Bovine eimeriosis in Swedish calves: Epidemiology and insights into sampling procedures.

Bovine eimeriosis is a common, globally distributed infection in housed calves aged from 3 to 12weeks. To date, no national prevalence study revealing the occurrence and distribution of Eimeria species under Swedish environmental and farming conditions has been performed. This study revealed the excretion of Eimeria bovis or Eimeria zuernii (alone or together) in 23% of all sampled calves (N=541) and 61% of all herds (N=99). The number of tested calves was critical for whether positive calves were detected or not. Nine other Eimeria species were identified, the most frequently reported being Eimeria ellipsoidalis (9% and 35% of positive calves and herds, respectively) and Eimeria auburnensis (4% and 19% of positive calves and herds, respectively). Not all calves shedding oocysts had diarrhoea and not all diarrhoeic calves shedded oocysts. Based on these present findings, Swedish cattle practitioners should include bovine eimeriosis as a relevant differential diagnosis to other common gastrointestinal pathogens in 3 to 12weeks old calves with diarrhoea or unthrifty calves without diarrhoea. When testing a herd for bovine eimeriosis, a sufficient number of faecal samples, i.e. 10 or more samples, should be examined to obtain a reliable picture of the infection status in a given farm.

Willingness to pay for compulsory deworming of pets entering Sweden to prevent introduction of Echinoccoccus multilocularis.

To investigate if the Swedish entry rules for pets to prevent the introduction of Echinococcus multilocularis (EM) are proportional (i.e. that their costs do not exceed the value of their benefits), a dichotomous-choice contingent valuation study was conducted. The study was performed before the first case of EM was detected in Sweden in February 2011. About 5000, randomly selected, Swedish citizens were invited to participate and 2192 of them (44%) accepted to do so. Missing information on whether or not one would accept to pay for keeping the rules for 143 respondents resulted in 2049 observations (41%) available for the estimation of willingness to pay (WTP), and missing information on personal characteristics for another 274 respondents reduced the number of observations available for sensitivity analysis to 1775 (36%). Annual expected WTP for keeping the rules ranged between € 54.3 and € 99.0 depending on assumptions about compensations demanded by respondents not willing to pay. The estimates are conservative since only answers from respondents that were absolutely certain they would pay the suggested bid were regarded as yes-responses. That WTP is positive implies that Swedish citizens perceived the benefits of the rules to be larger than their costs.

Combining information from surveys of several species to estimate the probability of freedom from Echinococcus multilocularis in Sweden, Finland and mainland Norway.

BACKGROUND: The fox tapeworm Echinococcus multilocularis has foxes and other canids as definitive host and rodents as intermediate hosts. However, most mammals can be accidental intermediate hosts and the larval stage may cause serious disease in humans. The parasite has never been detected in Sweden, Finland and mainland Norway. All three countries require currently an anthelminthic treatment for dogs and cats prior to entry in order to prevent introduction of the parasite. Documentation of freedom from E. multilocularis is necessary for justification of the present import requirements. METHODS: The probability that Sweden, Finland and mainland Norway were free from E. multilocularis and the sensitivity of the surveillance systems were estimated using scenario trees. Surveillance data from five animal species were included in the study: red fox (Vulpes vulpes), raccoon dog (Nyctereutes procyonoides), domestic pig, wild boar (Sus scrofa) and voles and lemmings (Arvicolinae). RESULTS: The cumulative probability of freedom from EM in December 2009 was high in all three countries, 0.98 (95% CI 0.96-0.99) in Finland and 0.99 (0.97-0.995) in Sweden and 0.98 (0.95-0.99) in Norway. CONCLUSIONS: Results from the model confirm that there is a high probability that in 2009 the countries were free from E. multilocularis. The sensitivity analyses showed that the choice of the design prevalences in different infected populations was influential. Therefore more knowledge on expected prevalences for E. multilocularis in infected populations of different species is desirable to reduce residual uncertainty of the results.

Ascarid infections in laying hens kept in different housing systems.

The present study was undertaken to investigate the prevalence of ascarid infections in Swedish commercial laying hens in 2004 and 2008 following a recent nationwide change to alternative housing systems but before anthelmintics became available. Also, the influence on prevalence of farm and flock characteristics and management was studied in 2004. The results showed that the overall prevalence was significantly higher in 2008 (38%; n = 64/169) compared with 2004 (24%; n = 44/186) (P = 0.001). Ascarid infections were rare in caged flocks, including furnished (enriched) cages, both years (2.4 to 4.3%), and were significantly more common in non-cage systems in both years (16.7 to 48.6% in 2004, and 28.6 to 77.1% in 2008 depending on the housing system). There was no significant difference in prevalence between hens kept on litter indoors and free-range/organic hens. The absence of a hygiene barrier at the entrance of the house or unit increased the risk of infection (P < 0.001), which suggests that parasite eggs were introduced horizontally to the farms. The risk of infection also increased with the age of equipment used in the barn; for example, the risk increased with an odds ratio of 7.5 (95% confidence interval = 2.3 to 25) when comparing equipment 1 year old with equipment ≥7 years old. The results of this study show that ascarid infections may re-emerge following a change to alternative housing. With the impending ban on conventional battery cages in the member states of the European Union, ascarid infections are likely to increase in importance and efficient control options such as hygiene barriers should be implemented on all farms.

Detection of Babesia divergens in southern Norway by using an immunofluorescence antibody test in cow sera.

BACKGROUND: The incidence of bovine babesiosis, caused by Babesia divergens (Apicomplexa: Piroplasmida) has decreased markedly since the 1930 s, but may re-emerge as a consequence of climate change and changes in legislation and pasturing practices. This is a potentially serious disease, with both economical and animal welfare consequences. Therefore, there is a need to survey the distribution of B. divergens. METHODS: We tested sera from 306 healthy pastured cows from 24 farms along the southern Norwegian coast by using an indirect immunofluorescence IgG antibody test (IFAT). Fractions of seropositive cows were compared by calculating 95% CI. RESULTS: The results of this test showed that 27% of the sera were positive for B. divergens antibodies. The fraction of antibody-positive sera that we detected showed a two-humped distribution, with a high fraction of positives being found in municipalities in the western and eastern parts of the study area, while the municipalities between these areas had few or no positive serum samples. CONCLUSIONS: Neither the farmers' observations nor the Norwegian Dairy Herd Recording System give an adequate picture of the distribution of bovine babesiosis. Serological testing of cows by using IFAT is a convenient way of screening for the presence of B. divergens in an area.

Anthelmintic efficacy on Parascaris equorum in foals on Swedish studs.

BACKGROUND: In the last few years stud farms have experienced increasing problems with Parascaris equorum infections in foals despite intensive deworming programs. This has led to the question as to whether the anthelmintic drugs used against this parasite are failing. This study aimed to investigate the efficacy of ivermectin, fenbendazole and pyrantel on the faecal output of ascarid eggs of foals. METHODS: A Faecal Egg Count Reduction Test (FECRT) was performed on nine large studs in Sweden. Anthelmintic drugs were given orally and faecal samples were examined for ascarid eggs on the day of deworming and 14 days later. Faecal Egg Count Reductions (FECRs) were calculated on arithmetic means of transformed individual FECRs and on arithmetic means of individual FECRs. RESULTS: Seventy-nine (48%) out of a total of 165 foals sampled were positive for P. equorum eggs before deworming and 66 of these met the criteria for being used in the efficacy assessment. It was shown that there was no, or very low activity of ivermectin on the output of ascarid eggs in the majority of the foals, whereas for fenbendazole and pyrantel it was >90%. CONCLUSION: Ivermectin resistance was shown in 5 out of 6 farms. Therefore, ivermectin should not be the drug of choice in the control of P. equorum infections in foals. According to the results of this study, fenbendazole or pyrantel are still effective and should be used against this parasite.

Clinical efficacy of selamectin in the treatment of naturally acquired infection of sucking lice (Linognathus setosus) in dogs.

A clinical study was performed in 21 dogs to evaluate the efficacy of selamectin for the treatment of naturally acquired infection of sucking lice (Linognathus setosus [L.setosus]) in dogs. Each dog was randomly assigned to one of two treatment groups. One group was treated with selamectin applied topically at a mean dosage of 7.9 mg/kg. The other group was treated with permethrin applied topically at a mean dosage of 85.7 mg/kg. At day 42 posttreatment, all animals remaining in the study (10 treated with selamectin and six with permethrin) were clear of lice. In both groups, the reduction in lice counts from pretreatment values to day 42 was statistically significant at P< or =0.0001. Selamectin applied topically appeared to be effective against L. setosus infection in dogs.

Efficacy of selamectin in the treatment of nasal mite (Pneumonyssoides caninum) infection in dogs.

In a laboratory study to evaluate the efficacy of selamectin for treatment of canine nasal mite infection, 12 purpose-bred beagles were experimentally infected with Pneumonyssoides caninum (P. caninum). Six of the dogs were treated with selamectin applied to the skin of the back at dosages of 6 to 24 mg/kg for three times at 2-week intervals. The remaining six dogs were an untreated control group. At necropsy 39 to 46 days after inoculation, no P. caninum mites were found in any of the treated dogs. In contrast, nasal mites were found in five of the untreated dogs. This difference was statistically significant at P=0.015.