Natividad Díez-Baños

Bronchopulmonary helminths of roe deer (Capreolus capreolus) in the northwest of Spain

From 1993 to 1995, 148 hunter killed roe deer (Capreolus capreolus L.) from game reserves in Lugo (northwestern Spain) were examined for lungworm infection. The overall prevalence of infection was high (66.2%). Infections were comprised to two species, Varestrongylus capreoli and Dictyocaulus noerneri with a prevalence of 62.0 and 18.2%, respectively. Significant differences in the prevalence and larval burdens in lungs and faecal samples were observed between different locations. The highest overall prevalence of lungworm infection was observed in the large reserve at Ancares (78%) in comparison to that in smaller reserves (61.7%). Considering that the species recorded in this study are highly host-specific, it is unlikely that roe deer represent a significant reservoir of lungworm transmissible to domestic ruminants in northwestern Spain.

Interspecific interactions in naturally acquired nematode communities from sheep abomasum in relation to age of host and season in four areas of León (Spain)

The abomasa of naturally infected ewes (407) and lambs (190) from four areas of León were collected weekly over 2 years in the abattoir of León (north-west Spain). The major species and morphs found were Teladorsagia circumcincta and Trichostrongylus axei and to a lesser extent Marshallagia marshalli and Teladorsagia trifurcata. The putative interactions between species were assessed by Euclidian distances based on the results of multivariate analyses. The estimation of interaction was either based on mean intensities of worm burdens or on frequencies of nematode species within individual hosts. The areas, years, seasons and categories of sheep (ewes or lambs) did not influence the interaction estimates. These were not dependent upon the size of worm burden. The majority of interactions were positive. Slight negative interactions were found only with T. circumcincta-T. axei, T. circumcincta-M. marshalli and M. marshalli-T. axei. Positive interactions were recorded between the less frequent species.

Gastrointestinal nematode infections in roe deer (Capreolus capreolus) from the NW of the Iberian Peninsula: assessment of some risk factors.

Intestinal contents of 218 roe deer hunted in the northwest (NW) of the Iberian Peninsula during the 2008-2009 hunting seasons were examined in order to provide information on the gastrointestinal (GI) nematode prevalence and intensity of infection and the possible influence of some environmental and intrinsic factors such as climatic conditions, age and sex. All the animals studied harboured GI nematodes, and a total of 20 different species belonging to ten genera were identified. Spiculopteragia spiculoptera/Spiculopteragia mathevossiani, Ostertagia leptospicularis/Ostertagia kolchida and Nematodirus filicollis were the most common. This is the first citation for Chabertia ovina, Cooperia pectinata, Cooperia punctata, Cooperia oncophora, Haemonchus contortus, Nematodirus spathiger, Oesophagostomum venulosum, Teladorsagia trifurcata, Trichostrongylus capricola, Trichostrongylus colubriformis, Trichostrongylus vitrinus and Trichuris capreoli in roe deer from the Iberian Peninsula. Prevalence and intensity were significantly higher in the abomasum, where infections with more than one GI nematode species were the most common; in the other intestinal segments infections with only one GI nematode species were the most prevalent. When considering the influence of the different risk factors on the prevalence of GI nematodes, the highest prevalence for most of the genera were observed in roe deer from coastal areas, where climatic conditions are more favourable for the development and survival of third stage larvae in the environment. Regarding the sex of the animals, the prevalence was, in general, higher in males than in females, probably due to behavioural and physiological sex-related differences. On the contrary, no differences were found in relation to the age of the animals. This study reveals that roe deer from the NW of the Iberian Peninsula are widely and intensely infected with gastrointestinal nematodes, which probably affect the health status of these ungulates.

Teaching veterinary parasitology throughout the world

In order to understand how the teaching of parasitology in veterinary schools and faculties in the world is carried out, a questionnaire was sent to all centres listed in the W.H.O. World Directory. A total of 91 replies were received. Additional information was obtained from the report of a symposium held in Hannover, Germany in 1978 and from the Education Committee of the American Association of Veterinary Parasitologists in 1981. The academic level, the place of parasitology in the veterinary curriculum, textbooks and practical instruction, evaluation techniques, teaching staff, institute organization and publications are discussed.

Efficacy of moxidectin 1% injectable against natural infection of Sarcoptes scabiei in sheep.

Thirty ewes naturally infected with Sarcoptes scabiei var. ovis, were allocated into three groups of 10 animals each. Animals in groups B and C were treated on day 0 and on days 0 and +10, respectively, with moxidectin 1% injectable at a dose of 0.2mg moxidectin/kg body weight (BW). Group A remained untreated. Seven days before treatment, the geometric mean of Sarcoptes scabiei var. ovis per square centimeter of skin in groups A, B and C were not significantly different. From the day of treatment to the end of the trial, the average number of mites/cm(2) increased in untreated animals and decreased in groups B and C, but these values were higher for group C. Active lesions produced by S. scabiei var. ovis consistently increased during the trial in the untreated animals; in group B the minimum count occurred on day +56 this reduction being more evident in group C (no lesions on days +49 and +56). Also in this group, the number of cured animals was 100%, therefore, the application of two treatments with moxidectin (group C) showed higher efficacy than a single treatment (group B). Body condition score decreased in the three experimental groups along the trial. All animals were individually weighed on days -1, +28 and at the end of the trial. No adverse reactions were observed in the animals treated with 0.2mg moxidectin/kg BW.

The experimental receptivity ofHelicella (Helicella) itala andCepaea nemoralis (Mollusca, Helicidae) to larvae ofMuellerius sp. andNeostrongylus linearis (Nematoda, Protostrongylidae) from chamois (Rupicapra rupicapra)

Two batches ofHelicella (H.) itala (adult specimens) and two ofCepaea nemoralis (adult and young specimens) were experimentally infected with larvae I (L-I) ofMuellerius sp. andNeostrongylus linearis obtained from the lungs and faeces ofRupicapra rupicapra. In assess larval development, the number and percentage of the total number of larvae (L-I+L-II+L-III) per mollusc were studied, together with the number and percentage of L-III per snail and the days on which the different larval stages were reached. The development ofMuellerius sp. andN. linearis was greater in larvae from faeces. For both species of molluscs, the values for the percentages of the total number of larvae and L-III were higher inN. linearis than inMuellerius sp., but there were no notable differences in the days on which the various larval stages were reached. Both nematodes achieved a greater degree of development in young specimens ofC. nemoralis than in adults. Whether the larvae came from facces or the lungs,H. (H.) itala was a better intermediate host thanC. nemoralis forMuellerius sp. andN. linearis.

Antigen characterization from second instars of oestrid bot flies for the detection of anti-Cephenemyia stimulator antibodies by ELISA in roe deer (Capreolus capreolus).

A study to determine the most appropriate antigen for use in the serodiagnosis of Cephenemyia (Diptera: Oestridae) infestation in roe deer (Capreolus capreolus) was carried out using immunoenzymatic tests. Serum samples from 43 roe deer from northern Spain were obtained post‐mortem and corresponding numbers of bot fly larvae established. Three antigen complexes were tested, including Cephenemyia stimulator Clark excretory/secretory antigens (CsES), C. stimulator somatic antigens (CsSA) and Oestrus ovis L. (Diptera: Oestridae) excretory/secretory antigens (OoES). In addition, the composition of each antigen was analysed using an electrophoresis system. Cephenemyia stimulator larvae were found in 25% of roe deer; the mean intensity of infection was 24.3 larvae per infested animal. In the antigen analysis, CsSA showed four exclusive bands of molecular weight (17–19, 62, 65 and 67–70 kDa). A positive correlation between immunoglobulin G (IgG) values and total number of larvae was found with CsES and CsSA. The highest sensitivity value, negative predictive value and negative likelihood ratio were obtained using CsES. The highest specificity value, positive likelihood ratio and kappa value were achieved with CsSA. The predictive values of the enzyme‐linked immunosorbent assay (ELISA) using CsES and CsSA reached statistical significance and seroprevalence values were 26–44%. The use of ELISA with CsES and CsSA seems promising in the non‐invasive diagnosis of Cephenemyia infestation in roe deer.

Efficacy of moxidectin 1% injectable and 0.2% oral drench against natural infection by Dictyocaulus filaria in sheep.

Two separate trials (I and II) with 34 and 32 Churra ewes, respectively, and distributed into two groups, have been carried out to evaluate the efficacy of two different formulations of moxidectin at a dose rate of 0.2mg/kg body weight (b.w.) against natural infection by Dictyocaulus filaria in sheep. Trial I was designed to evaluate a 1% moxidectin injectable formulation, whereas in trial II a 0.2% moxidectin oral drench formulation was used. The efficacy was measured on the basis of the reduction of the faecal larval counts and of adult worm recoveries at slaughter. In each trial, a group of animals was treated on day 0 with moxidectin 1% injectable or moxidectin 0.2% oral drench and the other group acted as untreated control. When the faecal larval counts was compared within the treated groups, the efficacy was over 95% until day +13, and 100% at the remainder of the sampling dates after the application of injectable moxidectin, whereas in trial II, the larvae per gram (lpg) of faeces increased until the first sampling time post treatment (p.t.), day +6, and zero counts were recorded for all animals by the following days. On the basis of adult worm recoveries at necropsy, the efficacy of the treatment was 100% in both trials, however, adult worms were detected at slaughter for all control sheep. These results indicate that moxidectin 1% injectable and moxidectin 0.2% oral drench, administered at 0.2mg/kg b.w., were 100% effective against D. filaria infection in sheep. No adverse reactions to the treatments were observed in the animals.

Faecal egg output, contamination of pastures and serum pepsinogen concentrations in heifers with natural gastrointestinal nematode infections in north-west Spain

In 1988, 1989 and 1990 second year grazing heifers, naturally infected with gastrointestinal nematodes, were separated into two groups, one of which was treated orally with albendazole. In 1988 and 1989 treatment was administered immediately after parturition (February), and in 1990 during the last term of pregnancy (December). Both treated and control animals were grazed on separate plots in a rotational system. Maximum faecal egg counts were observed around parturition, except in 1990, when treatment was given at the end of gestation. The main genera identified were Cooperia, Trichostrongylus, Ostertagia and Oesophagostomum. The number of Ostertagia larvae in the treated groups increased from 1989 to 1990, while the others decreased. Pasture contamination with third stage larvae (L3) was lower on the plots grazed by treated heifers. Maximum numbers of L3 were found in autumn, at the end of winter, and at the beginning of spring. Mean serum pepsinogen concentrations were significantly higher in the untreated groups. This concurs with the pattern for L3 on pasture. The trial shows that if a single treatment against gastrointestinal nematodes is carried out, and the animals remain on contaminated pastures, the parasitic load tends to level out after 4-5 months under favourable climatic conditions. However, the percentages of nematode genera occurring in the new populations may differ from those in the original infection.