Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    The True Story on Deficiencies After Sleeve Gastrectomy: Results of a Double-Blind RCT
    Heusschen, Laura ; Schijns, Wendy ; Ploeger, Nadine ; Deden, Laura N. ; Hazebroek, Eric J. ; Berends, Frits J. ; Aarts, Edo O. - \ 2020
    Obesity Surgery 30 (2020). - ISSN 0960-8923 - p. 1280 - 1290.
    Bariatric surgery - Deficiencies, micronutrients, vitamins, minerals - Morbid obesity - SG - Sleeve gastrectomy

    Background: Since a few years, the laparoscopic sleeve gastrectomy (SG) has become the most performed bariatric operation worldwide. However, as with all bariatric procedures, SG also leads to vitamin and mineral deficiencies post-operatively and standard multivitamin supplements are probably not sufficient. Objective: The present study evaluates the effectiveness of a specialized multivitamin supplement for SG patients (WLS Optimum 1.0, FitForMe, Rotterdam, the Netherlands), compared to a standard multivitamin supplement (sMVS). Design: A double-blind randomized controlled trial was performed. For 12 months, patients in the intervention group received WLS Optimum, containing elevated doses of multiple vitamins and minerals. Patients in the control group were provided with sMVS, containing 100% of the recommended dietary allowance. Results: In total, 139 patients were available for analysis (WLS Optimum, n = 69; sMVS, n = 70). Intention-to-treat analyses revealed more folic acid deficiencies and higher serum vitamin B1 levels in the WLS Optimum group. Per protocol analyses showed that in patients using WLS Optimum, serum folic acid and vitamin B1 levels were higher, serum PTH levels were lower, and only one patient (2.6%) was anemic compared to 11 patients (17.5%) using a sMVS (p < 0.05 for all). No differences were found in prevalence of deficiencies for iron, vitamin B12, vitamin D, and other vitamins and minerals. Conclusions: This optimized multivitamin supplement only affected serum levels of folic acid, PTH and vitamin B1, and anemia rates compared to a sMVS. There is a clear need to further optimize multivitamin supplementation for SG patients. Besides, non-compliance with multivitamin supplements remains an important issue that should be dealt with. Clinical Trial Registry: The study protocol was registered at the clinical trials registry of the National Institutes of Health (ClinicalTrials.gov; identifier NCT01609387).

    Host factors associated with Giardia duodenalis infection in dogs across multiple diagnostic tests
    Uiterwijk, Mathilde ; Nijsse, Rolf ; Kooyman, Frans N.J. ; Wagenaar, Jaap A. ; Mughini-Gras, Lapo ; Ploeger, Harm W. - \ 2019
    Parasites & Vectors 12 (2019)1. - ISSN 1756-3305
    Canine - DFA - Endoparasites - Giardiosis - IDEXX SNAP Giardia - Loose stool - qPCR

    Background: The aim of this study was to assess potential associations between Giardia duodenalis infection in dogs, as determined by three diagnostic tests, and dog's group of origin, fecal consistency, age, sex, neuter status, and co-infections with other gastrointestinal parasites. Methods: Fecal samples from 1291 dogs from four groups (household, shelter, hunting and clinical dogs) were tested with qPCR, rapid enzyme immunochromatographic assay (IDEXX SNAP® Giardia), and direct immunofluorescence (DFA, Merifluor) for presence of G. duodenalis. Moreover, fecal samples were tested with centrifugation sedimentation flotation (CSF) coproscopical analysis for presence of gastrointestinal parasites. Associations were expressed as odds ratios (ORs). Results: Several significant associations were found, of which a few were consistent for all three tests and Giardia positivity in general (positive with at least one of these tests). Dogs older than one year were significantly less likely to test positive for Giardia than younger dogs. Group-housed dogs, especially hunting dogs, were significantly more likely to test positive for Giardia compared to household and clinical dogs. A consistently significant association with Trichuris appeared to be driven by the high prevalence in hunting dogs. Although there was no significant association between loose stool and Giardia infection in the overall population, household dogs were significantly more likely to test Giardia-positive when having loose stool. Overall, Giardia-positive dogs with loose stool shed significantly more cysts, both determined semi-quantitatively with CSF and quantitatively by qPCR, than positive dogs with no loose stool. When other gastrointestinal parasites were present, significantly fewer cysts were detected with CSF, but this was not confirmed with qPCR. Conclusion: Giardia is the most common gastrointestinal parasite in Dutch dogs, except for hunting dogs, in which Trichuris and strongyle-type eggs (hookworms) prevailed. Giardia infection was not significantly associated with loose stool, except for household dogs. Young dogs and group-housed dogs were significantly more often Giardia-positive. These associations were consistent across diagnostic tests. Young dogs, clinical dogs and dogs with loose stool shed Giardia cysts in the highest numbers. If another gastrointestinal parasite was present lower numbers of cysts were observed by microscope (CSF), but not with a molecular method (qPCR).

    Comparing four diagnostic tests for Giardia duodenalis in dogs using latent class analysis
    Uiterwijk, Mathilde ; Nijsse, Rolf ; Kooyman, Frans N.J. ; Wagenaar, J.A. ; Mughini-Gras, Lapo ; Koop, Gerrit ; Ploeger, Harm W. - \ 2018
    Utrecht University
    giardiasis - canine - prevalence - diagnosis - Bayesian analysis
    Background To accurately diagnose giardiosis in dogs, knowledge of diagnostic test characteristics and expected prevalence are required. The aim of this work was to estimate test characteristics (sensitivity and specificity) of four commonly used diagnostic tests for detection of Giardia duodenalis in dogs. Methods Fecal samples from 573 dogs originating from four populations (household dogs, shelter dogs, hunting dogs and clinical dogs) were examined with centrifugation sedimentation flotation (CSF) coproscopical analysis, direct immunofluorescence assay (DFA, Merifluor Cryptosporidium/Giardia速), a rapid enzyme immunochromatographic assay (IDEXX SNAP Giardia速) and qPCR (SSU rDNA) for presence of G. duodenalis. Bayesian latent class analysis was used to determine test performance characteristics and to estimate G. duodenalis prevalence of each of the four dog populations. Results All tests were highly specific. IDEXX SNAP Giardia速 showed the highest specificity (99.6%) and qPCR the lowest (85.6%). The sensitivities were much more variable, with qPCR showing the highest (97.0%) and CSF the lowest (48.2%) sensitivity. DFA was more sensitive than IDEXX SNAP Giardia速, but slightly less specific. Prevalences of G. duodenalis differed substantially between populations, with the hunting dogs showing the highest G. duodenalis prevalence (64.9%) and the household dogs the lowest (7.9%). Conclusions This study identifies qPCR as a valuable screening tool because of its high sensitivity, whereas methods using microscopy for cyst identification or cyst wall detection should be used in situations where high specificity is required. G. duodenalis is a prevalent gastro-intestinal parasite in Dutch dogs, especially in dogs living in groups (hunting and shelter dogs) and clinical dogs.
    Comparing four diagnostic tests for Giardia duodenalis in dogs using latent class analysis
    Uiterwijk, Mathilde ; Nijsse, Rolf ; Kooyman, Frans N.J. ; Wagenaar, Jaap A. ; Mughini-Gras, Lapo ; Koop, Gerrit ; Ploeger, Harm W. - \ 2018
    Parasites & Vectors 11 (2018)1. - ISSN 1756-3305
    Bayesian analysis - Canine - Diagnosis - Giardiasis - Prevalence

    Background: To accurately diagnose giardiosis in dogs, knowledge of diagnostic test characteristics and expected prevalence are required. The aim of this work was to estimate test characteristics (sensitivity and specificity) of four commonly used diagnostic tests for detection of Giardia duodenalis in dogs. Methods: Fecal samples from 573 dogs originating from four populations (household dogs, shelter dogs, hunting dogs and clinical dogs) were examined with centrifugation sedimentation flotation (CSF) coproscopical analysis, direct immunofluorescence assay (DFA, Merifluor Cryptosporidium/Giardia®), a rapid enzyme immunochromatographic assay (IDEXX SNAP Giardia®) and qPCR (SSU rDNA) for presence of G. duodenalis. Bayesian latent class analysis was used to determine test performance characteristics and to estimate G. duodenalis prevalence of each of the four dog populations. Results: All tests were highly specific. IDEXX SNAP Giardia® showed the highest specificity (99.6%) and qPCR the lowest (85.6%). The sensitivities were much more variable, with qPCR showing the highest (97.0%) and CSF the lowest (48.2%) sensitivity. DFA was more sensitive than IDEXX SNAP Giardia®, but slightly less specific. Prevalences of G. duodenalis differed substantially between populations, with the hunting dogs showing the highest G. duodenalis prevalence (64.9%) and the household dogs the lowest (7.9%). Conclusions: This study identifies qPCR as a valuable screening tool because of its high sensitivity, whereas methods using microscopy for cyst identification or cyst wall detection should be used in situations where high specificity is required. G. duodenalis is a prevalent gastro-intestinal parasite in Dutch dogs, especially in dogs living in groups (hunting and shelter dogs) and clinical dogs.

    Medicijngebruik in de schapenhouderij : Aanknopingspunten voor verdere optimalisatie
    Verkaik, J.C. ; Antonis, A.F.G. ; Ploeger, Harm W. ; Vellema, P. ; Bokma-Bakker, M.H. - \ 2017
    Wageningen Livestock Research - 2
    Diergezondheid en kwaliteit staan hoog in het vaandel van de Nederlandse schapensector. Op verzoek van sector en overheid is een inventarisatie uitgevoerd. Schapenhouders zijn via een internetenquete rechtstreeks gevraagd naar het gebruik van antibiotica en wormmiddelen op hun bedrijf in 2013. In deze brochure vindt u een samenvatting van de belangrijkste bevindingen. Ook worden aanknopingspunten gegeven voor verdere optimalisatie van het medicijngebruik in de schapenhouderij
    Stalkaarten Schapen: Wijs met Wormen : Bewust wel/niet Behandelen
    Bokma-Bakker, M.H. ; Antonis, A.F.G. ; Ploeger, Harm W. ; Vellema, P. ; Verkaik, J.C. - \ 2017
    Wageningen Livestock Research - 4
    livestock farming - sheep - animal health
    Overzicht behandeling en preventie van wormbesmetting bij schapen
    Species composition of larvae cultured after anthelmintic treatment indicates reduced moxidectin susceptibility of immature Cylicocyclus species in horses
    Kooyman, F.N. ; Doorn, D.C. van; Geurden, T. ; Mughini-Gras, Lapo ; Ploeger, Harm W. ; Wagenaar, J.A. - \ 2016
    Veterinary Parasitology 227 (2016). - ISSN 0304-4017 - p. 77 - 84.
    For the control of cyathostomins in horses, the macrocyclic lactones (MLs), moxidectin (MOX) and ivermectin (IVM) are the most commonly used anthelmintics. However, reduced activity, observed as shortening of the egg reappearance period (ERP) has been described. Shortening of the ERP may be caused by a decreased susceptibility of immature worms for MLs. Alternatively, immature worms may develop faster into egg producing adults as a result of repeated ML treatments. The species composition of the larval cultures obtained shortly after ML and pyrantel (PYR) treatment can confirm the hypothesis of decreased ML susceptibility, as this is often class-specific, whereas faster development would also occur after treatment with anthelmintics with a different mode of action. From 3 farms with a known history of shortened ERP, 8 horses per farm were selected and divided into 2 groups. The MOX-PYR-MOX group was treated twice with MOX (day 0 and 126) and once with PYR (day 84) and the IVM-PYR-IVM group was treated twice with IVM (day 0 and 98) and once with PYR (day 56). Cultured infective larvae (L3s) were counted and differentiated with the reverse line blot on pooled samples. Per cyathostomin species, the number of larvae per gram was calculated. The efficacy of all ML treatments was 100% and a shortened ERP was found on all 3 farms. The species composition of the larval cultures after ML treatment did not differ significantly from that after PYR treatment in the IVM-PYR-IVM group, but it did differ in the MOX-PYR-MOX group. The larval cultures obtained after MOX treatment consisted mostly of Cylicocyclus nassatus, while after PYR treatment Cylicostephanus longibursatus was the most abundant species. In the cultures from 42 days after MOX treatment 6 cyathostomin species from 3 genera were found on the farm with the lowest activity (farm 1), while on the farm with the highest activity (farm 3) only 3 species from one genus were found in the same number of examined L3s. The high numbers of L3s of Cylicocyclus species 42 days after MOX treatment and the low numbers 42 days after PYR treatment can be explained by reduced susceptibility of the immature worms to MOX, but not by a faster development. In conclusion, shortening of the ERP following MOX treatment is most likely a process in which an increasing number of immature worms from an increasing number of species is becoming less susceptible to the active compound.
    Perceptions and actions of Dutch sheep farmers concerning worm infections
    Ploeger, H.W. ; Antonis, A.F.G. ; Verkaik, J.C. ; Vellema, P. ; Bokma-Bakker, M.H. - \ 2016
    Veterinary Parasitology 229 (2016). - ISSN 0304-4017 - p. 150 - 158.
    Gastrointestinal (GI) nematode infections are considered among one of the toughest challenges sheep farmers face worldwide. Control still is largely based on the use of anthelmintics, but anthelmintic resistance is becoming rampant. To facilitate implementation of alternative nematode control strategies and to reduce anthelmintic usage, the purpose of this study was twofold: (i) to gain insight in common practices, knowledge gaps and perceptions of farmers regarding nematode control, and (ii) to provide foci of attention for improving parasite control practices and transfer of knowledge within the sheep husbandry. An internet-based questionnaire was made available to all sheep farmers pertaining to the year 2013, resulting in 450 entered questionnaires for analysis. The two most important nematodes mentioned, were Haemonchus contortus and, to a lesser extent, Nematodirus battus. Of all respondents, 25.6% said they did not have any worm problems. Of these, almost a third did notice clinical signs that can be related to worm infections and about three quarters did use anthelmintics. Overall, clinical symptoms mentioned by farmers matched the worm species they identified as the cause of problems. Ewes and lambs were treated up to 6 times in 2013. On average, ewes were treated 1.53 and lambs 2.05 times. Farmers who treated their ewes more often, also treated their lambs more often (P < 0.001). Both ewes and lambs were frequently treated based on fixed moments such as around lambing, at weaning and before mating, rather than based on faecal egg counts. Treatments based on faecal egg counts were practiced, but on a minority of the farms (32.7%). The majority of the farms (75.6%) did not leave 2–5% of the sheep within a flock untreated. About 74% of farmers keep newly purchased animals quarantined for at least 10 days, but some (13.4%) leave quarantined animals untreated nor check faecal egg counts. Of farmers who do treat their quarantined animals, just 12.6% check the efficacy of the treatment. Slightly over 40% of the respondents said they did not experience bottlenecks in parasite control. Yet, over half of these said having problems with worm infections, over half did see clinical signs related to worm infections and over three quarters used anthelmintics. Within the group of farmers experiencing difficulties in parasite control, the most often mentioned bottleneck concerned pasture management (75.8%). When asking farmers for solutions, 90% of all respondents indicated they are willing to adjust their pasture management. Farmers are also interested in other methods to reduce the risk of worm infections, such as possibilities to enhance the immune system of sheep in general (71%), to increase specific genetic resistance to worms and to apply anti-parasite forages, both about 40%. Results of this study gave the following potential foci of attention: (1) making complex scientific knowledge more accessible to farmers through simple tools and applicable in the daily farming process; (2) changing the mindset of farmers about their current worm control practices, i.e. breaking long-standing habits such as treating ewes and lambs at fixed moments rather than based on actual worm infection monitoring data; (3) demonstrating effective pasture rotation schemes on specific farms and using these in extension work; (4) making farmers more aware that checking anthelmintic efficacy is important; (5) improving quarantine procedures; (6) creating a wider array of applicable alternative control measures from which individual farmers can choose what fits them most; and finally, (7) improving mutual understanding among farmers, veterinary practitioners and parasitologists alike.
    Recurrent patent infections with Toxocara canis in household dogs older than six months : a prospective study
    Nijsse, Rolf ; Mughini-Gras, Lapo ; Wagenaar, Jaap A. ; Ploeger, Harm W. - \ 2016
    Parasites & Vectors 9 (2016)1. - ISSN 1756-3305 - 11 p.
    Deworming - Dogs - Longitudinal study - Recurrent patent infections - Toxocara canis

    Background: To reduce environmental contamination with Toxocara canis eggs, the current general advice is to deworm all dogs older than six months on average four times a year. However, only a small proportion of non-juvenile household dogs actually shed T. canis eggs, and some dogs shed eggs more frequently than others. The identification of these frequent shedders and the associated risk factors is an important cornerstone for constructing evidence-based deworming regimens. The purpose of this study is to identify risk factors associated with recurrence of periods of shedding Toxocara eggs in a cohort of household dogs older than six months. Methods: We performed a prospective study (July 2011 to October 2014) on shedding Toxocara eggs in a cohort of 938 household dogs older than six months from all over the Netherlands. The median follow-up time was 14 months. Monthly, owners sent faecal samples of their dogs for Toxocara testing and completed a questionnaire. Dogs were dewormed only after diagnosis of a patent infection (PI). Survival analysis was used to assess factors influencing the time to first diagnosed PIs (FPI) and the time to recurrent PIs (RPI). Results: The overall prevalence of PIs was 4.5 %, resulting in an estimated average incidence of 0.54 PIs/dog/year. No PI was diagnosed in 67.9 % of the dogs, 17.5 % of the dogs went through only one PI and 14.6 % had > 1 PI. Prevalence of PIs always peaked during wintertime. Increased hazards for first diagnosed PIs were associated with coprophagy, geophagy, walking off-leash for = 80 % of walking time, reported worms in the faeces, feeding a commercial diet and suffering from urologic or respiratory conditions. Median time to reinfection was nine months. Factors associated with increased hazards for recurrent PIs were taking corticosteroids, changing dog's main purpose, and proxies for veterinary care-seeking behaviours. Conclusions: We concluded that targeted anthelmintic treatments in household dogs may be feasible as PIs tend to (re)occur in specific periods and in groups of dogs at high risk. Moreover, recurrent PIs appear to be influenced more by factors related to impaired immunity than environmental exposure to Toxocara eggs.

    Prevalence and risk factors for patent Toxocara infections in cats and cat owners’ attitude towards deworming
    Nijsse, R. ; Ploeger, H.W. ; Wagenaar, J.A. ; Mughini-Gras, L. - \ 2016
    Parasitology Research 115 (2016)12. - ISSN 0932-0113 - p. 4519 - 4525.
    Cat owners - Deworming - Household cats - Public health - Risk factors - Toxocara cati

    The prevalence of and risk factors for shedding Toxocara eggs in cats older than 6 months were determined by examining 670 faecal samples collected in 4 cross-sectional studies in the Netherlands. Additionally, cat owners provided information on their attitude towards routine deworming. Samples were examined using the centrifugal sedimentation flotation method. Overall Toxocara prevalence was 7.2 %. Multivariable logistic regression analysis revealed that young age and living in rural areas were significant risk factors for shedding Toxocara eggs. Moreover, the more time a cat was allowed to roam outdoors, the higher was its risk to shed Toxocara as compared to cats with no outdoor access at all. For 199 cats (81.6 % of cats subjected to a deworming regimen) owners provided the reason for treatment. The main reason for routine deworming (80.4 %) concerned the cat’s health and only 10.6 % of the cats were treated for public health reasons. Moreover, the generally advocated four-times-a-year deworming advice was applied on only 24.5 % of cats. We concluded that free roaming is a key factor in the acquisition of patent Toxocara infections leading to the environmental contamination with Toxocara eggs. Additionally, the knowledge of cat owners is still insufficient to expect them to make sound decisions on routine deworming.

    Toxocara canis in household dogs: prevalence, risk factors and owners’ attitude towards deworming
    Nijsse, R. ; Ploeger, H.W. ; Wagenaar, J.A. ; Mughini-Gras, L. - \ 2015
    Parasitology Research 114 (2015)2. - ISSN 0932-0113 - p. 561 - 569.
    Deworming frequency - Dog - Faecal samples - Gastrointestinal parasites - Toxocara canis - Toxocara eggs

    The prevalence of gastrointestinal parasites and risk factors for shedding of Toxocara eggs were determined for 916 Dutch household dogs older than 6 months. Additionally, the owners answered a questionnaire about their dogs and their attitude towards routine deworming was assessed. Faecal samples were examined using the centrifugal sedimentation flotation method. The overall prevalence of dogs shedding Toxocara eggs was 4.6 %. Multivariable logistic regression analysis revealed that the risk for 1–7-year-old dogs to shed Toxocara eggs was significantly lower (OR 0.38) than that of 6–12-month-old dogs. Compared to dogs walking ≤20 % of the time off-leash, those ranging freely 50–80 % and 80–100 % of the time had a significantly higher risk (OR 10.49 and 13.52, respectively) of shedding Toxocara eggs. Other risk factors were coprophagy (OR 2.44) and recently being kenneled (OR 2.76). Although the applied deworming frequency was not significantly associated with shedding Toxocara eggs, there was a trend towards no shedding in dogs under strict supervision that were dewormed 3–4 times a year. Most dog owners (68 %) recognized ‘dog’s health’ as the main reason for deworming. Only 16 % of dogs were dewormed four times a year. It was concluded that the prevalence of Toxocara egg-shedding household dogs is almost unchanged over recent years and that the knowledge of owners is insufficient to expect sound decisions on routine deworming.

    Een verdiepend onderzoek naar het medicijngebruik in de Nederlandse schapenhouderij : aanknopingspunten voor verdere optimalisatie
    Verkaik, J.C. ; Antonis, A.F.G. ; Ploeger, H. ; Vellema, P. ; Bokma-Bakker, M.H. - \ 2015
    Wageningen UR Livestock Research (Livestock Research rapport 933) - 46
    Environmental contamination with Toxocara eggs : A quantitative approach to estimate the relative contributions of dogs, cats and foxes, and to assess the efficacy of advised interventions in dogs
    Nijsse, Rolf ; Mughini-Gras, Lapo ; Wagenaar, J.A. ; Franssen, Frits ; Ploeger, Harm W. - \ 2015
    Parasites & Vectors 8 (2015)1. - ISSN 1756-3305
    Cats - Clean-up - Contamination - Contribution - Deworming - Dogs - Eggs - Environment - Foxes - Toxocara

    Background: Environmental contamination with Toxocara eggs is considered the main source of human toxocariasis. The contribution of different groups of hosts to this contamination is largely unknown. Current deworming advices focus mainly on dogs. However, controversy exists about blind deworming regimens for >6-month-old dogs, as most of them do not actually shed Toxocara eggs. We aim to estimate the contribution of different non-juvenile hosts to the environmental Toxocara egg contamination and to assess the effects of different Toxocara-reducing interventions for dogs. Methods: A stochastic model was developed to quantify the relative contribution to the environmental contamination with Toxocara eggs of household dogs, household cats, stray cats, and foxes, all older than 6 months in areas with varying urbanization degrees. The model was built upon an existing model developed by Morgan et al. (2013). We used both original and published data on host density, prevalence and intensity of infection, coprophagic behaviour, faeces disposal by owners, and cats' outdoor access. Scenario analyses were performed to assess the expected reduction in dogs' egg output according to different deworming regimens and faeces clean-up compliances. Estimates referred to the Netherlands, a country free of stray dogs. Results: Household dogs accounted for 39 % of the overall egg output of >6-month-old hosts in the Netherlands, followed by stray cats (27 %), household cats (19 %), and foxes (15 %). In urban areas, egg output was dominated by stray cats (81 %). Intervention scenarios revealed that only with a high compliance (90 %) to the four times a year deworming advice, dogs' contribution would drop from 39 to 28 %. Alternatively, when 50 % of owners would always remove their dogs' faeces, dogs' contribution would drop to 20 %. Conclusion: Among final hosts of Toxocara older than 6 months, dogs are the main contributors to the environmental egg contamination, though cats in total (i.e. both owned and stray) transcend this contribution. A higher than expected compliance to deworming advice is necessary to reduce dogs' egg output meaningfully. Actions focusing solely on household dogs and cats are unlikely to sufficiently reduce environmental contamination with eggs, as stray cats and foxes are also important contributors.

    Coprophagy in dogs interferes in the diagnosis of parasitic infections by faecal examination
    Nijsse, R. ; Mughini-Gras, L. ; Wagenaar, J.A. ; Ploeger, H.W. - \ 2014
    Veterinary Parasitology 204 (2014)3-4. - ISSN 0304-4017 - p. 304 - 309.
    Coprophagy - Coproscopical examination - Dogs - Nematodes - Roundworms - Toxocara

    Many dogs display coprophagic behaviour. Helminth eggs can passively pass the dog's digestive tract and this may result in a false positive diagnosis of infection with gastrointestinal helminth parasites. For a period of one year, faecal samples of dogs were examined monthly using the Centrifugal Sedimentation Flotation (CSF) technique with a sugar flotation solution (s.g. 1.27-1.30 g/cm(3)). If a sample tested positive for canine helminth eggs, the owner was asked to submit another sample after preventing the dog from eating faeces for 3 days. If the second sample again tested positive for the same type of helminth egg, the dog was considered to have a patent infection. If the second sample tested negative, the first sample was considered a false positive due to coprophagy. The focus of this study was on dogs shedding Toxocara eggs. At the first examination, 246 samples (out of 308 samples testing positive for canine-specific helminth eggs) tested positive for Toxocara spp. Of these, 120 (49%) tested negative at the second examination. Coprophagic behaviour was recognized by 261 of the 564 owners that answered the accompanying questionnaire. This concerned 391 dogs. Coproscopical examination also provided proof of coprophagy (e.g. oocysts of Eimeria spp. or non-dog typical helminth eggs) in dogs belonging to owners that did not report coprophagic behaviour in their dogs. Results indicate that coprophagy in dogs may result in an overestimation of the prevalence of patent helminth infections and that dogs may serve as a transport host for helminth eggs.

    De beheersing van wormbesmettingen bij schapen op bedrijven in de praktijk : waardevolle inzichten uit een internetenquête
    Ploeger, H. ; Antonis, A.F.G. ; Vellema, P. ; Verkaik, J. ; Bokma, M. - \ 2014
    schapenhouderij - wormen - spijsverteringskanaal - haemonchus contortus - nematodirus - parasitosen - anthelmintica - sheep farming - helminths - digestive tract - haemonchus contortus - nematodirus - parasitoses - anthelmintics
    Actuele ontwikkelingen in de preventie en bestrijding van maagdarmwormen bij schapen : Kernpunten uit een literatuurstudie
    Bokma-Bakker, M.H. ; Antonis, A.F.G. ; Ploeger, H. ; Vellema, P. ; Verkaik, J.C. - \ 2014
    Wageningen UR/Universiteit Utrecht
    schapenhouderij - maagdarmziekten - wormen - dierparasitaire nematoden - nematodirus battus - haemonchus contortus - teladorsagia circumcincta - schapenziekten - gastheer parasiet relaties - graslandbeheer - ziektebestrijding - dierveredeling - selectief fokken - voedersupplementen - schapenvoeding - sheep farming - gastrointestinal diseases - helminths - animal parasitic nematodes - nematodirus battus - haemonchus contortus - teladorsagia circumcincta - sheep diseases - host parasite relationships - grassland management - disease control - animal breeding - selective breeding - feed supplements - sheep feeding
    De schapensector gaat de parasitaire resistentie-ontwikkeling terugdringen. Ze wil dat doen door verbetering van de preventie en de bestrijding van maagdarmwormen. Experts hebben in 2013 een literatuurstudie uitgevoerd. Hierin zijn de belangrijkste binnen- en buitenlandse innovatieve ontwikkelingen voor verlaging van de infectiedruk opgenomen en vertaald naar toepasbaarheid onder de Nederlandse omstandigheden. Bekeken zijn de gebieden fokkerij, voeding, vaccinatie, beweiding, inzet van natuurlijke middelen en diagnostiek. In deze brochure zijn de belangrijkste bevindingen samengevat.
    Innovatieve ontwikkelingen voor beheersing van maagdarmwormbesmettingen bij schapen
    Bokma-Bakker, M.H. ; Antonis, A.F.G. ; Ploeger, H.W. ; Verkaik, J.C. - \ 2014
    Wageningen : Wageningen UR Livestock Research (Rapport / Wageningen UR Livestock Research 779) - 51
    schapenhouderij - maagdarmziekten - wormen - resistentiemechanismen - infectiviteit - dierziektepreventie - literatuuroverzichten - sheep farming - gastrointestinal diseases - helminths - resistance mechanisms - infectivity - animal disease prevention - literature reviews
    Deze literatuurstudie geeft een weergave van de actuele kennis op het gebied van innovatieve ontwikkelingen in binnen- en buitenland met betrekking tot terugdringen van resistentievorming, preventie en beheersing van maagdarmwormen bij schapen. Hierbij zijn nationale en internationale (innovatieve) ontwikkelingen met betrekking tot het verlagen van de parasitaire infectiedruk op het gebied van fokkerij, voeding, vaccinatie, beweiding en andere relevante velden meegenomen en vertaald naar toepasbaarheid onder de Nederlandse omstandigheden.
    Open data and beyond: Exploring existing open data projects to prepare a successful open data strategy
    Loenen, B. van; Bregt, A.K. ; Bruinenberg, J. ; Castelein, W. ; Doorn, L. van; Juffermans, P. ; Kulk, S. ; Mourik, D. van; Oosterom, P. van; Ploeger, H. ; Quak, W. ; Vries, M. de; Zweistra, M. - \ 2012
    Delft : OTB - 212 p.
    Lungworm outbreaks in adult dairy cows: estimating economic losses and lessons to be learned
    Holzhauer, M. ; Schaik, G. van; Saatkamp, H.W. ; Ploeger, H.W. - \ 2011
    Veterinary Record 169 (2011)19. - ISSN 0042-4900
    virus serotype 8 - dictyocaulus-viviparus - cattle - infection - resistance - mastitis - immunity - costs - herds
    Two lungworm outbreaks in dairy herds were investigated in order to estimate the resulting economic costs. On the two farms, with 110 and 95 cows, total costs were estimated at (sic)159 and (sic)167 per cow, respectively. Overall, milk production reduced by 15 to 20 per cent during the outbreaks. Five cows died on one farm, while on the other farm seven cows died as a result of the lungworm outbreak. On one farm, 51.7 per cent of the total costs was due to reduced milk production and 33.1 per cent was due to disposal of dead animals. On the other farm, it was 36.3 and 50.9 per cent, respectively. The remaining 13 to 15 per cent of the total costs were due to extra inseminations, laboratory diagnosis and treatments. The history and development of the outbreaks are described. One lesson from these outbreaks is that recognising that potentially lungworm-naive animals are to be introduced into the adult herd allows for timely measures (for example, vaccination) to prevent a lungworm outbreak.
    Novel foods: an explorative study into their grey area
    Verhagen, H. ; Boekhorst, J. te; Kamps, L. ; Lieshout, M.J. ; Ploeger, H. ; Verreth, D.M.I. ; Salminen, S. ; Loveren, H. van - \ 2009
    The British journal of nutrition 101 (2009)9. - ISSN 0007-1145 - p. 1270 - 1277.
    European Union Regulation 258/97 defines novel foods as food products and food ingredients that have not been consumed to a significant degree in the European Union before May 1997. However, there are new foods that for some reason are not considered as novel foods, though we think that safety of these products is not always a priori established. We defined a `grey area¿ which consists of such foods, and the present paper intends to raise awareness of this `grey area¿ of unidentified novel foods. The grey area of novel foods is divided into two categories: (1) food products or ingredients for which the current Regulation leaves too much space for different interpretations and (2) food products or ingredients that are not novel according to the current Regulation, because the current Regulation contains gaps. These categories are illustrated by means of products already on the market in The Netherlands. We found about two dozen examples of products that had not been identified as novel foods according the current Regulation, yet could be considered to be classified as novel foods and hence for which a safety evaluation (toxicological and/or nutritional) would be indicated
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