These data illustrate that this veterinary practice realized a reduction of 46% in total AMU and of 96% in critically important antibiotics (fluoroquinolones, cephalosporins of the third and fourth generation) compared with the Belgian benchmark from 2007 to 2009. Replacement of critically important drugs by an increased use of long-acting macrolides is worrisome. Mortality risk was very low compared with benchmarks referenced internationally and did not increase with decreasing AMU. Use of trimethoprim-sulfonamides was a risk factor, whereas use of oxytetracycline was a protective factor for mortality. The absence of a relationship with mortality at the current levels of AMU suggests that a further rational reduction is possible. Attention should be paid to consider different AMU benchmarks for different breeds and to include the veal company as a target for antibiotic awareness campaigns.

The risk of flax versus straw bedding on ileal impaction in colic horses: Retrospective analysis of 2336 cases (2008-2017)

While mature coastal bermudagrass hay is strongly associated with ileal impaction in the Southeastern United States, stabling on flax bedding has anecdotally been associated with this condition in Europe. The aim of this retrospective study was to investigate the association between ileal impaction and the use of flax shives compared to straw as bedding in horses with colic. Medical records of 2336 referral cases evaluated for abdominal pain between January 2008 and May 2017 at the Department of Large Animal Internal Medicine, Ghent University were reviewed. Diagnosis, date of admission, age, breed, gender, body weight and stable bedding were recorded. Conditional logistic regression analysis was used to assess the association between ileal impaction and each individual variable. Odds ratios (OR) and 95% confidence intervals (CI) were determined. Predictors with a value of P < 0.2 were included in a multivariable Cox regression model and Wald’s test was used to assess parameter estimate significance. Further, the association between survival to discharge and type of bedding or type of treatment (medical versus surgical) was analyzed for horses with ileal impactions. The proportion of colic cases stabled on flax bedding at home was 11.3%. The overall prevalence of ileal impaction was 4.2%. In the flax group, the prevalence of ileal impaction was 9.4% as opposed to 3.6% within the straw group. The OR of 2.8 (95% CI 1.7-4.7; P < 0.001) in the multivariable logistic regression model indicated that horses stabled on flax shives were approximately three times more likely to have ileal impactions than horses stabled on straw. There was no significant association found between ileal impaction and the period of admission, age, gender or body weight in a multivariable logistic regression model. The odds for having ileal impaction is approximately six times (OR 6.3; 95% CI 2.4-16.4; P < 0.001) higher in draft horses than in warmbloods in the multivariable logistic regression model. No significant association was found between survival to discharge and type of bedding or treatment. These results suggest that horses with colic that were housed on flax bedding are more likely to present ileal impactions than horses housed on straw.

Can heart rate variability parameters derived by a heart rate monitor differentiate between atrial fibrillation and sinus rhythm?

BACKGROUND

Heart rate variability (HRV) parameters, and especially RMSSD (root mean squared successive differences in RR interval), could distinguish atrial fibrillation (AF) from sinus rhythm(SR) in horses, as was demonstrated in a previous study. If heart rate monitors (HRM) automatically calculating RMSSD could also distinguish AF from SR, they would be useful for the monitoring of AF recurrence. The objective of the study was to assess whether RMSSD values obtained from a HRM can differentiate AF from SR in horses. Furthermore, the impact of artifact correction algorithms, integrated in the analyses software for HRV analyses was evaluated. Fourteen horses presented for AF treatment were simultaneously equipped with a HRM and an electrocardiogram (ECG). A two-minute recording at rest, walk and trot, before and after cardioversion, was obtained. RR intervals used were those determined automatically by the HRM and by the equine ECG analysis software, and those obtained after manual correction of QRS detection within the ECG software. RMSSD was calculated by the HRM software and by dedicated HRV software, using six different artifact filters. Statistical analysis was performed using the Wilcoxon signed-rank test and receiver operating curves.

RESULTS

The HRM, which applies a low level filter, produced high area under the curve (AUC) (> 0.9) and cut off values with high sensitivity and specificity. Similar results were obtained for the ECG, when low level artifact filtering was applied. When no artifact correction was used during trotting, an important decrease in AUC (0.75) occurred.

CONCLUSION

In horses treated for AF, HRMs with automatic RMSSD calculations distinguish between AF and SR. Such devices might be a useful aid to monitor for AF recurrence in horses.

Risk factors for antimicrobial use in food-producing animals: disease prevention and socio-economic factors as the main drivers?

The European Union requests an urgent decrease in antimicrobial use (AMU) in food producinganimals to reduce antimicrobial resistance in animals and humans and safeguard the efficacy of antimicrobials for future generations. The identification of risk factors (RFs) for AMU is essential to obtain a rapid reduction. The aim of this review was to summarize the current knowledge of RFs for AMU in veal calves, pigs and poultry. Thirty-three observational studies were included. Well-identified RFs for an increased AMU are frequent purchase of animals, herd size (large or small depending on the animal species), and a lack of selected biosecurity measures. Also in beef breed calves, more antimicrobials are used than in Holstein calves. AMU is influenced by the farmer, the veterinarian and by the integration. In general, socio-economic RFs are largely unexplored. The causal factors for AMU are multiple and complex, with possible confounding factors and unidentified interactions. Additional knowledge of socio-economic drivers appears particularly urgent to create tailor-made guidelines and awareness campaigns for each sector.

Paratuberculosis in dairy and pygmy goats: an underestimated problem?

Paratuberculosis is a chronic intestinal disease affecting goats and other ruminants worldwide. The objective of this review was to summarize current knowledge on the prevalence, diagnostic possibilities and possible prevention and control measures for paratuberculosis in dairy and pygmy goats in Europe. The herd level prevalence of Mycobacterium avium subspecies paratuberculosis (MAP) in dairy goat farms is very high, namely 71%, 63% and 86% in Germany, France and the Netherlands, respectively. The prevalence in pygmy goats is undocumented. Antibody ELISA, fecal culture and PCR testing are readily available for diagnosis. A highly suggestive finding for paratuberculosis is the presence of enlarged intestinal lymph nodes on abdominal ultrasonography. To control the disease a combination of ‘test and cull’ and environmental hygienic measures are recommended. In contrast to cattle, vaccination is available and might be an additional tool in the control program for goats. Vaccine antibodies are no longer detectable after one year, and therefore serological monitoring can be continued on vaccinating herds. The worrisome prevalence data from neighboring countries indicate the need for a prevalence study on dairy goat farms in Belgium.

Rational antimicrobial therapy for sepsis in cattle in face of the new legislation on critically important antimicrobials

Sepsis is a life-threatening condition in cattle, as in humans. Successful sepsis treatment requires a fast initiation of antimicrobial therapy with a broad-spectrum, bactericidal drug, administered intravenously. However, the new legislation limits the use of critically important fluoroquinolones and cephalosporins in food animal medicine, drugs which are considered highly effective for sepsis treatment and were previously frequently used for this indication. This article aims at providing an overview of the current knowledge of sepsis in cattle to aid practitioners in adapting their decision making process to treat sepsis. Sepsis incidence in cattle is likely seriously underestimated. This disease is almost unexplored in cattle, which makes it particularly difficult to design species specific guidelines. Sepsis diagnosis by blood culture reaches sufficient accuracy with the current laboratory technology. When adapting this procedure to a field environment, difficulties might arise, and the availability of adapted incubators in veterinary laboratories may be limited. However, these difficulties are likely to be overcome. Severe sepsis and septic shock are likely the only indications where the ‘urgency’ criterion of the new legislation would apply, but it is important to realize that alternative antimicrobial treatments with possibly similar efficacy are available.

Short communication: Effect of freezer storage time and thawing method on the recovery of Mycoplasma bovis from bovine colostrum

Mycoplasma bovis is an important cause of mastitis in dairy cattle, and pneumonia, arthritis, and otitis in calves. Milk and colostrum are considered important sources of infection for calves. knowledge on the effect of on-farm freezing (-18°C) and thawing methods on the recovery of M. bovis from colostrum samples is missing. In this study, 2 separate experiments were performed. The first experiment consisted of a longitudinal study examining the survival [as measured by log(10) reduction] of 2 M. bovis strains in frozen colostrum over 14 wk. The second experiment examined the effect of different thawing temperatures (45 and 20°C), thawing frequencies (once or twice), and initial colostrum titer (10⁴ or 10⁶ cfu/mL) on M. bovis survival. A single freeze-thaw cycle led to an approximate 1 log reduction of M. bovis titer, independent of the thawing temperature. Freezing for 14 wk did not significantly further reduce the titer of bacteria compared with freezing for 2 wk. A second freeze-thaw cycle further reduced the M. bovis count by approximately 0.5 log compared with a single freeze-thaw cycle. Thawing temperature and initial bacterial concentration did not significantly affect M. bovis reduction. In conclusion, storage of colostrum samples in the freezer at -18°C during epidemiological studies, herd monitoring, or test and cull programs will probably have little influence on qualitative bacteriological test results for M. bovis. The epidemiological or clinical relevance of an approximate 1 log reduction of M. bovis in colostrum is currently unclear.

Analyse van de arbeidssituatie en perceptie van de kwaliteit van de opleiding van dierenartsen afgestudeerd aan de Faculteit Diergeneeskunde van de Universiteit Gent

In een enquête werd gepeild naar de arbeidssituatie van dierenartsen afgestudeerd aan de Universiteit Gent en de perceptie van de kwaliteit van de opleiding. Hiervoor werden drie cohorten dierenartsen gecontacteerd die afgestudeerd zijn gedurende drie tijdsintervallen, met name tussen 2002 en 2004, 2009 en 2011 en tussen 2014 en 2016. Uit 488 ingevulde vragenlijsten (47% van de gecontacteerde respondenten) werd onder andere duidelijk dat dierenartsen in Vlaanderen gemiddeld 47 uur per week werken en relatief tevreden zijn over de invulling van hun job. Tachtig procent (meest recent afgestudeerde cohorte) en 68% (langst afgestudeerde cohorte) van de respondenten werkt als practicus en 81% van deze practici werkt in een groepspraktijk. Dierenartsen met de Belgische nationaliteit hebben voornamelijk het statuut van zelfstandige, terwijl dierenartsen met de Nederlandse nationaliteit voornamelijk in loondienst werken. De respondenten geven aan tevreden te zijn over het theoretische aandeel binnen de opleiding diergeneeskunde maar ervaren het praktisch onderricht als te beperkt. Tijdens de opleiding zou er volgens de respondenten meer nadruk gelegd moeten worden op eerstelijnsdiergeneeskunde, op het verwerven van communicatievaardigheden met klanten en collega’s en op praktijkmanagement.

A Deep Nasopharyngeal Swab Versus Nonendoscopic Bronchoalveolar Lavage for Isolation of Bacterial Pathogens from Preweaned Calves With Respiratory Disease

Background

Nonendoscopic bronchoalveolar lavage (BAL) is a practical alternative for a deep nasopharyngeal swab (DNS) to sample the airways of a large number of calves in a short period of time. The extent of commensal overgrowth and agreement of BAL with DNS culture results in preweaned calves are unknown.

Objectives

To compare commensal overgrowth and bacterial culture results between DNS and BAL samples.

Animals

A total of 183 preweaned calves (144 with bovine respiratory disease and 39 healthy animals).

Methods

Cross‐sectional study. Deep nasopharyngeal swab and BAL samples were taken from each calf and cultured to detect Pasteurellaceae and Mycoplasma bovis. Agreement and associations between culture results of DNS and BAL samples were determined by kappa statistics and logistic regression.

Results

Bronchoalveolar lavage samples were less often polymicrobial, more frequently negative and yielded more pure cultures compared to DNS, leading to a clinically interpretable culture result in 79.2% of the cases compared to only in 31.2% of the DNS samples. Isolation rates were lower in healthy animals, but not different between DNS and BAL samples. Only Histophilus somni was more likely to be isolated from BAL samples. In clinical cases, a polymicrobial DNS culture result did not increase the probability of a polymicrobial BAL result by ≥30%, nor did it influence the probability of a negative culture. A significant herd effect was noted for all observed relationships.

Conclusions and Clinical Relevance

Nonendoscopic BAL samples are far less overgrown by bacteria compared to DNS samples under the conditions of this study, facilitating clinical interpretation and resulting in a higher return on investment in bacteriologic culturing.

Nosocomial Intravascular Catheter Infections with Extended-spectrum Beta-lactamase-producing Escherichia coli in Calves after Strain Introduction from a Commercial Herd

An outbreak of intravascular catheter-related infections by extended-spectrum β-lactamase (ESBL)-producing Escherichia coli in calves in an animal teaching hospital is reported. Pulsed-field gel electrophoresis was used for strain typing to determine the origin and dissemination of these strains. All 19 strains harboured the blaCTX-M-14, and six strains also overexpressed their chromosomal AmpC gene. Evidence on the introduction of the strain from a beef herd, experiencing neonatal diarrhoea and increased mortality, to the clinic through admission of diarrhoeic calves was provided. Strains isolated from phlebitis cases from other herds up to 5 months later showed a high similarity with the initial strain, suggesting that the strain had become nosocomial. The catheter infections with ESBL/AmpC-producing E. coli resulted in a prolonged hospitalization, increased anti-microbial use and mortality. This report points towards the potential dangers of the emergence of ESBL/AmpC-producing bacteria in susceptible food animals and warns farmers and veterinarians for the facility by which they are introduced into another environment.

Solid feed provision reduces fecal clostridial excretion in veal calves

Enterotoxemia is characterized by a highly fatal hemorrhagic enteritis in cattle, caused by Clostridium perfringens. Production systems with intensive feeding, such as the veal industry, are predisposed. The primary objective of this study was to determine the effect of solid feed provision on fecal C. perfringens excretion in veal calves. Ten Holstein Friesian bull veal calves were randomly assigned to one of two test diets. Group 1 received solemnly milk replacer twice daily, while group 2 received milk replacer and a maximum of 300g solid feed/day, consisting of a mixture of 30% barley, 30% corn, 30% hulled wheat and 10% chopped straw. The number of C. perfringens per g feces or fecal clostridial counts (FCC) were determined for all calves. Mean FCC were significantly lower in the calves fed milk replacer and solid feed, than in the calves fed solemnly milk replacer. Although the correlation between FCC and enterotoxemia risk remains to be determined, the provision of solid feed to veal calves reduced clostridial excretion, which might contribute to the prevention of this disease.

Vraag & Antwoord

Anesthetica voor ovariëctomie bij de kat Afwezigheid van keurders vóór het slachten Ribfracturen bij koeien

Non-toxic perfringolysin O and α-toxin derivatives as potential vaccine candidates against bovine necrohaemorrhagic enteritis

Bovine necrohaemorrhagic enteritis is a fatal Clostridium perfringens type A-induced disease that is characterised by sudden death. Recently the involvement of perfringolysin O and α-toxin in the development of necrohaemorrhagic lesions in the gut of calves was suggested, and thus derivatives of these toxins are potentially suitable as vaccine antigens. In the current study, the perfringolysin O derivative PFO^L491D, alone or in combination with α-toxin derivative GST-cpa_247-370, was evaluated as possible vaccine candidate, using in vitro assays. PFO^L491D showed no haemolytic effect on horse red blood cells and no cytotoxic effect on bovine endothelial cells. Furthermore, calves immunised with PFO^L491D raised antibodies against perfringolysin O that could inhibit the perfringolysin O-associated haemolytic activity on horse red blood cells. Antisera from calves immunised with PFO^L491D had a significantly higher neutralising capacity against the cytotoxic effect of C. perfringens culture supernatant to bovine endothelial cells than serum from control calves (P <0.05). Immunisation of calves with PFO^L491D in combination with GST-cpa_247-370 elicited antibodies against perfringolysin O and α-toxin and consequently inhibited both the perfringolysin O-associated haemolytic activity and the α-toxin-associated lecithinase activity in vitro. Additionally, the neutralising ability of these antisera on the cytotoxic effect of C. perfringens culture supernatant to bovine endothelial cells was significantly higher than that from calves immunised with PFO^L491D (P <0.001). In conclusion, perfringolysin O derivative PFO^L491D is an immunogenic antigen that can potentially be used to produce vaccine against bovine necrohaemorrhagic enteritis. Including α-toxin derivative GST-cpa_247-370 has an additional protective effect and therefore vaccination of calves with a combination of both antigens seems even more promising.

Multicentric B-cell lymphoma in a pygmy goat

A six-year-old, male pygmy goat was referred with a sudden onset of peripheral lymphadenopathy, which initially started as enlarged inguinal lymph nodes. Clinical examination showed swollen retropharyngeal, prescapular and inguinal lymph nodes. Serologic testing for bovine leukemia, caprine arthritis-encephalitis virus and caseous lymphadenitis was negative. Fine needle aspirates of the prescapular lymph nodes were taken and revealed multiple, large lymphoblastic cells on cytology. Because of the poor prognosis and clinical deterioration, the animal was euthanized. Full necropsy was performed and showed generalized lymphadenopathy. Further histological and immunohistochemical investigation of the lymph nodes characterized this neoplasia as a multicentric large B-cell lymphoma.

Prevalence of respiratory pathogens in nasal swabs from horses with acute respiratory disease in Belgium

Contagious respiratory infections are an important cause of respiratory disease in horses, resulting in impaired pulmonary function, poor performance and sometimes severe illness. Although bacterial infections are often suspected to be involved, viruses are frequently overlooked and are an underestimated cause of respiratory disease outbreaks in horses. In this study, nasal swabs of 103 horses with acute symptoms of respiratory disease were analyzed for the presence of 13 different respiratory pathogens. Gamma herpesviruses were the most commonly detected, with 60% of the samples being positive, followed by streptococcus equi subsp. zooepidemicus infection (30%). Rhinovirus B, streptococcus equi subsp. equi, adenovirus 1 and EHV-4 were more rarely detected. Further research is necessary to correctly interpret the importance of gamma herpesviruses in horses, for example by screening a healthy control population. National surveillance of respiratory viruses in horses by PCR analysis on nasal swabs might be a useful, earlywarning system for viral epidemics.

Orale ivermectine-intoxicatie op een vleeskalverbedrijf

In deze casus wordt een vermoedelijk kwaadwillige, orale ivermectine-intoxicatie op een Vlaams vleeskalverbedrijf besproken. Alle 330 kalveren van twee tot vier weken oud werden in de eerste week na aankomst op het bedrijf getroffen. De symptomen waren ernstige depressie, het neerliggen in laterale of sternale positie, tremor en kopschudden. Uiteindelijk stierf 13,6% van de kalveren. De overige dieren herstelden gradueel met ondersteunende orale rehydratatietherapie over een termijn van vijf tot zeven dagen. In de kunstmelk kon een ivermectinegehalte van 35 mg/kg aangetoond worden. In het serum van drie kalveren werden ivermectinegehaltes van 0,75 mg/kg tot 1,1 mg/kg gevonden. De vermoedelijk toegediende dosering was 1,75 mg/kg lichaamsgewicht voor een gemiddeld kalf (40 kg). In deze casus wordt aangetoond dat orale toxiciteitsverschijnselen van ivermectine bij kalveren van twee tot vier weken oud kunnen optreden aan een dosis die 8,75 keer hoger is dan de geregistreerde therapeutische dosis voor subcutane toediening bij rundvee.

Health risks associated with the use of automatic milk feeders in calves

The objective of the present article was to summarize available evidence of the economic benefits and health risks associated with the use of automatic milk feeders (AMFs) in calves. Although AMFs are increasingly used in cattle production, clear evidence of their economic benefits (increased average daily gain, gradual weaning and reduced labor time) for the typical Belgian farm size and management is not available. Especially in smaller farms, where labor time is not a limiting factor, a careful economic consideration should be made. Regarding the association of AMFs with calf disease, studies have only been performed for bovine respiratory disease and confirmed an increased risk. However, since the use of AMFs is strongly related with several other risk factors (group housing at young age, large groups, age difference in a group, continuous system versus all-in/all-out), it is difficult to unequivocally identify the risk associated with AMFs alone. A group size of less than ten calves on a single drinking point, an all-in/allout grouping system and a minimum age at introduction to the automat of three weeks are recommended for farms with AMFs. To the authors’ knowledge, no scientific evidence supporting the presumed association of diarrhea and tongue ulcers with AMFs is available to date.

Gastro-intestinale Clostridium perfringens-infecties: een blijvend gevaar in de Belgische rundveehouderij

De intensivering van de moderne landbouw wordt geassocieerd met een toename van Clostridium perfringens-gerelateerde, gastro-intestinale problemen bij intensief gevoede runderen, zoals “hemorrhagic bowel disease” bij hoogproductief melkvee en enterotoxemie bij kalveren. Waar de pathogenese van hemorrhagic bowel disease nog grotendeels ongekend is, werden er de laatste jaren nieuwe inzichten in de pathogenese van enterotoxemie bekomen die een belangrijke repercussie op de aanpak van deze ziekte onder praktijkomstandigheden hebben. Ook andere clostridiumgeassocieerde maagdarminfecties, zoals “overeating disease” en neonatale clostridiose, worden regelmatig gediagnosticeerd. Overvoedering met structuurarme, eiwitrijke voeders is een overkoepelende risicofactor bij zowel HBD, enterotoxemie als overeating disease. Een goed uitgebalanceerd dieet dat zo stabiel mogelijk gehouden wordt, is dan ook het belangrijkste aandachtspunt op bedrijven die problemen hebben met clostridiose. Daarnaast dient bij jonge kalveren voldoende aandacht gegeven te worden aan een correcte en hygiënische biestverstrekking om problemen met neonatale clostridiose te vermijden.

A new predilection site of Mycoplasma bovis: Postsurgical seromas in beef cattle

Mycoplasma bovis is a highly contagious bacterium, which predominantly causes chronic pneumonia, otitis and arthritis in calves and mastitis in adult cattle. In humans, Mycoplasma species have been associated with post-surgical infections. The present study aimed to identify the bacteria associated with three outbreaks of infected seromas after caesarian section in Belgian Blue beef cattle. A total of 10 cases occurred in three herds which were in close proximity of each other and shared the same veterinary practice. M. bovis could be cultured from seroma fluid in five of the six referred animals, mostly in pure culture and was isolated from multiple chronic sites of infection (arthritis and mastitis) as well. DNA fingerprinting of the isolates targeting two insertion sequence elements suggested spread of M. bovis from chronic sites of infection (udder and joints) to the postsurgical seromas. Identical genetic profiles were demonstrated in two animals from two separate farms, suggesting spread between farms. Mortality rate in the referred animals positive for M. bovis in a seroma was 80% (4/5), despite intensive treatment. A massive increase in antimicrobial use was observed in every affected farm. These observations demonstrate involvement of mycoplasmas in outbreaks of postsurgical seromas in cattle.

Total plasma proANP increases with atrial dilatation in horses

Equine atrial natriuretic peptide (ANP) plasma concentrations are correlated with left atrial size. However, species-specific assays are lacking and the results from human assays are poorly reproducible. A new methodology called processing independent analysis (PIA) that measures the total proANP product in plasma has proven to be successful in human medicine, but has never been used in horses. The aims were to establish an equine proANP reference interval by measurement of the total proANP product using PIA and to examine the proANP concentrations in horses with atrial dilatation. Sample stability was studied by comparison of storage at -80°C and -20°C. Plasma samples were obtained from 23 healthy horses, 12 horses with moderate or severe valvular regurgitation without atrial dilatation and 42 horses with valvular regurgitation and atrial dilatation. The proANP concentration was significantly (P<0.001) higher in horses with atrial dilatation (761.4 (442.1-1859.1) pmol/l) than in healthy horses (491.6 (429.5-765.9) pmol/l; P<0.001) or horses with cardiac disease but without atrial dilatation (544.4 (457.0-677.6) pmol/l). A cut-off value (573.8 pmol/l) for detection of atrial dilatation was calculated. Sample storage at -80°C did not differ from sample storage at -20°C. The measurement of total proANP in plasma detects atrial dilatation in horses and may be useful for clinical evaluation in equine medicine.

Clinical Research Abstracts of the British Equine Veterinary Association Congress 2015

REASONS FOR PERFORMING THE STUDY

Yellow fat disease or steatitis is characterised by a local or general inflammation of fat tissue and is occasionally found in horses. Diagnosis is challenging because of the wide range of nonspecific clinical signs.

OBJECTIVES

To describe clinical signs, treatment, outcome and ultrasonographic findings in horses with steatitis.

STUDY DESIGN

Retrospective study (January 2008 to January 2015).

METHODS

History, clinical signs, ultrasonographic findings, diagnosis, treatment and outcome were recorded.

RESULTS

Twenty cases (18 horses, 2 donkeys; 9 mares, 9 stallions, 2 geldings) were retrieved from 13,707 patient records. Mean age was 1.6 (± 0.8) years (range 1 month-3.5 years). All cases appeared between October and February except for one (August). History included dullness, recumbency, decreased appetite and weight loss. Fever, ventral oedema, stiff/painful gait and painful neck were found. Low haematocrit, low vitamin E and selenium and increased levels of creatinine kinase and particularly lactate dehydrogenase were almost consistent findings. On ultrasound, ventral oedema was found. Subperitoneal, perirenal, mesenteric, coronary and caudal mediastinal fat showed homogenously increased echogenicity. Especially the subperitoneal fat was surrounded by oedema or free fluid. Increased amounts of abdominal, thoracic and pericardial fluid were often found. Fat biopsies were taken in the neck or from the retroperitoneal fat in the ventral flank. In all horses where fat biopsy was taken (n = 13), steatitis was confirmed. Treatment consisted of selenium and vitamin E (intra-muscular injection followed by oral treatment) supplementation and anti-inflammatory treatment (dexamethasone or prednisolone parenteral or oral) for at least 1-4 weeks. Fourteen animals (70%) survived. Full recovery took about 2-6 months.

CONCLUSIONS

Yellow fat disease may be underdiagnosed because of the nonspecific clinical signs. Ultrasound was extremely helpful for making a diagnosis. Recovery was rather slow but was achieved in 70% of the animals. Ethical animal research: Research ethics committee oversight not currently required by this conference: retrospective study of clinical records. Explicit owner informed consent for inclusion of animals in this study was not stated.

SOURCE OF FUNDING

Ghent University (institutional). Competing interests: None declared.

Clinical Research Abstracts of the British Equine Veterinary Association Congress 2015

REASONS FOR PERFORMING STUDY

Transcranial magnetic stimulation (TMS) is an electrophysiological technique used to elicit motor evoked potentials (MMEPs) to evaluate the functional integrity of the descending motor fibres in the spinal cord. Successful application of the technique was reported in horses with spinal cord compression. However, limited data are available on the correlation of TMS with histopathological changes.

OBJECTIVES

To determine sensitivity of TMS for assessing the integrity of the spinal cord in horses with compressive lesions of the spinal cord.

STUDY DESIGN

Case series.

METHODS

The study was conducted on 6 horses with spinal ataxia grade III-V/V admitted to the Faculty of Veterinary Medicine, Ghent University. The horses underwent TMS, radiography of the cervical or thoracolumbar vertebral column, and myelography (4/6). All horses were subjected to euthanasia and the spinal cord examined histopathologically.

RESULTS

In 5/6 horses MMEPs with abnormal onset latencies in both extensor carpi radialis muscles and cranial tibialis muscles were recorded, suggesting a cervical spinal cord lesion. Radiography revealed cervical vertebral malformation (4/5) with cervical vertebral canal stenosis (3/5) and tumour/osteomyelitis (1/5). In 1/6 horse MMEPs with normal onset latencies in extensor carpi radialis muscles and prolonged onset latencies in tibialis cranialis muscles were recorded, suggesting a thoracolumbar spinal cord lesion. Radiography revealed deformation of the 7th and 8th thoracic vertebrae. Myelography showed reduction in dural diameter and dorsal contrast column (4/4). Histopathological examination of the spinal cord confirmed compressive type lesions in all 6 horses with degenerative changes in the white matter of all funiculi, ballooning of myelin sheets, swollen axons, loss of axons and astroglial activation.

CONCLUSIONS

In this case series abnormal function of descending motor pathways as registered by TMS showed 100% sensitivity with the histopathological characteristics of compressive lesions in the spinal cord, but the number of horses is limited and further research is warranted. Ethical animal research: Research ethics committee oversight not currently required by this conference: the study was performed on material collected during clinical procedures. Explicit owner informed consent for participation in this study was not stated.

SOURCE OF FUNDING

Not applicable. Competing interests: None declared.

First confirmed case of bovine besnoitiosis in an imported bull in Belgium

Besnoitia besnoiti is a protozoan parasite known to cause important economic losses in the cattle industry in Africa, Asia and the Mediterranean area. In the last years, (re-) emergence of the parasite has been reported in France, Germany, Hungary and Italy with in some cases, establishment of an endemic infection. In this article, the first case of besnoitiosis in Belgium in a Blonde d’Aquitaine bull imported from the south of France is described. Additionally, a brief overview of the epidemiology of the disease is provided.

Surgical correction of pyelonephritis caused by multidrug-resistant Escherichia coli in a dairy cow

A four-year-old red Holstein Friesian cow was admitted to the clinic with fever and milk drop. Blood analysis revealed the presence of a chronic infection, and the diagnosis of pyelonephritis of the right kidney was made after repeated ultrasound examinations. The animal was treated with procaine benzylpenicillin, sulfadoxine trimethoprim, oxytetracycline and enrofloxacine but this therapy was not successful. Nephrectomy was performed after the left kidney proved to have a normal function. The removed right kidney was greatly enlarged and filled with pus. Escherichia coli was isolated from the kidney. The strain was multidrug-resistant, including resistance to aminopenicillins, streptomycin, sulfonamides and trimethoprim. The cow was treated with amoxicillin and clavulanic acid after the operation. Postoperatively, an abscess developed and a tube drain was placed during a second surgery to enable daily rinsing with a chlorhexidine solution. After a postoperative care period of two months, the animal was sent back to the farm, where it returned to an acceptable level of milk production. This case demonstrates that with basic surgical skills, a good preparation and knowledge of anatomy, nephrectomy is attainable for a first-opinion veterinarian, with an acceptable economic prognosis for the farmer.

Atypische myopathie bij het paard

Atypische myopathie (AM) is een vaak fatale weidemyopathie die snel opkomt in Europa. Uitbraken zijn meestal acuut en onverwacht en het is belangrijk dat dierenartsen en eigenaars weten hoe ze moeten omgaan met de kritieke patiënten van deze aandoening. Er zijn verschillende hypothesen beschreven omtrent de etiologie en pathogenese ervan. In deze review worden de belangrijkste hypothesen samengevat en enkele behandelingsmogelijkheden en preventieve maatregelen gesuggereerd. Op dit moment wordt gedacht dat AM ontstaat na opname van esdoornzaden. Deze zaden bevatten hypoglycine A, dat kan leiden tot multiple acyl-CoA dehydrogenasedeficiëntie (MADD). De behandeling is meestal gebaseerd op de klinische symptomen en gaat vaak niet verder dan een ondersteunende therapie. Daarom ligt de nadruk op de preventie van AM. Dit artikel is bedoeld als een praktische ondersteuning voor paardendierenartsen die te maken krijgen met AM.

Intestinal obstruction by Toxocara vitulorum in a calf

A one-month-old Belgian blue bull calf was referred to the animal hospital of the Faculty of Veterinary Medicine (UGhent) because of the sudden onset of severe colic. The animal showed intermittent recumbency, kicking to the abdomen, abdominal distension of the right quadrants, absence of feces and fluid-splashing and the presence of ping sounds on auscultation of the right side. Abdominal ultrasound showed distended, but still contractile small intestines with thickened walls. On exploratory laparotomy, a complete obstruction with adult Toxocara vitulorum extending from duodenum to mid-jejunum was diagnosed. On the punctum maximum of the obstruction, the ascarides were partially removed through an enterotomy. After vermifugation with doramectin, ascarides were found in the animal’s feces in the next days. In contrast to ascaride infections in puppies, piglets and foals, to the author’s knowledge, intestinal obstruction caused by T. vitulorum has not been described previously in calves.

Characteristics and challenges of the modern Belgian veal industry

In this paper, the modern Belgian veal industry is situated in a European context, and an overview is provided of the major past, present and future challenges for veal production. The production of white veal requires a specific diet and housing conditions to assure a controlled iron anemic state resulting in pale carcasses. In response to the increasing public concern about animal welfare, legal limits for hemoglobin (in 1990), the provision of a minimum quality of solid feed to assure ruminal health and group housing from the age of eight weeks on (in 2007), have been implemented sector-wide. The integrated structure of the sector likely made it possible to realize these radical changes at relatively short notice. Despite the pioneers role the veal industry played in the development of quality labels for food safety and all efforts made towards improved nutrition and housing, the veal production remains highly liable to public criticism on welfare issues. Nowadays, especially the intensive antimicrobial use in relation to high levels of antimicrobial resistance in commensal, pathogenic and zoonotic bacteria in veal calves is strongly criticized. The future challenge lies in the development of veal production systems, which require only few antibiotics, but safeguard animal welfare and revenue.

Assessment of two essential elements of BVDV control on selected Flemish dairy and beef farms

Bovine viral diarrhea virus (BVDV) is one of the most important viruses to cause disease in cattle worldwide. The virus is endemically present in Belgium. Clinical diagnosis of BVDV infection is difficult. Therefore, monitoring through testing is necessary to detect the presence of the virus on farms. As vaccination alone does not suffice for eradication, a combination of measures is required for successful control. Via a questionnaire, the BVDV policy on 241 selected Flemish cattle farms was investigated. This revealed some striking results. For the majority of the herds, the BVDV status was unknown (63%), and only 23% had a monitoring program in place. Furthermore, on seven out of ten (71%) BVDV-vaccinating farms, vaccination against BVDV was implemented as a strategy without knowing the actual BVDV status.

Spontaneous bleeding in a neonatal calf persistently infected with BVDV1b

A calf developed skin bleeding on the second day of its life. It was referred to the clinic onsuspicion of bovine neonatal pancytopenia (BNP). Hematology showed extreme thrombocytopenia,moderate anemia, but no leukopenia. A PCR test on a heparinized blood sample was bovine viraldiarrhea virus (BVDV) positive, as were the two BVDV antigen ELISAs performed three and tenweeks later. Non-cytopathic BVDV type 1b was isolated from the blood. Although the calf recoveredfrom hemorrhagic disease, and continued to be healthy, it was euthanized at eleven weeks of agebecause of persistent BVDV infection. On the basis of the case history, BNP could be excludedfrom the differential diagnosis. This case illustrates that hemorrhagic disease is not exclusivelyassociated with BVDV type 2 and that the clinical signs in neonatal calves infected with BVDV1bcan be identical to the clinical presentation of BNP.

Acute hemorrhagic syndrome by bracken poisoning in cattle in Belgium

In August 2007, two Belgian blue cows which had been on pasture for three months, showed highfever (41.4°C), epistaxis, melena, cutaneous bleeding, a stiff gait and red lesions on the udder. Bloodexamination revealed severe pancytopenia, and bluetongue virus serotype 8 could be demonstratedby PCR. Despite blood transfusion and supportive treatment, both animals died within 6 days afterthe initial symptoms. At necropsy, an explicit case of a blood coagulation disorder was observed.Inspection at pasture, one week later, showed the presence of numerous regenerated young fronds ofPteridium aquilinum. Whereas the stiff gait and the red lesions on the udder were likely bluetonguevirus associated, other symptoms were consistent with acute bracken poisoning (acute hemorrhagicsyndrome). The present report illustrates that also in Belgium, where the density of bracken fern isrelatively low, pastures should be carefully screened for the presence of young fronds.

Risk factors for Psoroptes ovis mange on Belgian Blue farms in Northern Belgium

The parasitic mite Psoroptes ovis causes important economic losses in Belgian Blue cattle. Because mange problems vary significantly between farms, a cross-sectional questionnaire survey and subsequent farm visits were performed to identify potential risk factors for P. ovis infections on Belgian Blue farms in Flanders, Belgium. The questionnaire was sent to 1800 beef farms to evaluate the presence and severity of psoroptic mange in the herd and to assess farm management practices, including antiparasitic treatments. Subsequently, about 10% of the farms with a completed questionnaire were visited to validate the questionnaire and to retrieve supplementary information on additional management parameters, such as barn infrastructure and climate. Associations between parasitism and putative risk factors were assessed by logistic regression. Out of 1800 contacted farms, 680 (38%) completed questionnaires were received. Data were collected from 238 barns during 66 farm visits. The questionnaire results demonstrated a high farm prevalence of mange (74%; 95% CI (70.7-77.3)) and half of the farmers declared that the problem was difficult to control. Nevertheless, in only 14% of the barns a high scratching index was recorded and in most of the sampled animals (80%) the affected body surface was less than 10%. This indicates that despite the high prevalence and the difficulty to control the infection, clinical signs were often quite moderate. Logistic regression analyses of the questionnaire and the farm visit data suggested that heavily infested farms treat more intensively against mange. On most farms mange occurred the whole year round and more problems with mange were found on farms where a higher number of animals were purchased per year. In addition, the disease was more prevalent when the animals had a lower hygiene score. This score was strongly correlated with environmental hygiene, indicating that transmission of mites from the environment to the animals should not be underestimated. Conflicting results were obtained on the effect of supplementing minerals on the occurrence of mange. In this study, temperature, light intensity and relative humidity in the barns, ventilation systems, barn infrastructure, animal stocking rate and blood mineral levels were not indicated as risk factors for mange. In conclusion, maintaining a good animal hygiene and if possible, avoiding introduction of cattle may help to control psoroptic mange in Belgian Blue cattle.