Serum proteinogram, acute phase proteins and immunoglobulins in dogs experimentally infected with Rangelia vitalii

Microencapsulated phytogenic in dog feed modulates immune responses, oxidative status and reduces bacterial (Salmonella and Escherichia coli) counts in feces

Improving the health and immunity of pets is a concern of the guardians, while maintaining the health of the animals directly impacts the owners' health and public health. The objective of this study was to produce a dog feed containing a microencapsulated phytogenic blend, as well as determine the impact of the additive on animal health and its intestinal microbiota. The composition included microencapsulated thymol, carvacrol, and cinnamaldehyde, at 300 mg/kg of feed. Ten male beagle dogs were divided into two groups, identified as follows: the control group (C; ingested the feed without the additive) and the treated group (T; consumed feed containing the phytogenic blend). The dogs received 300 g of feed/day divided into two meals. Greater neutrophil counts in group T and lymphocyte counts were observed at the end of the experiment, as well as levels of α2-globulins and γ-globulin, while β1 and β2-globulins levels were lower in group T. Serum nitrogen oxide levels were higher in group T. Levels of reactive oxygen species were lower in group T at days 30 and 45, unlike activity of glutathione peroxidase that was higher. We found less bacterial contamination in the feces of dogs in group T, i.e., total bacterial count, total coliform counts, and counts of Salmonella and Escherichia coli were lower on days 30 and 45. Phytogenic blend intake reduces bacterial counts in stool and improves antioxidant/oxidative status and immune responses.

Surface immunoglobulins of erythrocytes and platelets in dogs naturally infected by Rangelia vitalii

Rangelia vitalii is a protozoan of the Babesiidae family that parasitizes domestic and wild dogs in South American countries. The main laboratory findings in blood samples from animals infected by R. vitalii are anemia and thrombocytopenia. The aim of this study was to detect IgM and IgG immunoglobulins on the surface of red blood cells and platelets, as well as to determine the percentage of reticulated platelets and reticulocytes in dogs naturally infected by R. vitalii. Blood samples from twenty dogs seen at the Veterinary Hospital of the Federal University of Santa Maria (UFSM) were divided into two groups: the diseased group consisted of blood samples from 10 animals with the diagnosis of rangeliosis, and the healthy group (control) consisted of samples from 10 healthy animals. All diseased dogs showed normocytic normochromic anemia but showed no differences (p > 0.05) in reticulocyte counts compared to healthy dogs. Moreover, IgM and IgG immunoglobulins were detected on the surface of the plasma membrane of red blood cells from both groups, but the amounts did not differ between groups (p > 0.05). Thrombocytopenia in infected animals was classified as severe. The percentage of reticulated platelets was higher (p < 0.001) in diseased dogs than in healthy animals. Diseased animals showed more IgM immunoglobulins bound to the surface of platelets than did the healthy group (p < 0.001). However, the amount of IgG bound to the surface of platelets was not different between groups. In conclusion, we showed that R. vitalii caused immune-mediated thrombocytopenia since IgM immunoglobulins were found on the surface of platelets of diseased dogs. We suggest that the binding of immunoglobulins on platelet surfaces contributes to early destruction of these cells and, consequently, alterations in hemostasis. An increase in reticulated platelets was noted in response to thrombocytopenia, indicating active thrombopoiesis.

Rangelia vitalii and Hepatozoon canis coinfection in pampas fox Lycalopex gymnocercus from Santa Catarina State, Brazil

Rangelia vitalii is a haemoparasite that infects erythrocytes, white blood cells and the cytoplasm of endothelial cells of blood capillaries of canids in South America, and has been detected in both domestic dogs and sylvatic canids. Hepatozoon canis is a parasite that infects neutrophils and monocytes of many mammalian hosts. This study reports the infection of Lycalopex gymnocercus from Santa Catarina, Brazil, with R. vitalii and H. canis. The piroplasm was observed on both blood smears and molecular tests. Many large piroplasms were detected inside the erythrocytes, with round, oval, or teardrop-shaped organism, that occurred singly or in pairs. They had an abundant, pale blue cytoplasm and decentral dark red small nucleus. The animal was also infected with H. canis that was detected only by molecular tests. The majority of haematological and biochemistry parameters were within the reference values for domestic dog and wild canids.