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Biomedical subjects

F H Borgsteede

Publications and source records attributed to F H Borgsteede.

At least 19 recordsLinked to original sources

Management practices and use of anthelmintics on dairy cattle farms in The Netherlands: results of a questionnaire survey.

In December 1996, a questionnaire about farm management and parasite control measures in calves was sent to 956 randomly chosen dairy cattle farmers in The Netherlands. Another 150 farmers in the vicinity of Deventer who had vaccinated their calves in 1995 against lungworm were approached with the same questions. Our object was to investigate the consequences on worm control of the withdrawal of the lungworm vaccine from the market for reasons of possible BSE contamination of the vaccine. OF the returned questionnaires, 411 (43%) of the 'at random' group and 89 (59.3%) of the 'Deventer' group were valid. The most important data with regard to the farms of the 'at random' group (41) were: mean area 31.6 ha, mean number of calves 23, heifers 23 and milking cows 53. Sheep (mean 37) were present on 18.3% of the farms. With regard to management: 74.5% of the farmers turned the calves in their first year onto pasture, 25.5% kept them indoors. The average time on pasture was ca. 5 months. Rational grazing was practise on 81.4% of the farms, on 18.6% calves were set stocked. The first pasture of the calves was mown before turn-out on 72.9% of the farms. On 48.2% of these farms, calves were always moved to mown pastures. With regard to treatments: 33.8% of the farmers vaccinated their calves against lungworm in the years 1993, 1994 and 1995. Despite the withdrawal of the vaccine from the market in 1996, 7.2% of the farmers vaccinated their calves as recommended, with two doses, and 13.1% with a single dose. At turn-out, 41.5% of the farmers gave the calves a preventive anthelmintic treatment. Of these treatments, 66.9% were sustained of pulse release long acting device. During the grazing season, 36.6% of the farmers treated their calves. After housing 50.3% of the farmers gave a treatment. Signs of lungworm infection were noticed on 18.6% of the farms. Of the 'Deventer' group (89 farmers), 96.6% turned the calves out, Of these farmers, 86.0% had used the lungworm vaccine in 1995. In 1996, 52.7% of the farmers had vaccinated the calves:36.5% with a single dose and 16.2% with the double dose. Of the 35 farmers who did not vaccinate in 1996, 62.9% gave a preventive treatment at turn-out. Clinical signs of lungworm infection were not observed on the 12 farms which vaccinated the calves twice. On 11% of the farms which vaccinated once and on 14% of the farms which did not vaccinate, signs of lungworm infection were observed. It is concluded that more than 80% of Dutch dairy cattle farmers take appropriate measures to control gastrointestinal nematode and lungworm infections in calves in their first grazing season by grazing on aftermath, rotational grazing on mown pastures combined or not with preventive anthelmintic treatments. However, combinations of aftermath grazing and preventive treatment occurred on 30% of the farms. This may be overprotective and may prevent sufficient build up of immunity, causing worm problems at a later age. The withdrawal of the lungworm vaccine from the market did not cause a rise in lungworm problems. Some farmers did vaccinate, despite the withdrawal. The majority used other preventive treatment measures, mainly the application of long acting boli.

Animals

Effect of three sustained-release devices on parasitic bronchitis in first year calves.

The effect of three intraruminal sustained-release devices (SRD) against Dictyocaulus viviparus infection was tested in five groups of six calves. Group 1 served as untreated controls, and groups 2, 3 and 4 were dosed with a levamisole SRD, a fenbendazole SRD, and an ivermectin SRD, respectively. Group 5 was vaccinated against lungworm and received a levamisole SRD. The calves were turned out on May 28 and the devices given seven days later. All the calves received trickle infections with a total of 200 lungworm larvae between 9 and 34 days after turnout. They were housed on October 28, challenged with 5000 lungworm larvae and slaughtered three weeks later. No clinical signs of parasitic bronchitis were observed during the study. The treated groups gained significantly more weight (P < 0.05) than the controls, but did not differ among themselves. Larvae were first detected in the faeces of the control group between 25 and 32 days after the first infection, and had a group mean of 21 larvae per gram (lpg) after 60 to 80 days, after which the lpg gradually decreased. In group 2, larvae were detected near the end of the grazing season and never exceeded a group mean of 1.5 lpg. In group 3, a very low larval output was observed after housing (group mean 0.1 lpg). Groups 4 and 5 never became patent. The results of an ELISA followed the pattern of larval output; optical densities above the cut-off value were recorded in groups 1, 2 and 3. On the basis of worm recoveries after challenge, group 1 was immune. Group 4 had significantly more lungworms than group 2. There were no significant differences in worm numbers between groups 2, 3 and 5, but the worms in group 5 were retarded in growth (P < 0.05).

Animals

Studies on the survival of Ascaris suum eggs under laboratory and simulated field conditions.

A series of four experiments was carried out to study the survival of Ascaris suum eggs: in a pig slurry unit on a farm, in the laboratory under anaerobic conditions and different relative humidities (rH), and under simulated field conditions. Survival of eggs in the pig slurry unit was 20% after four weeks and 0% after 16 weeks. Anaerobic conditions had only a minor influence on survival: after 12 weeks, more than 80% of the eggs could still develop. At high relative humidities (100% and 75%), survival was respectively 96% and 62% after 12 weeks. At 47.5% rH, survival dropped to 0% after 10 weeks and at 7.5% rH in 8 weeks. A. suum eggs kept in pig slurry under dry and sunny outdoor conditions survived for 2-4 weeks, whereas under wet and shady conditions, 90% of the eggs were still viable after 8 weeks.

Anaerobiosis

Parasites of stomach and small intestine of 70 horses slaughtered in The Netherlands.

The prevalence of metazoan parasites in the stomach and small intestine was investigated in 70 horses slaughtered in the period February 1994-July 1994. Most horses were young (1.5-3 years) and in good condition. Trichostrongylus axei was the most prevalent parasite species in the stomach (51.4%), followed by Gasterophilus intestinalis (41.4%) and Habronema spp. (4.3%). In the small intestine, Parascaris equorum (28.6%) and Paranoplocephala mamillana (1.4%) were found. The mean worm burden of T. axei was 957 (max. 8502), of G. intestinalis 21 (max. 84), of Habronema spp. 3 (max. 5), and of P. equorum 32 (max. 308). One single specimen of P. mamillana was seen. All bots of G. intestinalis were in the third instar stage. No seasonal pattern and no influence of the parasites on the condition of the horses could be observed.

Animals

Selection for high levamisole resistance in Haemonchus contortus monitored with an egg-hatch assay.

To investigate the characteristics of selection for levamisole resistance in Haemonchus contortus, the consecutive nematode generations of an in vivo selection were monitored with a newly developed egg-hatch assay. The in vivo selection was started with a population not previously exposed to any anthelmintics (SHS). At first, the levamisole resistance progressed gradually in successive nematode generations by treating sheep with increasing doses of levamisole, the initial dose being 1 mg kg-1. Treatment with 5 mg kg-1 levamisole resulted, however, in a steep increase of resistance. The selection was ended after six generations, since a level of 30 mg kg-1 levamisole, which is not far from the toxic level for sheep, was reached. The final population, RHS6, was studied in a controlled test. Treatment of RHS6-infected sheep with 30 mg kg-1 levamisole caused an 80% decrease of faecal egg output, and a reduction of 34% in worm numbers. It was remarkable that only the number of female adults was reduced. RHS6 showed a reduced viability, but a fertility similar to the starting population SHS.

Animals

Benzimidazole resistance in cyathostomes in horses in the Ukraine.

The efficacy of treatment with cambendazole was tested in 1-year-old horses on a farm in Dubrovka, Ukraine. Thirty-five horses were treated. Their egg output was compared on the day of treatment and 14 days later with that of 33 untreated horses. Before treatment the mean number of eggs g-1 faeces was 614 in the controls and 766 in horses that had been treated. After 14 days the mean egg output in the controls was 580 and in the treated horses 369. This means a reduction of 54.5%. Only cyathostome larvae could be cultured from faeces collected after treatment. It can be concluded that benzimidazole resistance in cyathostomes is present in the Ukraine.

Animals

Evaluation of an ELISA for the routine diagnosis of Dictyocaulus viviparus infections in cattle.

An enzyme-linked immunosorbent assay (ELISA) that detects antibodies against Dictyocaulus viviparus in experimentally and naturally infected cattle was evaluated for its sensitivity, specificity, the moment of seroconversion and persistence of the anti-D. viviparus response and precision. The first three parameters were compared with those of an indirect haemagglutination assay (IHA). Specificity and sensitivity of both assays were assessed in sera collected from calves experimentally infected with pure isolates of D. viviparus, Ostertagia ostertagi, Cooperia oncophora, Nematodirus helvetianus, Ascaris suum or Fasciola hepatica, and from parasite-naive calves. The specificity of both the ELISA and IHA was very high, 99.2% and 99.6%, respectively. The sensitivity of the ELISA (100%) was significantly higher than that of the IHA (78.1%). In experimentally infected cattle, D. viviparus-specific antibodies were first detected with the ELISA between days 28 and 42 post-infection (p.i.), whereas the IHA only became positive between days 42 and 70. With the ELISA, antibody levels persisted until day 168 p.i. The IHA remained positive until the end of the experiment (day 196). None of the vaccinated animals were seropositive with the ELISA, whereas 25% of the calves were seropositive with the IHA. The seroprevalence of D. viviparus infections was determined in a field study with 467 sera from cattle of 64 herds; 227 (48.6%) of the animals were seropositive with the ELISA whereas only 38 (8.1%) scored positive with the IHA. To determine the precision of the ELISA, a total of five laboratories participated in trials, in which panels of strong positive, positive, and weak positive candidate sera were tested blind according to an international (International Standard ISO 5725, 1986) standard procedure. The repeatability and reproducibility of the ELISA were 0-16% and 14-26%, respectively. After these promising results it was decided to introduce this ELISA in 1995 as a routine test in all Animal Health Services in the Netherlands, replacing the IHA and faecal examinations for lungworm.

Animals

A survey of anthelmintic resistance in nematodes of sheep in The Netherlands.

The prevalence of anthelmintic resistance in nematodes of sheep was surveyed in 1994 on 70 farms in the Netherlands. An in vitro egg hatch assay, faecal egg count reduction (FECR) 14 days after treatment, and larval cultures were used as methods of investigation. Oxfendazole was tested on 69, ivermectin on 51, and levamisole on 36 farms. The median effective dose (ED50) of thiabendazole could be determined on 64 farms. On 60 farms (94%) the ED50 value was > or = 0.12 microgram ml-1, which is indicative of the presence of benzimidazole (BZ) resistance. On two farms egg output was too low to do a FECR test. Based on the results of the FECR test, BZ resistance was present on 56 farms (84%), on 2 farms there was a suspicion of resistance and on 9 farms no resistance could be found. No clear indications were found for the presence of resistance against ivermectin or levamisole. BZ resistance was demonstrated in Haemonchus contortus, Cooperia curticei, Ostertagia spp. and/or Trichostrongylus spp. No resistance was observed in species from the genus Nematodirus, Chabertia ovina and/or Oesophagostomum spp.

Animals

Anthelmintic resistant nematodes in goats in The Netherlands.

A suspected case of anthelmintic resistance on a farm with Angora and Anglo-Nubian goats was confirmed in a controlled test. Twelve lambs of sheep were infected with larvae cultured from faeces of the goats. The lambs were allocated to four groups: untreated controls and lambs treated 21 days after infection with 5 mg kg-1 oxfendazole, 0.2 mg kg-1 ivermectin or 7.5 mg kg-1 levamisole. The lambs were slaughtered 1 week later and post-mortem worm counts were performed. Benzimidazole resistance was found in Haemonchus contortus, Teladorsagia circumcincta, Cooperia curticei and Trichostrongylus colubriformis with the efficacy of oxfendazole being 68%, 31%, 21% and 48% respectively. No resistance was found against levamisole or ivermectin.

Abomasum

Coccidial and helminth infections in goats kept indoors in the Netherlands.

An investigation was carried out on coccidial and helminth infections in goats kept indoors on five farms in the Netherlands. The goats were individually sampled. Coccidial oocysts were identified and nematode eggs counted. Larval cultures were made and infective larvae identified to the generic or species level. The goats were divided into three groups according to their age: kids, those weaned but not served, and older goats. Oocysts were found in 26 out of 27 kids (96.3%), in 52 out of 55 weaned but not served goats (94.5%), and in 72 out of 110 older goats (65.5%). Eimeria ninakohlyakimovae was the most common species in all groups with an overall prevalence of 82%, followed by Eimeria arloingi (78%) and Eimeria aspheronica (53.3%). Other species present were Eimeria alijevi (50%), Eimeria christenseni (39.3%), Eimeria caprina (38.7%), Eimeria hirci (28.7%) and Eimeria jolchijevi (7.3%). Nematode eggs were seen on four of the five farms. It appeared that on two farms some goats, although now kept indoors, had been on pasture in the past. These goats excreted low numbers of eggs of Ostertagia and/or Trichostrongylus, Strongyloides papillosus, Haemonchus contortus, Trichuris spp. and larvae of Muellerius capillaris. In goats that were kept exclusively indoors, infections with Strongyloides papillosus were found on two farms in the older group and on one farm also in the group weaned but not served. On two farms Skrjabinema ovis was incidentally observed by the farmer in older goats. This was confirmed by faecal examinations on one farm. All kids were free of nematode infection.

Animals

Data on the prevalence of tapeworm infestations in horses in The Netherlands.

The prevalence of tapeworm infestations was investigated in 70 horses slaughtered in the period February 1994-July 1994. Most horses were half-breed, young (1.5-3 years), and in good condition. They were bought for slaughter by dealers on local markets, and their treatment history was therefore unknown. Tapeworm infestations were seen in 16 horses (23%). Fifteen (21%) had an infection with Anoplocephala perfoliata. One horse had a single specimen of Paranoplocephala mamillana. The average number of A. perfoliata was 45 and the highest number was 508.

Animals

The effect of parasites on wildlife.

Populations of animals which live in the wild are regulated by many biotic and abiotic factors. Parasites are one of the biotic factors. Parasites may influence their hosts in different ways. They may cause the death of the host due to a direct lethal effect or an indirect effect. Direct lethal effects may occur if killing is a part of the life cycle of the parasite or if hosts and parasites have not developed an equilibrium. The introduction of hosts or parasites into a new environment with suitable hosts or parasites is an example. Death by parasitism may also be caused by a combination of the emaciating effects of parasites combined with factors such as bad weather conditions, environmental pollution or human handling. Parasites may also influence the behaviour of their hosts. If the hosts are intermediate hosts in the life cycle of the parasites, the alterations in behaviour may make them an easier prey for their predators, the final hosts. Parasites may also influence the reproductive success of the hosts. In this respect the relationship between the red grouse (Lagopus lagopus scoticus) and the caecal nematode Trichostrongylus tenuis has been well worked out.

Animals

[Anthelmintic resistance in sheep nematodes in The Netherlands].

The prevalence of anthelmintic resistant nematodes in sheep was investigated in 1994 with a faecal egg count reduction test (FECRT) and an egg hatch assay (EHA) on 71 farms in the Netherlands. A benzimidazole (oxfendazole) was tested on 70 farms, ivermectin on 51 farms, and levamisole on 35 farms. Based on the FECRT benzimidazole resistance was present on 56 farms, 2 were suspected, on 9 no resistance was observed, while 3 farms could not be tested due to a too low egg output before treatment. No clear indications for resistance to ivermectin and levamisole were found. Benzimidazole resistance was demonstrated in Haemonchus contortus, Cooperia curticei, Ostertagia spp. and/or Trichostrongylus spp. No resistance was seen in species from the genus Nematodirus, Chabertia ovina and/or Oesophagostomum spp. De results of the EHA confirmed the results of the FECRT. On 59 farms the ED50 value was > 0.12 microgram ml-1 thiabendazole.

Animals

The reappearance of strongyle eggs in faeces of horses treated with pyrantel embonate.

The reappearance of strongyle eggs in the faeces of horses treated with pyrantel embonate was studied. The horses (103) were divided in 11 groups on 8 different farms. The efficacy of pyrantel embonate against strongyles, based on egg count reduction tests, was 99.8%. Mean weekly egg counts performed between week 2 and week 9 after treatment showed that 5 weeks after treatment the egg output passed the 90% reduction level. It is concluded that strategic treatments of horses with pyrantel embonate for the prevention of strongylosis should be administered with intervals of 6 weeks.

Animals

Recommendations for the control of anthelmintic resistant nematodes of farm animals in the EU.

As a result of a recent European Union meeting on anthelmintic resistant nematodes of farm animals, a list was made of nine proposals for research and five to control anthelmintic resistance. The most important were the need to have standardised and new tests to monitor the development and spread of resistant nematodes in sheep, goats, horses, cattle and pigs, and for education of veterinary surgeons and farmers in the optimal control strategies to be used to delay the development of anthelmintic resistance in nematodes.

Animals

The efficacy and persistent anthelmintic effect of ivermectin in sheep.

The direct efficacy and the long-term persistent anthelmintic effect of an oral suspension and an injectable formulation of ivermectin at a dose rate of 0.2 mg kg-1 was studied in sheep. Lambs were infected experimentally with Haemonchus contortus, Trichostrongylus vitrinus and Cooperia curticei. After 3 weeks they were treated with an oral suspension or with an injection, and reinfected with the same dose of larvae 3, 6 or 10 days after treatment. Post-mortem worm counts showed no persistent effect of the oral suspension. The injectable formulation showed an excellent persistent effect for up to 10 days against H. contortus. Reinfection with C. curticei 3 days after treatment resulted in a 64% reduction of the worm burden, but reinfection after 6 and 10 days was 100% reduced. The reduction of T. vitrinus was 46% after 3 days and 92% after 6 and 10 days.

Administration, Oral