Prevalence of ectoparasites and associated risk factors in the communal sheep population of Mbashe Local Municipality, Eastern Cape Province

Abstract

Background: Ectoparasites pose a significant veterinary problem worldwide, including in South Africa. Ectoparasites pose a significant problem for welfare and animal health in the sheep producing areas. Infestations of sheep with ectoparasites are linked with a wide range of clinical manifestations and health issues, which include, among others, abscesses, mechanical tissue damage, weight loss, irritation, anaemia, lameness, and in extreme cases, affected animals even die. The study aims to identify the external parasites and associated diseases prevalent in the communal sheep population of the Mbhashe Local Municipality, Eastern Cape Province. Methodology: The study employed a cross-sectional study design to achieve the objectives, which involved stratified randomly selected individuals from several sheep flocks. Data collection included the clinical examination, collection of ticks, skin scraping and other visible external parasites from the selected animals. A stereo microscope was used to examine the collected samples and identify them using morphological keys and descriptions. A structured questionnaire was administered through in-person interviews with the sheep owners during sample collections. The aim was to gather information of on the socio-economic profile of sheep farmers, their awareness of ectoparasites, and good animal health and husbandry practices. Results: The overall prevalence of ectoparasites recorded was 42.0% (95% CI, 39-46%) among 697 sheep examined. Ectoparasite species found were Rhipicephalus appendiculatus (18.5%), Hyalomma rufipes (5.5%), Psoroptes ovis (13%), Bovicola ovis (12.1%), Ligognathus africanus (1%) and Melophagus ovinus (2.4). The assessment of tick infestations based on risk factors revealed slightly higher prevalence rates in males (24%), mixed breeds (30%), adult sheep (24%), and animals with good condition scores (24%), although these differences were not statistically significant. The prevalence of mite infestations was higher in male sheep than 2 in female sheep, at 19.0% and 11.0%, respectively and differed significantly (X = 8.054, p = 0.005). The prevalence of mite infestations was also positively associated with body condition scores of sheep (X² = 616.436, p < 0.001), with the highest infestations (95%) detected in sheep with poor body condition scores. Further multivariable regression analysis of the prevalence of mite infestation revealed that it was significantly associated with sex (OR = 1.9, 95% CI: 1.2-3.0, p < 0.001) and body condition score (OR = 45.78, 95% CI: 7.224-290.231, p < 0.001). The farmers' responses revealed that 97% considered sheep scab to be very important, followed by lameness at 74%, pulpy kidney at 70% and heartwater at 53%. The clinical signs observed by these farmers are consistent with those reported and documented in the literature regarding the clinical manifestations of sheep scab. The farmers stated observing itchiness or scratching against fences or walls (33%). Loss of wool (27%), skin lesions/wounds (22%) and weight loss (18%) during sheep scab outbreaks.

Conclusion:

The outcomes of this study revealed ectoparasites that are prevalent in the sheep population of the Doti community, in the Idutwa area of Mbhashe local municipality. Ectoparasites pose a significant threat to the health, productivity, and welfare of sheep in most sheep farming areas. The results of this study reveal that sheep scab is the major challenge facing sheep farmers in this area. To reduce the effects of ectoparasites on sheep, control methods tailored to the endemic ectoparasites in the area should be carefully designed and implemented. Furthermore, raising awareness of the importance, prevention and control of ectoparasites among smallholder sheep producers is crucial.