EFFICACY OF IVERMACTIN AGANIST SOME NATURALLY ACQUIRED GASTRO-INTESTINAL PARASITIC INFECTION IN MULES

The activity of a single subcutaneous injection of ivermectin at dose of 200 mcg/kg of body weight was evaluated against naturally acquired gastro-intestinal parasites in mules. Faecal samples were examined at the time of treatment and weekly thereafter up to 4 weeks. Results indicated that invrmectin was highly effective (100%) against Oxyuries equi, Strongyloides westeri, Tristostronglus axei, Trichhonema spp., and Strongylus spp. as judged one week after ivermectin administration. Complete elimination of Parascaris equorum eggs occurred two weeks after treatment. In contrast, ivermectin was not effective against the tape worms, Anoplocephala spp.. Infected animals had low levels of haemoglobin and red blood cells counts and an elevated packed cell volume, white blood cells and erythrocyte sedimentation rate. These values returned to normal values 21 days post treatment. No adverse reaction was recorded in the treated animals.

HELMINTHOFAUNA OF HORSES IN TYUMEN REGION

Today, helminthous invasions in horses are one of the important problems for veterinary specialists, since the action of helminths significantly affects the general condition of horses, allergic and toxic manifestations of diseases are observed, external qualities are worsened, performance, endurance, natural resistance are reduced, which leads to the emergence of diseases of various etiologies. We set the goal – to study the helminthofauna of horses in the Tyumen region. For the study of horse helminthoses, an animal survey was conducted in the period 2017–2020. As a result of the data obtained, it was found that horses have a mixed helminthose invasion consisting of nematodes of the Oxyuridae family (Oxyuris equi) during the parasitization of which, in horses, it was revealed – the rumpleness of the hair-covering of the dock, the formation of bald patches and the release of white plaque from the anal orifice, with Ascaridae (Parascaris equorum) there were seizures of cough and nasal secretions, as well as horses had reduced appetite and increased fatigue, with Strongyloididae (Strongyloides westeri) – foals had a delay in molting and an increase in abdominal volume, the Strongylata suborder caused digestive disorder with colic attacks. To prevent the spread of helminthous invasions, it is necessary to carry out the main integrated system for control helminthosis, which includes veterinary, sanitary and therapeutic and preventive events.

Endoparasites of donkeys (Equus asinus) used in commercial skin exploitation in the Northeast of Brazil

The present study identified the main endoparasites present in donkeys (Equus asinus) used in skin exploitation located in Cando municipality, Bahia State, Northeast of Brazil. The samples were collected from September 2019. Feces were collected from the rectal ampulla of 34 animals, macroscopically visualized for parasitic forms, and microscopically evaluated to identify endoparasites forms using the McMaster method. Parasitological results were associated with sex, age, and bodyweight Stata Corp LLC 14. Endoparasites were found in 82.3% of the animals, with the egg count ranging from 50 to 1050 eggs per gram (EPG). The sole presence of superfamily Trichostronglylidae was observed in 67.6% of the donkeys, in 8.8% co-infected by Trichostronglylidae and Eimeria spp., while Trichostronglylidae and Strongyloides westeri was detected in 2.9%, and simultaneous infection by Trichostronglylidae, Strongyloides westeri, and Oxyuris equi was observed in 2.9%. The occurrence of parasitic infections varies according to nutritional status, age, sex, and environmental exposure (p>0.05). A high occurrence of infection was observed in young animals and those with lower body weight.

Helminth infections in Italian donkeys: Strongylus vulgaris more common than Dictyocaulus arnfieldi

Donkeys have been used as working animals for transport and farm activities worldwide. Recently, in European countries, there has been an increasing interest in donkeys due to their use as pets, onotherapy or milk production. During 2014–2016, a countrywide survey was conducted to determine prevalence and risk factors of principal helminth infections in 1775 donkeys in 77 Italian farms. A questionnaire on management and parasite control practices was filled out for each farm. Faecal samples were examined using a modified McMaster technique, a centrifugation/flotation method and a sedimentation technique. Pooled coprocultures were performed for differentiation of strongylid eggs. Strongyles were the most common parasites detected (84.9%), followed by Dictyocaulus arnfieldi (6.9%), Oxyuris equi (5.8%), Parascaris spp. (3.6%), Anoplocephala spp. (1.0%), Strongyloides westeri (0.3%). Coprocultures revealed an omnipresence of cyathostomins (100%), followed by Strongylus vulgaris (31.0%), Poteriostomum spp. (25.0%), Triodontophorus spp. (9.0%), Strongylus edentatus (7.0%), Strongylus equinus (5.0%). Logistic regression analysis identified breed, co-pasture with horses, living area, herd size and number of treatments as significantly associated with strongyles. Sex, age, living area and herd size were significantly associated with Parascaris spp. Dictyocaulus arnfieldi was significantly associated with sex, grass, co-pasture with horses, living area and herd size. Strongylus vulgaris was significantly associated with living area and herd size. The mean number of anthelmintic treatments/year was 1.4; most of the donkeys (71.8%) were dewormed using an ivermectin drug. It is important to design parasite programs to specifically address both D. arnfieldi and S. vulgaris in donkeys, and this is especially important if donkeys co-graze with horses.

Coprological detection of equine nematodes among slaughtered donkeys (Equus asinus) in Kaltungo, Nigeria

Aim: This study aimed to investigate the prevalence and intensity of nematode infection among slaughtered donkeys in Kaltungo, Nigeria. Materials and Methods: A total of 72 fecal samples were examined by salt flotation and the modified McMaster fecal egg count technique to morphologically identify nematodes eggs and determine their egg per gram (EPG) outputs. Results: Out of a total of 72 (100%) donkeys sampled, 36 (50%) tested positive, but the prevalence of nematodes was independent of the age, sex, and breed of donkeys (p>0.05). Among the four species of nematodes identified in single and mixed infections, Strongylus spp. (27.8%) and Dictyocaulus arnfieldi (13.9%) were the most prevalent followed by Strongyloides westeri (5.6%) and Trichonema spp. (5.6%). Infected donkeys had moderate overall mean EPG (801.39±611.3) with no statistical differences between age groups and sexes (p>0.05), but means of EPG were significantly higher (p<0.05) in Duni (1026.92±719.55) than Idabari (673.91±514.75). Light EPG count was recorded among 63.9% of infected donkeys, while 16.7% and 19.4% had moderate and severe infections, respectively. Conclusion: The prevalence and importance of equine nematodes were discussed in connection to their epidemiology and control. Furthermore, the preponderance of light infection may suggest that donkeys in this environment developed resistance to nematode infection and are potential reservoirs for other equines.

Fatal parasite-induced enteritis and typhlocolitis in horses in Southern Brazil

Diseases related to the alimentary system are the main cause of death in horses. This retrospective study aimed to describe the pathological findings of fatal parasite-induced enteritis and typhlocolitis caused by cyathostominae, Eimeria leuckarti, Balantidium coli, and Strongyloides westeri in horses. The records of parasite-induced intestinal lesions in horses necropsied in Southern Brazil between 2005 and 2017 were reviewed. Ten horses had fatal parasitic enteritis and/or typhlocolitis, and the main causes were: cyathostominae typhlocolitis (6/10), E. leuckarti enteritis (1/10), S. westeri enteritis (1/10), B. coli colitis related to cyathostominae (1/10), and infection by multiple agents (1/10). Cyathostominae typhlocolitis showed marked mucosal thickening, with multifocal elevated nodules containing tangled filiform parasites. Microscopic examination revealed that the mucosa and submucosa had encysted parasitic structures surrounded by eosinophilic and granulomatous inflammation. E. leuckarti enteritis was microscopically characterized by macrogamonts, microgamonts, and oocysts inside the host cells. S. westeri enteritis showed microscopic atrophy of the villi with numerous mucosal encysted parasitic structures. B. coli typhlocolitis showed severe diffuse mucosal reddening, with microscopic superficial mucosal necrosis associated with multiple protozoan trophozoites. Fatal parasite-induced enteritis and typhlocolitis are important causes of death in horses in Southern Brazil.

Morphological features of development of Strongyloides westeri (Nematoda, Rhabditida) in vitro

Strongyloides westeri (Ihle, 1917), a parasitic horse nematode, has an unusual lifecycle, which allows it to exist for a long time in the environment. Morphometric features of eggs, larvae and free-living S. westeri were studied in vitro under different temperature regimes. The optimal temperature for their embryonic development is 25 °С, under which 90% of the first stage rhabditiform larvae are formed and released within 7 hours of cultivation. The temperatures of 20 and 30 °С are less favorable for their development. Embryonic development of Strongyloides has four stages that differ in morphology and size. The eggs of a parthenogenetic female are 3.7% longer and 19.6% wider than eggs isolated from free-living females of S. westeri. In embryogenesis, the eggs shorten by 4.4 μm (6.5%) and widen by 5.35 μm (8.3%). New data were obtained on postembryonic development of S. westeri. The differential morphometric features of stage 1 and 2 rhabditiform larvae which grow both in length and width (33.7% and 30.4% respectively) are established. The development of filariform larvae is associated with loss of bulbous thickening and formation of cylindrical oesophagus. Simultaneously, the body elongates, and the gut becomes shorter. Differential morphometric features of free-living males and females of S. westeri are the length and width of body, length of oesophagus, gut, tail end, and size of spicules. Postembryonic development of the free-living and parasitic generations from rhabditiform larvae is temperature-dependent. Most of the free-living generations of Strongyloides (54.0%) are formed at 20 °С, and filariform larvae mostly (70.0%) develop at 30 °С. The obtained results of morphological studies improve differential diagnostics of the nematode at various stages of development and further advance the study of its intraspecific variability.