Spiculopteragia asymmetrica is a gastrointestinal nematode frequently found in the abomasum of cervids including roe deer (Capreolus capreolus), red deer (Cervus elaphus) and fallow deer (Dama dama). It is rare in some domestic and sylvatic bovids and camelids primarily in the Palearctic and Eurasia.1-3 The history and geographic distribution of Spiculopteragia spp. in the world is not completely known. The first report of S. spiculoptera was from white tailed deer on Anticosti Island, Quebec, Canada, however, the origin of this parasite on the island has not been clarified. The historical geographic range of Spiculo-pteragia considered herein, apparently includes the Palearctic and Eurasia. However, the current geographic range has expanded through translocation of infected hosts. Consequently, S. spiculoptera has become established in New Zealand, Australia, and Argentina and S. asymmetrica in New Zealand, USA, Argentina and Turkey.4-6 The life cycle of Spiculopteragia spp.in sylvatic ruminants are direct, however, specific details of larval development and adult longevity are undetermined. Adults reside in abomasum, embryonated eggs are passed in feces, and the first through third larval stages are free-living. The prepatent period requires between two and three weeks.7
There is no report of Spiculopteragia species from cervids in Iran. This study described the existence and the morphology of S. asymmetrica in red deer.
Materials and Methods
During December and February 2010, two Cervus elaphus were died in Semeskandeh sanctuary in Sari, Mazandaran province. These animals were autopsied. For the first deer infectious necrotic hepatitis and for the second one impaction was diagnosed as the cause of death. To determine the helminthes infection, the content of abomasum, small intestine and large intestine were washed away separately throw a sieve (mesh 100) and infestation rate was evaluated through counting the total worms. In the abomasums of both of deer several worms were recovered. Nematodes were cleaned with physio-logical saline and preserved in a solution of 70% ethanol. After cleaning, morphometric data were determined using a calibrated light microscope with ocular micrometer (Leitz, Wetzler, Germany) and a camera lucida (Carl Zeiss, Jena, Germany). Furthermore, five live deer from mentioned area were used for assessment of helminthes infection by parasitological examinations. For this purpose, each animal was treated by 0.2 mg kg-1 subcutaneous injection of Ivermectin 1% (Razak Pharmaceutical Co., Tehran, Iran) to purge intestinal worm. All collected fecal specimens were passed through a sieve and worms recovered as mentioned above. For determination of eggs in the feces, the fecal samples were collected and examined by flotation method with mixing saturated zinc chloride and saturated sodium chloride solution (Density=1.52).
For confirmation of diagnosis, five male and five female nematodes were sent to US National Parasite Collection, Baltimore Avenue, Beltsville, USA. The specimen was deposited, as S. asymmetrica with the code number: USNPC, 104365.
Based on morphological characteristics recovered nematodes were diagnosed as S. asymmetrica and all of the examined animals were infected only with this species.
Number of worms recovered from two dead animals were 275 (90 male and 185 female) and 327 (102 male and 225 female). In the fecal examination of treated animals a few number of worms (45.0 ± 5.0) were also recovered. Nematode descriptions are as follow:
Male: They are small and thin. Length of body is 6.5 ± 1.5 mm. Anterior end without cuticular thickening. There are longitudinal ridges on cuticle. Cervical papillae are present (Fig. 1A). The two spicules are dark brown color and almost equal size (249.0 ± 15.0 µm). The spicules on their terminal part have a nod with size of 9.0 ± 1.0 µm, height of 15.0 ± 1.7 µm (Figs. 1B and 2).
Female: Average size of female was 8.5 ± 2.0 mm. Vulva lies 2.5 to 2.7 mm from the end of tail (Fig. 3A). In the examination of fecal samples of treated animals, strongyle-type eggs were observed. The eggs are oval and have a length of 82.0 ± 7.0 µm and a width of 44.0 ± 5.0 µm (Fig. 3B).
Fig. 1. A) Spiculopteragia asymmetrica, anterior end, cervical papilla (Arrows); B) Spicules of S. asymmetrica, terminal nod (Arrow).
Fig. 2. Spicules of S. asymmetrica in Cervus elaphus (Drawing by camera lucida).
Fig. 3. A) Female S. asymmetrica; vulva (Arrow), (Drawing by camera lucida); B) Strongyle type egg recovered from feces by flotation method.
Spiculopteragia is a parasitic nematode in many species of cervids and domestic animals in the world and it may be regarded as a pathogen in wild ruminants. Red deer and Roe deer are primarily main reservoir hosts of Spiculo-pteragia but domestic livestock can rarely get infected. The taxonomic status of Spiculopteragia is not clear and little is known about its pathology and epidemiology. The genus Spiculopteragia is similar to Ostertagia but differs in that males have no gubernaculum and their spicule have a nod at the posterior end.
There have been some studies for evaluation of parasitic infection in wild cervids and several species have been reported in this genus from America, Europe and Asia.1,4-6 Fruetel and Lankester reported S. spiculoptera from captive woodland caribou in Ontario, Canada.7,8 The first report of S. asymmetnica in the United States was from fallow deer on Little St. Simons Island, Georgia, USA.9 Subsequent records were from fallow deer from Kentucky,10 and Texas.11 Rossi et al. reported S. spiculoptera in the roe deer in Italy.12 Detected nematode species in roe deer in Turkey were identified as S. spiculoptera and S. mathevossiani.6 There is no study on helminths infection of red deer in Iran and also Spiculopteragia species are not previously reported. Based on morphological characteristics detected nematodes in red deer were diagnosed as S. asymmetrica. This is the first report of existence of S. asymmetrica from cervids in Iran. However, additional studies are needed to evaluate epidemiology and morphology of the parasite in wild life animals.
Authors would like to sincerely thank Professor Eric Hoberg in US National Parasite Collection, Animal Parasitic Diseases Laboratory for identification confirmation of nematode.