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Guidelines are provided for evaluating the efficacy of anthelmintics in swine which, in conjunction with other sets of guidance such as those of the International Cooperation on Harmonization of Technical Requirements for Registration of Veterinary Medicinal Products (VICH GL7 and VICH GL16), should encourage the adoption of uniform registration requirements globally. Testing of efficacy should be carried out according to the principles of "Good Clinical Practice" (VICH GL9, 2000). Data obtained according to these guidelines should be internationally acceptable for the registration of anthelmintics for swine. Further, the use of the guidelines should expedite development, government review, and approval of anthelmintics for swine, as well as contribute towards reducing costs and the number of experimental animals used for drug testing.

Piglets experimentally infected with 10,000 oocysts of Isospora suis in three identical trials (n = 50) were examined clinically and coproscopically from 5 to 11 days post-infection (d.p.i.), weighed in weekly intervals until the fourth week of life and compared to age-matched asymptomatic controls (n = 17). Furthermore, 17 infected piglets were histologically examined on days 5-14 p.i. Infected animals had a significantly lower weight gain than the controls and showed diarrhoea throughout, with maximum prevalence and intensity on 6 d.p.i. Half of the animals had diarrhoea for only 2 days or less. The number of diarrhoea days was negatively correlated with weight gain. Oocyst excretion started on 5 d.p.i. with peak prevalences and declined afterwards; a smaller peak was seen on 10 d.p.i. All animals excreted parasites at least once, and most of them excreted for 5-7 days. Oocyst excretion intensity paralleled the prevalence and ranged from 220 to 251,501 oocysts per gram of faeces (opg). Most samples contained 4 x 10(3) to 4 x 10(4) opg. The opg values were negatively correlated with faecal scores (samples with diarrhoea contained less oocysts) of the same day and the previous day. Histologically, necrosis followed by atrophy of the villi was most pronounced in the early stage of infection throughout the jejunum and ileum but declined thereafter. On 14 d.p.i., villous atrophy was still noticeable in the jejunum. Histology is difficult to quantify and requires large animal numbers, although the effects are visible for some time. Weight gain and faecal score can be affected by other factors than parasite infection. From the compiled data, we conclude that the established model is suitable to study piglet isosporosis with oocyst excretion being the most reliable parameter, although individual variations are considerable. A negative correlation between excretion and diarrhoea may be responsible for the difficulties in the detection of the parasite in field samples.

Summary Nationwide surveys for the occurrence of Isospora suis were carried out in Germany, Austria and Switzerland including a questionnaire regarding herd size, health status and management practices and a coccidiosis sampling kit for pooled faecal samples from litters of suckling piglets. A total of 184 veterinary practices participated in the survey and returned 1745 samples (331 kits) from 324 farms in the north (n = 98), south (n = 84), centre/east (n = 42) and west (n = 10) of Germany, Austria (n = 61) and Switzerland (n = 29) with larger farms in north and centre/east (average number of sows: 270 and 500) and smaller ones in the south (95), Austria (60) and Switzerland (43). Larger farms tended to have better hygienic standards (slatted floors, disinfection of the farrowing units). The majority of the participating farms (93.5%) reported problems with diarrhoea in piglets at 2–3 weeks of age, significantly associated (P

Information on the efficacy of pharmaceutical protocols for the prevention of the major canine filarioses (i.e., Dirofilaria immitis, Dirofilaria repens, and Acanthocheilonema reconditum) under natural conditions is scant. Chemoprophylaxis for canine filarioses under field conditions deserves to be studied more fully and information about vector biology, ecology, and seasonality has to be well appreciated to correctly set control protocols. It is advisable that researchers planning field trials to assess the efficacy of any product for the prevention of canine vector-borne diseases should consider different eco-epidemiological aspects of diseases, including their dynamics of transmission, which are driven by complex interactions between animals, pathogens, and vectors.

Bioassays were developed and applied to test the role of eicosanoids and pH changes in ecdysis of Oesophagostomum dentatum. Exsheathment (80-100%) was achieved by subjecting third-stage larvae (L3) either to chlorine (hypochlorite assay) for 5 min or by incubating them in HCl followed by addition of NaHCO3 (pH-change assay) with subsequent cultivation at 38.5 degrees C/10% CO2 for 1 week. Addition of the lipoxygenase (LOX) inhibitor diethylcarbamacine (DEC) to the larvae resulted in a reduction of the exsheathment rates which could be restored by the addition of leukotrienes (LT)B4, LTC4, LTD4 and LTE4. Addition of the cyclooxygenase (COX) inhibitor acetylsalicylic acid (ASA) also resulted in decreased exsheathment rates both in the hypochlorite and in the pH-change assays in a dose-dependent manner. However, the primary COX products (prostaglandins) were not able to reverse this effect, in contrast to LTC4. It was concluded that: (1) both tests are suitable for bioassaying the effect of substances on exsheathment, and (2) eicosanoids involved in the control of exsheathment of L3 of O. dentatum are primarily LT.

For the first time, larvae and nymphs of Amblyomma tigrinum ticks were found on three species of wild birds (Zenaida auriculata, Callipepla californica and Nothoprocta perdicaria) in Chile. A significant higher number of A. tigrinum was found on fledglings of Z. auriculata and N. perdicaria than on adults of these species of birds. A significant higher number was also observed on N. perdicaria living in non-irrigated areas as compared with irrigated areas. Infestation levels were 6.5, 6.3 and 10.2 ticks for Z. auriculata, C. californica and N. perdicaria, respectively. Our results suggest that birds are important in the maintenance of the life cycle of A. tigrinum ticks in the area.

Summary The prevalence of Eimeria infections was investigated in an initial survey in 54 sow herds of small (five sows) to large (1600 sows) size by random sampling (n = 1204). All sows of four Eimeria-positive medium-sized farms (63 or 130 sows) were re-examined 40–99 days after the first visit. A follow-up survey over the whole reproductive cycle was subsequently performed in a positive herd of 130 animals where faecal samples of 43 sows were repeatedly collected on seven successive farm visits. In 44 farms (81.5%) parasite stages (eggs of strongylids, Trichuris, Ascaris, Strongyloides, oocysts of Eimeria and Isospora) were identified in sow faeces, strongylids being the most prevalent intestinal parasites (34 farms resembling 63%) followed by Eimeria spp. (28 farms resembling 52%). Of the 1204 random samples collected during the initial survey 8.6% contained Eimeria oocysts. Oocysts of E. polita and E. debliecki were present in each of 25 Eimeria-positive samples selected for species differentiation. Eimeria suis was diagnosed in 84%, E. scabra in 60%, E. porci in 52%, E. perminuta in 49% and E. spinosa in 20% of these specimens. At the second visit the prevalence rates of Eimeria infections had either increased or decreased. In the follow-up study Eimeria infections were found to be most frequent (82%) at the service station. At the quarantine unit and the gestation stable 50 and 48% of the 43 sows were Eimeria positive. The lowest prevalence of Eimeria infection was observed in the farrowing unit (14%). With respect to the reproductive state of the sows highest infection rates were seen 2 weeks after weaning (72%) continuously decreasing until 2 weeks after farrowing (14%). A periparturient rise of oocyst excretion was not observed. The infestation rate remained low until 1 week before weaning (16%). Low infection intensities clearly dominated. Clinical disease was not associated with Eimeria infection.

En la provincia de Ñuble (Chile), entre Noviembre de 1994 y abril de 1995, se examinaron 235 tórtolas (Zenaida auriculata) para detectar endo y ectoparásitos. Los siguientes endoparásitos fueron aislados (prevalencia en %): Killigrewia delafondi (9,4%), Raillietina sp. (1,7%), Echinostoma sp. (0,9%), Heterakis gallinarum (0,4%) y Eimeria labbeana (5,5%). Los ectoparasitos identificados correspondieron a: Falculifer isodontus (55,7%), Diplaegidia columbae (73,2%), Amblyomma sp. (5,1), Columbicola baculoides (64,7%), Bonomiella sp. (8,5%), Hohorstiella sp. (4,7%) y ácaros de la familia Trombiculidae (6,8%). Ácaros de la familia Trombiculidae, el cestodo K. delafondi y el protozoo E. labbeana habían sido registrados previamente en Chile. Los otros nueve parásitos representan el primer registro para tórtolas en Chile

During several excavations of archeological sites in the Moquegua Valley, Southern Peru, various guinea pig mummies (Cavia aperea f. porcellus) have been discovered. They belong to the Chiribaya Culture (900-1100 AD). The outstanding preservation of the mummified animals gave rise to the idea of a paleoparasitological analysis. In the fur, numerous well preserved ectoparasites (lice, fleas, mites) could be recovered. Generally, ectoparasite remains are rarely found among archeological material. This is the first account of an extensive ectoparasitological analysis of animal mummies in Peru. A modified technique for recovery and preservation of the ectoparasites has been developed.

In order to test various viability assays for Cryptosporidium parvum oocysts were used to infect HCT-8 cells in vitro or baby mice. Infected cells were either stained with fluorescent anti- Cryptosporidium -antibody or lysed and subjected to C. parvum- specific PCR after 48 h. Titrations with infective oocysts were performed and compared to oocysts disinfected with Neopredisan © for 2 h at varying concentrations. Caecal smears and histological sections from infected animals were examined in parallel. The number of foci of parasite development in vitro after immunofluorescent staining correlated well with the infection dose. PCR was less quantifiable and the results were not always reproducible, especially when low infection doses were used. Disinfection resulted in a dose-dependent reduction of oocyst infectivity when compared to the controls in all three assays. The infection of cells cultured in vitro with oocysts of C. parvum provides a suitable tool for the estimation of viability after treatment with chemical disinfectants. Immunofluorescence is easy to perform and gives quantitative results, while PCR-based detection of parasite DNA, although possible, requires the use of more sophisticated tools for quantification.

* Departamento Ciencias Pecuarias, Facultad de Medicina Veterinaria, Universidad de Concepcion, Casilla 537,Chillan, Chile.** Instituto de Parasitologia, Escuela de Med. Veterinaria, Universidad de Leipzig, Leipzig, an der Tierklinik 33,D-04103 Leipzig, Alemania.*** Instituto de Investigaciones Silvestres, Escuela de Med Veterinaria de Hannover, Bunteweg 17, D-30559,Hannover, Alemania.**** Museo Nacional de Historia Natural de Turinguen, An der Brucke 3, D-07407 Rudolstadt, Alemania.DANIEL GONZALEZ*, ARWID DAUGSCHIES**, KLAUS POHLMEYER***, LUIS RUBILAR*,OSCAR SKEWES * y EBERHARD MEY****

In order to evaluate the prevalence of Isospora suis in conventional piglet production in Germany, pooled faecal samples from 327 pig litters from 18 pig production units (20-320 sows each) were examined. At least 10 litters from each farm were investigated. I. suis was present on 83% of the farms and 42.5% of the litters, the infection rate being highest in the third week of age (48.2%). I. suis was found more frequently in samples of diarrhoea than in firm faeces (49.2% compared to 22.2%). Twenty naturally infected piglets from six of these farms underwent examination post mortem, including histology, virology and bacteriology. Histological examination revealed atrophy of the villi in various degrees, mild crypt hyperplasia, fusion of the villi, metaplastic epithelium, erosions and necrosis, especially in the medium and the posterior jejunum and in the ileum. Asexual and sexual developmental stages of the parasite were found in varying numbers in the epithelium of the whole of the small intestine. Bacteria and viruses were mostly excluded as the cause of diarrhoea, and it was concluded that I. suis was the primary pathogen inducing distinct changes and clinical symptoms of diarrhoea.

The blood-sucking activities of the liver fluke, Fasciola hepatica, are likely to cause alterations in coagulation during the course of infection; and the effect of F. hepatica on various coagulation parameters was studied during the course of acute and chronic fasciolosis of sheep over a period of 17 weeks. Whole blood and plasma samples from infected sheep (with 800 metacercariae each) and uninfected controls were collected weekly until 17 weeks post-infection (w.p.i.) and the activated partial thromboplastin time (APTT), prothrombin time (PT) and thrombin time (TT) were determined. Additionally, adult F. hepatica were recovered from bile ducts, incubated for the production of excretory/secretory products (ESP) or homogenised and the effect of fluke products on APTT, PT and TT was determined. Anaemia was evident in infected sheep from 8 w.p.i. until 17 w.p.i. Plasma APTT was accelerated during 8, 9, 12, 14, 16 and 17 w.p.i., while PT was prolonged at 8–11 w.p.i. and TT at 10, 14 and 17 w.p.i. Addition of worm ESP or homogenate to plasma resulted in an enhancement of the intrinsic pathway (APTT) together with a prolongation of the extrinsic and common pathways (PT, TT) of coagulation. It was concluded that F. hepatica contains and releases substances that may contribute to coagulation changes in vivo. Further characterisation of the active substance(s) in vitro revealed heat inactivation, a size >30 kDa and inhibition by the proteinase inhibitors Complete and EDTA for the APTT-accelerating substance(s). The TT-deceleration, in contrast, was increased after heating.

The development and application of a standardized model for testing of anticoccidial disinfectants are described. Due to its economic impact, tenacity of oocysts, and reproducibility of the course of infection Eimeria tenella has been chosen as test organism. Oocysts of the Houghton strain were more susceptible to disinfection with 4% TP4 (Preventol) than oocysts of a field isolate (FI 292/1) as determined by sporulation inhibition and lysis. Scoring of intestinal lesions and of oocyst numbers in mucosal scrapings in chicken infected with various doses of oocysts were found unsuitable for assessment of disinfectants. Because strain differences were observed only Houghton strain oocysts were applied for further testing. Guidelines for standardized in vivo testing of disinfectants have been stipulated by the German Veterinary Society (DVG) on the basis of these studies. When applied for testing of Neopredisan (NP) in two separate laboratories similar results were obtained. Inhibitory activity (IA; proportion of inactivated oocysts) of 92.9 and 90.6% were calculated for 3% NP and of 95.2 and 96.8% for 4% NP after treatment with the disinfectant over 120 min. According to the guidelines IA of at least 95% is required for certification of sufficient disinfecting efficacy by the DVG.

Isospora suis and Eimeria are frequent coccidian parasites of pigs. The unsporulated oocysts of Eimeria species and of I. suis are difficult to differentiate. Therefore, a species-specific PCR was developed. PCR products were amplified from Eimeria polita, Eimeria porci, and Eimeria scabra using primers from the conserved 18S rRNA regions and were subsequently sequenced. Based on variable sequence regions, primers were constructed for the differentiation of the three Eimeria species and I. suis. Using a combination of PCRs detecting one or two species, all four coccidian species were detected (theoretical lower detection level: DNA content of 250 oocysts of each Eimeria species or 25 oocysts of Isospora in 1microl) and differentiated. The PCR-based differentiation of the above mentioned species provides a useful alternative to microscopy.

Eicosanoids are lipid mediators with multiple functions in vertebrate tissues and invertebrate organisms. In this review the roles of eicosanoids — mostly prostaglandins (PGs), thromboxanes and leukotrienes — in parasite physiology and host-parasite interactions are discussed. PGs are present in the saliva of blood-sucking arthropods facilitating feeding by increasing local blood flow and prolonged attachment of ticks by immune suppression. Release of various eicosanoids has also been demonstrated for a number of protozoan and metazoan endoparasites. These substances appear to play a role in penetration, immune suppression, inflammation or modulation of haemostasis, enabling parasite invasion and establishment. Moreover, endogenous eicosanoids serve various functions in parasite metabolism and physiology. In many parasitic infections eicosanoids are involved in host pathology, e.g. granuloma formation, coagulapathy, secretory diarrhoea, or fever. Immune suppression by induction of PG release, in particular PGE2, by host defence cells appears to be a common feature of many parasitic infections and is thought to be important for parasite establishment. Contradictory results have been obtained for gastrointestinal nematode infections, which probably reflect the considerable differences between the various models employed. Although most of the available studies indicate an important role for eicosanoids in parasites and parasitic infections, our current knowledge is still fragmentary and more data are urgently needed.

Mixed fecal samples of 264 litters from five piglet production farms (155–238 sows/farm) were investigated three times during the suckling period for the occurrence of Isospora suis over the period of 1 year. On all five farms Isopora suis was found to be a common endoparasite with infection rates being highest in litters of 3–4 weeks of age. By the end of the third investigation period the cumulative infection rate was 53.8% of the litters ranging from 20.0% to 81.5% for the single farms. During the suckling period the infection rate increased from 18.6% to 32.6% and then to 37.7%. Diarrhea was present in 66.3% of the sampled litters with the highest rates at the end of the suckling period. 63.4% of the litters which showed diarrhea and 34.8% of those without diarrhea excreted I. suis within the study period. Diarrhea was recorded for 78.2% of the I. suis-positive litters and for 52.5% of the Isospora-negative litters. In summer and fall the occurrence of I. suis was higher (66.3% and 61.0%, respectively) than in spring and winter (47.7% and 37.9%, respectively). In litters with diarrhea and pathogenic E. coli I. suis often occurred simultaneously. Above-average hygiene measures and mainly perforated pen floors seemed to lower the risk of isosporosis. With the exception of Strongyloides ransomi other parasites were not found in the fecal samples of suckling piglets. Two specialized piglet rearing farms, a conventional large-scale rearing unit and a farm managed according to the segregated early weaning (SEW) system were examined three times during the 6–7 week rearing period. In both units I. suis was common, but was not correlated with diarrhea. In the SEW unit the infection rates decreased from 37.5% to 20.2% and to 4.1%, while the infection rate in the conventional unit slightly increased from the first (17.2%) to the second (21.9%) investigation and stayed at this level at the third sampling.

In the search for a serology tool for the diagnosis of nonpatent as well as patent infections with Oesophagostomum dentatum in pigs a water-soluble, unglycosilated antigen of about 30 kDa specific for the third-stage larvae of the parasite was purified by ion-exchange chromatography. In Western blots, the antigen was first detected by antibodies at day 7 postinfection. Cross-reactivity with O. quadrispinulatum, Ascaris suum, or Trichuris suis was not detected. It is suggested that this protein is a suitable tool for the species-specific serodiagnosis of O. dentatum infection in pigs.

We performed a total of 14 trials to evaluate the culture conditions suited best for the in vitro production of fourth-stage larvae (L4) of Oesophagostomum dentatum. Chicken embryo extract was shown to be redundant, whereas pig blood serum, trypticase, liver extract, and yeast extract proved to be important medium ingredients. Development to L4 could be moderately accelerated by increases of temperature (40 degrees C) and of CO2 concentration (20% in air), but the total yield of L4 could not be improved. Thus, conditions of 38.5 degrees C and 10% CO2 are recommended for routine application.

The effects of experimental infection of calves with Sarcocystis cruzi on the blood coagulation cascade were investigated. Calves were inoculated orally with 1×10 5 sporocysts (group S1, n = 6) or with 5×10 5 sporocysts of S. cruzi (group S2, n = 3). A group of eight calves served as non-infected controls (group C). The animals were bled once during the first 4 weeks of infection and twice a week thereafter until day 40 p.i. The following parameters were measured: activated partial thromboplastin time, prothrombin time, thrombin time, reptilase time, thrombin coagulase time, factors XII, XI, X, IX, VIII:C, VII, V, prekallikrein, fibrinogen, α 2-antiplasmin, antithrombin III, α 1-antitrypsin, α 2-macroglobulin, haematocrit, haemoglobin, numbers of erythrocytes and thrombocytes. The infected calves developed acute sarcocystiosis from 25 (S1) or 29 (S2) days p.i. onwards. During the acute disease, antiproteases tended to elevated values and thrombocyte counts were generally reduced. In group S1 prolonged prothrombin time and reduced activities of factors VII or V were found. In group S2 accelerated prothrombin time and activated partial thromboplastin time, as well as elevated factor X activities, were recorded even before the onset of clinical disease at 19 days p.i. While prothrombin time returned to normal levels thereafter, activated partial thromboplastin time remained short. Activities of factor V, factor VII and factor X were significantly reduced in group S2 at the onset of acute sarcocystiosis, and one of the three calves died at 29 days p.i. The other parameters were not significantly affected by either dose of infection. No evidence for a classical disseminated intravascular coagulation syndrome could be found; however, it was demonstrated that S. cruzi alters plasma coagulation in a dose-dependent way.

The apparent digestibilities (AD) of dry matter (DM), organic matter (OM), crude ash (CA), crude fiber (CFi), crude fat (CFa) crude protein (CP) and nitrogen-free extracts (NFE) and the nitrogen balance were investigated during experimental Eimeria bovis coccidiosis in calves. noninfected pair-fed controls and controls fed on a normal plan of nutrition were included in the study to allow differentiation between the effects of infection and of changes in feed intake. Primary infection with 5 x 10(4) oocysts (n = 4, group A) caused mild diarrhea and calves infected primarily with 1 X 10(5) oocysts (n = 5, group B) suffered from mild (three calves) to severe hemorrhagic (two calves) diarrhea. No clinical disease was seen after reinfection of the group A calves with 1 X 10(5) oocysts. The primary infection with 5 X 10(4) oocysts or reinfection with twice the primary inoculum did not affect AD of nutrients or the overall nitrogen balance (RT). AD of DM, NFE or OM were higher in group B during patency and in the pair-fed group C calves (n = 5) than in the reinfected but healthy group A calves. AD of CFi of the group B calves even exceeded the values of the pair-fed controls. The two calves of group B that suffered from hemorrhagic diarrhea and anorexia had low values of AD of CP during the acute phase of the disease and the plasma nitrogen levels were reduced in this group. Severe clinical coccidiosis transiently reduced the nitrogen balance. It is concluded that the transient increase of AD of nutrients, especially of CFi, during clinical coccidiosis reflect hypomotility and that anorexia and intestinal leakage impair the nitrogen balance and cause weight depression.

Oesophagostomum dentatum, one of the most common nematodes in pigs, causes the formation of subepithelial granuloma in the large intestine. To investigate possible changes in epithelial function or response during the infection we incubated epithelia of pig proximal colon in Ussing chambers at different days post infectionem (p.i.). Transepithelial conductance, gt, and the Cl flux from serosal to mucosal, JClsm, were increased on day 2 p.i., when the nematodes penetrate the epithelium of the large intestine, and declined toward control levels thereafter. Histamine, PGE2 and carbachol caused transient increases in short circuit current, Isc, and conductance that could partly be attributed to a higher JClsm. The Isc responses were highest on the days of nematode penetration in or out of the epithelium (days 2 and 14 p.i.) and did decline on day 7 p.i. during the histotropic development of the parasite. This reduced epithelial reaction on day 7 p.i. might be an adaptation to secretory stimuli released from the inflammatory cells in the intestinal wall or might reflect modulation by the parasite and could be responsible for the absence of marked clinical signs during the infection.

The dynamics of production and excretion of leukotrienes by parasitic larvae of Oesophagostomum dentatum and their role for the development of the larvae were studied. Larvae were cultured in vitro to the fourth stage (L4). Leukotriene B4 (LTB4) was detected in homogenates and in supernatant of larvae, with the homogenate-protein-based values steadily decreasing during development. The homogenate-protein-based values of peptidyl leukotrienes (pepLT) remained fairly stable in both homogenates and supernatants, whereas the wormcount-based pepLT values increased significantly. The addition of diethylcarbamazine (DEC) to the culture medium straight from the beginning of culturing (12.8 or 25.5 mmol/l) reversibly hampered growth and development to L4. Application of DEC at 12.8 mmol/l beginning on day 13 of in vitro cultivation exerted no significant effect on further development to L4. LTB4 appeared to counteract the inhibition of development by DEC. The results of this study indicate that endogenous LTs participate in regulation of the growth and development of O. dentatum.

Eimeria bovis causes catarrhalic to haemorrhagic diarrhea, sometimes lethal, in calves. Two randomized blinded studies were conducted to examine the efficacy of toltrazuril (5 % oral suspension, single application) on experimental E. bovis infection. Sporulated oocysts of a pathogenic field strain were orally inoculated at a dose of 5×104 (study 1) or 1×105 (study 2) per calf (1-5 weeks old). Calves were allocated to groups of 8 to 9 animals as follows: A: sham treated control (both studies); study 1 (toltrazuril at 14 days post infection, dpi): B: 5 mg/kg body weight (bw), C: 15 mg/kg bw, D: 25 mg/kg bw; study 2 (15 mg toltrazuril/kg bw): E: treatment at 12 dpi, F: treatment at onset of clinical coccidiosis (18 dpi). General health, fecal consistency, oocyst excretion (opg) and body weight were assessed. In study 2, two to three calves each were necropsied for the pathomorphological examination of the intestines at dpi 16, 20, 28 (groups A and E) or at dpi 20, 28, 35 (group F). In study 1 onset of clinical coccidiosis was observed in the sham treated controls (A) at dpi 18 to 21 with mean oocyst counts of 4511 opg. Toltrazuril distinctly reduced the prevalence and severeness of diarrhea. Oocyst excretion was suppressed in most calves (14 out of 26) of groups B, C and D, the remaining calves excreting only few oocysts. Consequently, the mean opg were low with values of 106 (B), < 1 (C) and 2.5 (D). Early treatment (E) controlled the infection and prevented clinical disease while the effect of late treatment (F) was limited. The efficacy of toltrazuril was positively dose-correlated. The application of 15 mg toltrazuril/kg bw within the prepatent period recommended for the control of E. bovis infection.

Isospora suis may cause disease and economic loss in intensive piglet production units. Field studies have shown that litter mates develop varying severeness of isosporosis although initial infection pressure is considered to be identical in a particular farrowing pen. Experimental studies were conducted to evaluate the course of isosporosis under controlled clinical conditions. Piglets artificially infected at the age of 3 days each with 104 sporulated I. suis oocysts suffered from diarrhea from 2 days post infection (dpi) until 9 dpi while oocyst excretion lasted from 6 to 13 dpi. A lower infection dose (1×103 oocysts) resulted in onset of diarrhea at 6 dpi with a prolonged period of disease (10 days) and of oocyst excretion (4-16 dpi). The application of only 100 oocysts within 24 hours after birth caused severe disease starting at 7 dpi. Clinical isosporosis lasted for 6 days and oocysts were excreted from 5 to 14 dpi. Infection at an age of 11 days induced mild diarrhea for a maximum period of 2 days and only few oocysts were detected at 4 to 6 dpi, in one piglet from 7 to 9 dpi. It is concluded that the course of isosporosis is less related to the infective dose than to the age of the piglets. Artificial infection of 30 % of a litter with 1x103 oocysts per piglet at the age of 3 days resulted in rapid spread of isosporosis across the whole litter. However, oocyst excretion and clinical disease was less pronounced on a litter base when only two piglets initially received a low dose of 100 oocysts. Thus, initial contamination of the farrowing pen is obviously related to the course of isosporosis in the respective litter.

Angiostrongylus (A.) vasorum is a nematode that causes angiostrongylosis in domestic and wild canids. Red foxes (Vulpes vulpes) and raccoon dogs (Nyctereutes procyonoides) are suspected of providing a wildlife reservoir for A. vasorum infections in pet dogs. To obtain data on the occurrence of A. vasorum in wildlife, red fox and raccoon dog carcasses (hunted or found dead) were collected from January to September 2009 in the Federal State of Brandenburg, Germany. Lung tissue samples were subjected to DNA extraction and examined for the presence of A. vasorum DNA by means of real-time PCR. A. vasorum DNA was detected in 11 out of 122 (9.0 %) lungs of red foxes and in none of the lung samples of raccoon dogs. These data suggest that red foxes are a reservoir of A. vasorum infections for pet dogs in this area.

Filarial infections of dogs are attracting attention across Europe because of the risk of spread into previously non-endemic areas (e.g. Dirofilaria repens with Culicidae as vectors) and as emerging zoonotic agents. The occurrence of filarial infections in German dogs has been analysed based on 8,545 samples collected either from imported animals or following travel into endemic regions. All samples were tested by means of modified Knott's test and heartworm antigen assay within the period 2008 - 2010. Heartworm antigen was detected in 127 samples (1.49 %; 95 % CI: 1.25 - 1.77 %), but only 38 dogs also had microfilariae in their blood samples. On the other hand, 125 animals (1.46 %; 95 % CI: 1.23 - 1.74 %) were only positive in the Knott's test. For discrimination by means of PCR and sequencing a total of 73 blood samples as well as two samples of adult worms were included, which have been sent by veterinarians during 2008 - 2010. A mono-infection caused by D. repens was detected in 35 cases, while D. immitis was proven in 15 samples, with 6 of these showing a combination of D. immitis and D. repens. Imported Dipetalonema dracunculoides (transmitted by Rhipicephalus sanguineus or Hippobosca longipennis) or Acanthocheilonema reconditum (fleas and lice serve as intermediate hosts) infections were diagnosed in 24 cases and in a single sample a co-infection of A. reconditum and D. repens was evident. D. repens was the most common filarial infection imported and it was introduced into Germany from eleven European countries. Slovenia and Hungary are reported for the first time as endemic for D. repens and A. reconditum, respectively. Furthermore this study reports, to the best of our knowledge, for the first time import of D. dracunculoides from the Canary Islands, A. reconditum from Majorca, D. immitis from Corfu and a co-infection of D. repens and A. reconditum from Spain as well as mixed infections of D. repens and D. immitis from Corfu, Sardinia and Bulgaria. Co-infections with other arthropod-borne infections as well as therapeutical follow-up were also considered. Selamectin (as spot-on formulation) was not able to clear microfilaraemia in dogs infected with either D. repens, A. reconditum or D. dracunculoides, whereas a topical moxidectin/imidacloprid formulation was able to eliminate microfilariae in one dog infected with A. reconditum.

Ten halothane-positive pigs (stress sensitive, group A) and ten halothane-negative pigs (stress insensitive, Group C) with a mean body weight of 36 kg were each inoculated orally with 50,000 sporocysts of Sarcocystis miescheriana. Twelve halthane-positive pigs (Group B) and ten halothane-negative pigs (Group D) served as non-infected controls. Thirteen weeks post infection (p.i.) the lean: fat ratios of the pigs of the infected groups A and C were lower (A, 1:0.41 +/- 0.09; C, 1:0.50 +/- 0.10) than those of the pigs of the non-infected groups B and D (B, 1:0.50 +/- 0.08; D, 1:0.55 +/- 0.08). The back-fat thickness, the fat thickness 'A' and the fat thickness 'B' were thinner in infected pigs than in non-infected pigs. The difference in Lendenstärkespeckquotient (Loin Fat Thickness Quotient) (LSQ) between infected and non-infected pigs was not statistically significant. The values of the water-holding capacity were lower in infected pigs than in non-infected pigs, the difference being statistically significant only in the halothane-negative groups (C, 0.45 +/- 0.02; D, 0.48 +/- 0.04). The water-absorbing capacity was significantly higher in the infected groups (A, 5.92 +/- 3.99%; B, 2.26 +/- 1.08%; C, 8.96 +/- 2.90%; D, 4.97 +/- 2.51%). In conclusion, it can be said that there was a slight tendency towards a better carcass quality and a better water-binding capacity in infected pigs, although this was combined with reduced growth rates.

Ten halothane-positive pigs (Group A) and ten halothane-negative pigs (Group C) were each infected per os by 50,000 sporocysts of Sarcocystis miescheriana when they had reached a mean body weight of 36 kg. Twelve halothane-positive pigs (Group B) and ten halothane-negative pigs (Group D) served as non-infected controls. Thirteen weeks p.i. (post infection), the pigs were slaughtered and the carcass weights and the number of cystozoites in several muscles were determined. In addition, 11 parameters of meat quality were measured in Musculus longissimus dorsi (M.l.d.) and Musculus semimembranosus (M.s.): pH and temperature 30 min and 24 h p.m. (post mortem), electrical conductance 45 min, 60 min and 24 h p.m., colour brightness (FOP) and rigor values 30 min and 24 h p.m. Additionally, the AMP, ADP, ATP and lactate contents were determined in samples from the M.l.d. The mean carcass weights of the infected pigs (A: 79.9 +/- 6.9 kg; C: 76.3 +/- 11.6 kg) were lower than those of the pigs of the non-infected groups (B: 85.7 +/- 8.0 kg; D: 87.5 +/- 7.0 kg). The pH values at 24 h p.m. were significantly higher in the M.l.d. of infected pigs than in M.l.d. of non-infected pigs. Electrical conductance in the M.s. at 45 min p.m. was significantly higher in the halothane-negative infected pigs, but at 24 h p.m., the mean values of electrical conductance in the M.s. of the pigs of both infected groups were significantly lower than in the control groups. FOP values at 30 min p.m. were raised in the M.l.d. of the halothane-negative infected pigs, but at 24 h p.m., differences between infected and non-infected pigs could no longer be found. Mean rigor values were higher in the pigs of the infected groups at 24 h p.m., but the difference from the non-infected groups was not statistically significant. AMP was reduced only in the meat of halothane-positive infected pigs, while lactate was reduced in both infected groups. Using conventional methods for the determination of meat quality, the hypothesis of impaired meat quality in Sarcocystis-infected pigs could not be confirmed. The meat quality parameters investigated were, in part, better in infected pigs than in non-infected controls.