Prevalence of Gastrointestinal Parasites and Associated Risk Factors Among Dairy Cattle in Bangladesh: An 8-Year Retrospective Study

BACKGROUND

Gastrointestinal (GI) parasitism remains a critical challenge in livestock health management, particularly in tropical regions where environmental conditions favor parasite proliferation. This study conducted an 8-year retrospective analysis (2017-2024) of GI parasites in dairy cattle across 11 districts in Bangladesh.

METHODS

Data were sourced from a private veterinary diagnostic laboratory, with a focus on the prevalence, types, and trends of GI parasites as well as associated risk factors. GI parasites were identified using different coproscopic methods including direct smear, flotation, and sedimentation. Statistical analysis was performed using descriptive analysis, followed by Poisson regression.

RESULTS

The most prevalent parasites identified were Schistosoma spp. (57.3%) and Paramphistomum spp. (22.6%), with notable peaks in prevalence during the years 2019 (65%) and 2021 (62%) for Schistosoma spp. and in 2017 (32%) for Paramphistomum spp. Other parasites, such as Balantidium (B.) coli, presented a lower but consistent prevalence (9.8%), whereas Fasciola spp. and Haemonchus spp. were identified less frequently. The analysis revealed that various factors significantly influenced parasite incidence, including seasonal variations, district-specific ecological conditions, and animal-related factors. Statistical analyses, particularly Poisson regression, demonstrated that male cattle (RR: 0.30, 95% CI: 0.230-0.401) had a lower risk of infection with Schistosoma spp. than females, whereas regions with abundant water bodies, such as Manikganj (RR: 11.9, 95% CI: 6.801-20.648, p < 0.001), Mymensingh (RR:7.9, 95% CI: 2.243-27.78, p < 0.01), and Narayanganj (RR: 6.6, 95% CI: 3.867-11.177, p < 0.001), presented higher prevalence rates. Seasonal trends revealed increased prevalence rates during the winter (Schistosoma spp.: RR: 1.5, CI: 1.090-1.919, p < 0.05; Paramphistomum spp.: RR: 1.03, 95% CI: 0.322-3.299; B. coli: RR: 1.2, 95% CI: 0.672-2.151; and Fasciola spp. RR: 2.5, 95% CI: 1.322-4.555), which aligns with periods of more significant water usage and potential exposure to contaminated sources.

CONCLUSION

This study underscores the need for targeted parasite control programs, particularly in high-risk areas, and advocates for improved livestock management practices and regular veterinary interventions to mitigate the economic and health impacts of GI parasites. These findings provide valuable insights for developing tailored parasite management strategies to increase the productivity and well-being of dairy cattle in Bangladesh.

Gastrointestinal parasites in free grazing goats from Ayacucho, Peru: prevalence and risk factors associated with infection in herds

This study assessed the prevalence and risk factors associated with gastrointestinal parasite infection in goats in Ayacucho, Peru. Fecal samples were collected from a total of 254 goats from four districts of Ayacucho: Ocaña (89), Colca (76), Pacaicasa (64), and Luricocha (25) during the dry season; recording the location, sex, and age of the animals. The fecal samples were analyzed using the flotation technique in salt and sugar solution, and modified McMaster egg counting techniques for eggs/oocysts (epg/opg) of gastrointestinal parasites. The associations between location, sex, and age with the prevalence of gastrointestinal parasites were analyzed using the chi-square test. Fecal samples showed an overall parasite prevalence of 87.80%. The identified parasites were Eimeria spp. (86.22%), Strongyle type eggs (STE) (65.75%), Skrjabinema spp. (7.87%), Trichuris spp. (3.15%) and Moniezia spp. (3.15%). There was a significant association between the location and the presence of parasites (p < 0.05); where STE was more prevalent in the district of Colca (98.68%); Trichuris spp. in Pacaycasa (9.38%); Skrjabinema spp. (48.00%), Moniezia spp. (12.00%) and Eimeria spp. (100%) were more prevalent in Luricocha. Sex had a significant association with the prevalence of Eimeria spp., Skrjabinema spp. and Moniezia spp. (p < 0.05); while age had a significant association with parasitosis only for Trichuris spp. and Moniezia spp. (p < 0.05). The epg/opg values revealed a higher parasite burden in goats from Colca compared to the other locations (p < 0.05). There was also no statistical relationship between fecal egg/oocyst counts and sex or age, nevertheless, there were moderate and high parasitic burdens. The high prevalence of parasites such as nematodes, cestodes, and coccidia suggests the need to implement strategic control and prevention programs in free-grazing goats. Location and sex were the most relevant risk factors for parasitosis in Ayacucho, Peru.

Comparison of the first time detected Oesophagostomum asperum with Oesophagostomum columbianum in sheep and goats in Bangladesh based on the trinity: Morphology, morphometry and genetic diversity

Oesophagostomum spp. (Family: Chabertiidae) is keeping a low profile in terms of severity in Bangladesh while maintaining economic loss through disguise within sheep and goats. The study was performed to identify prevalence, confirmation of species through morphology and morphometry followed by phylogeny using ITS2 and COX1 genes. In total 384 slaughterhouse-sourced small and large intestines were pooled from Mymensingh, Kishoreganj, Netrokona, Sherpur and Tangail districts of Mymensingh division. Followed by isolation, O. columbianum and O. asperum were identified following their key morphological features. Notably, O. asperum was first time detected in Bangladesh. The overall prevalence of Oesophagostomum spp. was found 60.93%. The prevalence of O. columbianum (64.95%) was almost double than that of O. asperum (35.04%). Among several characters, only the distance between anus to tail tip showed a significant morphological disparity in female. The Neighbor-joining (NJ) phylogenic trees based on ITS2 and COX1 genes confirmed the study species. The first time identified O. asperum along with morphometry and phylogeny will add value to the fact that nematodes are invisibly present with high prevalence in this country. This study will help to draw specific attention to command a practical control strategy for intervening in economic loss.

Seasonal Prevalence of Helminthic Infections in the Gastrointestinal Tract of Sheep in Mazandaran Province, Northern Iran

Helminthic infection is the major cause of the sheep's reduced productivity. In this study, a total number of 240 fecal samples of sheep from stationary flocks of four different zones of Mazandaran province (Amol, Babol, Sari, and Nowshahr cities) were examined each season, out of which 53.33% of animals were affected by the helminthic infections. The most prevalent infecting parasites were the Trichostrongylidae (46.61%), followed by the Fasciola (9.96%). In addition, the Strongyloides had the lowest proportion with only 2.39%. The other detected parasites included Chabertia (5.98%), Cooperia (3.19%), Nematodirus (3.19%), Trichuris (5.58%), Toxocaridae (4.78%), Haemonchus (4.78%), Ostertagia (5.58%), Oesophagostomum (4.78%), and Dicrocoelium (3.19%). The nematodes had the highest percentage with 86.85%, whereas the trematodes followed them with 13.15%. No significant difference was observed between the infection level in females and males, with 56.9% and 43.94% rates of infection, respectively. Significantly lower infection was observed in winter compared with the other seasons. Trichostrongylidae was the dominant genus across all seasons. It was also noted that winter had the lowest percentage of helminthic infection significantly. The eggs per gram of feces was also estimated, and it showed that a significant number of sheep are infected with a moderate number of parasites. In a conclusion, even though livestock farmers have been using antiparasitic drugs in their livestock in recent years, parasitic infection still exists in livestock. Thus, a proper implementation of helminthic infection control programs in this area should be employed as the key element for reducing the high prevalence of livestock helminthic infection.

Epidemiology, prevention and control of gastrointestinal helminths of small ruminants in the Caribbean region-a scoping review

This review gathered information from peer-reviewed publications on the epidemiology, prevention and control of gastrointestinal helminths (GIHs) parasites of small ruminants in the Caribbean region from 1990 to 2021. Literature search was performed on four electronic databases using a combination of search terms and Boolean operators. Results showed that gastrointestinal nematodes (GINs) were the most common parasites, with seven genera documented across six reviewed countries. Haemonchus contortus was the most common species occurring in all six countries, and predominant in occasions where mixed infections were observed. Moniezia species were the only Platyhelminth species documented in Trinidad and Grenada. The overall prevalence of GIH infections was observed to be high in goats than in sheep. A high level of anthelminthic resistance (AR) with H. contortus was reported, whilst other nematodes showed to be effectively controlled by one or more anthelmintic drugs. FAMACHA© method was applied in the identification of anaemic animals for selective treatment, hence contributing to the decreased use of anthelmintic drugs. There is a need for national surveys of GIHs and AR in small ruminants in the Caribbean countries. Surveys, coupled with the use of molecular techniques to detect and identify species of GIHs present in the Caribbean region, as well as their epidemiology which will inform development of integrated control strategies is recommended. There is also a need to create awareness to small ruminant farmers in the region on the prevailing challenge of AR and limit wanton use of anthelminthics to reduce or prevent AR in small ruminants.

Prevalence and resistance to gastrointestinal parasites in goats: A review

Gastrointestinal parasitism, particularly nematode infection, is a major health issue affecting goats worldwide, resulting in clinical diseases and productivity loss. Prevalent gastrointestinal parasites (GIPs) affecting goats in South Africa are the Strongyloides papillosus, Eimeria spp., and Strongyles, especially the Haemonchus contortus and Trichostrongylus spp. According to the issues discussed in this paper and by other authors, the prevalence and intensity of various GIPs vary with an animal's location, breed, age, sex, and season. Because GIPs easily develop resistance to chemical treatment, selecting and breeding genetically GIP-resistant animals would be a relatively simple and inexpensive strategy for reducing or eliminating the current reliance on chemotherapy. Potential phenotypic indicators for selecting GIP-resistant goats include parasitological, immunological, and pathological phenotypic markers. Synergistic use of these indicators should be encouraged for a more accurate simplified genotype selection of resistant animals. Genes with Mendelian inheritance, particularly those involved in immunoregulatory mechanisms, have been identified in goats. Exploring this knowledge base to develop cost-effective molecular tools that facilitate enhanced genetic improvement programs is a current challenge. Future statistical and biological models should investigate genetic variations within genomic regions and different candidate genes involved in immunoregulatory mechanisms, as well as the identification of single nucleotide polymorphisms known to affect GIP infection levels.

Prevalence of Helminthic Infections in the Gastrointestinal Tract of Cattle in Mazandaran Province (Northern Iran)

Ruminant parasites are found in all parts of the world, including the tropical and subtropical regions. Mazandaran province (northern Iran) is one of the areas prone to the activity of gastrointestinal parasites in ruminants. This study was performed in 2020, in order to identify common parasites of cattle gastrointestinal tract, the percentage of the infection, the effect of seasons, and livestock on the amount of infection and determine the severity of infection. In this study, seven genera of gastrointestinal parasites including Strongyloides, Haemonchus, Ostertagia, Cooperia, Trichostrongylus, Oesophagostomum, and Chabertia were identified among 240 cattle. Overall, 34.58% of cows were infected with different kinds of parasites. Based on the average percentage of livestock infected with gastrointestinal parasites across different seasons, winter had the lowest percentage (18.33%) compared to other seasons, which has a statistically significant difference (P < 0.05). Also, we observe that the female cattle's infection rate, in comparison with males, had no significant difference (P < 0.05). Moreover, 67.17% of the cattle had a moderate level of infection. Despite the fact that farmers use antiparasitic drugs, helminthic infections in cattle are still high. In conclusion, the lack of proper implementation of helminthic infection control programs as well as antiparasitic drug resistance in this area can be a key element for the high prevalence of livestock helminthic infection in these areas.

The prevalence of intestinal parasite infections in goats from smallholder farms in Northern Thailand

The present study determined the prevalence of gastrointestinal (GI) parasites in small ruminants kept in smallholder farms in Phitsanulok, Northern Thailand. A total of 885 goats from 31 smallholder farms were selected randomly between May 2019 to January 2020. Fecal samples were collected to estimate fecal egg counts and oocysts counts using the modified McMaster technique. Furthermore, pooled fecal samples from each of the farms were cultured in order to differentiate third-stage larvae of nematode. Examination of fecal samples revealed that 885 were positive for one or more parasites, giving an overall prevalence of 87.2 %, of which 38.6 % were infected with one and 48.6 % with multiple parasite. Strongyles and Eimeria oocysts were the most prevalent. Haemonchus contortus and Strongyloides papillosus were the predominant species based on the percentage of larvae in fecal cultures. Tapeworm eggs were encountered in 14.2 % of all samples. No significant difference in gastrointestinal parasite prevalence was associated with sex of the host. Infection was significantly (P = 0.009) highest in poor body conditioned goats (72.0 %) as compared to moderate (48.9 %) and good body conditioned (50.0 %) goats. This report on prevalence of GI parasites of small ruminants in smallholder farms in Northern Thailand reveals a high endoparasitic infections that appeared well-adapted to environmental conditions. Further studies on endoparasite control are required to establish the impact of parasitism on productive performance, including monitoring control parasite programs are needed for better health and productivity.

A large-scale epidemiological investigation on trematode infections in small ruminants in Bangladesh

BACKGROUND

The important trematode species in small ruminants: Paramphistomum sp., Fasciola spp. and Schistosoma spp. seriously affect the productivity of domestic ruminants in endemic areas.

METHODS

In the present study, we identified the potential risk factors associated with trematodes infections in small ruminants in seven topographic zones of Bangladesh using simple sedimentation and modified Stoll' ova counting technique.

RESULTS

A total of 2440 samples were examined, where 965 were found positive with one or more trematode species with an overall prevalence of 39.5% (95% CI, 37.6%-41.5%) and intensity of infection was 264.77 ± 9.86 egg per gram of faeces. Three trematode species were identified namely Paramphistomum sp. (34.1%, 32.2%-36.0%), Fasciola spp. (7.5%, 6.5%-8.6%) and Schistosoma spp. (2.7%, 2.1%-3.5%). Prevalence of co-infection was 4.8%. The spatial distribution of trematode infections varied from 29.5% to 53.6%. Univariate analysis revealed that physiological condition of females, body condition, farming system, deworming and season were significantly (p < 0.05) associated with trematodes infections in small ruminants. By multiple logistic regression model, three factors such as physiological condition of females (pregnant and lactating), poor body condition and animals without deworming were identified as potential risk factors for trematodes infection in small ruminants.

CONCLUSION

Trematode infections are prevalent in the study areas and Paramphistomum sp. is most common in different areas among the identified trematodes species. Government should take necessary action to appraise an effective control strategy of trematode infections in small ruminants.

Awareness and control methods of gastrointestinal parasites of merino sheep among farmers from different agro-ecological zones of Lesotho

Background and Aim:

Sheep production plays a crucial role in the economy of Lesotho by increasing economic state of the rural poor. However, gastrointestinal parasites infection is the most limiting factor in sheep productivity and has a highly detrimental effect on the sheep industry. Therefore this study aimed to evaluate farmers’ awareness and understanding of controlling gastrointestinal parasites of merino sheep in four Lesotho agro-ecological zones.

Materials and Methods:

Data were collected using a simple random sampling of 106 farmers in the lowlands, foothills, mountains, and Senqu river valley. Data were analyzed using the Statistical Package for the Social Sciences (version 20.00). Descriptive statistics were employed with cross-tabulations and tested with Chi-square and post hoc tests.

Results:

The majority of farmers (80%) were aware of the gastrointestinal parasites. Most farmers (70%) reported a high prevalence of gastrointestinal parasites and associated it with lamb mortality in summer and autumn. Farmers use anthelmintics for treating gastrointestinal parasites in animals, and 93% of them reported the effectiveness of the drugs. However, more than 80% of farmers routinely use anthelmintics. The results revealed that 81.5%, 66.7%, 80%, and 66.7% of farmers from the lowlands, foothills, mountains, and Senqu river valley, respectively, keep sheep in non-roofed enclosures cleaned only after rains to avoid mud. Communal grazing is used as the main source of animal feeding where different livestock species share the same rangelands. Most farmers (more than 70%) believed that grazing lands were the main source of gastrointestinal parasites transmission.

Conclusion:

Farmers in Lesotho are aware of gastrointestinal parasites and apply control methods to combat the gastrointestinal parasites in merino sheep. However, a need still exists for them to be empowered with skills for improving management systems and the knowledge on how the gastrointestinal parasites behave at different times of the year and in different agro-ecological zones. This will assist them in adhering to the dosing schedule designed by animal health experts.

Etiopathological and hematobiochemical profiles in goats with gastrointestinal disorders

Background and Aim

Gastrointestinal (GI) disorders in small ruminants limit production efficiency and productivity growth in the livestock sector, thereby directly preventing farmers from augmenting their income. This study aimed to provide detailed insight into the etiology, hematobiochemical parameters, and epidemiological risk factors of GI disorders in goats and to determine the pathology associated with the disorders.

Materials and Methods

Over the period of 2018-2019, 500 goats in and around Bhubaneswar, Odisha, India, were screened for GI disorders based on clinical signs. Blood samples from the control (n=10) and treatment (n=25) groups were collected for both hematological and serum biochemical alterations. Fecal examinations (n=220) were conducted for parasitic, bacterial, and virological assessments. Detailed necropsy and histopathological evaluations were conducted on 27 goats.

Results

The GI disorder prevalence rate and mortality rate among the 500 goats analyzed were 44.4% and 12.27%, respectively. Chi-square analysis showed a significantly higher occurrence of GI disorders among the goats that were between 6 months and 1.5 years old (58.72%), were of the Ganjam breed (45.49%), had a poor body condition (71.11%), and were housed with an earthen floor (55.22%). The most common etiological risk factor observed was parasitic infection (65.45%), followed by bacterial (18.18%) and mixed infection (9.54%). Blood analysis showed neutrophilia and eosinophilia in infected goats, in addition to anemia; significant decreases in total protein, globulin, albumin, and glucose levels; and significant increases in aspartate transaminase and alanine aminotransferase levels. The major histopathological findings were infiltration of mononuclear cells and desquamation of the intestinal and ruminal mucosa.

Conclusion

Stakeholders should focus not only on parasitic infections and other important etiological risk factors for GI disorders in goats but also on proper farming management practices to help enhance the income of farmers. The hematobiochemical alterations and pathomorphological changes reported in this study can be used by field veterinarians as guidelines for clinical evaluation and disease severity assessment.

Prevalence and fecal egg load of gastrointestinal parasites of Angora goats in four agro-ecological zones in Lesotho

Background and Aim:

Goats are reared for their meat, mohair and other socio-cultural needs in Lesotho. Helminth infections are some of the major setbacks in the goat production industry due to their negative impact on animals’ health, resulting in significant losses on meat and mohair production and death. A cross-sectional study was conducted to determine the prevalence, fecal egg infestation, and morphological identification of gastrointestinal parasites in goats.

Materials and Methods:

Fecal samples were collected from 765 goats and subjected to McMaster egg counting techniques using the flotation method. Statistical analyses were performed using the Statistical Package for the Social Sciences (SPSS v.26.0).

Results:

The overall prevalence of gastrointestinal parasites was 94.7%, and the identified gastrointestinal parasites were nematodes (64.7%), coccidia (25.8%), and cestodes (4.2%). Haemonchus contortus was identified as the prevalent gastrointestinal nematode species found in goats. The prevalence and fecal egg count of gastrointestinal parasites were significantly higher (p<0.05) in goats located in the highlands and Senqu River Valley, while goats in the lowlands demonstrated a significantly (p<0.05) higher prevalence of H. contortus. Immature goats and kids were more significantly (p<0.05) prone to gastrointestinal parasites.

Conclusion:

The nematodes and coccidia infestations were prevalent in goats located in the highlands and foothills, respectively, whereas nematode and coccidia fecal egg loads were higher in goats located in the foothills and Senqu River Valley, respectively.

Anthelmintic resistance and prevalence of gastrointestinal nematodes infecting sheep in Limpopo Province, South Africa

Background and Aim:

Previous studies recorded the prevalence of gastrointestinal nematodes (GIN) in Limpopo Province. However, the studies did not address the seasonal patterns of infection and did not cover all districts of Limpopo Province, namely; Capricorn, Sekhukhune, Waterberg, Mopani, and Vhembe. It is, therefore, important to provide up to date information on the prevalence and seasonal occurrence data of GIN in all districts of Limpopo province. The present study was conducted to determine the occurrence of anthelmintic resistance (AR) and document the prevalence of GIN infecting sheep in five districts of Limpopo Province, South Africa.

Materials and Methods:

Forty animals in each district were used for fecal egg count reduction test (FECRT) to determine AR against ivermectin (0.2 mg/kg), levamisole (LEV) (5 mg/kg), and albendazole (7.5 mg/kg). Egg hatch test (EHT) was used to determine AR against thiabendazole (TBZ) and micro-agar larval development test (MALDT) was used for both TBZ and LEV. Naturally, infected sheep (n=780) were sampled for prevalence across five districts of Limpopo. FAMACHA^© eye-color score estimations were also performed for each study animal.

Results:

FECRT showed occurrence of AR in most of the districts and a few with suspected resistance. EHT results showed AR development against TBZ for all districts, while the MALDT showed no AR against LEV in all districts, but detected AR against TBZ in Sekhukhune, Capricorn, and Waterberg. Haemonchus contortus was the most resistant species. A high nematode prevalence (88-100%) and 1210-1861 eggs per gram (EPG) was observed in all districts during the hot wet season, decreasing to 75-80% (453-1202 EPG) during the cold dry season. The sheep revealed a FAMACHA^© mean score of 3, indicating mild anemia during the hot wet season except for Vhembe district that revealed a FAMACHA^© mean score of 4 during the hot wet season, indicating anemia.

Conclusion:

AR recorded in Limpopo Province may be due to under-dosing caused by lack of weighing equipment and high treatment frequencies due to lack of proper training on anthelmintic use. The detection of AR in Limpopo is an important finding because it will help in outlining effective management systems against GIN.

Occurrence of Gastrointestinal Parasites in Small Ruminants in the Central Part of Myanmar

Gastrointestinal parasite infection in small ruminants remains one of the major economic losses caused by reduced productivity. A total of 380 faecal samples were taken from 280 sheeps in Magway and Pwintbyu Townships and 100 goats in Natmauk Township, Myanmar. Faecal flotation and sedimentation methods were carried out to detect the presence of parasitic infections. Faecal egg and oocyst counts were carried out using the McMaster technique. The overall occurrence of gastrointestinal parasites in small ruminants was 98.4% (374/380). The occurrence of gastrointestinal parasites in sheep (99.3%) was higher than that in goats (96%). The highest occurrence was found in Eimeria spp. (96%), followed by Trichostrongyle (77.1%), Trichuris spp. (35%), and Moniezia expansa (14%). The mixed infection rate was 84.8% (317/374), while a single infection was 15.2% (57/374). The mean eggs per gram (EPG) and oocysts per gram (OPG) of faeces were ranged from 50 to 600 and 50 to 29,800, respectively. Among the 4 nucleotide sequences isolated, one sequence was 94.10-94.47% similarity with Trichostrongylus colubriformis, reported from Laos, and three sequences showed 96.64-99.46% identity with Haemonchus contortus from Laos, China, India, and Mongolia. As gastrointestinal parasite infection in small ruminants was relatively high in the study area, the development of appropriate treatment and control measures should be provided to reduce production losses.

Natural nodular worm infection in goats induces eosinophil extracellular DNA trap (EET) formation

Extracellular DNA Trap (ET) formation by granulocyte is a strong innate immune machinery that plays crucial roles in trapping and killing of pathogens. Here, we show Eosinophil Extracellular DNA Trap (EET) formation in goats naturally infected with nodular worms (Oesophagostomum columbianum, Strongyloidae: Nematoda). By a slaughterhouse based survey, we found that 60% goats were infected with nodular worms. We detected numerous, hard and pale yellow to dark black nodules of variable sizes (0.25-2 cm) in the large intestine and the number of nodules were significantly (p < .05) higher in the cecum (21.7 ± 17.9) than in the colon (10.1 ± 9.9). Histologically, pink colored circumscribed caseous mass was surrounded by a dense zone of infiltration and fibrous proliferation along with massive infiltration of eosinophils in and around the necrotic mass. DAPI staining revealed huge accumulation of extracellular DNA, which formed wide ridge like structure surrounding the necrotic zone. Massive release of eosinophils cationic proteins (ECP), a helmintho-toxic substance, was found into the lesions. Collectively, our results suggest that nodular worm infection induces EETosis and ECP release, and is one of the major parasitic problem affecting Black Bengal goats that causes distortion of normal architecture of the gut wall.

A field study on the occurrence of gastrointestinal nematodes in sheep over the wet and dry seasons in two West Indian Islands

Gastrointestinal nematode (GIN) infestations are a major constraint to sheep production in the West Indies (WI). Intensive and semi-intensive management systems are most commonly employed. These islands display tropical weather patterns with wet and dry seasons. Semi-intensive farming combined with increased rainfall during the wet season has been reported to be most favourable for development and survival of GIN. This study was conducted to determine whether there was a relationship between GIN burdens in sheep with seasonality and management practices of farmers in Trinidad and Tobago (T&T). Farms were visited on a monthly basis from January to December 2017. A maximum of ten sheep, three to nine months of age, were selected from each farm. A total of 3,053 faecal samples were collected and analysed using the Modified McMaster technique. Environmental data on daily precipitation and temperature were collected from the Trinidad and Tobago Meteorological Office during the period of sampling. A mixed effects negative binomial regression model was constructed to analyse the relationship between gastrointestinal nematode faecal egg counts (GINFEC) with season, management system and use of dewormers as fixed effects and farm as a random effect. Average diurnal temperatures of T&T fluctuated between 23.2°C to 32.6°C and 23.9°C to 32.3°C in the dry and wet seasons, respectively. Average daily precipitation ranged between 1.6-1.8 mm and 6.1-8.5 mm during the dry and wet seasons, respectively. A decreased risk of 0.34 (95% CI 0.25-0.47, p < .0001) for GINFEC was observed in dewormed animals versus not dewormed. Semi-intensive management systems experienced an increased risk of GINFEC by 1.39 (95% CI 1.05-1.84, p = .021) compared with intensive and the risk of GINFEC was reduced by 0.40 (95% CI 0.33-0.49, p < .0001) in the wet season versus the dry. A higher prevalence of GIN was observed during the drier months of the year. Climatic conditions observed in T&T remained favourable for GIN survival, development and distribution year-round. Proper management is therefore required for reducing the occurrence of GIN in sheep of T&T throughout the year. This is the first reported study in the WI on the influence of seasonality and management on GIN infestations in sheep during the dry and wet seasons. Further investigation is needed to elucidate why GIN burdens appear to be higher in the dry season than the wet season. This study can be used as a baseline for public education in T&T as well as other developing countries.

Prevalence of gastrointestinal parasites in communal goats from different agro-ecological zones of South Africa

Aim:

A longitudinal study was conducted to assess the epidemiology of common gastrointestinal parasite (GIP) infections affecting goats in South Africa as influenced by agro-ecological zone (AEZ), sampling season, and the age and sex of animals.

Materials and Methods:

A total of 288 goats (101 male and 187 female) were randomly sampled during winter and summer in areas representing four AEZs (arid: 80; semi-arid: 76; humid: 62; and dry sub-humid: 70) of South Africa. Fecal samples from each animal were collected from the rectum, and the presence of GIP eggs was determined using a modified McMaster technique. A sample was considered positive when a minimum of one GIP egg was detected under the microscope. Fecal cultures were prepared, and infective larvae were collected and identified. The data were analyzed by MiniTab17 (2017) using the FREQ procedure, and the association between the independent factors and the prevalence of various GIPs were evaluated using the Pearson Chi-square test (p<0.05).

Results:

The overall prevalence of GIP in the present study was 37.1%, with a mean prevalence of 30.0, 26.4, 31.1, 36.6, and 59.6% for Eimeria spp., Trichuris, Strongyloides papillosus, Moniezia spp., and strongyles, respectively. There was a significant (p<0.05) association between the prevalence of strongyles, Trichuris, Moniezia spp., and AEZs, whereas an insignificant (p>0.05) association was observed for the prevalence of Eimeria spp. and S. papillosus. A significant (p<0.05) association between goat age and prevalence of all GIPs was observed, where the prevalence was higher in young goats, followed by adults, and then by suckling goats. The prevalence of various GIPs was similar between male and female goats. The percentage of infection with Eimeria spp., Trichuris, S. papillosus, and strongyle parasitic infections was marginally higher in males than in females, whereas that of the Moniezia spp. was higher in females. A significant (p<0.05) association between the prevalence of Eimeria spp. and sampling season was observed, and there was an insignificant (p>0.05) association between the other GIPs and sampling season. The prevalence of Eimeria spp. infection was higher in winter (34.0%) than in summer (26.0%).

Conclusion:

AEZs and goat age are the most important risk factors influencing GIP infections in South African communal goats. These epidemiological parameters are important for outlining effective parasite control management systems against these GIPs in goats.