A significant increase in the incidence of caseous lesions in the lymph nodes of slaughter pigs prompted a large-scale investigation in five slaughterhouses in The Netherlands. In total, 158,763 pigs from 2,899 groups underwent gross examination. At least one pig with caseous lesions in the submaxillary and/or mesenteric lymph nodes was observed in each of 154 of the 2,899 groups examined (5%). In total, 856 pigs (0.5%) were affected. As many as five pigs in each of 141 of the 154 positive groups (91.5%) had lymph node lesions. Greater numbers of pigs with affected lymph nodes were found in 13 groups (8.5%). Four pigs had lesions in the kidneys, liver, or spleen. Acid-fast bacteria were detected by microscopic examination of 121 of 292 Ziehl-Neelsen-stained smears of caseous lesions (41%). In a follow-up study, Mycobacterium avium complex (MAC) bacteria were isolated from 219 of 402 affected lymph nodes (54.2%). Ninety-one of the isolated strains were analyzed by restriction fragment length polymorphism (RFLP) typing with insertion sequence IS1245 as a probe. All but 1 of these 91 strains contained IS1245 DNA, indicating that pigs in The Netherlands carried almost exclusively M. avium bacteria and no other bacteria of MAC. Only one pig isolate exhibited the bird-type RFLP pattern. MAC isolates from 191 human patients in The Netherlands in 1996 were also typed by RFLP analysis. Computer-assisted analysis showed that the RFLP patterns of 61% of the human isolates and 59% of the porcine isolates were at least 75% similar to the RFLP patterns of the other group of strains. This indicates that pigs may be an important vehicle for M. avium infections in humans or that pigs and humans share common sources of infection.

In the Netherlands Salmonella Paratyphi B variant Java increased in poultry from less than 2% of all isolates before 1996 to 60% in 2002. Despite exposure to contaminated meat is high, human patients with Java infection are rare (0.3% of all isolates). However, 50% of the human isolates showed PFGE profiles identical to the poultry clone. Resistance to flumequin in S. Java increased from 3% between 1996-2000 to 19% in 2001, and 39% in 2002, while that of other serotypes in poultry remained at about 7%. S. Java is also fast becoming less sensitive to ciprofloxacin.

The prevalence of granulomatous lesions in lymph nodes of pigs was studied. From January till August 2004 in two slaughterhouses in The Netherlands 2,116,536 pigs were examined for the presence of granulomatous lesions in the submaxillary lymph nodes. In 15,900 (0.75%) of these pigs, lesions could be detected. Nine farms with the highest incidence of lesions were selected for a more detailed pathological and bacteriological examination. On these farms, the prevalence of lesions in sub-maxillary lymph nodes ranged from 2.3 to 5.7% with a mean of 3.0%. From 1276 pigs that were sampled, 98 (7.7%) displayed granulomatous lesions in the sub-maxillary lymph nodes and one (0.1%) pig showed lesions in its mesenteric lymph node. Mycobacterium avium subsp. avium (MAA) could not be isolated from the lymph nodes of the 99 pigs with lesions and from a selection of lymph nodes (n = 61) of pigs without lesions. Rhodococcus equi was isolated from 44 out of 98 (44.9%) of the sub-maxillary lymph nodes with granulomatous lesions and from two mesenteric lymph nodes without lesions. A comparison of former studies and the current results indicate that the prevalence of MAA infections in slaughter pigs has strongly decreased over the last decade, whereas R. equi is highly prevalent. The high incidence of granulomatous lesions associated with the bacteriological presence of R. equi could be considered as a serious cause of misdiagnosis of MAA infections in cases where meat inspection is carried out by inspection for granulomatous changes of lymph nodes only. #

SUMMARYIn early 1991, the Dutch pig industry was struck by Porcine Reproductive and Respiratory Syndrome (PRRS). Data from 91 breeding and/or farrow to finish herds that were positive for PRRS were used to investigate the impact of PRRS on productivity and to evaluate the relationship between PRRS and farm and management factors. The farms involved used the CBK management information system. Results show that herd performance was severely affected by PRRS over a period of 4-6 months. A rough economic evaluation, using a fixed price for piglets, indicated that the economic loss on the 91 farms averaged Hfl. 215,-(= £65) per sow per year due to a decreased number of piglets raised per sow per litter, a prolonged farrowing interval and a higher replacement rate of sows. The analysis of possible risk factors did not reveal major factors that could be helpful in reducing the negative effect of PRRS on Piglets Reared per Sow per Year and on the Economic Index of farms experiencing an outbreak of PRRS.

Resumen Se trata de un ensayo con Tetramisol (Ripercol) en cerdos naturalmente infestados. La dosis de 10 ó 15 mg./kg. da una reacción secundaria pasajera, mientras la dosis más pequeña (5 mg./kg.) no da reacciones. Las dosis de 5 hasta 15 mg./kg. son eficaces contra Metastrongylus apri adultos y Chaerostrongylus pudendotectus, totalmente o casi totalmente. La dosis de 15 mg./kg. es eficaz contra Ascaris suum (maduros e inmaduros). La dosis de 5 mg./kg. no fue estudiada en este ensayo contra Ascaris. El medicamento se puede utilizar por vía oral o subcutánea. Los resultados fueron comprobados por exámenes coprológicos y necropsia. El medicamento es utilizable en casos clínicos. Se discute el método coprológico utilizado para los huevos de Metastrongylus. Zusammenfassung „Tetramisol” beim Schwein: Versuche in Ecuador mit natürlich infizierten Ferkeln (Metastrongylus und andere Nematoden) „Tetramisol” (Ripercol) wurde bei natürlich infizierten Ferkeln versucht. Die Dosierungen von 10 und 15 mg/kg produzierten vorübergehende Nebenwirkungen, während die kleinste Dosis (5 mg/kg) keine Nebenwirkung ergab. Die Dosierungen von 5 bis 15 mg/kg sind (vollständig oder fast vollständig) gegen Metastrongylus apri und Chaerostrongylus pudendotectus (geschlechtsreife Würmer) wirksam. Die Dosis von 15 mg/kg ist wirksam gegen Ascaris suum (junge und geschlechtsreife Würmer). Die Dosis von 5 mg/kg wurde nicht in diesem Versuch gegen Ascaris erprobt. Das Mittel kann per os oder subkutan verwendet werden. Die Ergebnisse wurden durch Kotuntersuchungen und Sektion gesichert. Das Präparat kann in Fällen klinischer Erkrankung angewendet werden. Schließlich wird die Kotuntersuchungsmethode für Metastrongyluseier diskutiert. Summary Tetramisol in the pig: studies in Ecuador with piglets naturally infection with metastrongules and other nematodes Tetramisol (Ripercol) was studied in naturally infested pigs. Doses of 10 and 15 mg./kg. produced temporary side effects, whereas the smallest dose (5 mg./kg.) showed none. Doses of 5 to 15 mg./kg. are entirely or almost entirely effective against Metastrongylus apri and Chaerostrongylus pudendotectus (sexually mature worms). A dose of 15 mg./kg. is effective against Ascaris suum (young and sexually mature worms). A dose of 5 mg./kg. was not tried against ascaris in these experiments. This medicament can be used orally or subcutaneously. The results were confirmed by examination of faeces and by autopsy. The preparation can be used in clinically affected animals. The technique used to detect metastrongylus eggs in faeces is discussed. Résumé «Tetramisol» chez le porc: Essais effectués en Equateur sur des animaux infestés naturellement par Metastrongylus et autres nematodes Les auteurs ont essayé le «Tetramisol» (Ripercol) chez des porcs naturellement infestés. Les doses de 10 et 15 mg/kg ont donné une réaction secondaire passagère, tandis que la dose plus petite (5 mg/kg) n'a pas donné de réaction. Les doses de 5 à 15 mg/kg sont efficaces contre Metastrongylus apri et Chaerostrongylus pudendotectus...