Aim: The present study was designed to investigate the prevalence and identification of gastrointestinal parasites in feces samples of dromedary camels (Camelus dromedarius) in Algeria based on microscopic examination. Materials and Methods: A total of 717 fresh fecal samples obtained from 28 farms at Steppe and Northern Sahara regions of Algeria were processed for microscopic examination after concentration by formalin-ether sedimentation and flotation techniques. In addition, microscopic examination of Cryptosporidium spp. was done by modified Ziehl-Neelsen staining and Lugol staining procedure was used for the detection of Giardia cysts. Results: Microscopic examination indicated an infection rate of gastrointestinal parasites of 48.26% (346/717). Protozoan infections were recorded at 17.02% (122/717), whereas helminth infections were recorded at 23.71% (170/717). In addition, mixed infection (protozoans and helminths) was seen at 7.53% (54/717). No correlation was found between infection and age of the animals, nor the consistency of the stool samples; in addition, neither influence of sex nor breed of camels was observed. Eighteen genera of gastrointestinal parasites were revealed; including four genera of protozoa, 12 Nematoda, one Cestoda, and one Trematoda. Strongyloides spp. and Eimeria spp. showed the highest rate of parasitism, while Cooperia spp. was observed with the lowest prevalence. Cryptosporidium spp. was detected in 13 among 717 examined samples (1.81%). Conclusion: The parasite fauna infecting the gastrointestinal tract of the Algerian dromedary is much diversified. The detected parasites in camels are similar to counterparts in other ruminants, posing serious challenge to animal farming. Future studies should be carried out to better understand the epidemiology of these parasitic diseases and their economic and public health impact.

Blastocystis is a ubiquitous intestinal protist that infects a broad range of vertebrate hosts, including equines. In this study, we characterized the prevalence, associated risk factors, and subtype diversity of Blastocystis sp. in fecal samples from five equine species (horses, donkeys, ponies, mules, and a zebra) collected from four Algerian provinces between December 2021 and December 2022. Of 197 fecal samples examined using microscopy and probe-based quantitative PCR (qPCR), 74 (37.6%) were positive for Blastocystis sp. Univariate analysis revealed significant associations between Blastocystis detection and equine species (p = 0.009), breeding system (p = 0.039), and climate zone (p = 0.045): horses (45.2%, 47/104) had a higher detection rate than donkeys (27.0%, 24/89), and animals raised under intensive systems (55.3%, 21/38) were more frequently positive than those in semi-extensive (36.7%, 11/30) or extensive (32.6%, 42/129) systems. Detection rates were higher in semi-arid (48.7%) and humid (30.6%) zones than in arid (25.0%) and sub-humid (15.8%) zones. No variable retained independent significance in the multivariable logistic regression analysis. Subtype determination was performed by nested PCR and Sanger sequencing of the SSU rRNA gene. Among 25 sequences of sufficient quality for subtype assignment, seven subtypes were identified: ST1 (n = 3, 12%), ST2 (n = 3, 12%), ST3 (n = 3, 12%), ST4 (n = 9, 36%), ST10 (n = 3, 12%), ST24 (n = 1, 4%), and ST33 (n = 3, 12%). Two additional sequences displayed polymorphisms consistent with ST48 but were too short for definitive assignment (ST48-like). Horses harboured subtypes ST1–ST4, ST10, ST33, and ST48-like; donkeys harboured ST1, ST2, ST4, ST24, ST33, and ST48-like; and ST10 was identified in mule and zebra samples. This is the first molecular survey of Blastocystis sp. in equines from Algeria and reveals the presence of zoonotic subtypes (ST1–ST4) alongside the putatively equid-associated subtype ST33, underscoring the importance of investigating equines as potential reservoirs under a One Health umbrella.