Diagnosis of Hepatozoon canis in young dogs by cytology and PCR

Abstract

BackgroundHepatozoon canis is a widespread tick-borne protozoan affecting dogs. The diagnosis of H. canis infection is usually performed by cytology of blood or buffy coat smears, but this method may not be sensitive. Our study aimed to evaluate the best method to achieve a parasitological diagnosis of H. canis infection in a population of receptive young dogs, previously negative by cytology and exposed to tick infestation for one summer season.ResultsA total of 73 mongrel dogs and ten beagles younger than 18 months of age, living in an animal shelter in southern Italy where dogs are highly infested by Rhipicephalus sanguineus, were included in this study. In March-April 2009 and in October 2009, blood and bone marrow were sampled from each dog. Blood, buffy coat and bone marrow were examined by cytology only (at the first sampling) and also by PCR for H. canis (second sampling). In March-April 2009, only one dog was positive for H. canis by cytological examination, whereas in October 2009 (after the summer season), the overall incidence of H. canis infection by cytological examinations was 43.9%. Molecular tests carried out on samples taken in October 2009 showed a considerably higher number of dogs positive by PCR (from 27.7% up to 51.2% on skin and buffy coat tissues, respectively), with an overall positivity of 57.8%. All animals, but one, which were positive by cytology were also PCR-positive. PCR on blood or buffy coat detected the highest number of H. canis-positive dogs displaying a sensitivity of 85.7% for both tissues that increased up to 98% when used in parallel. Twenty-six (74.8%) out of the 28 H. canis-positive dogs presented hematological abnormalities, eosinophilia being the commonest alteration observed.ConclusionsThe results suggest that PCR on buffy coat and blood is the best diagnostic assay for detecting H. canis infection in dogs, although when PCR is not available, cytology on buffy coat should be preferred to blood smear evaluation. This study has also demonstrated that H. canis infection can spread among young dogs infested by R. sanguineus and be present in the majority of the exposed population within 6 months.

Molecular detection of Ehrlichia canis in dogs from three districts in Punjab (Pakistan)

“…could be due to many factors including the distribution and population density of the vector (Otranto et al 2011), the sampling methodology and the characteristics of the targeted dog population (Gomes et al 2010;De Miranda et al 2014). An analysis of risk factors indicated that male dogs were more often infected with E. canis than the females, but this association was statistically non-significant (P = 0.15) confirming previous studies reporting that there is no correlation between the sex and the presence of E. canis infection in dogs (Rani et al 2011;Aktas et al 2015).…”

Brazilian canine hepatozoonosis

“…Recently, Otranto et al (2011) have suggested that cytological evaluation on buffy coat is a more sensitive test than blood smear evaluation.…”

“…Recently, Otranto et al (2011) suggested that PCR on buffy coat and blood is the best diagnostic assay for detecting H. canis infection in dogs.…”

Complex clinical presentations of tick-borne diseases in dogs in Sri Lanka

“…It has been speculated that dogs infected with vector-transmitted pathogens may develop persistent General Clinical findings infection within systemic circulation and therefore may be Critical determinants of infection severity are virulence more prone to develop anti-nuclear of the organism, age, antibodies (ANA) (Smith et al, 2004). It has been suggested that in persistent VBD infections, prolonged antigenic stimulation due to ineffective apoptosis or defective removal of cell debris by neutrophils and macrophages might lead to production of perinuclear ximately 28% of males was antineutrophil cytoplasmic autoantibodies (pANCA) critically anemic (HCT <10%), compared with 14% (Karagianni et al, 2012) females. Rottweilers, Labradors, Boxers and cross bred dogs of Detection of parasites in blood and tissues any age were more susceptible for Babesiosis and Detection of piroplasms can be done morphologically, Ehrlichiosis than other breeds.…”

“…Therefore, TNFa production is detrimental to the host as it enhances inflammation, leading to abnormal perfusion,tissue hypoxia, sepsis and systemic inflammatory response (S neorickettsiosis infections can be distinguished by PCR has been developed for simultaneous detection of western immunoblotting (Harrus and Waner, 2011 (Harrus and Waner, 2011). sensitivity in detecting H. canis in buffy coat, blood and Persistent titres may occur in persistent infections, bone marrow is high with PCR compared with cytology reinfection, treatment failure, and an abnormal immune using the same tissue (Otranto et al, 2011). response.…”