Seasonal differences in the intensity of acute phase response in dogs infected with Babesia canis.

The highest number of acute Babesia canis cases in dogs is recorded over the February-May (Feb-May) period, which also represents the optimal climate conditions for tick activity in Belgrade, Serbia. A possibility that the acute phase response is more intense in dogs developing the disease in the Feb-May period compared with the response in other time periods of the year was tested. A total of 63 client-owned dogs with acute B. canis infection were enrolled and the routine hematology and biochemistry parameters-serum amyloid A (SAA), IgG against B. canis, level of parasitemia, ceruloplasmin (CER), paraoxonase-1 (PON-1), and fibrinogen-were measured. Acute phase indexes (API) were calculated as (SAA×CER)/(Iron×PON-1) and (SAA×CER)/(Albumin×Iron). Statistics included Kruskal-Wallis test and logistic regression analysis. The results showed that in the Feb-May period, the following parameters were lower: creatinine, albumin, iron, and level of parasitemia. Furthermore, increased API values were more probable in the Feb-May than in the other periods. Together, higher acute phase response intensity and presumptive hemodilution in the Feb-May period indicate a more acute course of B. canis infection than in other time periods of the year.

Systemic inflammatory response syndrome in dogs naturally infected with Babesia canis: Association with the parasite load and host factors.

The common signs of canine babesiosis caused by an infection with Babesia canis are fever, anorexia, lethargy, pulse alterations, anemia, and occasionally mild icterus. Dogs with these clinical signs can be divided into two groups: those with acute-phase reaction and those with systemic inflammatory response syndrome (SIRS). Factors associated with the occurrence of SIRS in canine babesiosis have not been thoroughly researched. This article outlines a cross-sectional study of 54 client-owned dogs with an acute B. canis infection, and evaluates the differences in age, gender, laboratory findings, parasite load, and seroreactivity against B. canis between the SIRS and the SIRS-free dogs. We have analyzed a complete blood count, serum biochemistry, serum amyloid A, ceruloplasmin, paraoxonase-1, serology, and PCR testing using standard methodologies. The frequency of SIRS among the investigated dogs reached 0.59. Male dogs and those seronegative against B. canis, were more frequent in the SIRS group, whilst age and parasite load could not be associated with the presence of SIRS. Dogs with SIRS had a lower count of total leukocytes, neutrophils, lymphocytes, and monocytes, and a lower concentration of iron and bilirubin compared with SIRS-free dogs. No significant differences in the concentration of acute-phase proteins have been noticed to exist between the groups of dogs. Further, the seronegative dogs had a lower count of lymphocytes and monocytes and a higher parasite load than the seroreactive dogs. Multivariate logistic regression analysis has identified leukopenia (<6 × 109/L) and monocytopenia (<0.2 × 109/L) as independent associates of SIRS in the investigated dogs, thus implying that these routine tests could be used as reliable markers for SIRS.

A short-term and long-term relationship between occurrence of acute canine babesiosis and meteorological parameters in Belgrade, Serbia.

Belgrade, the capital of the Republic of Serbia, is an endemic location for canine babesiosis caused by Babesia canis. This tick-borne disease occurs seasonally in regions with moderate continental climate. However, recent clinical data show that: 1) some cases of canine babesiosis have been recorded during the winter, and 2) canine babesiosis is spreading to the northern parts of Europe with a colder climate, which is a region previously free of this disease. Our study investigates the occurrence of canine babesiosis in different seasons over 2013-2016, and explores a short-term link between meteorological parameters and number of diagnosed cases of canine babesiosis in Belgrade. It also looks into possible long-term correlations that span one year before the onset of the disease. Based on 872 recorded cases over four years, our results show a bimodal seasonal distribution of canine babesiosis, with a pronounced peak in the spring, and a less conspicuous one in the autumn. Throughout the year, even over the coldest and warmest periods, there is a broad range of temperatures and relative humidities when the disease is recorded. Over one year prior to the spring and autumn onset of the disease, we found a noticeable impact of temperature and relative humidity, and to a lesser extent, of atmospheric pressure and cloud cover, on the number of diagnosed cases. These findings imply short-term and long-term relationships between occurrence of acute canine babesiosis and certain meteorological parameters, and they open further questions that need to be investigated in order to understand the epidemiology of this disease.

Association of acute Babesia canis infection and serum lipid, lipoprotein, and apoprotein concentrations in dogs.

BACKGROUND: Babesia canis infection induces a marked acute phase response (APR) that might be associated with alteration in lipid and lipoprotein metabolism and disease prognosis. HYPOTHESIS: Dogs with B. canis-induced APR develop dyslipidemia with altered lipoprotein concentration and morphology. ANIMALS: Twenty-nine client-owned dogs with acute B. canis infection and 10 clinically healthy control dogs. METHODS: Observational cross-sectional study. Serum amyloid A (SAA) was measured using ELISA. Cholesterol, phospholipids, and triglycerides were determined biochemically. Lipoproteins were separated using agarose gel electrophoresis. Lipoprotein diameter was assessed by polyacrylamide gradient gel electrophoresis; correlation with ApoA-1 (radioimmunoassay) and SAA was determined. RESULTS: Dogs with B. canis infection had a marked APR (median SAA, 168.3 µg/mL; range, 98.1-716.2 µg/mL) compared with controls (3.2 µg/mL, 2.0-4.2 µg/mL) (P < .001). Dogs with B. canis infection had significantly lower median cholesterol (4.79 mmol/L, 1.89-7.64 mmol/L versus 6.15 mmol/L, 4.2-7.4 mmol/L) (P = .02), phospholipid (4.64 mmol/L, 2.6-6.6 mmol/L versus 5.72 mmol/L, 4.68-7.0 mmol/L) (P = .02), and α-lipoproteins (77.5%, 27.7%-93.5% versus 89.2%, 75.1%-93.5%) (P = .04), and higher ApoA-1 (1.36 U, 0.8-2.56 U versus 0.95 U, 0.73-1.54 U) concentrations (P = .02). Serum amyloid A correlated with high-density lipoproteins (HDLs) diameter (rho = .43; P = .03) and ApoA-1 (rho = .63, P < .001). CONCLUSIONS AND CLINICAL IMPORTANCE: Major changes associated with B. canis-induced APR in dogs are related to concentration, composition, and morphology of HDL particles pointing to an altered reverse cholesterol transport. Parallel ApoA-1 and SAA concentration increase is a unique still unexplained pathophysiological finding.

Acute-phase response in Babesia canis and Dirofilaria immitis co-infections in dogs.

Babesia canis and Dirofilaria immitis are emerging and geographically overlapping vector-borne pathogens in dogs. Infection with B. canis leads to acute-phase response (APR) that can be mild to severe and results in either non-complicated or complicated forms of the disease. The aim of this study was to determine whether acute B. canis infection is more severe in dogs with underlying asymptomatic D. immitis infection. Dogs of both sexes, different ages and breeds, with naturally occurring mono-infections with B. canis (n=13) and D. immitis (n=18) and co-infected dogs (n=7) were enrolled as well as healthy controls (n=15). Routine haematology and biochemistry, agarose gel electrophoresis (agEF) protein fraction separation and enzyme-linked immunosorbent assay (ELISA) for serum amyloid A (SAA) were performed. Based on clinical and laboratory findings, sepsis was diagnosed in the majority of dogs with acute B. canis infection with or without underlying asymptomatic D. immitis infection. Overall, haematology, biochemistry and agEF pattern changes were induced and dictated by acute B. canis infection whether or not the dogs had an asymptomatic D. immitis infection. D. immitis infection slightly influenced the level of anaemia, slightly aggravated the level of dehydration and increased the concentration of γ-globulins in acute-phase B. canis infection. D. immitis infection prevented B. canis-induced leukopenia. SAA equally increased in dogs with acute B. canis infection with or without underlying D. immitis infection. The level of SAA was not changed in dogs with asymptomatic D. immitis when compared to the controls. In conclusion, asymptomatic D. immitis infection does not influence overall APR after acute B. canis infection.