2008 - 77 (3)

Paper in Dutch

Mycoplasma suis (formerly known as Eperythrozoon suis) is an epicellular bacterium that affects porcinered blood cells. M. suis infections occur worldwide and are associated with weakness and anemia in sucklingand weaned pigs, and reproductive disorders in sows. The present field report describes the detection of M.suis in anemic piglets originating from a Belgian farrow-to-finish herd. The herd was experiencing increasedpiglet mortality (16%) in the farrowing unit and had a high percentage of repeat breeders (22%). A controlprogram using antimicrobials and hygienic and sanitary measures significantly decreased the number ofclinically anemic piglets and the mortality rate in the farrowing unit. However, it did not have any significantinfluence on the reproductive failure of the farm. The lack of a significant effect on reproductive failure wasprobably due to the circulation of porcine reproductive and respiratory syndrome virus (PRRSV) on thefarm.

Bacteriological examination of fecal samples from diarrheic dogs invariably results in the isolation ofEscherichia coli. The association of the presence of this bacterium with enteric disease in dogs is not clear. In thisstudy, the association between the presence of E. coli virulence genes and diarrhea in dogs was confirmed. For thispurpose, E. coli isolates recovered from the feces of 34 healthy dogs and 25 dogs with diarrhea aged 7.5 months to10 years, were tested for the presence of 17 virulence genes. Virulence genes were not detected in 15 of the 25 and15 of the 34 isolates from dogs with or without diarrhea, respectively. In the other isolates, the presence of genesencoding the toxins cytotoxic necrotising factor (CNF) 1, CNF2, verotoxin (VT) 1 and VT2 and/or the adhesinsintimine, F5 fimbriae and F41 fimbriae was demonstrated. There was, however, no significant difference in theprevalence of virulence genes between E. coli isolates from the diarrheic and non-diarrheic adult dogs examined.Because diagnostic markers in the E. coli isolates are absent, the examination of canine feces on the presence ofthis bacterium is of little diagnostic value.

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.

In equine practice, phytotherapy is meeting the increasing demand of horse owners for "natural", safetreatment methods. Long-term use of NSAIDs can cause severe adverse effects, hence the growing popularityof anti-inflammatory phytotherapeutics. At the current time, several different herbal mixes are beingcommercialized, which makes it difficult for horse owners and veterinarians alike to make a well-foundedchoice.Harpagophytum procumbens (devil’s claw), Salix spp. (willow) and Ribes nigrum (blackcurrant), three plantsthat are often used in these mixes, have been evaluated both in vitro and in vivo. Based on published studiesand the evaluation of these studies, for example by the Cochrane Collaboration, there seems to be someevidence for Harpagophytum procumbens and Salix spp. having a stronger analgesic and anti-inflammatoryeffect than placebos in humans. In horses, however, only one limited clinical study on Harpagophytum hasbeen performed up until now, while no studies were found on the use of Salix in horses. More research isneeded before any claims concerning efficacy or safety can be made regarding the use of these plants intreating horses. It has also been claimed that Ribes nigrum leaves have an anti-inflammatory effect, thoughthis has not yet been clinically proven either in humans or in horses.Although veterinary phytotherapy is as old as animal husbandry itself, little scientific proof can be foundregarding its uses. More research is needed before phytotherapy can be advertised as a valuable and safealternative to the more conventional treatment protocols.

Paper in Dutch

This case report describes the occurrence of a second episode of clinical signs of disc associated Wobblersyndrome almost 2 years following ventral decompressive surgery and a rather rare complication aftermyelographic examination in the same dog.

Disc associated Wobbler syndrome (DAWS) is the most prevalent and most typical Wobbler syndrome indogs. It is typically seen in the middle-aged Dobermann Pinscher. Caudal cervical spinal cord compressionis caused by protrusion of the annulus fibrosus of the intervertebral disc into the spinal canal, sometimes incombination with ligamentum flavum hypertrophy and malformed vertebrae. Clinical signs vary from neckpain to tetraplegia. The diagnosis is generally made using myelography. There is a lot of controversyconcerning the treatment of this disease. Many surgical techniques have been developed for it, but little isknown about the conservative treatment. Objective data about the prognosis of this disease is scarce.

The genetic material of the bovine papillomavirus (BPV) can be detected in virtually all equine sarcoids.Eight different types have been described, all inducing benign proliferation of epithelium in cattle. BPV-1 and -2are less strictly species-specific and can induce equine sarcoids in horses. Historically, association betweenBPV and equine sarcoids has been demonstrated using inoculation studies and detection of BPV DNA and BPVgene expression. The BPV genome is composed of 6 early and 2 late genes, with E5 and E6 being the mostimportant transforming genes. Specific BPV-1 variants associated with equine sarcoids have been reported,suggesting circulation of the virus between horses. In horses, a non-productive BPV infection occurs, withonly transcription of early genes, responsible for genome maintenance, regulation of cell growth and celltransformation. There is no formation of new infectious virus particles as is the case in the natural host.