Lungs of 40 ruminants from Bulgaria with natural small lungworm (Nematoda: Protostrongylidae) infections were investigated, including 16 goats, 15 sheep, 7 mouflons, and 2 chamois.Muellerius capillaris, M. tenuispiculatus, Cystocaulus ocreatus, Neostrongylus linearis,andProtostrongylus brevispiculuminfections were predominantly associated with nodular lesions, andProtostrongylus rufescens, Protostrongylus hobmaieriandProtostrongylus rupicapraewere associated with extensive lesions located mainly along the length of the large bronchi. The extent of lung abnormalities was most severe in the sheep. Alveolitis, parasite granulomas, damage of the alveolar septa, hyperplasia of the lung associated lymphoid tissue, and sclerosis of the parenchyma were found upon microscope examinations. In the goats compared to the sheep and mouflons, the terminal bronchi, bronchioles, and alveoli were more affected than the interstitium. Our research shows that the pathological lesions in the lungs of ruminants infected with protostrongylids depend on both the helminth and the host species. To our knowledge, this work is the first to provide data on the pathomorphological lesions in mouflon lungs infected with protostrongylids.

There are numerous challenges associated with helminth control in captive animals. The aim of the present paper is to provide an overview of the research on deworming of captive herbivorous mammals, the associated problems and the solutions sought, in order to derive recommendations for practice in the relevant institutions. The research was conducted by searching electronic internet databases and following the bibliographies in the published articles. The articles found are presented in summarized form. Most of the results relate to herbivores of the family Bovidae, followed by the families Cervidae, Equidae, Elephantidae, Camelidae and Giraffidae. Systematic data are presented on the types of anthelmintics used, dosages and application regimens for different animal species. Anthelmintics were administered at doses similar to or even higher than those used in farm animals, with no evidence of side effects. Treatment results often depended on the animal and parasite species. Incomplete cure, reinfection, and resistance to anthelmintics were the most common problems in the field. Based on the literature reviewed, the optimal prevention measures include the following: quarantine of newly arrived animals; daily or as intensive as possible cleaning of droppings; regular change of substrate in the enclosures; and monitoring of possible infections and their qualitative and quantitative composition (monthly or at least every two months). For treatments and monitoring effectiveness, recommendations include the following: individual assessment of the need for treatment; selective choice of anthelmintics; post-treatment examination between the 10th and 14th day after deworming; carrying out a group treatment after a preliminary drug effect test; conducting mass deworming only in case of a significant increase in fecal egg counts, highly pathogenic helminth species and a deterioration in the condition of the animals. In the future, more attention should be paid to new approaches such as biological control by saprophytic fungi or natural compounds as an alternative to anthelmintics. This would help minimize the use of anthelmintics, protect refugia and allow animals to remain healthy by maintaining a balance with the low levels of parasites present.

One hundred and ten faecal samples and five lungs of red deer (aged 2 to 8 years) coming from the State Hunting Enterprise Vitinya in Bulgaria (Balkan Mountain) were examined. A larvoscopic examination of the faeces and helminthological necropsies, pathoanatomical and histological examinations of the lungs were performed. The overall prevalence of protostrongylids was 70% (77/110), and the prevalence of Elaphostrongylus cervi and Varestrongylus sagittatus was 68% (75/110), and 27% (30/110), respectively. In 25% (28/110) of the faecal samples, mixed infection with V. sagittatus and E. cervi was found. Mixed protostrongylid infections with those two species were detected in lungs of all animals. The macroscopic lesions found in the lungs parasitized by those helminths were classified as follows: gray, dark-red to black stained portions on the lungs surface varying in shape and size; brown-black nodes clearly differentiated from the surrounding tissue; small, hard subserous nodules. The most frequently observed microscopic abnormalities were desquamatous bronchitis, alveolitis associated with accumulations of alveolar macrophages and eosinophilic granulocytes, haemorrhages in the alveoli and the alveolar septa, development of parasitic granulomas in the interstitium as well as a peribronchial, perilobular, disseminated and intralobular hyperplasia of the lymphoid tissue. The macroscopic and microscopic alterations depended on the species of the parasites found in the inflammatory areas. The infections with E. cervi were most often associated with the lesions on the lungs surface varying in color, shape and size and with the small, hard subserous nodules, and those with V. sagittatus – with the brown-black nodes clearly differentiated from the surrounding tissue .

Introduction: Pathomorphological changes in the lungs, stomach, and small intestines of wild boars infected with Metastrongylus spp., Ascarops strongylina , and Macracanthorhynchus hirudinaceus were investigated. Material and Methods: Dissection of 11 wild boars was performed, and parasitised organs were histologically investigated by common techniques. Results: Macroscopic lesions in the lungs infected with Metastrongyus spp. were seen within the apical parts of the large lobes, irregular in form, pale greyish in colour, and compact in consistency. The main pathohistological findings were: the presence of parasite forms, and lymphocytes and neutrophils in the lumen of bronchi and bronchioles, desquamation of the bronchial and bronchiolar epithelium, emphysema, thickening of alveolar septa, hyperaemia, alveolitis, infiltration of the interstitial tissue with giant cell, monocytes and eosinophils, and peribronchial and disseminated lymphoid hyperplasia. The principal observations accompanying infection with A. strongylina were inflammation and focal mucosal damage in the stomach, the latter clearly demarcated from the surrounding tissues. Severe injuries in the place of attachment of M. hirudinaceus to the wall of the small intestine were seen. Intestinal villi, underlying mucosa, and submucosa were destroyed, and an intense inflammatory reaction was present. Conclusion: The histopathological lesions showed wide diversity, varying from mild to severe; but none of them were lethal.