Hepatozoon canis in hunting dogs from Southern Italy: distribution and risk factors

Abstract

Hepatozoon canis is a hemoprotozoan organism that infects domestic and wild carnivores throughout much of Europe. The parasite is mainly transmitted through the ingestion of infected ticks containing mature oocysts. The aims of the present survey were to determine the prevalence of H. canis in hunting dogs living in Southern Italy and to assess potential infection risk factors. DNA extracted from whole blood samples, collected from 1433 apparently healthy dogs living in the Napoli, Avellino, and Salerno provinces of Campania region (Southern Italy), was tested by a quantitative real-time polymerase chain reaction (qPCR) assay to amplify H. canis. Furthermore, the investigated dog population was also screened by qPCR for the presence of Ehrlichia canis, a major tick-borne pathogen in Southern Italy, in order to assess possible co-infections. Two hundred dogs were H. canis PCR-positive, resulting in an overall prevalence of 14.0% (CI 12.2-15.9). Breed category (P < 0.0001), hair coat length (P = 0.015), and province of residence (P < 0.0001) represented significant risk factors for H. canis infection. The presence of H. canis DNA was also significantly associated with E. canis PCR positivity (P < 0.0001). Hunting dogs in Campania region (Southern Italy) are frequently exposed to H. canis, and the infection is potentially associated with close contact with wildlife. Further studies are needed to assess the pathogenic potential of H. canis, as well as the epidemiological relationships between hunting dogs and wild animal populations sharing the same habitats in Southern Italy.

Potential Role of Hepatozoon canis in a Fatal Systemic Disease in a Puppy

“…The relocation of dogs is one main driver fostering the emergence of vector-borne diseases, including hepatozoonosis, in previously free areas [ 17 , 29 , 30 ]. Accordingly, the dog of the present report was adopted from southern Italy, i.e., an endemic area for H. canis [ 5 , 28 , 31 ], and moved to an area of Northern Italy where this protozoan had never been described thus far. The uncontrolled movement of potentially infected dogs can be dangerous as R. sanguineus , the main vector of H. canis , is widespread in Northern Italy and in general in Europe, and present all year around [ 32 , 33 ].…”

“…Hepatozoonosis is an emerging vector borne disease (VBD) of both dogs and cats, caused by different species belonging to the genus Hepatozoon [ 1 , 2 ]. Canine hepatozoonosis is caused by Hepatozoon canis that infects dogs worldwide, and Hepatozoon americanum that has been reported, to date, only in the Americas [ 1 , 3 , 4 , 5 ]. Dogs are intermediate hosts of Hepatozoon spp.…”

“…In Europe, the main vector of H. canis is the brown dog tick Rhipicephalus sanguineus in which it is transmitted transstadially [ 5 , 6 , 7 ]. Although the ingestion of an infected tick is the most common source of infection, transplacental transmission and carnivorism have been reported as alternative routes [ 1 , 8 ].…”

“…Given the emergence of canine hepatozoonosis in European regions [ 5 , 17 ], knowledge on its epidemiology and clinical features should be implemented. The present report describes a fatal systemic disease in a young dog infected with H. canis .…”

First Report on Molecular Diagnosis and Phylogenetic Analysis of Hepatozoon canis in Naturally Infected Domesticated and Stray Dogs from Jhang, Pakistan

“…In the current study it was seen that environmental setting influences the prevalence of H. canis as the dogs in rural areas are more infected than the urban areas. The livestock population is significantly high in the rural areas and in contact dogs may get the ticks transferred from other animals and become the source of infection to nearby dogs as described by (Pacifico et al 2020). The ticks attached hide themselves in long coat and remain unnoticed from the owner's observation.…”