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Genetic characterization and pathogenic effects of Hepatozoon canis infection in police dogs in Egypt



Hepatozoon canis is a protozoan parasite transmitted to dogs through ingesting the arthropod vector (hard ticks), which contains mature protozoal oocysts harboring infectious sporozoites.


This study aims to evaluate the blood parameters, biochemical assays and histopathological appraisal of infected police dogs with Hepatozoon canis, from kennels in the police academy of Egypt during 2020–2021.


Red blood cells count, hemoglobin, hematocrit, blood platelets and white blood cells count from collected blood samples were analyzed, and serum albumin, creatinine, urea, aspartate aminotransferase and alanine aminotransferase were analyzed from serum samples. Polymerase chain reaction amplified the 18S ribosomal RNAgene of the Hepatozoon species for genetic analysis, and the deoxyribonucleic acid products were sequenced and added to GenBank.


The present study resulted in 5% of the police dog population being infested with Rhipicephalus sanguineus. This study registered the sequences of the Hepatozoon canis 18S ribosomal RNAgene in Egypt for the first time in Genbank (MW362244.1–MW362245.1). The biochemical assay revealed that the parasite severely affected the protein, significantly increasing serum albumin in positive polymerase chain reaction testing dogs.


A thorough inspection discovered that 100 police dogs had clinical symptoms like fever, emaciation and anemia, while the other 200 were healthy and had no evident clinical indicators.

1 Background

Numerous parasites can harm dogs’ health and well-being because they are hosts for many of them. One of the most prevalent diseases in dogs is tick infestation; these canines are infected by several protozoan parasites, including Babesia canis, Hepatozoan canis (H. canis) and Ehrlichia canis (E. canis) [23]. Hepatozoonosis, a canine vector-borne illness caused by H. canis, has lately been discovered in South and North America [9]. Dogs from tropical, subtropical or temperate climes are more likely to develop autochthonous infections with H. canis, and the three-host tick species Rhipicephalus sanguineus (R. sanguineus) serves as their primary vector for transmission [26, 27, 43]. In contrast to other arthropod-transmitted diseases, this one is contracted by eating infected ticks rather than by tick bites. The sporozoite will be released in the stomach of dogs that unintentionally consume the brown dog tick (R. sanguineus), which has a sporocyst stage that forms following sporogony [2]. Sporozoites that have been transmitted by a tick bite pass via mononuclear cells and travel through the blood or lymph to the visceral organs of their vertebrate hosts, including the bone marrow, spleen and lymph nodes, where they mature into the meront stage [37, 9]. Canines with H. canis infections can present with anything from severe and potentially fatal clinical symptoms, such as acute lethargy, cachexia and anemia, to asymptomatic, in otherwise healthy canines. Merozoites infect leukocytes, but the protozoan’s later-found gamont stage (which is infectious for ticks) was discovered earlier [43]. Infection with H. canis in dogs is primarily asymptomatic, but it can occasionally result in a condition marked by cachexia, lethargy and anemia that can be mild to lethal [47]. In dogs with high parasitemia, the condition can be severe and cause anemia, lethargy and cachexia in addition to other clinical symptoms ranging from asymptomatic (caused by low parasitemia) to severe (anemia) and exhibiting signs of cachexia and cachexia. However, the most common clinical symptoms in infected dogs include anorexia, fever, depression, weight loss and lymphadenopathy [30, 44]. Although there is a chance for mild nonregenerative anemia, leucocytosis with neutrophilia and monocytosis, or mild thrombocytopenia, hematological abnormalities in hepatozoonosis are less severe [18]. Lethargy, fever, anorexia, weight loss, lymphadenomegaly and anemia are examples of severe clinical symptoms that are typically linked to a high parasite load.

The parasite can be seen in histopathological specimens, where micromerozoites create the typical “wheel spoke” pattern of mature meronts by aligning in a circle around a central opaque core. Polymerase chain reaction (PCR), one molecular approach, has recently evolved above other techniques due to its increased sensitivities and specificities for detecting the target pathogens in peripheral blood [10]. In addition, sequence analysis has been used for identifying and diagnosing epidemiological studies of Hepatozoon infections [34, 29]. Therefore, this study aimed to morpho-molecular identification using the 18S ribosomal RNA (18S rRNA) gene of H. canis that infects the police dogs at K9 kennels in a police academy in Egypt. In addition to genetic characterization and sequencing, they constructed phylogenetic analysis. Biochemical assays and blood parameters were examined. Histopathological alternations of the infected tissues from freshly dead dogs were studied.

2 Methods

2.1 Sample collection

2.1.1 Investigated dogs

Between January 2020 and February 2021, 300 police dogs were examined from the K9 kennels at the Police Academy in Egypt. The examined dogs were between 2.5 and 12 years old. For morphological identification of the protozoan parasite, blood samples were analyzed. This study was approved by the ethical committee of the animal care and use of the Faculty of Veterinary Medicine, Cairo University, with number Vet Cu 01122022624.

2.1.2 Ticks

A total of 300 ticks (adult male, female and nymph stage) were collected from one hundred dogs located in K9 kennels at the police academy of Egypt. The method of collecting ticks was done according to Abdullah et al. [1]. The preserved ticks are in 70% ethyl alcohol for identification [15].

2.1.3 Blood samples

Three hundred blood samples were taken from the sick police dogs (K9). A thorough inspection discovered that 100 police dogs had clinical symptoms like fever, emaciation and anemia, while the other 200 were healthy and had no evident clinical indicators. Each dog’s cephalic vein was used to draw blood, which was then placed in a tube with ethylene diamine tetra acetic acid (EDTA). Additionally, they drew blood into simple test tubes to obtain serum for biochemical analysis.

2.2 Parasitological examination

The blood smears were air dried, methanol absolute was used to fix them, and Giemsa stain was used to color them. Under a light microscope (X40 and 100) (OLYMPUS CX41), Soulsby [49] and Zaki et al. [52] examined the dyed blood smears to evaluate whether H. canis infection was present.

2.3 Hematological and biochemical analysis of blood infected with H. canis

To identify the various blood parameters, red blood cells (RBCs) count, hemoglobin (Hb), hematocrit (Hct), blood platelets (PLT) count and white blood cells (WBCs) count [25] potentially alter during canine hepatozoonosis infection. Hematological analysis was performed on 300 whole blood samples using EDTA (idexx-vet. auto read-USA). Additionally, serum was submitted to spectrophotometric techniques employing (idexx-catalyst-USA) to determine serum albumin, creatinine, urea, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) [4,5,6,7, 5, 6]. At the Egyptian police academy’s K9 lab, they completed the complete hematological and biochemical analysis of blood.

2.4 Genetic characterization of H. canis

PCR was utilized to amplify the 18S rRNA gene of the hepatozoon species, and the deoxyribonucleic acid (DNA) produced was subsequently sequenced. DNA extracted from blood samples taken from police dogs (n = 100). Utilized an amplifying primer set for the Hepatozoon 18S rRNA gene to determine the DNA sequences of the PCR products from all samples [13, 17, 41, 45]. The DNA was extracted from 2ml blood using the QIAGEN DNA blood kits by the aid of the automatic extraction tool QIAcube. One sample of DNase/RNase-free distilled water was used as a blind control in the DNA extraction cycle. The forward primers Hep-F (5′-ATA CAT GAG CAA AAT CTC AAC-3′) and Hep-R (5′-CTT ATT ATT CCA TGC TGC AG-3′) are used to amplify the whole 18S rRNA gene under the circumstances outlined by [19, 41]. The amplified sequence gene was obtained from a 700-bp fragment of the 18S rRNA gene. The following procedures were used for amplification: 40 cycles of denaturation at 94 °C for 30 s, annealing at 45 °C for 30 s and chain extension at 72 °C for 90 s. The initial denaturation took place for 5 min at 94 °C. The final stage was performed with a 5-min final extension at 72 °C [13, 22, 50].

The assembled sequences were bioedit using the Edit Seq tools (Lasergene; DNASTAR, INC., Madison, WI, USA) using Edit Seq tools.

2.5 Histopathology

The necropsied liver and spleen samples from fifteen police dogs that had recently died of infection were preserved in 10% neutral buffered formalin. Tissue specimens were routinely processed, embedded in paraffin and cut into 5 µm sections. Hematoxylin and eosin (H&E) staining was performed on tissue sections [12]. We used an Olympus BX43 light microscope with a DP-27 Olympus camera to analyze stained tissue slides.

2.6 Statistical analyses

All data were expressed as mean ± S.E. (standard error) [7]. Statistical comparison between the mean of the different groups (positive and negative PCR testing dogs) was made by independent samples T-Test. The sensitivity and specificity of histopathology were compared with PCR (gold standard) by the Chi-square test. Values of P ≤ 0.05 were considered statistically significant. SPSS version 26 was utilized for the analyses (SPSS Inc, Chicago, IL, USA). Statistics were judged significant at P ≤ 0.05 or higher [33, 51].

3 Results

3.1 Identification of ticks

Examination of the three hundred police dogs revealed that 200 were healthy and without tick infestation, and one hundred were infested with ticks and showed clinical signs. The identified tick specimens as R. sanguineus with an infestation rate (30%). The detected male ticks were characterized by a dark brown color and the presence of grooves on the dorsal surface of the body. In contrast, the female ticks were characterized by scutum covering the anterior body and a short hypostome (wider than long). All developmental stages of ticks were determined (adult male, female and nymph stage) from the infested police dogs (Fig. 1).

Fig. 1
figure 1

A A police dog infested with brown dog ticks. B The collected male and female R. sanguineus were widely distributed brown dog ticks. C Postmortem examination of dogs infected with H. canis showing hemorrhagic liver. D Postmortem examination of dogs infected with H. canis showing enlarged spleen (splenomegaly)

3.2 Ticks distribution

The prevalence rate of infestation with ticks investigated was 30.0% on police dogs. The detected R. sanguineus ticks from soft parts of dogs from the neck, chest area and inner sides of the forelegs. German shepherd breed of dogs was more sensitive to tick infestation with a prevalence of 88% than Malino, 12%. The intensity rates of infestation differ ranged from mild (less than ten ticks on the body) (66%), moderate (10–20 ticks on the body) (23%) and severe (more than 20 ticks on the body) (11%) (Table 1). Regarding the gender-investigated dogs, a male was the more prevalent by 90% of the total sample, followed by a female (10%).

Table 1 Erythrogram and leukogram parameters in positive and negative H.canis PCR testing dogs

3.3 Blood film examination

Microscopically examined blood film with Giemsa-stained to determine the prevalence of infection (5.0%) with H. canis. No other hemoparasites were diagnosed in the blood smears.. A microscopic field of infected dogs included 2 and 5 H. canis gamonts per field of parasites with oil immersion lens. In the cytoplasm of the leukocyte, a capsule encased the protozoan. These gamonts are clear to pale blue and oval to elliptical structures found in monocytes, neutrophils or cytoplasm. Also, a host cell enlarges, and its nucleus is displaced, as seen in blood smears; the mature gamonts are ellipsoidal (intra-cytoplasmatic ellipsoid-shaped) within neutrophils. The organism typically moves the nucleus to one side of the cell. H. canis gamonts’ determined dimensions were 10.1–10.9 mm and 5.3–6.6 mm (Fig. 2).

Fig. 2
figure 2

The thin stained blood smears from police dogs revealed the presence of H. canis gamonts, ellipsoid-shaped gamont in leukocyte cells. The mature gamonts of H. canis showed gamonts ellipsoidal within neutrophils, where enlargement of the host cell and displacement of the host cell nucleus (× 100)

3.4 Molecular characterization

The universal primers indicated earlier in this work were successfully used to amplify the H. canis 18S rRNA region analysis. This blood protozoan parasite produced purified PCR products that were immediately sequenced and assembled at 700 bp (Fig. 3).

Fig. 3
figure 3

Purified PCR products from H. canis at 700 bp

3.5 BLAST analysis and phylogenetic tree

10% of the studied dogs had H. canis positive as determined by PCR and amplicon sequencing. In the current study of H. canis 18S fragment sequences, there was slight variation among the H. canis sequences with others previously registered in GenBank. The registered presently obtained H. canis sequences in GenBank with the specified accession codes (MW362244.1 and MW362245.1). In BLAST analysis, clustered together with other H. canis sequences deposited in GenBank, all sequences of investigated piroplasms were 99.98–100.0% nucleotide identical to H. canis from dogs. The present sequence (MW362244.1) revealed that 100.0% nucleotide identity to sequences from dogs in KJ605145.1, MF142765.1, LC 018194.1, KU535868.1, LC018203.1, KP233215.1, JX027010.1, FJ497018.1, MZ476776.1 and KF692039.1 in India, Qatar, Portugal, Pakistan, Portugal, Brazil, Nigeria, Croatia and Brazil, respectively, while revealing 99.98% nucleotide identity to sequences from dogs in India (MG050161.1 and KX377968.1) (Fig. 4). Moreover, the obtained sequence (MW362245.1) revealed that 100.0% nucleotide identity to sequences from dogs in Nigeria and India: JQ976623.1 and MG018464.1.

Fig. 4
figure 4

Phylogenetic tree of the 18S rRNA gene sequences of H. canis created using the neighbor-joining method. Sequences with accession numbers have been taken from GenBank for comparison

3.6 Hematological and biochemical analysis

The erythrogram showed that RBCs and Hb were significantly lower in PCR-positive H. canis testing dogs (10%) compared to the negative H. canis testing dogs. On the other hand, Hct and PLT showed a nonsignificant difference in positive PCR testing dogs compared with negative PCR testing dogs. Results of the leukogram showed that WBCs were significantly higher in PCR-positive H. canis testing dogs compared to the negative H. canis testing dogs, as shown in Table 1.

Serum albumin showed a significant increase in positive PCR testing dogs compared with negative PCR testing dogs. On the other hand, AST and ALT showed no significant difference between negative and positive PCR testing dogs, as shown in Table 2.

Table 2 Results of liver function in positive and negative H. canis PCR testing dogs

As shown in Table 3, the kidney function tests performed on the studied dogs revealed no statistical difference in the levels of urea and creatinine between the dogs with negative and positive PCR results.

Table 3 Results of kidney function in positive and negative H. canis PCR testing dogs

3.7 Histopathological finding

Postmortem examination of dead dogs infected with H. canis showed hemorrhagic liver and enlargement of the spleen. Moreover, observed sections contained early meronts with their limited number of nuclei. They have exhibited maturing meronts characterized by an increased number of merozoites. The meronts resembled wheel spoke which arranged circularly. Regarding liver samples (Fig. 5d–f), diffuse areas of hepatic hemorrhages with substantial parenchymal loss were observed. The hepatocytes suffered hepatocellular degeneration and necrosis. Also, notice heavily infiltrated mononuclear inflammatory cells in the portal sites.

Fig. 5
figure 5

Photomicrograph of a–c spleen and d–f liver of dog, H&E-stained, showing a the presence of different stages of H. canis in splenic tissue, b monozoic cyst in the mononuclear cells of the host that contained single cystozoite (black arrow) dislocating the host cell nucleus to the periphery, an early meront with limited number of nuclei (red arrow), maturing meront with increased number of nuclei (arrowhead) and the wheel spoke-shaped meronts (green arrow). c Single cystozoite within the host cell (black arrow) and wheel spoke-shaped meront (green arrow); note the presence of golden yellow to brown deposits of hemosiderin pigment. d Areas of hemorrhage (stars) within the liver parenchyma, e marked hepatocellular necrosis (red stars) and f mononuclear inflammatory cells infiltration in the portal area (black arrow) (× 100)

The microscopic description of the spleen Fig. 5a–c revealed marked lymphoid depletion and a significant expansion of red pulp. The spleen contained enormous amounts of active macrophages. Hemosiderosis was evident with the presence of numerous hemosiderin-laden macrophages. Furthermore, notice the different developmental stages of H. canis in the splenic tissue. The monozoic cysts within the host mononuclear cells caused a peripheral dislocation of the host nucleus to the periphery of the cells.

Moreover, observed sections contained early meronts with their limited number of nuclei. They have exhibited maturing meronts characterized by an increased number of merozoites. The characteristic wheel spoke meronts of Hepatozoon, the circularly detected peripherally arranged merozoites. Regarding liver samples (Fig. 5d–f), observed diffuse areas of hepatic hemorrhages with substantial parenchymal loss. The hepatocytes suffered hepatocellular degeneration and necrosis. Also, notice heavily infiltrated mononuclear inflammatory cells in the portal sites.

4 Discussion

The protozoan parasite H. canis infects dogs by ingesting ticks, which may negatively affect their health and well-being. The present study revealed that all infected cases were infested by R. sanguineus only with a 30% infestation rate, and this observation agreed with previous reports by [14, 16, 24, 40, 32]. On the other hand, H.canis has also been detected in other tick species, including Rhipicephalus microplus, Haemaphysalis longicornis and Haemaphysalis flava [48]. Ixodes ricinus is widespread in Europe, and H. canis DNA was detected in one I. ricinus tick collected from the environment in Italy [24], but additional studies suggested that this tick species does not act as a vector for H. canis [26]. Transstadial transmission of H. canis from R. sanguineus larvae to nymphs has been described [27]. Furthermore, the discovery of H. canis in additional tick species (Ixodes sp.) offers fresh insights into potential novel vectors for this parasite [38]. They found that H. canis DNA was ubiquitous in red foxes, Ixodes canisuga nymphs and I. hexagonus in Germany.

The prevalence of H. canis infection in the current microscopic result was 5%, which is greater than the figures for stray dogs in Cuba obtained by Dáz-Sánchez et al. 19 and Aktas et al. [3] in Turkey (1%). El-Dakhly et al. [21] in Japan, Oliveira et al. [40] in Brazil, and Khalifa and Attia [32] in Egypt recorded that Hepatozoon gamont infection in the dog peripheral blood was 23.6%, 8.1% and 30%, respectively. This variation in the prevalence of H. canis was caused by various ecological conditions, including the degree of tick manifestation [42].

This study investigated the prevalence of tick-borne pathogens H. canis from infested police dogs in Egypt and found that the prevalence was 10% with PCR using the 18S rRNA gene. Previous research recorded that the prevalence of H. canis from dogs by PCR was 11.4% in Thailand [31] 30% in India [46], 57.8% in Italy [42], 32.5% in Italy [20], 14% in Italy ([43] and 88.8% in South Africa [39]. In addition, [14] illustrated that 13.5% of domestic dogs were positive for Hepatozoon spp. DNA. On the other hand, Aktas et al. [3] in Turkey detected a low occurrence (1%) of H. canis infection in dogs.

The findings of the phylogenetic analysis showed that the sequences of H. canis that had been obtained clustered with other H. canis sequences from carnivores (dogs and foxes) from other nations, which may indicate the presence of H. canis strain in necropsied. The findings of the phylogenetic study also demonstrated that the current most prevalent H. canis sequence is closely linked to H. canis sequences obtained from dogs, confirming the notion that foxes and jackals are essential carriers of this parasite [35].

The partial H. canis 18S rRNA gene sequences found in the investigated police dogs in our study are phylogenetically similar to those found in dogs previously (MW362244.1), revealing that 100% nucleotide identity of H. canis sequences from different countries in India, Qatar, Portugal, Pakistan, Brazil, Nigeria, Croatia and Brazil with accession numbers in GenBank (KJ605145.1, MF142765.1, LC 018194.1 and KU535868.1). Concerning this, the obtained H. canis sequence (MW362245.1) revealed 100.0% nucleotide identity of H. canis sequences from dogs in Nigeria and India (JQ976623.1 and MG018464.1).

The sampled police dogs’ hematological results revealed a modest (10%) percentage of H. canis infection, comparable to the findings on dogs living in Brazilian cities [28, 36]. Hematology and serum biochemistry revealed that the H. canis-infected animals did not exhibit significant changes in blood characteristics; however, 5 dogs did have anemia, which is a common finding of H. canis infection [8, 28, 51] although it is also a frequent sign for other diseases. Only three dogs showed leucocytosis, a hematological symptom of canine hepatozoonosis, and had the greatest parasitemia (1%) [8, 28, 51]. It may be due to the inflammatory response to tissue invasion and multiplication by H. canis, which can be exacerbated by secondary bacterial infections concomitant with other hematozoa.

All animals showed hyperproteinemia, the only change detected by serum biochemistry. However, this finding could be explained by the fact that the dogs also had conditions like Babesia spp. or E. canis based on Kwon et al. [34]. Infection with H. canis led to mild hypoglycemia, mild hyperproteinemia, elevated alkaline phosphatase and decreased blood creatinine, and chloride concentrations in a 2-year-old intact male Maltese dog in Korea. This result concurred with their conclusions.

The H. canis-infected stray dogs did not exhibit significant blood serum abnormalities in a laboratory, despite the possibility that they had concurrent illnesses. The absence of clinical symptoms may be related to the relatively low parasitemia of the infected canines (1%). Animals with high parasitemia exhibited a more severe systemic manifestation of the infection than canines with low parasitemia, according to [11].

5 Conclusion

H. canis is one of the series of hemiparasites that cause risk to health and wellness in police dogs. This study registered the sequences of the H. canis18S rRNA gene in Egypt for the first time in Genbank (MW362244.1- MW362245.1). Concerning, the results of the Biochemical assay revealed that the parasite has a severe effect on the protein that serum albumin significantly increased in positive PCR testing dogs. According to this study, treating the hemiparasites infecting dogs, eliminating the tick infestation and spraying the neighborhood where the dogs dwell are all advised (ground, dog kennels and wall).

Availability of data and materials

All the authors declare that all the data supporting the results reported in our article were found included in this article only.


H. canis :

Hepatozoon canis

R. sanguineus:

Rhipicephalus sanguineus

E. canis:

Ehrlichia canis


Ethylenediaminetetraacetic acid


Red blood cells count


White blood cells count






Blood platelets count


Aspartate aminotransferase


Alanine aminotransferase


Polymerase chain reaction


Deoxyribonucleic acid

18S rRNA:

18S ribosomal RNA


Hematoxylin and eosin


Standard error


  1. Abdullah S, Helps C, Tasker S, Newbury H, Wall R (2016) Ticks infesting domestic dogs in the UK: a large-scale surveillance program. Parasit Vectors 9:391

    Article  PubMed  PubMed Central  Google Scholar 

  2. Aktas M, Özübek S (2017) Transstadial transmission of Hepatozoon canis by Rhipicephalus sanguineus (Acari: Ixodidae) in field conditions. J Med Entomol 54:1044–1048

    Article  CAS  PubMed  Google Scholar 

  3. Aktas M, Özübek S, Altay K, Balkaya İ, Utuk AE, Kırbas A, Şimsek S, Dumanlı N (2015) A molecular and parasitological survey of Hepatozoon canis in domestic dogs in Turkey. Vet Parasitol 209(3–4):264–267

    Article  CAS  PubMed  Google Scholar 

  4. Attia MM, El-Gameel SM, Ismael E (2020) Evaluation of tumor necrosis factor-alpha (TNF-α); gamma interferon (IFN-γ) genes and oxidative stress in sheep: immunological responses induced by Oestrus ovis (Diptera: Oestridae) infestation. J Parasit Dis 44(2):332–337.

    Article  PubMed  PubMed Central  Google Scholar 

  5. Attia MM, Abdelsalam M, Korany RM, Mahdy OA (2021) Characterization of digenetic trematodes infecting African catfish (Clarias gariepinus) based on integrated morphological, molecular, histopathological, and immunological examination. Parasitol Res 120:3149–3162

    Article  PubMed  Google Scholar 

  6. Attia MM, Soliman SM, Salaeh NMK, Salem HM, Mohamed Alkafafy M, Saad AM, El-Saadony MT, El-Gameel SM (2021) Evaluation of immune responses and oxidative stress in donkeys: immunological studies provoked by Parascaris equorum infection. Saudi J Biol Sci.

    Article  PubMed  PubMed Central  Google Scholar 

  7. Attia MM, Khalifa MM, Mahdy OA (2018) The prevalence of Gasterophilus intestinalis (Diptera: Oestridae) in donkeys (Equus asinus) in Egypt with special reference to larvicidal effects of neem seed oil extract (Azadirachta indica) on third-stage larvae. Open Vet J 8:423–431

    Article  PubMed  PubMed Central  Google Scholar 

  8. Baneth G, Harmelin A, Presentez BZ (1995) Hepatozoon canis in two dogs. J Am Vet Med Assoc 206:1891–1894

    Article  CAS  PubMed  Google Scholar 

  9. Baneth G (2011) Perspectives on canine and feline hepatozoonosis. Vet Parasitol 181:3–11

    Article  PubMed  Google Scholar 

  10. Baneth G, Sheiner A, Eyal O, Hahn S, Beaufils JP, Anug Y (2013) Redescription of Hepatozoon felis (Apicomplexa: Hepatozoidae) based on phylogenetic analysis, tissue and blood form morphology, and possible transplacental transmission. Parasit Vectors 6:1–10

    Article  Google Scholar 

  11. Baneth G, Weigler B (1997) Retrospective case–control study of hepatozoonosis in dogs in Israel. J Vet Intern Med 11:365–370

    Article  CAS  PubMed  Google Scholar 

  12. Bancroft JD, Gamble M (2008) Theory and practice of histological techniques. Elsevier, London

    Google Scholar 

  13. Baticados AM, Baticados WN, Carlos ET, Carlos SM, Villarba LA, Subiaga SG, Magcalas JM (2011) Parasitological detection and molecular evidence of Hepatozoon canis from canines in Manila Philippines. Vet Med Res Rep 5:7–10

    Google Scholar 

  14. Chisu V, Giua L, Bianco P, Masala G, Sechi S, Cocco R, Piredda I (2023) Molecular survey of Hepatozoon canis infection in domestic dogs from Sardinia. Italy Vet Sci 10:640

    PubMed  Google Scholar 

  15. Dantas-Torres F (2010) Biology and ecology of the brown dog tick. Rhipicephalus sanguineus Parasites Vectors 3:26

    Article  PubMed  Google Scholar 

  16. Dantas-Torres F, Latrofa MS, Weigl S, Tarallo VD, Lia RP, Otranto D (2012) Hepatozoon canis infection in ticks during spring and summer in Italy. Parasitol Res 110:695–698

    Article  PubMed  Google Scholar 

  17. De Miranda RL, O’Dwyer JR, de Castro LH, Metzger B, Rubini AS, Mundim AV, Eyal O, Talmi-Frank D, Cury MC, Baneth G (2014) Prevalence and molecular characterization of Hepatozoon canis in dogs from urban and rural areas in Southeast Brazil. Res Vet Sci 97(2):325–328

    Article  PubMed  Google Scholar 

  18. De Bonis A, Colombo M, Terragni R, Bacci B, Morelli S, Grillini M et al (2021) Potential role of Hepatozoon canis in a fatal systemic disease in a puppy. Pathogens 10:1193

    Article  PubMed  PubMed Central  Google Scholar 

  19. Díaz-Sánchez AA, Hofmann-Lehmann R, Meli ML, Roblejo-Arias L, Fonseca-Rodríguez O, Castillo AP, Cañizares EV, Rivero EL, Chilton NB, Corona-González B (2021) Molecular detection and characterization of Hepatozoon canis in stray dogs from Cuba. Parasitol Int 80:102200

    Article  PubMed  Google Scholar 

  20. Ebani VV, Bertelloni F, Turchi B, Filogari D, Cerri D (2015) Molecular survey of tick-borne pathogens in Ixodid ticks collected from hunted wild animals in Tuscany. Italy Asian Pac J Trop Med 8:714–717

    Article  CAS  PubMed  Google Scholar 

  21. El-Dakhly KM, Goto M, Noishiki K, El-Nahass E-S, Hirata A, Sakai H, Takashima Y, El-Morsey A, Yanai T (2013) Prevalence and diversity of Hepatozoon canis in naturally infected dogs in Japanese Islands and Peninsulas. Parasitol Res.

    Article  PubMed  Google Scholar 

  22. Elsawy BSM, Nassar AM, Alzan HF, Bhoora RV, Ozubek S, Mahmoud MS, Kandil OM, Mahdy OA (2021) Rapid detection of equine Piroplasms using multiplex PCR and first genetic characterization of Theileria haneyi in Egypt. Pathogens 10(11):1414.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  23. Filipović-Kovačević M, Beletić A, Božović-Ilić A, Milanović Z, Tyrrell P, Buch J, Breitschwerdt EB, Birkenheuer AJ, Chandrashekaret R (2018) Molecular and serological prevalence of Anaplasma phagocytophilum, A. platys, Ehrlichia canis, E. chaffeenses, E. ewingii, Borrelia burgdorferi, Babesia canis, B. Gibson and B. vogeli among clinically healthy outdoor dogs in Serbia. Vet Parasitol Reg Stud Rep 14:117–122.

    Article  Google Scholar 

  24. Gabrielli S, Kumlien S, Calderini P, Brozzi A, Iori A, Cancrini G (2010) The first report of Hepatozoon canis identified in Vulpes vulpes and ticks from Italy. Vector Borne Zoonotic Dis 10:855–859

    Article  PubMed  Google Scholar 

  25. Gad SA, El-Demerdash AS, Khalifa MM, Magdy MM (2023) Hematological and molecular profiling of some blood pathogens in dog breeding farm in Egypt. J Adv Vet Res 13(3):344–351

    Google Scholar 

  26. Giannelli A, Ramos RA, Dantas-Torres F, Mencke N, Baneth G, Otranto D (2013) Experimental evidence against transmission of Hepatozoon canis by Ixodes ricinus. Ticks Tick Borne Dis 4(391–4):15

    Google Scholar 

  27. Giannelli A, Ramos RA, Di Paola G, Mencke N, Dantas-Torres F, Baneth G et al (2013) Transstadial transmission of Hepatozoon canis from larvae to nymphs of Rhipicephalus sanguineus. Vet Parasitol 196:1–5

    Article  PubMed  Google Scholar 

  28. Gondim LFP, Konayagawa A, Alencar NX, Biondo AW, Takahira RF, Franco SRV (1998) Canine hepatozoonosis in Brazil: description of eight naturally occurring cases. Vet Parasitol 74:319–323

    Article  CAS  PubMed  Google Scholar 

  29. Hodžić A, Alić A, Prašović S, Otranto D, Baneth G, Duscher GG (2017) 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 144:650–661

    Article  PubMed  Google Scholar 

  30. Ivanov A, Tsachev I (2008) Hepatozoon canis and hepatozoonosis in the dog. Trakia J Sci 6:27–35

    Google Scholar 

  31. Jittapalapong S, Rungphisutthipongse O, Maruyama S, Schaefer JJ, Stich RW (2006) Detection of Hepatozoon canis in stray dogs and cats in Bangkok. Annals of The New York Academy of Sciences, Thailand

    Book  Google Scholar 

  32. Khalifa MM, Attia MM (2023) Pathogenic effects of Hepatozoon canis (Apicomplexa: Hepatozoidae) on pet dogs (Canis familiaris) with amplification of immunogenetic biomarkers. Comp Clin Pathol.

    Article  Google Scholar 

  33. Khalifa MM, Ramadan RM, Youssef FS, Auda HM, El-Bahy MM, Taha NM (2023) Trichinocidal activity of a novel formulation of curcumin-olive oil nanocomposite in vitro. Vet Parasitol Reg Stud Rep 100880:1–9

    Google Scholar 

  34. Kwon SJ, Kim YH, Oh HH, Choi US (2017) First case of canine infection with Hepatozoon canis (Apicomplexa: Haemogregarinidae) in the Republic of Korea. Korean J Parasitol 55(5):561–564

    Article  PubMed  PubMed Central  Google Scholar 

  35. Majlathova V, Hurnikova Z, Majlath I, Petko B (2007) Hepatozoon canis infection in Slovakia: imported or autochthonous? Vector Borne Zoonotic Dis 7:199–202

    Article  PubMed  Google Scholar 

  36. Massard CA (1979) Hepatozoon canis (James, 1905) (Adeleida: Hepatozoidae) cães do Brasil, com umarevisão do gêneroemmembros da ordemcarnı́vora. Departamento de Parasitologia, Universidade Federal Rural do Rio de Janeiro, Seropédica, Tese (MestradoemMedicinaVeterinária—ParasitologiaVeterinária), p 121

    Google Scholar 

  37. Murata T, Inoue M, Tateyama S, Taura Y, Nakama S (1993) Vertical transmission of Hepatozoon canis in dogs. J Vet Med Sci 55:867–868

    Article  CAS  PubMed  Google Scholar 

  38. Najm NA, Meyer-Kayser E, Hoffmann L, Pfister K, Silaghi C (2014) Hepatozoon canis in German red foxes (Vulpes vulpes) and their ticks: molecular characterization and the phylogenetic relationship to other Hepatozoon spp. Parasitol Res 113:2679–2685

    Article  PubMed  Google Scholar 

  39. Netherlands EC, Carlie S, Louis H, du Preez N, Tshepo P, van Louis O, Barend L (2021) Molecular confirmation of high prevalence of species of Hepatozoon infection in free-ranging African wild dogs (Lycaon pictus) in the Kruger national park, South Africa. Int J Parasit Parasit Wildl 14:335–340

    Article  Google Scholar 

  40. Oliveira LV, Oliveira RR, Alcântara ET, Álvares FB, Feitosa TF, Brasil AW, Vilela VL (2021) Hematological, clinical, and epidemiological aspects of Hepatozoon canis infection by parasitological detection in dogs from the rural area of Sousa, Paraíba. Brazil Ciência Rural 51(3):e20200233

    Article  Google Scholar 

  41. Olmeda SA, Armstrong PM, Rosenthal BM, Valladares B, del Castillo A, de Armas F, Miguelez M, González A, Rodríguez JA, Spielman A, Telford SR (1997) A subtropical case of human Babesiosis. Acta Trop 67(3):229–234.

    Article  CAS  PubMed  Google Scholar 

  42. Otranto D, Dantas-Torres F, Weigl S, Latrofa MS, Stanneck D, Decaprariis D, Capelli G, Baneth G (2011) Diagnosis of Hepatozoon canis in young dogs by cytology and PCR. Parasit Vectors 4:55

    Article  PubMed  PubMed Central  Google Scholar 

  43. Pacifico L, Braff J, Buono F, Beall M, Neola B, Buch J, Sgroi G, Piantedosi D, Santoro M, Tyrrell P, Fioretti AE, Breitschwerdt B, Chandrashekar R, Veneziano V (2020) Hepatozoon canis in hunting dogs from Southern Italy: distribution and risk factors. Parasitol Res 119(9):3023–3031

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  44. Pasa S, Kiral F, Karagenc T, Atasoy A, SeyrekK. (2009) Description of dogs naturally infected with Hepatozoon canis in the Aegean region of Turkey. Turk J Vet Anim Sci 33(4):289–295

    CAS  Google Scholar 

  45. Ramadan RM, Khalifa MM, Kamel NO, Abdel-Wahab AM, El-Bahy MM (2020) The use of Giardia immunogenic protein fraction to distinguish assemblages in humans and animals. World’s Vet J 10(3):421–428

    Google Scholar 

  46. Rani PAM, Irwin PJ, Coleman GT, Gatne M, Traub RJ (2011) A survey of canine tick-borne diseases in India. Parasit Vectors 4:141

    Article  Google Scholar 

  47. Sasanelli M, Paradies P, Lubas G, Otranto D, de Caprariis D (2009) Atypical clinical presentation of coinfection with Ehrlichia, Babesia and Hepatozoon species in a dog. Vet Rec 164:22–23

    Article  CAS  PubMed  Google Scholar 

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

    Article  PubMed  PubMed Central  Google Scholar 

  49. Soulsby E (1982) Helminths, arthropods and protozoa of domesticated animals, 7th edn. Baillière Tindall, London

    Google Scholar 

  50. Salem HM, Yehia N, Al-Otaibi S, El-Shehawi AM, Elrys AAME, El-Saadony MT, Attia MM (2021) The prevalence and intensity of external parasites in domestic pigeons (Columba livia domestica) in Egypt with special reference to the role of deltamethrin as insecticidal agent: the prevalence and intensity of external parasites in domestic pigeons (Columba livia domestica). Saudi J Biol Sci.

    Article  PubMed  PubMed Central  Google Scholar 

  51. Vojta L, Mrljak V, Beck R (2012) Haematological and biochemical parameters of canine hepatozoonosis in Croatia. Vet Arhiv 82(4):359–370

    Google Scholar 

  52. Zaki AA, Attia MM, Ismael E, Mahdy OA (2021) Prevalence, genetic, and biochemical evaluation of the immune response of police dogs infected with Babesia vogeli. Vet World 14(4):903–912

    Article  CAS  PubMed  PubMed Central  Google Scholar 

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We want to acknowledge the staff of the Egyptian Police Academy Veterinary Health Care Unit at K9 that supports the investigation and evaluation of blood analysis of police dogs.


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Authors and Affiliations



Zaki A.A. collected the samples. Mahdy O.A, Attia M.M and Kahlifa M.M identified the parasites and did the molecular analysis. Al-Mokaddem A.K did the histopathological examination. All authors shared in writing this manuscript and revised it. All authors have read and approved the final manuscript.

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Correspondence to Marwa M. Attia.

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This study was approved and followed the guide of the Ethical committee of the Cairo University, Faculty of Veterinary Medicine; these experiments were performed in compliance with the ARRIVE guidelines.

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I declare that the collection of samples from animals was conducted per local Ethical Committee laws and regulations regarding the care and use of laboratory animals.

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Mahdy, O.A., Khalifa, M.M., Zaki, A.A. et al. Genetic characterization and pathogenic effects of Hepatozoon canis infection in police dogs in Egypt. Beni-Suef Univ J Basic Appl Sci 13, 40 (2024).

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