Periparturient increase in faecal egg counts in a captive population of mohor gazelle (Gazella dama mhorr)

Effects of age, sex, lactation and social dominance on faecal egg count patterns of gastrointestinal nematodes in farmed eland (Taurotragus oryx)

The eland is a large African antelope that can be bred in a temperate climate, under similar conditions and production systems as cattle. However, knowledge of parasites in farmed elands outside the area of their native habitat is still limited, and information concerning factors that influence these parasites is lacking. Therefore, faecal samples from an entire herd of elands, including calves and adult females and males, were examined monthly over a one year period. Almost 84% of the animals were found to be positive for gastrointestinal nematodes. Strongyle-type eggs were most frequently detected (prevalence 75%), followed by Capillaria sp., Nematodirus sp. and Trichuris sp. eggs. Following culturing eggs to infective larvae, Teladorsagia sp., Trichostrongylus sp., Nematodirus sp., Cooperia sp. and Oesophagostomum sp. were identified. Following necropsy of two calves that died during the study one abomasal nematode (Teladorsagia circumcincta), five small intestinal nematode species (Nematodirus helvetianus, N. spathiger, Cooperia oncophora, C. curticei and Capillaria bovis) and two large intestinal nematodes (Oesophagostomum venulosum and Trichuris ovis) were recovered. From these findings, it is evident that the eland harbours nematodes that are typical for domestic cattle and small ruminants. Morphological and morphometric analyses of recovered nematodes revealed that these parasites do not require any special morphological adaptation to establish infection in elands. The faecal output of strongyle-type and Nematodirus sp. eggs was seasonal, with the highest egg production taking place during spring and summer. Calves had higher faecal egg counts (for all the monitored nematode species) than adults did. Lactation in females was significantly (P<0.0001) associated with higher strongyle nematode egg shedding. Social dominance also affected faecal egg count patterns. The lower the hierarchical position among adults (regardless of sex), the higher the risk of nematode infection. This effect was evident for strongyles (P<0.0001) and Capillaria sp. nematodes (P=0.0065). The results of our study suggest that control measures applicable in domestic cattle and small ruminants might be similarly applicable for controlling gastrointestinal nematode infections in captive farmed elands.

First description of gastrointestinal nematodes of Barbary sheep (Ammotragus lervia): the case of Camelostrongylus mentulatus as a paradigm of phylogenic and specific relationship between the parasite and its ancient host

The gastrointestinal helminth fauna of 24 Barbary sheep or Aoudad (Ammotragus lervia sahariensis) maintained in the Parque de Rescate de la Fauna Sahariana (PRFS, CSIC, Almeria, Spain) was analyzed. Most animals (87.5 %) were parasitized, and multiple infections were highly present. The following species were identified: Camelostrongylus mentulatus, Teladorsagia circumcincta, Marshallagia marshalli, Ostertagia ostertagi, O. leptospicularis, O. lyrata, Haemonchus contortus, Teladorsagia trifurcata, Trichostrongylus vitrinus, T. colubriformis, T. probolorus, T. capricola, Nematodirus spathiger, N. abnormalis, N. filicollis, N. helvetianus, Trichuris spp. and Skrjabinema ovis. Teladorsagia circumcincta was the most prevalent nematode in abomasum (52.6 %) followed by C. mentulatus (50 %). However, this latter nematode had the greater mean intensity and abundance. In the small intestine, T. colubriformis and T. vitrinus had the highest prevalence (36.4 %); the last one showed also the greater mean intensity and abundance. It should be emphasized the presence of Skrjabinema ovis (prevalence 39.1 %) in the large intestine, showing the greater mean abundance and intensity, although with a low values. Camelostrongylus mentulatus could be the most primitive nematode of the family trichostrongylidae recovered in this study; attending to its high prevalence, mean abundance and mean intensity, the possible specificity between this parasite and the Aoudad is discussed.

Avoiding bias in parasite excretion estimates: the effect of sampling time and type of faeces

The study of host-parasite relationships usually requires reliable estimates of parasite intensity, which is often estimated from parasite propagule concentration in faeces. However, parasite excretion in faeces may be subject to variation due to endogenous or exogenous factors that must be identified to obtain reliable results. We analysed the effect of the hour of sample collection on propagule counts of 2 intestinal parasites infecting the red-legged partridge: the capillarid nematode Aonchoteca caudinflata and coccidia of the genus Eimeria (Protozoa). Also, we test whether there are differences in propagule counts between caecal and intestinal faeces. Individual faecal samples from infected birds were collected daily at 4 different hours during several days. The hour of the day exerted a very strong effect on propagule counts, excretion of both types of parasites showing a clear and constant increase from dawn to dusk. Also, capillarid eggs were more abundant in intestinal than in caecal faeces, whereas the inverse pattern was found for coccidian oocysts. Standardization of the hour of sample collection or statistical control of this variable is recommendable to prevent bias. Similarly, in bird species with long caeca, consistent collection of one type of faeces may avoid significant errors in parasite burden estimates.