Emerging Insights into Feline Hepatozoonosis in Türkiye: Molecular Detection and Phylogenetic Characterization from the Aegean Coast

Selin Hacılarlıoğlu; Metin Pekağırbaş

doi:10.4274/tpd.galenos.2025.88609

ABSTRACT

Objective

The aim of this study is to investigate the presence, prevalence, and molecular characteristics of Hepatozoon spp. infection in domestic cats living in Aydın and İzmir provinces, located on the Aegean coast of Türkiye. The study specifically focuses on species identification and genotype distribution.

Methods

A total of 203 blood samples from domestic cats were analyzed for Hepatozoon spp. using polymerase chain reaction (PCR). Among the 67 PCR-positive samples, 10 (five for each province) were selected for sequencing, and bidirectional Sanger sequencing was performed. The obtained sequences were evaluated using basic local alignment search tool and phylogenetic analyses, and genotype identification was based on the 18S rRNA gene region. Additionally, potential risk factors such as age, sex, health status and housing type were statistically analyzed for their association with Hepatozoon spp. infection.

Results

The overall prevalence of Hepatozoon spp. in cats was determined to be 33.0% (67/203). The infection rate was 43.69% in Aydın and 22% in İzmir, and this difference was found to be statistically significant (p=0.001). All 10 sequenced samples were identified as Hepatozoon felis, and all isolates belonged to Genotype I. A significant association was found between age and infection, with a particularly high infection rate of 44% observed in cats aged one year or younger (p=0.020).

Conclusion

This study revealed a high prevalence of Hepatozoon spp. infection among cats in western Türkiye, with all sequenced isolates identified as Genotype I. The notably high infection rate observed in young cats raises the possibility of transplacental transmission. These findings underscore the need for further investigations to clarify the transmission routes and risk factors associated with this protozoan parasite, the epidemiology of which remains insufficiently understood.

Keywords:

Tick-borne disease, Hepatozoon felis, domestic cat, genotype, Türkiye

INTRODUCTION

Hepatozoonosis is a disease caused by Hepatozoon species which are apicomplexan protozoan parasites belonging to the family Hepatozoidae. These parasites infect mammals, birds, reptiles, and amphibians and are transmitted by various arthropod vectors. The transmission of Hepatozoon species occurs through ingestion of infected invertebrates, such as ticks, mites, mosquitoes, or fleas, which act as definitive hosts (1, 2). Although Hepatozoon infection in dogs is well documented, data on feline hepatozoonosis remain limited (1). The prevalence of infection has been found to vary between 0.6% and 83.3% in various regions depending on the lifestyle of the cats, the geographical area, the diagnostic method used, and the type of samples tested (3). It has been noted that infection in cats is predominantly subclinical, with the potential for exacerbation in animals with compromised immune systems or co-infections (4, 5).

Three different Hepatozoon species have been reported in felids so far, namely Hepatozoon felis (H. felis), Hepatozoon canis and Hepatozoon silvestris (6). Among them, H. felis is the earliest identified and most widespread species, affecting both wild and domestic felids worldwide (7). This species, which is the primary causative agent of feline hepatozoonosis, a disease of veterinary importance, was first detected in domestic cats in India (8). Although H. canis infections have only been described sporadically in domestic and wild felids, H. felis infections are subclinical without a significant local inflammatory response (5, 7).

It has been hypothesized by some researchers that different species or genotypes may possess distinct biological characteristics and pathogenic potential (5, 9). However, the most prevalent H. felis variant in the world is believed to be a species complex comprising multiple variants, including a genotype on a global scale. Furthermore, it has been hypothesized that multiple genotypes or species may circulate among cats in the same country or a more limited area (3, 10). Phylogenetic analyses of H. felis, the most prevalent species infecting cats, utilizing partial 18S rRNA gene sequences, have identified two distinct genotypes: The more common genotype I and genotype II, characterized by a lower prevalence (11). Also, (12) reported a high genetic diversity with the existence of two different genotypes of H. felis as a result of 18S rRNA gene sequence analysis. Additionally, Panda et al. (12) reported high genetic diversity, identifying two distinct genotypes of H. felis based on 18S rRNA gene sequence analysis.

In a recent study, H. silvestris was identified as a new species infecting cats. Subsequently, this species has been detected in several European wild and domestic cats, including those in Türkiye (6, 9, 13, 14). In contrast to the typically subclinical nature of H. felis, H. silvestris has been implicated as the causative agent of severe clinical conditions such as fatal myocarditis and intussusception suggesting a potentially higher virulence to domestic cats (15, 16).

The majority of research on Hepatozoon infections in Türkiye has focused on canine hosts and tick vectors, and comprehensive study data on cats are quite limited (14, 17-27). In particular, information regarding the prevalence, species and genotype distribution, as well as potential risk factors such as age, sex, health status, and housing conditions, is notably scarce. Addressing these gaps is essential for elucidating transmission dynamics and developing effective preventive veterinary strategies.
The current findings emphasize the need for further research to better understand the epidemiology of Hepatozoon spp. infections in cats. Accordingly, the present study was conducted to investigate the presence, prevalence, molecular characteristics, and phylogenetic structure of Hepatozoon species in domestic cats from Aydın and İzmir provinces, located on the Aegean coast of Türkiye, while also evaluating potential risk factors associated with infection.

METHODS

Ethically Approval

The study was performed under the instructions and approval of the Institutional Animal Ethics Committee of Aydın Adnan Menderes University (protocol no: 64583101/2024/019, date: 18/01/2024). Animal owners participating in the study were informed about the purpose and procedures of the research, and written informed consent was obtained before blood sample collection.

Blood Samples

In this study, a total of 203 blood samples were used from domestic cats as part of the MSc thesis titled “Investigation of the Prevalence of Ehrlichia Species in Cats Living in İzmir and Aydın Provinces”. These samples were collected from cats brought to veterinary hospitals or clinics in the Aydın and İzmir provinces, located in the Aegean coast of Türkiye, between 2024 and 2025. The age of the animals was recorded at the time of sampling and categorized into three groups: One year or younger, 1-4 years, 4 and over 4 years. Blood samples were collected in tubes containing ethylene diamine tetraacetic acid (EDTA) (BD Vacutainer®, Franklin Lakes, NJ, USA) for polymerase chain reaction (PCR) analysis and were stored at -20 °C until further processing.

Genomic DNA Extraction, PCR Amplification and Sequencing

Genomic DNA was extracted from the collected blood samples (200 µL) using the Invitrogen Genomic DNA Extraction kit (Invitrogen by Life Technologies, Thermo Fisher Scientific, USA), following the manufacturer’s protocol. A total of 200 µL of each blood sample was used for DNA extraction. Amplification of an approximately 600 bp fragment of the 18S rRNA gene of Hepatozoon spp. was performed using the primer pair HepF300: 5′-GTT TCT GAC CTA TCA GCT TTC GAC G-3′ and Hep900: 5′-CAA ATC TAA GAA TTC ACC TCT GAC-3′, following the protocol described by Ujvari et al. (28). PCR reactions were carried out using a Techne TC-512 thermocycler (Techne, UK), in a final volume of 50 µL, containing 1X PCR buffer, 2 mM MgCl₂, 0.2 mM of each deoxynucleotide triphosphate, 0.25 U of VitaTaq DNA polymerase, 0.5 µM of each primer, and 2 µL of DNA template. The amplification process included an initial denaturation at 94 °C for 3 min, followed by 35 cycles of denaturation at 94 °C for 30 s, annealing at 60 °C for 30 s, and extension at 72 °C for 1 min, followed by a final extension step at 72 °C for 10 min. A positive and a negative control were included in all PCR reactions. The positive control consisted of DNA extracted from a naturally infected dog, while double-distilled water was used as the negative control. A total of 10 µL of each PCR product was electrophoresed on a 1.5% agarose gel containing SafeView™ nucleic acid stain (10 µL/mL; ABM Inc., Richmond, Canada) in Tris-acetate-EDTA buffer. Electrophoresis was conducted using a horizontal gel system at 120 V for 1 hour. For species identification, PCR products from Hepatozoon-positive samples were sequenced bidirectionally using the same primers through Sanger sequencing at Atlas Biotechnology (Ankara, Türkiye). However, due to financial constraints, only ten positive samples (five from each province) were selected for sequencing. The resulting sequences were aligned and assembled into consensus sequences using Geneious Prime 2025.1.2 software (https://www.geneious.com). These consensus sequences were subsequently compared with reference sequences in the GenBank database using the basic local alignment search tool (BLAST) algorithm (https://blast.ncbi.nlm.nih.gov/Blast.cgi). The resulting sequence data were submitted to the GenBank database under the following accession numbers: PV765406- PV765415.

Phylogenetic Analysis

A phylogenetic tree was constructed using the online tool available at https://www.phylogeny.fr. The reference sequences retrieved from the NCBI GenBank database (https://www.ncbi.nlm.nih.gov) AY628681.1, KC138533.1, and LC179794.1 (H. felis); KY649446.1 and KC138531.2 (H. canis); and AF130361.1 (H. catesbianae) (11); OQ862293-OQ862310 (22); OM214003-OM214012 (14) were used in the analysis. GenBank accession number, host and country of origin were included in the phylogenetic tree.

Statistical Analysis

All statistical analyses were performed using the SPSS software package (IBM SPSS for Windows, version 25). Associations between potential risk factors and the presence of infection were assessed using the chi-square (χ²) test. A p-value less than 0.05 was considered statistically significant.

RESULTS

Demographic Characteristics and Molecular Prevalence of Hepatozoon spp.

A total of 203 domestic cats were included in this study, comprising 100 from İzmir and 103 from Aydın provinces. Of these, 129 were female and 74 were male. Based on age distribution, 75 cats were younger than 1 year, 118 were between 1 and 4 years old, and 10 were older than 4 years. Regarding housing conditions, the majority were outdoor cats (n=161), followed by cats with both indoor and outdoor access (n=12), while only 30 were strictly indoor cats. Importantly, all animals included in the study had no prior history of antiparasitic treatment.

Among the total 203 blood samples screened, 67 (33.0%) were found to be positive for Hepatozoon spp. by PCR. Region-specific prevalence rates were 22.0% (22/100) in İzmir and 43.6% (45/103) in Aydın.

Sequence and Phylogenetic Analysis

Phylogenetic analysis of Hepatozoon-positive samples was conducted based on the 18S rRNA gene sequences obtained in this study, along with reference sequences retrieved from the GenBank database. Both BLAST results and phylogenetic tree reconstruction confirmed that all positive samples belonged to H. felis (Figure 1). Nucleotide sequence analysis of the H. felis 18S rRNA gene revealed a sequence similarity ranging from 98.58% to 100%. Moreover, the H. felis sequences obtained in this study clustered with previously reported sequences from Türkiye (11, 22), which have been classified as H. felis genotype I.

Risk Factor Analysis

Out of 203 cats examined, 67 (33.00%) were positive for Hepatozoon spp. by PCR. Statistical analysis revealed a significant association between infection and age (p=0.020), with the highest positivity observed in cats ≤1 year (44.00%) (Table 1). A significant difference was also found between provinces, with higher prevalence in Aydın (43.6%) compared to İzmir (22.00%) (p=0.001) (Table 1). No significant associations were detected for sex (p=0.288), housing type (p=0.363), or clinical status (p=0.625), although slight differences in infection rates were noted across categories (Table 1). These findings suggest that younger age and geographic location may act as potential risk factors for Hepatozoon spp. infection in the studied cat population, while sex, housing conditions, and clinical status showed no statistically significant associations.

DISCUSSION

This study primarily aimed to investigate the presence and molecular characterization of Hepatozoon spp. in domestic cats from two provinces in the Aegean coast of Türkiye, with a particular focus on species identification and genotype distribution. Of the 203 cats tested, 33.0% (67/203) were found to be positive for Hepatozoon spp. by PCR analysis. This notably high prevalence highlights the widespread presence of this protozoan parasite in feline populations in the western part of Türkiye. Among the 67 Hepatozoon-positive cats, 10 samples were successfully sequenced. Subsequent BLAST and phylogenetic analyses confirmed that all sequenced samples belonged to H. felis (Figure 1).

Previous studies have demonstrated the presence of Hepatozoon spp. infection in cats in Türkiye, with varying prevalence rates reported across different regions. The prevalence observed in this study (33.0%) is considerably higher than those reported in previous molecular studies conducted in other regions of Türkiye, which documented infection rates of 2.37%, 10.8%, and 18.64% (14, 22, 23). In a study conducted on 1012 stray cats from İzmir province, which is located in the same region as the current study (23%), reported a much lower prevalence of H. felis (2.37%) compared to our findings. Notably, the samples used in that study were collected approximately a decade earlier than those analyzed in the present investigation. It is possible that ecological changes in recent years such as global warming, rapid urban population growth, and the increased transcontinental movement of companion animals have contributed to a rise in the transmission rates of vector-borne pathogens worldwide (29), potentially influencing the current distribution of Hepatozoon spp. infections.

The prevalence of Hepatozoon spp. detected in Aydın (43.69%) was significantly higher than that observed in İzmir (22%) (p=0.001). A review of the existing literature reveals that the prevalence of Hepatozoon spp. infection in cats shows considerable variation across different geographical regions worldwide, with reported rates ranging wide 0.6-83.3% (3, 5, 10, 11, 30-33). The findings of the present study are in agreement with this broad global variability in prevalence rates. Although the samples in both provinces were selected in equal numbers and from cats with similar characteristics, specifically stray cats without a history of antiparasitic treatment, the results varied. This discrepancy may be attributed to the fact that some of the sampling areas in Aydın shifted from urban to rural settings.

Although biological and epidemiological knowledge about H. felis remains limited, Rhipicephalus sanguineus is considered one of its main potential vectors (34). The ingestion of ticks during grooming behavior in cats may also contribute to the transmission of Hepatozoon species (2). In the present study, the previously reported presence of tick species belonging to the genus Rhipicephalus in the study area (35) supports the infection rates observed.

In the current study, all sequenced samples were identified as H. felis. These findings are consistent with previous molecular investigations conducted in Türkiye, particularly in İzmir and Tekirdağ, where H. felis was the only Hepatozoon species detected in cats, with prevalence rates of 2.37% and 10.8%, respectively (22, 23). However, a recently published study from the northern part of Türkiye reported the presence of both H. felis and H. silvestris in feline hosts (14). Additionally, a case report from Aydın documented the detection of H. canis in a cat by both microscopic examination and PCR analysis; however, sequence analysis was not performed in the study (26).

The taxonomic status of Hepatozoon spp. infecting felids is not fully established (10). H. felis has been identified as the predominant species infecting cat populations worldwide (7). Due to the high genetic variability observed across various studies, H. felis has been proposed to represent a species complex (36). To date, phylogenetic analysis based on 18S rRNA sequences revealed that two distinct genotypes of H. felis genotypes I and II have been reported in domestic cats (11). Among these, genotype I is recognized as the most common genotype infecting domestic cats. Pereira et al. (11) reported that H. felis genotype I has been detected in cats from Europe, Asia, Africa, and South America. Phylogenetic analysis in this study revealed that all sequenced isolates clustered within H. felis Genotype I. Similarly, studies conducted in Türkiye have also identified H. felis genotype I (14, 22), supporting the notion that this genotype is the most prevalent one in the country.

In a study conducted by Attipa et al. (31), non-healthy cats were found to have a threefold higher risk of Hepatozoon spp. infection compared to healthy individuals (p=0.010); however, the authors noted that the observed health problems might not be directly caused by hepatozoonosis and could instead result from coinfections with other pathogens. In the present study, no statistically significant association was found between Hepatozoon spp. infection and the presence of viral, bacterial, or other parasitic agents, possibly due to the limited number of infected animals (34 out of 203). Additionally, in line with previous findings (2, 14, 31), no significant association with sex was observed.

To date, studies have not identified a significant association between age and Hepatozoon infection in cats (2, 7, 14, 31). However, in the present study, a statistically significant difference was observed in cats aged one year or younger (p=0.020). Similarly, Attipa et al. (31) reported that 21% of kittens under six months of age tested positive for Hepatozoon spp. In line with these findings, the present study found a Hepatozoon spp. positivity rate of 44% among cats aged one year or younger, which was statistically significant. When comparing overall age distributions, it appears that differences in age group classifications among studies may lead to inconsistent results. Nonetheless, the notably high infection rates detected in young cats in this study are of particular importance. These findings raise the possibility of vertical (transplacental) transmission from queen to offspring. Indeed, studies on H. canis in dogs have demonstrated that transplacental transmission is possible (37, 38). Vertical transmission is an important adaptation in many parasites that enables the persistence of infection within a population.

Previous studies have reported a significant association between infection and outdoor access (7, 14, 31). In the present study, a statistically significant difference was initially detected in cats reported to live indoors. However, interviews conducted with cat owners revealed that these animals had frequent contact with other animals that had access to outdoor environments. Upon reevaluation of the living conditions, it became evident that these cats were indirectly exposed to external sources. These findings support the vector–host transmission route and indicate that animals living outdoors or in contact with the outdoor environment are at increased risk of infection.

The present study provides valuable insights into the current epidemiological status of Hepatozoon spp. infections in domestic cats from two provinces located in the Aegean cost of Türkiye. Molecular analyses confirmed that H. felis is the predominant species circulating in these areas, particularly among free-roaming cats.

Hepatozoon spp. infections in cats appear to be largely asymptomatic or present with occasional subclinical manifestations, which may contribute to underdiagnosis in routine clinical practice (7). Given the relatively high prevalence of Hepatozoon spp. observed in present study and its widespread distribution among free-roaming feline populations (22, 33), this parasitic infection warrants further attention.

CONCLUSION

In conclusion, this study provides up-to-date epidemiological data on feline hepatozoonosis in western Türkiye and confirms H. felis genotype I as the predominant species. Raising awareness among veterinarians and incorporating Hepatozoon spp. into routine diagnostic panels is essential, particularly in areas with high stray cat populations. Further molecular surveillance and larger-scale studies are needed to better understand transmission dynamics and potential risk factors.

Ethics

Ethics Committee Approval: The study was performed under the instructions and approval of the Institutional Animal Ethics Committee of Aydın Adnan Menderes University (protocol no: 64583101/2024/019, date: 18/01/2024).

Informed Consent: Animal owners participating in the study were informed about the purpose and procedures of the research, and written informed consent was obtained before blood sample collection.

Acknowledgments

The authors would like to thank Yusuf Darçın for their valuable contributions to the study.

Authorship Contributions

Concept: S.H., M.P., Design: S.H., M.P., Data Collection or Processing: S.H., M.P., Analysis or Interpretation: S.H., M.P., Literature Search: S.H., M.P., Writing: S.H., M.P.

Conflict of Interest: No conflict of interest was declared by the authors.

Financial Disclosure: This research was partially supported by Aydın Adnan Menderes University Scientific Research Projects Coordination Unit with the code ADU-BAP VTF-24002.

References

Baneth G. Perspectives on canine and feline hepatozoonosis. Vet Parasitol. 2011; 181: 3-11.

Schäfer I, Kohn B, Nijhof AM, Müller E. Molecular detection ofHepatozoon species infections in domestic cats living in Germany. J Feline Med Surg. 2022; 24: 994-1000.

Morelli S, Traversa D, Di Cesare A, Colombo M, Grillini M, Paoletti B, et al. Geographical isolation and hyperendemicity ofHepatozoon felis: epidemiological scenario in Skopelos, Greece, and phylogenetic analysis. Curr Res Parasitol Vector Borne Dis. 2024; 6: 100202.

Díaz-Regañón D, Villaescusa A, Ayllón T, Rodríguez-Franco F, Baneth G, Calleja-Bueno L, et al. Molecular detection ofHepatozoon spp. and Cytauxzoon sp. in domestic and stray cats from Madrid, Spain. Parasit Vectors. 2017; 10: 1-9.

Morelli S, Diakou A, Traversa D, Di Gennaro E, Simonato G, Colombo M, et al. First record ofHepatozoon spp. in domestic cats in Greece. Ticks Tick Borne Dis. 2021; 12: 101580.

Grillini M, Beraldo P, Frangipane di Regalbono A, Dotto G, Tessarin C, Franzo G, et al. Molecular survey ofCytauxzoon spp. and Hepatozoon spp. in felids using a novel real-time PCR approach. Front Vet Sci. 2023; 10: 1113681.

Baneth G, Sheiner A, Eyal O, Hahn S, Beaufils JP, Anug Y, et al. Redescription ofHepatozoon felis (Apicomplexa: Hepatozoidae) based on phylogenetic analysis, tissue and blood form morphology, and possible transplacental transmission. Parasit Vectors. 2013; 6: 102.

Patton WS. The haemogregarines of mammals and reptiles. Parasitology. 1908; 1: 318-21.

Hodžić A, Alić A, Prašović S, Otranto D, Baneth G, Duscher GG.Hepatozoon silvestris sp. nov.: morphological and molecular characterization of a new species of Hepatozoon (Adeleorina: Hepatozoidae) from the European wild cat (Felis silvestris silvestris). Parasitology. 2017; 144: 650-61.

Traversa D, Di Cesare A, Morelli S, Paoletti B, Grillini M, Di Regalbono AF, et al.Hepatozoon spp. in stray cats from the metropolitan area of Rio de Janeiro, Brazil. Parasite. 2024; 31: 26.

Pereira C, Maia JP, Marcos R, Luzzago C, Puente-Payo P, Dall’Ara P, et al. Molecular detection ofHepatozoon felis in cats from Maio Island, Republic of Cape Verde and global distribution of feline hepatozoonosis. Parasites Vectors. 2019; 12: 1-9.

Panda R, Nehra AK, Ram H, Karikalan M, Garg R, Nala RR, et al. Phylogenetic analysis and haplotype networking ofHepatozoon felis infecting wild animals in Gir National Park, Gujarat, India. Parasitol Res. 2024; 123.

Giannelli A, Latrofa MS, Nachum-Biala Y, Hodžić A, Greco G, Attanasi A, et al. Three differentHepatozoon species in domestic cats from southern Italy. Ticks Tick Borne Dis. 2017; 8: 721-4.

Önder Z, Pekmezci D, Yıldırım A, Pekmezci GZ, Düzlü Ö, Kot ZN, et al. Microscopy and molecular survey ofHepatozoon spp. in domestic cats and their ticks: first report of H. silvestris from Türkiye. Parasitol Int. 2025; 104: 102979.

Kegler K, Nufer U, Alic A, Posthaus H, Olias P, Basso W. Fatal infection with emerging apicomplexan parasiteHepatozoon silvestris in a domestic cat. Parasites Vectors. 2018; 11: 1-5.

Simonato G, Franco V, Salvatore G, Manzocchi S, Dotto G, Morelli S, et al. First autochthonous clinical case ofHepatozoon silvestris in a domestic cat in Italy with unusual presentation. Parasites Vectors. 2022; 15: 1-7.

Aktas M, Özübek S, Altay K, Balkaya I, Utuk AE, Kirbas A, et al. A molecular and parasitological survey ofHepatozoon canis in domestic dogs in Turkey. Vet Parasitol. 2015; 209: 264-7.

Altay K, Aydin MF, Aytmirzakizi A, Jumakanova Z, Cunusova A, Dumanli N. Molecular survey of hepatozoonosis in natural infected dogs: first detection and molecular characterisation ofHepatozoon canis in Kyrgyzstan. Kafkas Univ Vet Fak Derg. 2019; 25: 77-81.

Aydin MF, Sevinc F, Sevinc M. Molecular detection and characterization ofHepatozoon spp. in dogs from the Central part of Turkey. Ticks Tick Borne Dis. 2015; 6: 388-92.

Bölükbaş CS, Pekmezci D, Gürler AT, Pekmezci GZ, Güzel M, Açici M, et al. Molecular survey ofHepatozoon canis in dogs from Samsun Province of Northern Part of Turkey. Etlik Vet Mikrobiyol Derg. 2016; 27: 104-7.

Karagenc TI, Pasa S, Kirli G, Hosgor M, Bilgic HB, Ozon YH, et al. A parasitological, molecular and serological survey ofHepatozoon canis infection in dogs around the Aegean coast of Turkey. Vet Parasitol. 2006; 135: 113-9.

Koçkaya ES, Güvendi M, Köseoğlu AE, Karakavuk M, Değirmenci Döşkaya A, Erkunt Alak S, et al. Molecular prevalence and genetic diversity ofHepatozoon spp. in stray cats of İzmir, Türkiye. Comp Immunol Microbiol Infect Dis. 2023; 101: 102060.

Muz MN, Erat S, Mumcuoglu KY. Protozoan and microbial pathogens of house cats in the province of Tekirdag in western Turkey. Pathogens. 2021; 10: 1144.

Orkun Ö, Nalbantoğlu S.Hepatozoon canis in Turkish red foxes and their ticks. Vet Parasitol Reg Stud Reports. 2018; 13: 35-7.

Pekağirbaş M, Demirbilek MV, Şimşek E, Aydin HB, Kanlioğlu H, Oryaşin AG, et al. Molecular characterization ofHepatozoon spp. in naturally infected dogs in Aydın province. Ankara Univ Vet Fak Derg. 2025; 72: 237-42.

Tuna GE, Bakırcı S, Dinler C, Battal G, Ulutaş B. Molecular identification and clinicopathological findings of Hepatozoon sp. infection in a cat: first report from Turkey. Turkiye Parazitol Derg. 2018; 42: 286-9.

Tas T, Pala MF, Emirikci A, Adanır R, Yukarı BA, Kose O. Microscopic and PCR survey ofHepatozoon spp. and Anaplasma phagocytophilum in dogs from Antalya city of Türkiye. Med Weter. 2025; 81: 164-72.

Ujvari B, Madsen T, Olsson M. High prevalence ofHepatozoon spp. (Apicomplexa, Hepatozoidae) infection in water pythons (Liasis fuscus) from tropical Australia. J Parasitol. 2004; 90: 670-2.

Paz S. Climate change: A driver of increasing vector-borne disease transmission in non-endemic areas. PLOS Med. 2024; 21: e1004382.

Criado-Fornelio A, Ruas JL, Casado N, Farias NA, Soares MP, Müller G, et al. New molecular data on mammalianHepatozoon species (Apicomplexa: Adeleorina) from Brazil and Spain. J Parasitol. 2006; 92: 93-9.

Attipa C, Papasouliotis K, Solano-Gallego L, Baneth G, Nachum-Biala Y, Sarvani E, et al. Prevalence study and risk factor analysis of selected bacterial, protozoal and viral, including vector-borne, pathogens in cats from Cyprus. Parasites Vectors. 2017; 10: 1-10.

Otranto D, Iatta R, Baneth G, Cavalera MA, Bianco A, Parisi A, et al. High prevalence of vector-borne pathogens in domestic and wild carnivores in Iraq. Acta Trop. 2019; 197:105058.

Carbonara M, Iatta R, Sgroi G, Papadopoulos E, Lima C, Bouhsira E, et al. Hepatozoon species infecting domestic cats from countries of the Mediterranean basin. Ticks Tick Borne Dis. 2023; 14.

Bhusri B, Sariya L, Mongkolphan C, Suksai P, Kaewchot S, Changbunjong T. Molecular characterization ofHepatozoon felis in Rhipicephalus sanguineus ticks infested on captive lions (Panthera leo). J Parasit Dis. 2017; 41: 903-7.

Bakırcı S, Aysul N, Bilgiç HB, Hacılarlıoğlu S, Eren H, Karagenç T. Tick bites on humans in Southwestern Region of Turkey: Species diversity. Turkiye Parazitol Derg. 2019; 43: 30-5.

Harris DJ, Halajian A, Santos J, Rampedi KM, Xavier R. Genetic diversity of Hepatozoon (Apicomplexa) from domestic cats in South Africa, with a global reassessment of Hepatozoon felis diversity. J S Afr Vet Assoc. 2019; 90: e1-6.

Murata T, Inoue M, Tateyama S, Taura Y, Nakama S. Vertical transmission ofHepatozoon canis in dogs. J Vet Med Sci. 1993; 55: 867-8.

Schäfer I, Müller E, Nijhof AM, Aupperle-Lellbach H, Loesenbeck G, Cramer S, Naucke TJ. First evidence of vertical Hepatozoon canis transmission in dogs in Europe. Parasit Vectors. 2022; 15: 296.