Hepatic Helminths in Red Deer in Two Climatic Regions in Spain

Hepatic helminths in red deer in two climatic regions in Spain. Valcárcel, F. Centro de Investigaciones Agropecuarias Dehesón del Encinar Consejería de Agricultura, JCCM Abstract: Elaeophora elaphi was detected in 14.7% of 183 li vers of red deer, Cervus elaphus, in two climatic regions of Spain. Overall mean in tensity (3.9 worms per liver) was in fluenced by age and prevalence was significantly higher in the dly area (2 1. 5%) than in the mid-wet area (5.3%). Fasciola hepatica (adults and eggs) and Dicrocoelium dendriticum (eggs) were found in the mid wet and in the dly area, respectively. Key words: Red deer, Elaeophora elaphi, Fasciola hepatica, Dicrocoelium dendriticum, prevalence, intensity, seasonality, dry areas, mid-wet areas Resumen: Se ha detectado la presencia de Elaeophora elaphi en el 14.7% de 183 hígados de ciervo rojo procedentes de dos áreas climáticas de España. El promedio de infección (3.9 vermes por hígado) estuvo influido por la edad así como la prevalencia fue significativamente mayor en la zona seca (21.5%) que en la semihúmeda (5.3%). Fasciola hepatica (adultos y huevos) y Dicrocoelium dendriticum (huevos) se detectaron en la zona semihumeda y seca, respectivamente. Palabras clave: Ciervo rojo, Elaeophora elaphi, Fasciola hepatica, Dicrocoelium dendriticum, prevalencia, intensidad, áreas secas y semihúmedas 1. Introduction Elaeophora elaphi was first described in the Table l. Characteristics, climate data and number of examined portal vein ofthe red deer Cervus elaphus by Hernández samples from the study sites. Rodríguez et al. (1986). Later, some authors have Annual Red deer reported data about pathogenicity or prevalence Median Characteristics temperature Rainfa ll examined (Carrasco et al., 1995 and 1998, San Miguel et al., 1999; (oC) (mm) Corchero et al., 2000; Luzón et al., 2001). Fasciola Dryarea hepatica has be en reported recently in red deer on the (Toledo and Mediterranean Iberian Peninsula (Maia et al., 1999; Corchero et al., Ciudad Real) tableland 15.2 314.9 107 Mid-wet area Conti nental 2000; Hidalgo Arguello et al. , 2001). Therefore, little is (Cuenca) mountain forest 13.1 47\.6 76 known about the epidemiology of hepatic helminths in this ungulate. The aim of this study was contribute to our knowledge of its prevalence and seasonal dynamics to the climatic characteristics of the game reserves in red deer in two climatic regions in Spain. (Table 1). Age was calculated according to dental eruption and a sectional cut of an incisor. 2. Material and methods After the veterinary inspection, livers (n= 183) The study was carried out from October 1997 and faeces (n= 168) were collected and transported to to December 2000. The deer were grouped according the laboratory. Blood samples (n= 74) were collected from the heart immediately after being shot. Parenchyma and hepatic vessels were opened Corresponding author: Dr. Féli x Valcárcel longitudinally in order to recover the helminths. Centro de investigaciones Agropecuarias Dehesón del Encinar Trematoda egg output was detected by McMaster 45560 -Oropesa (To ledo, Spain) Te\. 925 450 443 Fax. 925 450447 analysis. A modified Knott technique was used to E-mail : [email protected] Revista Ibérica de Parasitología (2003), 63 (1-2), 1-4 © 2003 Sociedad Española de Parasitología (SEP) 2 Valcárcel, F., Hepatic helminths in Spanish red deer detect first-stage larvae of filarial nematodes. Parasite identification was performed according to Hernández Rodríguez et al. (1986) and Meana et al (2000). X2 and T-test were performed to establish statistical differences. 3. Results 3.1 Nematodes 1., . :.1dry __ __ GLOBAL Specimens or calculus covering dead specimens of E elaphi were found in 27 (14.7%) of Figure 1. Seasonal prevalence of Elaeophora elaphi in red deer in t{vo climatic regions in Spain (mid-wet area: Cuenca; dly the examined red deer. Area influenced the infection area: Toledo and Ciudad Real). Arrow point out significant of Cervus elaphus by E elaphi, prevalence being difference between climatic areas for the same season. significantly higher in the dry are a (p<0.01) although the level of infection was quite similar in both climatic regions (Table 2). Prevalence was 8 always lower in the mid-wet area but dynamic was quite similar in both areas reaching the highest B 6 levels of infected animals from summer to winter b (Fig. 1). Prevalence during autumn was significantly higher in the dry area than in the mid-wet area 4 b I (p=0.10). In contrast, the intensity of infection was e clearly influenced by season, showing a summer 2 autumn trend in the dry area while in the mid-wet a area animals were more heavily infected during winter (Fig. 2). o The level of infection decreased with age. spring summer autumn winter o mid-wet O dry Prevalence, on the other hand, was high in the youngest red deer, dropped significantly in animals Figure 2. Seasonal mean intensity of E.elaphi in red deer in two between 3-4 years and then rose significantly with the climatic regions in Spain (mid-wet area: Cuenca; dry area: age (Fig. 3). Toledo and Ciudad Real). Bars with different letters are signi We have not found significant influence of ficantly different (capital letters refer to mid-wet area and the stocking rate or sex in Eelaphi infection. No lower-case refer to dry area). Arrows point out significant dif ference between climatic areas for the same season. microfilariae was found in the blood samples. worms/liver % h . .} : :1prevalence e 100 ...... mean intensity 8 Table 2. Prevalence, mean intensity and range of Elaeophora 80 elaphi in Cervus elaphus in Spain. Mid-wet afea (Cuenca), Dry 6 area (Toledo-Ciudad Real) 60 4 40 Prevalence Mean intensity SD Min Max 20 2 (%) (wonns/liver) (mm) Total 14.75 3.96 3.50 15 O O Male 17.89 4.41 3.91 15 1-2 3-4 5-6 7-8 9-10 >10 Female 11.36 3.20 2.70 8 years X2 It-test ns ns Mid-wet area 5.26 3.75 2.06 6 Figure 3. Evolution of prevalence and mean intensity of E. elaphi Dryarea 21.50 4.00 3.73 15 in Cervus elaphus in Spain by age group. Bars with different X2 1t -test P<O.OI ns letters are significantly different. 3 Valcárcel, F., Hepatic helminths in Spanish red deer 3.2. Tremalodes (Carrasco el al., 1998) that may produce a significant Fasciola hepatica (adults) were found in decrease in the intensity of infection when animal s three livers and two faeces (eggs) from the mid-wet are immunocompetent and the number of worms area, with a significantIy higher prevalence in stays low despite the animal s having more females than in the males (P<O.OI). Dicrocoelium opportunities to become infected over the years. dendrilicum ( eggs) was only identified in one Fasciola hepalica has be en found in red deer animal from the dry area (Table 3). from other countries (McDiarmid, 1975; Watson and Charleston, 1985; Maia et al., 1999; Maia, Table 3. Prevalence (% of infected animal s), mean intensity and range (flukes per liver or eggs per gram of faeces) of 2001) but was first reported in Spanish red deer Fasciola hepatica and Dicrocoelium dendriticum in Cervus very recently (Corchero el al., 2000; Hidalgo elaphus in Spain. Argüello et al., 2001). Outside the Iberian Peninsula this trematode is present in 31% of wild animals N Prevalence Mean intensity SO Min Max (Bairth and Schaich, 1973; Shimalov and Shimalov, Fhepatica adults Total 183 1.64 5.00 6.08 12 2000). The absence of this species in the dry area Oryarea 107 agrees with other studies in the same region on red Mid·wet area 76 3.95 5.00 6.08 12 deer and domestic sheep and goats (Valcárcel el al., Male 29 3.45 1.00 0.00 I I 1998; San Miguel el al., 1999; Valcárcel and García Female 47 4.26 7.00 7.07 2 12 X2 I t·test ns P<O.OI Romero, 1999). The detection in the mid-wet area Fhepatica is probably due to the more suitable habitat egg output 168 1.19 15 15 15 conditions for the intermediate hosts. D.dendriticum Although the prevalence of Dicrocoelium egg output 168 0.60 90 90 90 dendriticum in the faeces is very low, it is important because this is the first reference about this 4. Discussion trematode in Cervus elaphus in this dry part of The life cycle of E. elaphi is unknown but Iberian Peninsula. tabanid vectors could be associated with The role of red deer as definitive host for transmission, as they are for E. schneideri (Soulsby, E. elaphi is generally accepted, but the endemic 1987). Tabanid development needs warmth and distribution (only in Spain) and the limiting character light (Valcárcel el al., 2001), so dry habitats seem to of the infection (abundance of calculus of dead be appropriated for vector development. This could nematodes, the absence of microfilariae detected in partially explain the higher prevalence in Toledo blood analysis) make us wonder if it is just an Ciudad Real and the presence of E. elaphi in other accidental host. In consequence, further studies must dry areas (Hernández Rodríguez el al., 1986; be done in order to determine its importance as a Carrasco et al., 1995and 1998; Luzón et al., 2001). parasite in red deer. It could also explain why E. elaphi has not been detected in other Iberian wet areas (Antón Muñoz et 5. Acknowledgements al., 1985; Maia el al., 1999; Hidalgo-Argüello et al., The author thanks Doctors Corchero, García Romero, 2001; Bruno de Sousa, 2001).

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