Abstract: Parascaris equorum (ascarid; roundworm) is a common nematode parasite which occurs in the small intestine of immature horses world-wide. Adult female ascarids lay eggs in the small intestine, and these eggs pass into the environment within the feces of the host. P. equorum is one of the rare nematodes which induce absolute acquired immunity. Most horses become immune during the first year of life, so patent ascarid infections are rarely diagnosed in horses over two years of age. The aim of this study was to determine the prevalence of infection with parascaris equorum in Tehran’s riding clubs. The prevalence and rate of infection was determined based on the coproscopic examination. Fecal samples were tested for the presence of parascaris using suspend method. In this investigation, 442 fecal samples of horses from North-East of Tehran’s riding clubs examined. From the viewpoint of parascaris roundworms, fecal samples were obtained from each box separately and send in containers with plastic lid. The samples were then transferred to the parasitology lab for further examination. The infection was recognized based on the observation of parascaris eggs in coproscopic examination. The infection rate in the foal in this study was zero percent. Another interesting result was increasing the infection rate in horses of 10 years or even older and gelding. Out of 442 samples, the infection rate in the samples taken in summer, was 3.16%, and in the fall, winter and spring it was 2.4%, 10% and 3.16% respectively. The infection rates in relation to the age, sex, excursion condition, seasons and deworming programs was studied too. The results showed that the local and the imported horses should be monitored parasitologically, because endoparasites may create a major epizootiolocall problem when these animals are kept in an organic raising system. Deworming program is to be continued with proper methodology, dose and throughout the productive age of the horses.

Abstract: Systematic faunal studies in the district Schwerin showed at the present time there are 3 more or less damage-biotopes existing in the districts of Perleberg, Ludwigslust and Parchim; 5 river sources can be considered as potential sources, 5 are temporary and 2 are ephemeral whilst in 3 further areas environmental influences such as effluent impairs the flow of the river and the developmental stages of Simuliidae were not observed.--The following species were found: Boophthora erythrocephala, Wilhelmia salopiensis, Wilhelmia equina, Odagmia ornata, Eusimulium aureum and Eusimulium lundstroemi.--The damage statistics covering the period 1966--1971 showed in the district of Schwerin, due to Simuliid attacks, 38 cattle died, 170 were seriously ill; in 1967 5 horses were seriously ill; in 1971, 3 pigs died and 27 were seriously ill.--The symptoms were manifested by pathological petechiae, scabs and oedema, also by insufficiency of the heart and circulatory system, diminished performance and growth disturbance. In severe cases heart and circulation failure occurred, paresis, coma and death followed.--The real economic significance of the Simuliid attacks rest with its strong and prolonged distrubance in young animals, as well as in pronounced irreparable diminished performance in diseased dairy cattle.

Abstract: Each month for a 1-year period (October through September), equine fecal masses containing eggs of strongylid nematodes were placed outdoors on small grass plots in Saskatchewan, Canada. Thereafter, feces and grass from the plots were sampled after intervals of 1 week or longer, and the strongylid eggs and larvae recovered were counted. These observations were made over a 2-year period. Development of eggs to infective larvae occurred in all experiments, except those established in October, December, and January. Infective larvae from experiments set up in April through September survived that winter. During the summer, there was a gradual build up of infective larvae in the fecal masses, which reached a peak in August and September and then decreased into the winter. These results are discussed in the context of the control of strongylid parasites of horses on the Canadian prairie and in other areas of the world with a similar climate and similar horse management practices.