Dromedary camels, Camelus dromedarius Linnaeus (Artiodactyla, Camelidae), are vital to the livelihoods of nomadic and pastoralist communities in the Sahara Desert. However, they are susceptible to ectoparasites, which can significantly impact their health and productivity, as well as their potential role in transmitting zoonotic diseases. This study aimed to investigate the prevalence, species composition, and infestation levels of ectoparasites in dromedaries from different camel herds (CH) across northern Algeria's Sahara Desert. Additionally, we assessed the effects of CH and camel age and sex on parasite loads and infestation patterns regarding the host's affected body region. A total of 68 camels out of 135, randomly selected from four herds CH1-CH4, were surveyed for ectoparasites. Ectoparasites were counted, collected, and identified in the laboratory. Pearson correlation tests were employed to analyze the relationship between parasite indices. Similarity analysis was conducted to compare ectoparasite species composition among the sampled CH. The overall infestation level of ectoparasites across the CH was 61.76% with 511 ectoparasite individuals identified. Significant regional variation in tick prevalence was observed: CH1 (88.24%), CH2 (64.71%), CH3 (58.82%), and CH4 (35.29%) (p < 0.001). The most prevalent ectoparasites were ticks, with four species identified: Hyalomma dromedarii Koch (Ixodida, Ixodidae) (45.21%), Hyalomma marginatum marginatum Koch (Ixodida, Ixodidae) (18%), Rhipicephalus sanguineus sensu lato Latreille (Ixodida, Ixodidae) (7.63%), and Ixodes ricinus Linnaeus (Ixodida, Ixodidae) (4.9%). In addition, one mite species, Sarcoptes scabiei Linnaeus (Sarcoptiformes, Sarcoptidae), one flea species, Ctenocephalides arabicus Jordan (Siphonaptera, Pulicidae), and one fly species, Wohlfahrtia magnifica Schiner (Diptera, Sarcophagidae), were identified. Similarity analysis showed a 70% overlap in ectoparasite species composition between herds, suggesting common environmental and management-related risk factors. Overall, the abdomen exhibited the highest percentage of ectoparasites at 22.7%, followed by the neck and sternum (17.8%), and the anal and tail area (17.4%). Adults accounted for 86.1% of infestations, with notable contributions from the abdomen (17.0%) and neck/sternum (15.9%), while young camels made up only 13.9%. The high ectoparasite infestation level, particularly ticks, underscores the need for a comprehensive control plan, especially in herds managed under extensive or nomadic systems. Future research should focus on identifying risk factors and exploring ectoparasite control strategies to reduce the burden on camel health and prevent potential zoonotic disease transmission in the region.

A camel herd sampling and epidemiological survey were conducted

Four sites located in different municipalities were investigated using a simple random sampling, characterized by two modes of camel husbandry: periurban and extensive. The periurban system focuses on selling camel milk to travelers on the main roads. The study commenced in March and concluded in June 2021, coinciding with the onset of the hot dry season in the study area. The assistance of public veterinarians was essential to facilitate access to the farms and communication with breeders. The owners of the surveyed camels provided their verbal consent for tick sample collection. The total number of camels across the four surveyed herds was 135. Herd sizes varied from 17 to 40 camels, with a higher number of females than males in each camel herd (CH) surveyed. The age range of camels among the four herds varied from four months to eight years. The primary camel populations and breeds identified in this study include Sahraoui, Naili Reguibi, Châambi, and Ouled Sidi Cheikh. This diversity in breeds may be attributed to camel herders obtaining camels from different regions of Algeria. Camel breeders have varying levels of experience in camel husbandry, ranging from ten years (CH4) to 15 years (CH1). Other breeders (CH2, CH3) have acquired their knowledge of this occupation through succession from family members (father or grandfather), having interacted with camels since childhood without undergoing specialized training in the field. As shown in Table 1, the predominant camel breeding system is periurban intensive. Notably, the majority of breeders (75%) also raise several other animal species, such as sheep, goats, and cattle, in the same stable.

Sampling and collection of ectoparasites

Quota sampling (n = 17) was employed from the total number of animals in each herd, with each quota sample (n) comprising two age categories: adult camels aged 3 to 8 years and calves aged ≤ 6 months, including both sexes. Additionally, several anatomical locations were recorded for all ectoparasites. The primary objective was to obtain samples that are as representative as possible of the general parasitic infestation state of each examined camel, without modification. Sampling was conducted in accordance with species life profiles, as recommended by Walker et al. (2003). To count ectoparasites and collect samples for laboratory identification, all body parts of the sampled camels were visually inspected. Ectoparasites such as ticks, mites, and fleas were enumerated. For the estimation of fly infestation, every visible lesion, including fly larvae, was considered. The collected samples were placed individually in labeled vials. Collection was performed using specialized forceps, ensuring that the rostrum of the parasite was completely removed from the animal's skin. The ectoparasites collected were stored in hermetically sealed vials with 70% alcohol added until the identification stage.

Identification of ectoparasitic species

The confirmation of ectoparasite identification was conducted in the parasitology laboratory at Biskra University (Algeria), where a voucher of the specimens was also deposited and preserved for future reference. After measuring body tick size, the specimens were examined using a binocular magnifying glass (MOTIC, 20×), followed by an optical binocular microscope with 40× magnification. Subsequently, samples were photographed and identified based on the determination keys and identification criteria outlined by Walker et al. (2003) and Meddour-Bouderda and Meddour (2006). Abundance data were obtained by counting the number of individuals of each species.