Toxocara vitulorum in suckling calves in The Netherlands.

A Dutch farmer with beef cattle and suckling calves noticed one of the calves suffering from diarrhoea and observed large white worms near the perineum. In the faeces of this calf, eggs of Toxocara vitulorum were found. The majority of the cows in the herd were of the Piemontese breed previously imported from southern France. Treatment with albendazole was successful. Two other calves had positive faecal egg counts. One month after treatment of these calves with doramectin, no eggs were found. To prevent further infections on the farm and dissemination of this uncommon infection to other farms, the farmer decided to have all his cattle slaughtered.

Potential role of hares in the spread of liver fluke in the Netherlands.

Hares (Lepus europeanus) sharing pasture with cattle from six locations in the Netherlands were examined for the presence of liver fluke (Fasciola hepatica) and shown to have prevalences of infection ranging from 0 to 41%. The mitochondrial haplotypes of liver flukes present in the hare populations were determined and compared with those found in cattle from a farm where triclabendazole resistance has been reported. Phylogenetic analysis indicated that the flukes present in the hares belonged to the same clades as those present in the cattle. A consideration of the life cycle of the liver fluke and the seasonal breeding pattern and ecology of hares supports the suggestion that hares may act as a refugia for liver fluke and as a vector for the spread of drug-resistant genotypes.

[An unusual roundworm (Toxocara vitulorum) infection in suckling calves]. / Een ongebruikelijke spoelworm (Toxocara vitulorum)-infectie bij zoogkalveren.

A 2-month-old suckling calf had complaints of diarrhea and roundworms near the perineum. Faecal examination showed the presence of a high number of roundworm eggs of Toxocara vitulorum. The calf was a daughter of a Piemontese cow, born on the farm, but with a grandmother imported from France. This case describes the measures taken on the farm to prevent clinical problems and dissemination of the infection to other farms.

Anthelmintic effects of phytogenic feed additives in Ascaris suum inoculated pigs.

Two experiments were performed to determine the anthelmintic effect of some phytogenic feed additives on a mild infection of Ascaris suum in growing and finishing pigs. Usually, an infection of A. suum is controlled by using conventional synthetic drugs. Organic farmers, however, prefer a non-pharmaceutical approach to worm control. Therefore, phytotherapy could be an appropriate alternative. In the first experiment, a commercial available organic starter diet was supplemented with 3% of a herb mixture, adding 1% Thymus vulgaris, 1% Melissa officinalis and 1% Echinacea purpurea to the diet, or with 4% of a herb mixture, thereby adding the mentioned herbs plus 1% Camellia sinensis (black tea). A negative control group (no treatment) and a positive control group (treatment with conventional synthetic drug flubendazole) were included. In the second experiment, the anthelmintic properties against A. suum of three individual herbs, Carica papaya, Peumus boldus and Artemisia vulgaris, each in a dose of 1%, were tested. Pigs were infected with 1000 infective worm eggs each. Each experiment was performed with 32 individually housed growing pigs (8 replicates/treatment), which were monitored for 67 days. It was hypothesized that the herbs would block the cycles of the larvae, thereby preventing the development of adult worms. Therefore, phytogenic feed additives were not supplied during the whole experimental period, but only from the start until D39. Pigs were inoculated with infective worm eggs during five consecutive days (D17-D21). At D67 all pigs were dissected, whereafter livers were checked for the presence of white spots. Also numbers of worms in the small intestine were counted. In experiment 1, the numbers of worm-infected pigs were similar for both the herb supplemented (groups 3 and 4) and the unsupplemented (group 1) treatments (5-6 pigs of 8), while the treatment with flubendazole (group 2) resulted in 0 infected pigs. In experiment 2, herb addition (groups 2-4) did not significantly reduce the number of worm-infected pigs compared to the negative control (group 1). It can be concluded that the tested herb mixtures and individual herbs in the diets of growing and finishing pigs did not decrease the number of pigs which were infected with A. suum, although the herb mixture without black tea and also boldo leaf slightly (P<0.10) reduced the number of worms in the intestinal tract. The tested herb mixtures and individual herbs did not affect the performance of the pigs.

A comparison of the efficacy of two ivermectin formulations against larval and adult Ascaris suum and Oesophagostomum dentatum in experimentally infected pigs.

A study was conducted to evaluate and compare the efficacy of two injectable formulations of ivermectin (IVM-1 and IVM-2) at a dose rate of 0.3 mg/kg bodyweight versus placebo in the treatment and control of larval and adult stages of Ascaris suum and Oesophagostomum spp. in experimentally infected pigs. Seventy helminth free pigs were allocated on a liveweight basis to 7 groups each comprising 10 pigs (A-G). Group A served as an untreated control group. Groups B and C were used to investigate the efficacy of both formulations against adult stages of A. suum and Oesophagostomum spp., Groups D and E for efficacy against larval stages of A. suum and Groups F and G for efficacy against larval stages of Oesophagostomum spp. Pigs of groups A, B, C, D and E were infected on Day-0 with 1000 infective A. suum eggs each. Infective larvae of Oesophagostomum spp. (10,000/pig) were given on Day-0 to pigs of Groups F and G and on Day-21 to pigs of Groups A, B and C. Treatment was given to pigs of Group A (saline as placebo) on Day-7 and -28, IVM-1 to pigs of Group F on Day-7, pigs of Group D on Day-14 and pigs of Group B on Day-49. IVM-2 was given to pigs of Group G on Day-7, Group E on Day-28 and Group C on Day-49. Pigs of Groups F and G were sacrificed on Day-28, pigs of Groups A, D and E on Day-49 and pigs of Groups B and C on Day-56. Post mortem worm counts showed the following efficacies: (IVM-1) against larval A. suum 100%, against adult A. suum 94.4%, against larval Oesophagostomum spp. 52.0% and against adult Oesophagostomum spp. 83.0%. (IVM-2) against larval A. suum 100%, against adult A. suum 90.3%, against larval Oesophagostomum spp. 94.0% and against adult Oesophagostomum spp. 94.7%.

[A case of very serious Sarcoptes mange in alpacas (Lama pacos)]. / Een geval van ernstige Sarcoptes-schurft bij alpaca's (Lama pacos).

After the diagnosis sarcoptic mange in four alpaca's (Lama pacos) we have tried to control this infection. Despite three treatments with doramectin, three with ivermectin, four with amitraz and two with diazinon we were unable to get the animals free of Sarcoptes mites and their condition deteriorated. One animal died six month after the first treatment. The three remaining animals were euthanized one month thereafter.

A survey of gastrointestinal pig parasites on free-range, organic and conventional pig farms in The Netherlands.

The prevalence of gastrointestinal parasites in suckling piglets, weaners, fattening pigs and sows was studied from November 2001 to October 2002 on 16 free-range farms (FRF), 11 organic farms (OF) and 9 conventional farms (CF) by means of faecal examinations of composite samples. Each farm was visited four times with a 3-month interval. Infections with coccidia were found on 43.8% of the FRF, 90.9% of the OF and 66.7% of the CF. Sows had the highest prevalence, particularly on FRF (87.5%) and OF (80%). Ascaris suum was present on 50% of the FRF, 72.7% of the OF and 11.1% of the CF, whereas fattening pigs on FRF (42.9%) and OF (54.5%) had the highest prevalence. Oesophagostomum spp. were observed on 25% of the FRF, 27.2% of the OF and 22.2% of the CF. The infection was most prevalent in the sows on all farm types: 37.5% on FRF, 30% on OF and 22.2% on CF.Trichuris suis was found on 37.5% of the FRF, 36.4% of the OF and 11.1% of the CF. Again, this infection was most prevalent in the sows, particularly on the FRF (50%) and OF (30%). No other gastrointestinal parasite species were found and no clinical signs were observed. No seasonal trends could be distinguished. In many cases, when an age group on a farm was positive for a certain parasite, it remained so during the whole study. This indicates that this parasite was really 'endemic' on that farm. The results of this study demonstrate that the prevalence of helminth infections of pigs on farms with outdoor facilities is higher than in pigs on conventional farms.

Efficacy of a topically administered combination of emodepside and praziquantel against mature and immature Ancylostoma tubaeforme in domestic cats.

This paper reports the efficacy of emodepside/praziquantel spot-on (Profender), Bayer AG, Leverkusen, Germany), a novel broad-spectrum anthelmintic for dermal application, against L4 larvae and immature adult and adult stages of Ancylostoma tubaeforme in cats. The formulation contains 2.14% (w/w) emodepside and 8.58% (w/v) praziquantel, with emodepside being active against gastrointestinal nematodes and praziquantel against cestodes. Five randomized, blinded and controlled laboratory studies demonstrated 100% efficacy of emodepside/praziquantel spot-on against mature A. tubaeforme and an efficacy of >95% and >97%, respectively, against L4 larvae and immature adults (based on worm counts after necropsy) at approximately the minimum proposed dose rate in cats of 3.0 mg emodepside and 12.0 mg praziquantel/kg body weight. No adverse reactions to the treatment were observed. It is concluded that emodepside/praziquantel spot-on is an effective and safe treatment against infections with mature and immature A. tubaeforme. Emodepside/praziquantel spot-on will considerably facilitate the treatment of cats against nematodes and cestodes compared with orally administered preparations.

Attempt to detect evidence for tick-borne encephalitis virus in ticks and mammalian wildlife in The Netherlands.

To investigate if tick-borne encephalitis virus (TBEV) is present in mammalian wildlife species or ticks in The Netherlands, serum samples and ticks were tested for TBEV antibodies and TBEV RNA, respectively. Serum samples were collected from wild boar (666), deer (13), fox (399), and rodents (90), and were tested for TBEV antibodies, using ELISA, and SN test or HI test. Over a period of 4 years, a total of 906 ticks was collected from seven regions in The Netherlands. In four different regions, this was done on a monthly basis and during four consecutive summers. All ticks were tested for TBEV RNA by RT-PCR. TBEV antibody was detected by ELISA in two (0.5%) sera of foxes and 49 (7%) sera of wild boar, but not confirmed by HI or SNT. TBEV RNA was not detected in any of 906 ticks. It was concluded that there is no real evidence for a TBEV reservoir in ticks or wildlife in The Netherlands.

[Drug resistance makes new control measures of stomach parasites in small ruminants necessary]. / Resistentie maakt nieuwe aanpak van de bestrijding van maagdarmwormen bij kleine herkauwers noodzakelijk.

Control of parasitic gastroenteritis in small ruminants is threatened by the worldwide growing problem of anthelmintic resistance. Therefore, alternative approaches for worm control are imperative. Of utmost importance is to slow down selection pressure for anthelmintic resistance by using alternative control measures combined with minimal anthelmintic usage. New control options for the Netherlands are discussed.

[Death by cyathostominosis]. / Sterfte door cyathostominosis.

In autumn 2002 and 2003, the Animal Health Service received several young horses for post mortem investigation that had died or had been euthanised. It was found that severe cyathostominosis was the cause of death. The aetiology, pathology and diagnosis of this infection is discussed. Advice is given for preventative measures and usage of anthelmintics.

[Echinococcus multilocularis: the prevalence of the fox tapeworm with possible serious consequences for humans]. / Echinococcus multilocularis: de kleine lintworm van de vos met mogelijk grote gevolgen voor de mens.

The prevalence of the fox tapeworm in foxes (final host) and muskrats (one of the intermediate hosts) in the Netherlands and Europe has been discussed. The tapeworm was found in 9.4% of the investigated foxes from the province of Groningen and in 0.2% of the muskrats from the same region. Also in the province of Limburg positive foxes were found, but no positive muskrats. Possible ways of infection for humans are described together with methods for prevention. It is concluded that at this moment risks for humans to become infected are minimal, but vigilance and monitoring of foxes and muskrats remains needed.

Myiasis in sheep in The Netherlands.

In 1999, among 164 randomly selected Dutch sheep farmers, a questionnaire was carried out to estimate the prevalence of myiasis in sheep and to investigate factors associated with the occurrence of myiasis. The total number of sheep and/or lambs on the reference date 1 August 1999 was 12,200: 5243 ewes, 225 rams, 3393 ewe- and 3339 ram lambs. On 86 (52.4%) of the farms 349 (2.9%) of all sheep and/or lambs contracted myiasis, of which two died. Myiasis was seen significantly more frequently on farms with over 25 ewes compared to smaller farms. Cases of myiasis were detected from April to September, with a peak (47.1%) in August. Occurrence of myiasis was most frequently associated with hot and humid weather and was mainly observed (69.1%) in the area around the tail.Ewes and ewe lambs had significantly more myiasis when compared with rams and ram lambs. There was no relationship with tail docking, with breed, with the time of shearing, with the kind of soil (clay, sand, etc.), with the environment (bush, trees, water, etc.), with the type of treatment (pour on, dipping, spraying), the used insecticides (synthetic pyrethroïds, diazinon, cyromazin, etc.), the number of preventive treatments, the time of treatment or the number of observations on the herd (once a day, once a week, etc.).

Ascarid nematodes in domestic and wild terrestrial mammals.

The biology of the ascarid nematodes has been discussed in the context of their important economic role in farm animals, pet animals and zoo animals with special attention to carnivores and primates. In farm animals, infection with the most common roundworm of horses (Parascaris equorum) and swine (Ascaris suum) depend on many factors such as environmental conditions (larval development in the egg and egg survival), age of the host, breed, husbandry system, hygiene and treatment schedule. The monoxenic ascarids Toxocara canis and T. cati are the most important nematodes in carnivorous animals (dogs, cats, foxes) and carnivores in the zoo. In the period of March 2000 till March 2001, 57.1% of examined representatives of Felidae, Ursidae and Canidae in the Zoological Garden of Wroclaw were found to be infected with ascarids (T. canis, T. cati, Toxascaris leonina). The prevalence of T. canis in the Canidae was 66.7%, of T. cati in the Felidae was 14.3%, while 57.1% of the Felidae carried T. leonina infection. Ascaris lumbricoides, a typical parasite of primates, was found in some gorillas, chimpanzees and orang-utans during parasitological survey.