Anthelmintic Efficacy in Sheep and Goats under Different Management and Deworming Systems in the Region of Lisbon and Tagus Valley, Portugal.

Infections caused by gastrointestinal parasites have been described worldwide as one of the most important issues impacting small ruminant production. The systematic administration of anthelmintic (AH) drugs without following good practice principles has led to an increase in anthelmintic resistance (AR). There is scarce information regarding AH efficacy in small ruminants in Portugal. This study aimed to characterize by in vivo methods the presence and level of AR in four farms in the region of Lisbon and Tagus Valley. All four farms kept small herds in extensive management systems and used different deworming protocols. The active substances used were fenbendazole and a combination of mebendazole plus closantel in a dosage according to the manufacturers' instructions. On day 0 (T0), fecal samples were collected from all study animals, and animals in the treatment group (n = 40) were dewormed with the AH previously chosen by the assistant veterinarian. Animals in the control group (n = 30) did not receive any AH drug. The fecal sample collection was repeated on day 15 (T15), and the control group was treated. Egg counts were performed using the McMaster method for the eggs per gram (EPG), and AR was evaluated by the fecal egg count reduction test (FECRT) with a 95% confidence level (CL). The results from this experiment indicated that the four farms presented AR with two farms to fenbendazole (FECRT of 48% and 85%) and two farms to mebendazole plus closantel (FECRT of 66% and 79%). These results indicate that the gastrointestinal parasites of the four studied Portuguese farms are resistant to benzimidazoles, which suggests an increase in AR regarding nematodes in small ruminant production systems in Portugal.

The global prevalence of Spirometra parasites in snakes, frogs, dogs, and cats: A systematic review and meta-analysis.

BACKGROUND: Spirometra infection is aneglected food- and waterborne disease with worldwide distribution. OBJECTIVES: The present study aims to estimate the global prevalence of Spirometra species in snakes, frogs, dogs and cats. METHODS: Multiple databases (PubMed, Scopus, ProQuest, Web of Science and Google Scholar) were searched for relevant literatures published up to March 2022. RESULTS: Among 131 data sets (including 113 articles) that met the inclusion, 15 investigations reported Spirometra infection in snakes, 23 in frogs, 41 in dogs and 52 in cats. The pooled prevalence (95% confidence interval) in intermediate hosts and definitive hosts was found to be 0.313% and 0.089%, respectively. Based on continent, the infection was most prevalent in Asia for studies on snakes (0.696%) and frogs (0.181%), while Africa (0.224%) and Oceania (0.203%) were the regions with the highest pooled prevalence rates of the infection in dogs and cats, respectively. Among different diagnostic methods, the highest pooled prevalence was related to morphological method for studies on snakes, frog and cats with rate of 0.665%, 0.189% and 0.104%, respectively. Regarding studies on dogs, the highest pooled prevalence was observed for molecular technique (0.101%). CONCLUSIONS: The results presented here revealed the importance of establishing a prevention and control measure focused on protection of aquaculture systems from being contaminated with faeces of dogs and cats, and raising awareness of parasitic zoonotic diseases to decrease the transmission risk.

Gastrointestinal Parasitism in Miranda Donkeys: Epidemiology and Selective Control of Strongyles Infection in the Northeast of Portugal.

In Portugal, equine parasitism in pasture animals is characterized by high parasitic burden and high helminthic biodiversity; both factors are potentially pathogenic for their hosts. The decrease in the number of donkeys over the last years in Portugal, their importance in rural lowland and mountain ecosystems and pastures and the scarce information regarding their parasitism led to this research, which aimed to evaluate the parasitological status of a Miranda donkey breed population, a native breed mainly located in the northeast of Portugal. This study provides better knowledge of their gastrointestinal parasitism, particularly strongyles, and the assessment of a targeted selective treatment (TST) as an alternative control approach of their parasitism. A longitudinal observational study was developed during a period of five years in a population of 62 Miranda donkeys. At first, strategic deworming of these animals was performed every semester, but this was progressively replaced by a TST approach according to the levels of Eggs per Gram (EPG). This new deworming strategy was conducted in association with a regular parasitological monitoring of the animals every three months, being dewormed with ivermectin when egg shedding was higher than 500 EPG. Over the study period, a decrease of the annual prevalence rate of infection by gastrointestinal strongyles was observed, from 35.5% to 19.4%, as well as a negative binomial distribution of parasitic strongyles in donkeys submitted to selective anthelminthic control. The prevalence rate of infection was higher in females (39.5%), in individuals under four years (46.7%) and in those presenting a lower body condition (40.8%). The egg output was higher in animals younger than four years (589.3 EPG) than in those older than 10 years (533.6 EPG) (p < 0.05). However, no differences were observed according to sex during the study period. Results from this study allowed to note the influence of swampy pastures and of the weather changes in the epidemiology of strongylosis in Miranda donkeys. Moreover, it was possible to establish the annual epidemiological curve of strongyle egg shedding, with June being the month with the highest EPG, December having the lowest EPG and March and September showing intermediate numbers. Overall, a lower biodiversity of gastrointestinal parasites was observed. Cyathostomum sensu lato was the most prevalent genus and Strongylus vulgaris was the most observed large strongyle of the Strongylidae family. Trichostrongylus axei and Parascaris sp. were other nematodes with a minor frequency. The higher prevalence of strongyles at the beginning of the study showed a progressive decrease throughout the research period, and also for parasite biodiversity. Therefore, a targeted selective treatment seems to be a rational anthelminthic control approach in Miranda donkey strongyle infection and in other gastrointestinal parasites, since it reduces the antiparasitic treatments, the parasite' prevalence and the EPG level. However, a loss of parasite biodiversity was noted at the end of the study period, as Cyathostominae were the only isolated strongyles. This can be a challenging situation in the long run, taking the ability of these nematodes to adapt easily to any deworming program, meaning that fecal EPG monitoring should be kept as a rule to a rational parasite control program.

Identification of third stage larval types of cyathostomins of equids: An improved perspective.

Cyathostomins comprise around 50 parasite species of equids, offering a great challenge regarding their individual identification. The objective of our work was to improve identification of infective third stage larvae (L3) with a morphological key supplemented with detailed scientific illustrations based on our research and available literature. The highlighted features were; the number, arrangement, and shape of intestinal cells (IC), general features and the total body length of the eight different Cyathostomin sensu latum types (Type A, B, C, D, E, F, G, H), Gyalocephalus capitatus, and Posteriostomum spp. Due to variability, we were unable to define final body length measurements to differentiate L3 of cyathostomins. However, IC characteristics displayed a higher difference between L3 types than total body length. Through the number and arrangement of IC, 14 species were classified within three larval types. The classification of L3 into distinct larval types sensu latum gives us the advantage of reducing the number of probable species presented in equine faecal samples using a low-cost technique when monitoring the parasite fauna present in individual horses or on the farm level. The present improved identification key shall increase the diagnostic capabilities of classical equine parasitology techniques, using general L3 morphology thereby pragmatically improving regional and transnational epidemiological and biodiversity studies. The present key may also assist in defining the cyathostomin community in cyathostominosis clinical cases and within drug resistant populations across different management systems and geographical locations.

Teaching Veterinary Parasitology in Portugal in the 21st century - Changes, challenges and opportunities after the Bologna process.

Veterinary education in Portugal began in 1830, but individualised teaching of parasitology started in 1911 at the Faculty of Veterinary Medicine, University of Lisbon (FMV-ULisboa). Parasitology and Parasitic Diseases were taught in the 3rd and 4th years of the veterinary course, respectively. In 2007/2008, a new curriculum was implemented as a consequence of the Bologna Process (BP), with Parasitology converted into "Parasitology I" (General Parasitology, Arthropods and Protozoology) and "Parasitology II" (Helminthology), being taught in the 1st and 2nd semesters of the 2nd year of the course, respectively. "Parasitic Diseases" became a one-semester subject in the 4th year. BP was intended to harmonise university courses, foster mobility and cooperation among European Universities, but instead there have been major challenges in reducing student contact and an erosion of Parasitology I and II as basic subjects, which were moved to 2nd year. In spite of these changes, the way subjects have been taught since then shows that veterinary students are satisfied with Parasitology; academic success ranges from 70% to 90%; the number of Master and PhD theses in Parasitology has increased; and students share their research results in classes and at conferences in our faculty and abroad. This shows how research and teaching of Veterinary Parasitology are tightly inter-linked and critical, presenting an opportunity to motivate future students to study Parasitology and Parasitic Diseases in such a challenging tertiary education environment in Portugal.