Age Dynamics of Helminthic Infestations in Dogs in the Plain Belt of Dagestan

Introduction. Among the animal infestations, a large number of zooanthroponoses have been identified. Therefore, it is necessary to study the mechanisms of helminthiases behaviour and to constantly monitor the helminth fauna in animals that have close contact with humans.
The work aimed at studying the age-related features of dogs infestations in the plains of Dagestan, including studying the presence of specific types of helminths. The main attention was paid to the influence of environmental factors and dogs’ lifestyle on the helminthic infestations prevalence and intensity in different age groups.
Materials and methods. Age dynamics of helminthic infestation was studied in domestic dogs that were in self-walking and in stray dogs of different ages and sexes. Dogs were divided into three categories: of age 1–6 months old (puppies), of age 1–2 years old (juvenile animals) and adult specimens. In the work the method of animal and human complete helminthological dissection was used, as well as some other methods, such as sequential washing, flotation with the use of saturated solution of ammonium nitrate, Berman-Orlov method of larvoscopy and methods of examinations used in sanitary helminthology.
Results. The results show that puppies are infested with 5 types of helminths out of 19 identified in dogs with probability of up to 40 % and the infestation intensity of up to 72 items. In general, infestation rates in puppies were low. The highest prevalence was observed for E. granulosus with infestation extensity 10.0 % and the infestation intensity varying from 12 to 72 items. T. canis also had a high prevalence rate of 40.0 % with infestation intensity from 7 to 19 items. On the other hand, T. hydatigena and A. caninum had the lowest prevalence rate of 6.6 % with infestation intensity from 3 to 12 items. It was found that juvenile animals of 1-2 years old and adult dogs were infested with 12 different types of helminths. It should be emphasized that dogs aged 1-2 years old were especially susceptible to infestation at this stage. In total, six different types of helminths were identified with the high prevalence rate (ranging from 26.6 to 53.3 %) and infestation intensity (from 7 to 109 items). Indicators of the infestation intensity and extensity were higher in dogs infested with E. granulosus and T. canis namely IE 40.0 % and II 21 to 109 items for first species, and 53.34 % and 11–61 items for second species. Helminthiases found in adult dogs were similar to those found in juvenile animals aged 1 to 2 years old, but with a lower degree of infestation. The highest infestation extensity and the highest infestation intensity was observed for E. granulosus and T. canis, respectively – 26.6 %, and 4–16 items. On the other hand, the lower rates were observed for M. xanthosomus, A. alata, D. immitis and T. mystax, with IE 6.6 % and II 1–9 items. It was found that in comparison with juvenile animals, adult dogs are much less likely to be infested with helminths, and this is most likely due to the formation of the age-related immunity.
Discussion and conclusions. It was found that the character of helminthic infestations in dogs, depending on their age, is influenced by the changes in natural and climatic conditions, environmental factors and animals keeping and care practices.

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