Original article(s)

Between August 2001 and October 2006, enteric reovirus strain (ERS) infections were diagnosed in 21Belgian broiler flocks. ERS isolates were derived either from liver, gastrocnemius tendon, bursa, pancreas,intestinal tract and trachea, or from pools of multiple organs.The clinical complaints were very similar in all infected flocks and consisted of uneven or retarded growth,wet litter and/or lameness in 71%, 38% and 29% of the cases, respectively. Increased mortality occurred in52% of the flocks. In 81% of the cases the clinical signs had been showing up in multiple successive rounds,often for over a year. The most consistent lesions found were hepatitis, myocarditis, pancreatitis,proventriculitis, enteritis and tenosynovitis of the gastrocnemius tendon. Concurrent infections with E. coli,O. rhinotracheale, FAV or IBV were observed in 48% of the flocks, predominantly those that wereexperiencing increased mortality.It has been concluded that ERS type reoviruses frequently infect Belgian broilers, causing a disease entitywhich can be aggravated by concurrent infections with other agents. Since the parents of most of the affectedbroiler flocks had been well vaccinated against reovirus with vaccines containing classic reovirus strains,the present observations may indicate insufficient protection from these vaccines against ERS strains.

Desmotomy of the accessory ligament of the deep digital flexor tendon is a frequently performed surgical techniquein foals to treat flexural limb deformity of the distal interphalangeal joint. In this retrospective study with 40foals varying in age from 15 days to 18 months, 53 desmotomies were performed. The follow-up period varied from2 to 12 years. In 85% (34/40) of the foals a desmotomy had a successful outcome. Both type 1 and 2 flexural deformitiescould be corrected.Preoperative changes in hoof conformation, which appeared especially in older foals (mean age 10.2 months),could also be corrected. The prognosis in foals with a bilateral flexural deformity was less favorable. Changes of thedistal phalanx on radiographic examination seemed to play a role in preoperative lameness but did not have any effecton the post-operative outcome of the desmotomy.Although changes in hoof conformation in older foals can successfully be corrected through desmotomy, surgicalcorrection in young foals is preferred, since changes in hoof conformation in these patients are rather rare. In theopinion of the authors, desmotomy should not be postponed if conservative treatment does not improve a type 1 deformitywithin a couple of weeks, or in case of severe deformity (type 2).

Reliable estimates of boar fertility potential from semen evaluation could be a valuable tool for boar selection.The aim of this study was to investigate the morphology and the detailed motility parameters of dilutedboar semen and to relate these to their predictive value concerning conception and farrowing rate, littersize and the number of live born piglets. In addition, the optimal time for evaluation of the motility of preservedsemen with respect to its predictive effect on fertility was determined. One hundred ejaculates from 38 boarswere evaluated morphologically by eosin-nigrosin staining and different motility characteristics were assessedusing Computer Assisted Semen Analysis (CASA). The motility was determined at 15, 45 and 120 minutesafter incubation at 37°C. The conception rate, farrowing rate, litter size and number of live born pigletswere registered from 276 sows inseminated with these ejaculates. Different regression models were used to evaluatethe predictive value of the semen characteristics on these fertility parameters, taking into account theeffect of herd, parity and weaning to estrus interval.The motility characteristics of the spermatozoa varied significantly during the 15 to 120 minutes of incubation.The longer the incubation time, the more the velocity parameters along the actual cell path decreased,while the parameters of straightforward movement increased. The predictive value of individual semen parameterson conception and farrowing rate was very small. The predictive value of certain associations of differentsemen parameters, on the other hand, was significant.The percentage of motile spermatozoa had a significant (P<0.05) and positive effect on the total numberof piglets born (litter size) and on the number of live born piglets, independent of the time of measurement (X20.38-1.00 and 0.41-1.00, respectively). Accurate evaluation of the motility of a semen dose is therefore imperativefor estimating its predictive value relating to fertility.In conclusion, since the time of evaluation after warming the samples significantly influences the motilityparameters, CASA measurement should be done when the cells are completely acclimatized to 37°C. On thebasis of the available data, a 45 min incubation period appeared to be sufficient. The percentage of motilespermatozoa, as assessed by CASA on diluted semen, offers detailed predictive information regarding littersize, irrespective of the time of measurement.

The fertility of high yielding dairy cows has decreased during the last 25 years. For example, the calving-interval(CI) has extended with 30 days (from 390 days in 1992 to 420 days in 2008). Consequently, practitioners dealing withherd health management, are often faced with farmers’ questions about the financial impact of an extended CI.Numerous studies have attempted to calculate the economic consequences of an extended CI. Some researchersbased their investigations on real data and analyzed them retrospectively, while others simulated situations by complexmodels. Undoubtedly, the lactation curve is the most important contributor to these calculations, besides a whole rangeof other factors, which may influence the economic results in a positive or negative way. Consequently, conclusionsare not always that unambiguous. In general the conclusion is that an extended CI will result in a loss of money.Extending the CI from 395 days to 432 days for instance results in a loss of € 2.08 per cow per day; in total € 77 percow (37 days).Because the lactation persistency is rather plastic, some managerial measures, such as a higher milking frequencyand the use of bovine somatotropin, can be taken to increase the persistency resulting in a less negative or even apositive economic balance.

Starting from December 2006, Enterococcus cecorum infections with a clinical course have increasinglybeen observed in Belgian broilers. The present paper describes the characteristics of the disease on the basisof observations in 10 different farms. The affected chicks always suffered from paresis and lameness. Onsetof the signs was usually within the first 2 weeks of life, and it resulted in up to 7% increased mortality startingfrom day 21-32. The cocks were affected significantly more often than the hens. Lesions of osteomyelitisof the caudal thoracic vertebrae compressing the spinal cord and/or arthritis of the hock joints were consistentlyfound. E. cecorum was always isolated from these lesions. The disease was recurrent in successive roundsin 9 out of the 10 farms. Antibiotic treatment was only successful when initiated preventively from the firstweek of life onwards. Other infections often associated with similar signs were not detected. It can be concludedthat E. cecorum infections form an important emerging disease in broilers, leading to high mortality rates.

Although pigs contaminated with Salmonella rarely show clinical symptoms, control is important becauseof the public health concern. Both producers and consumers are interested in procedures for minimizing therisk of Salmonella infections. This study outlines the entire production path for fresh pork in Belgium, fromfarm to fork. Additionally, it describes the different critical points for Salmonella contamination, with emphasison those steps that need extra attention and/or improvement. The data was collected by means of questionnairesat the different steps of the process. In total, 3658 questionnaires were collected, which made itpossible to draw up a nationwide image of the pork production process.In the primary production phase, there are several points relating to biosecurity that can be improved inorder to minimize the risk for Salmonella in fattening pigs that are sent to slaughter. In the slaughterhouse,there has been an increase in the number of pigs or carcasses that become infected with Salmonella. Attentionshould be paid to avoiding contact of the feces and tonsils of contaminated pigs with the carcass, and strict hygienicmeasures should be taken to avoid cross-contamination.During transformation and distribution of the carcasses, there is a low risk of further spreading of Salmonellaspp. Finally, during consumer phase, the risk for Salmonella contamination increases because ofinappropriate temperature conditions during storage, manipulation of meat and possible cross-contaminationwith other food products, and the consumption of insufficiently heated and/or raw meat.The present study illustrates that the risk of Salmonella infection by consumption of fresh pork is relativelylow under Belgian conditions. Nevertheless, it can be further decreased by implementing additional controlmeasures, mainly in slaughterhouse and in domestic kitchen.

A large fluctuation in normal serum vitamin E (alpha-tocopherol) concentrations (> 2 μg/ml) has beendemonstrated in normal horses. The purpose of this study was to verify the fluctuation in serum vitamin E inhorses with deficient levels (< 1.5 μg/ml) and to assess the diagnostic value of a single serum sample todetermine the vitamin E status in a deficient horse. Serum vitamin E levels were monitored over a period of24 hours in 6 normal horses and in 22 horses with clinical signs that may be related to vitamin E deficiency.The serum vitamin E levels varied widely within each horse, and the coefficient of variation (CV) wassignificantly larger in the deficient horses (mean CV: 41%), compared to the horses with normal levels (meanCV: 14%). In a small proportion of the deficient horses, the vitamin E levels varied from deficient to normalwithin 24 hours. The sensitivity of a single sample compared to the “true value” determined by the averageof the samples, was 91%. The sensitivity in case of 2 serum samples increased to 97%. These findings suggestthat a single serum value does not always provide reliable information about the true vitamin E status in adeficient horse and analyzing 2 serum samples allows a more accurate estimation of the vitamin E status. Theconclusion therefore is that when a serum vitamin E value > 1.5 μg/ml is found in clinically suspected horses,a second serum sample should be evaluated.

The results of the analysis of equine and bovine blood samples with the automated pocH-100iV DIFF hematologyanalyzer were compared with the results obtained with reference methods or other analyzers (VetABC, Coulter Counter ZF, Coulter LH 750 analyzer). For equine blood and most parameters in bovine bloodgood to excellent correlations between methods and analyzers were obtained. For bovine blood good to poorcorrelations and significant differences were obtained between the pocH-100iV DIFF and other methods oranalyzers mainly for hematocrit and hemoglobin determinations and platelet counts. Overall the pocH-100iVDIFF seems to be a reliable and user-friendly analyzer.

This study analyzes the clinical aspects of contaminated and infected synovial cavities in horses and evaluatestheir prognosis after treatment. The medical records of 195 affected horses referred between June 1999and July 2004 were reviewed. Twenty-six horses were euthanized or returned home without further treatment.Therapeutic strategies for the remaining 169 horses were not different from those reported in other recentstudies, except that lavage was performed predominantly without endoscopic visualization. Follow-up wasobtained by questionnaire for 150 of 169 treated horses. The outcome was considered successful (survival withoutresidual lameness) in 109 of 150 horses (72.7%). Iatrogenic synovial infection, the presence of radiographicsigns on admission and the use of regional antibiotic perfusion were significantly related withnon-successful outcome. Overall, the outcome in the present study appeared to be slightly less favorable comparedto other recent reports, although it certainly improved for horses with deep nail puncture wounds.

In 20 dogs and 1 cat a diagnosis of tetanus was made based on the typical clinical signs and a possible woundhistory. In 7 animals a tooth abnormality was considered as the entrance way of the bacteria. By means of radiographyof the thorax several animals were evaluated for the presence of possible complications such as aspiration pneumonia,megaoesophagus or hiatal hernia. The treatment existed mainly of metronidazole as an antibiotic, acetylpromazineto control the muscle spasms and additional supportive therapy. The survival rate was 71%.