The occurrence of canine hepatozoonosis in Thailand is primarily caused by Hepatozoon canis. Recently, the relationship of hematology and biochemistry with this disease has been studied, but knowledge regarding the relationship between the quantity of H. canis intracellular gamonts and the hematological profile has not yet been reported. The objective of this study was to investigate the clinical, hematological and biochemical profile of H. canis-positive dogs and the relationship of the number of H. canis gamonts, animal signalment, and hematological and biochemical values. A total of 185 H. canis-positive blood samples were examined, including buffy coat smears and comprehensive data. The number of gamonts was randomly counted from buffy coat smears samples (75/185). The dogs infected with H. canis presented to the animal hospital mostly for health status checks, anorexia, or accidents. Observations from the physical examination on the first day of registration included systemic abnormalities such as digestive, integument, respiratory, urogenital, etc. Most of the dogs showed clinical signs of systemic abnormality in more than one system. Our study shows that plasma proteins are correlated with the number of H. canis gamonts, using Spearman's rho correlation coefficient with significant difference (p <0.05). This finding could be applied to improve the diagnosis and treatment of canine hepatozoonosis.
Beta toxin (CPB) is a lethal toxin and plays a key role in enterotoxemia of ruminants caused by Clostridium perfringens type C strain. The existing vaccines based on crude CPB need time-consuming detoxification and difficult quality control steps. In this study, we synthesized the rCPBm4 of C. perfringens type C strain and small ubiquitin-like modifier (SUMO)-tag CPBm4 (rSUMO-CPBm4) by introducing four amino acid substitutions: R212E, Y266A, L268G, and W275A. Compared with rCPBm4, rSUMO-CPBm4 was expressed with higher solubility in Escherichia coli BL21 (DE3). Neither rCPBm4 nor rSUMO-CPBm4 was lethal to mice. Although rCPBm4 and rSUMO-CPBm4 were reactogenic with polyclonal antibodies against crude CPB, rabbits vaccinated with rSUMO-CPBm4 developed significant levels of toxin-neutralizing antibody (TNA) titers that conferred protection against crude toxin challenge. These data suggest that genetically detoxified rSUMO-CPBm4 is a promising subunit vaccine candidate for C. perfringens type C beta enterotoxemia.