Prevalence and risk factors of hypoglycemia in virulent canine babesiosis

Hypoglycemia is a common complication of virulent canine babesiosis. A study was conducted to determine the prevalence of and potential risk factors for hypoglycemia in canine babesiosis from Babesia canis rossi. Plasma glucose concentration was measured at presentation in 250 dogs with babesiosis, of which 111 were admitted to hospital. The prevalence of hypoglycemia (<60 mg/dL) was 9% (23/250). Twenty-two hypoglycemic dogs required admission, making the prevalence of hypoglycemia in admitted dogs 19.8%. Sixteen dogs had severe hypoglycemia (<40 mg/dL), of which 5 had glucose < 18 mg/dL. Hyperglycemia (>100 mg/dL) was present in 38 dogs, of which 21 were admitted. Risk factors for hypoglycemia identified by univariate analysis were collapsed state (P < .00001), severe anemia (P = .0002), icterus (P = .003), age < 6 months (P = .02), and vomiting (P = .03). After logistic regression analysis, collapsed state (odds ratio [OR] = 18; 95% CI, 1.9-171; P = .01) and young age (OR = 2.8; 95% CI, 0.8-9.7; P = .1) remained significantly associated with hypoglycemia. Toy breeds and pregnant bitches were not at higher risk for hypoglycemia than other dogs. Blood glucose concentration should ideally be measured in all dogs requiring inpatient treatment for babesiosis but is mandatory in collapsed dogs; puppies; and dogs with severe anemia, vomiting, or icterus. Many dogs have probably been misdiagnosed with cerebral babesiosis in the past, and hypoglycemia should be suspected in any dog with coma or other neurological signs.     

Electrolyte level and blood pH in dogs infected by various 18S RNA strains of Babaesia canis canis on the early stage of babesiosis

The purpose of the studies was to determine electrolyte disturbances and blood pH changes in dogs with babesiosis and possibly show a connection between the Babesia (B.) canis strain causing the infection and the intensity of these irregularities. 40 animals (group 1) with early babesiosis and 40 healthy dogs (group 2) were studied and their blood pH and blood levels of potassium, chlorides; calcium and sodium were determined. At the same time, molecular typing of parasites was carried out to detect which B.canis strain (18S RNA-A or 185 RNA-B) had caused the disease in dogs of group 1. In group 1, four dogs were acidaemic, twelve had normal blood pH, and 24 were alkalaemic. Potassium concentration was below normal in 16 out of 40 dogs (40%) and normal in 24 dogs. Hypochloremia was present in 36 out of 40 dogs; chloride was normal in the remaining four animals. Serum sodium concentration was low in 16 of 40 dogs, normal in 20 of 40 dogs and high in four dogs. Calcium concentration was normal in all 40 dogs. In dogs of group 2 no abnormalities of haematological or blood biochemical parameters were observed. 29 out of the 40 dogs of group 1 were infected with the 18S RNA-A strain and eleven with the 18S RNA-B strain of Babesia canis canis. We did not observe any correlation between the type of strain causing the infection and the electrolyte disturbances in the serum of sick dogs. Hypocalaemia was observed in ten specimen infected with 18S RNA-A and six infected with 18S RNA-B. Additionally, in dogs infected with 18S RNA-A, hypochloraemia (28), hyponatraemia (10), hypernatraemia (2) were observed, as well as blood pH drop (4) or increase (14). The 18S RNA-B-infected dogs suffered from hypochloraemia (8), hyponatraemia (6), hypernatraemia (2) and increase in blood pH (10).The studies conducted did not answer the question of whether the type of electrolyte disturbances in dogs with babesiosis can be connected with the strain of the parasite that induced the disease, as happens in the case of other clinical parameters (Adaszek et al., 2009). Further studies in this respect, conducted on a larger group of animals, are necessary.     

Babesia canis canis in dogs from Hungary: detection by PCR and sequencing

Canine babesiosis in Hungary has always been a severe and frequent disease, attributed to infection with Babesia canis transmitted by Dermacentor reticulatus. Identification of the disease agent has been based merely on size and morphology of the intraerythrocytic parasites and no evidence has been found concerning the subspecies (genotype) of B. canis. Therefore, a molecular survey on natural Babesia infection of dogs in Hungary using PCR and sequence analysis was attempted to clarify the subspecies (genotype) and to obtain information on the occurrence of B. canis. A total of 44 blood samples from dogs showing clinical signs of babesiosis were collected. A piroplasm-specific PCR amplifying the partial 18S rRNA gene yielded an approximately 450 bp PCR product in 39 (88.6%) samples. Thirteen positive samples originated from Budapest and 26 from 21 other locations. Five PCR products were chosen randomly for sequencing. The partial 18S rDNA sequences were submitted to GenBank (accession numbers AY611729; AY611730; AY611731; AY611732 and AY611733). The sequences showed 100% homology to one another or differed by one nucleotide. BLAST search against GenBank revealed the highest similarity (99.8 or 100%) with Babesia canis canis. The implication of these data, for the further study and diagnosis of canine babesiosis is discussed.     

Autochthonous cases of canine babesiosis in the canton Solothurn

Starting in November 2003 a series of five clinical cases of canine babesiosis was registered in the region of Oberg?sgen (canton Solothurn). All presented dogs showed increased body temperature, thrombocytopenia and hemoglobinuria, and none of the dogs had been abroad or visited endemic regions in the southern or western part of Switzerland so far. Babesia canis was detected in the blood smears of all five patients, but only three had detectable specific antibodies against this parasite. However, seroconversion was found in a second sample collected from the negative dogs at a later timepoint, confirming the diagnosis of canine babesiosis. The blood samples of two parasitized dogs were used for DNA-isolation and were tested with a Babesia-specific PCR, detecting the 18S rRNA-gene. Sequencing of the amplified products revealed a 100% identity with the sub-species B. canis canis. The ticks Rhipicephalus sanguineus and Dermacentor marginatus are potential vectors for B. canis. In the area where the infection with B. canis was suspected a total of 152 ticks was collected and characterized; one was a female R. sanguineus.Although babesia could not be detected in the latter tick and the final prooffor the complete life cycle is still lacking, it is very probable that B. canis has become autochthonous in the canton Solothurn.     

Ehrlichia canis in dogs in Yucatan, Mexico: seroprevalence, prevalence of infection and associated factors

The aim of this study was to determine the prevalence of infection, seroprevalence, and factors associated with antibody response to Ehrlichia canis in dogs of Yucatan, Mexico. The study was carried out in four veterinary clinics located in Merida, the capital city of Yucatan, Mexico. Blood samples were obtained from a total of 120 dogs, and each animal was physically examined to determine age and sex, as well as to record any clinical signs of platelet-related bleeding. Blood samples were analyzed for antibodies to E. canis using an ELISA test, and thrombocyte counts were calculated. Blood smears were prepared to detect typical morulae in leukocytes. The prevalence of infection, seroprevalence and associated factors were calculated. A primary screening was performed using 2 x K contingency tables of exposure variables. All variables with P< or =0.20 were analyzed by a logistic-binomial regression. Fifty-three (44.1%) of the 120 dogs were found to be seropositive to E. canis. In six dogs (5.0%) typical morulae of E. canis were observed in monocytes. These six cases were positive for antibodies and were thrombocytopenic. The following factors associated with seropositive animals were: platelet-related bleeding (Yes: OR=10.26, CI=2.50-42.16, P=0.001), thrombocytopenia (Yes: OR=18.91, CI=4.47-80.03, P=0.000) and age (2-4 years: OR=6.77, CI=1.76-25.97, P=0.005; >4 years: OR=4.24, CI=1.04-17.21, P=0.043).     

Detection and molecular characterization of Babesia canis vogeli from naturally infected dogs and Rhipicephalus sanguineus ticks in Tunisia

Canine babesiosis, caused by intra-erythrocytic Babesia, is a tick-borne disease of worldwide importance. No information on canine babesiosis has been documented in Tunisia. Detection and analysis of Babesia species from naturally infected dogs and ticks recovered from dogs were attempted by reverse line blot hybridization and nucleotide sequence analysis based on 18S rRNA gene. Out of 180 blood samples collected from domestic dogs in 4 villages situated in different bioclimatic zones, 12 were positive for Babesia canis vogeli. In addition, a total of 160 Rhipicephalus sanguineus were analysed; only one male was infected by B. canis vogeli. This is the first report on the detection of DNA belonging to B. canis vogeli in domestic dogs and in R. sanguineus in Tunisia.     

Autochthonous canine babesiosis in The Netherlands

Outbreaks of autochthonous babesiosis, caused by Babesia canis, occurred in The Netherlands in the spring and autumn of 2004 affecting 23 dogs. Nineteen animals recovered after treatment, whereas four dogs died. Adult Dermacentor reticulatus ticks collected from these dogs indicate that canine babesiosis could become endemic in The Netherlands.     

Babesia canis canis and Babesia canis vogeli infections in dogs from northern Portugal

Canine babesiosis represents an important veterinary medical problem. This study describes the molecular characterization of babesial parasites detected in eight clinically suspected dogs from northern Portugal, affected by lethargy, muscle tremors, weight loss, pale mucous membranes, hyperthermia or red-coloured urine. Microscopic examination of peripheral blood smears showed large intraerythrocytic piroplasms morphologically compatible with Babesia canis in all eight animals. DNA was extracted from blood on filter paper, and a Babesia spp. infection confirmed by polymerase chain reaction (PCR) amplification of a 408bp fragment of the 18S rRNA gene. Analysis of PCR-derived sequences revealed that seven dogs were infected with B. canis canis and one with B. canis vogeli. This is the first molecular identification report of both the species B. canis and the subspecies B. canis canis and B. canis vogeli in dogs from Portugal.     

The prevention of transmission of Babesia canis canis by Dermacentor reticulatus ticks to dogs using a novel combination of fipronil, amitraz and (S)-methoprene

Four groups of seven dogs were treated topically with a novel combination of fipronil, amitraz and (S)-methoprene in a spot-on formulation (CERTIFECT?, Merial Limited, GA, USA) on 28, 21, 14 and 7 days prior to tick infestation, respectively and acaricidal efficacy and transmission blocking compared with an untreated control group (seven dogs). All dogs were infested with adult Dermacentor reticulatus ticks harbouring Babesia canis canis. Babesia canis canis was transmitted by D. reticulatus to all seven untreated control dogs, confirmed following demonstration of clinical signs, by the detection of B. canis parasites in thin blood smears and B. canis canis PCR-RLB DNA assay on blood and the development of B. canis canis antibody titres by 14-21 days after tick infestation. The majority of treated dogs remained sero-negative for 42 days after infestation. Therefore, the treatment of dogs with CERTIFECT applied up to 28 days prior to infestation with D. reticulatus harbouring B. canis canis, successfully prevented the development of clinical signs of canine babesiosis.     

Canine babesiosis in Slovenia: molecular evidence of Babesia canis canis and Babesia canis vogeli

Canine babesiosis, caused by intraerythrocytic Babesia spp., is a tick-borne disease of worldwide importance. No information on canine babesiosis has been documented in Slovenia. Therefore, 238 dogs admitted to the Small animal clinic in Ljubljana from the years 2000 to 2002 were tested for the presence of babesial parasites in the blood. Based on clinical, microscopic and molecular investigations, 14 dogs (5.9%) were determined as being infected with babesiae. Clinical signs relating to acute haemolysis, fever, anorexia, depression and haematological abnormalities such as anaemia and thrombocytopenia were noticed in most of the 14 infected dogs. The morphology of the parasites was indicative of Babesia canis infection. Two subspecies were detected, namely B. canis canis (11 dogs, 4.6%) and B. canis vogeli (3 dogs, 1.3%) using PCR and subsequent sequence analysis of portions of nns rRNA gene. In addition, based on nucleotide sequence analysis, the 11 isolates of B. c. canis could be subdivided into three groups, whereas the three B. c. vogeli isolates were genetically identical. The results of this study demonstrate the presence of canine babesiosis due to B. c. canis and B. c. vogeli in Slovenia.     

Confirmation of occurrence of Babesia canis vogeli in domestic dogs in South Africa

The prevalence of Babesia infections in domestic dogs in South Africa was studied using reverse line blot hybridization and 18S sequence analysis. Babesia canis vogeli was confirmed for the first time in domestic dogs in South Africa. Out of a total of 297 blood samples collected from domestic dogs in Bloemfontein, East London, Johannesburg, Durban and from the Onderstepoort Veterinary Academic Hospital, 31 were positive for Babesia canis rossi, whereas B. c. vogeli was detected in 13 dogs. None of the dogs carried both parasites. The detection of B. c. vogeli has implications with regard to prevalence and varied clinical manifestation of canine babesiosis in South Africa.     

Endocrine predictors of mortality in canine babesiosis caused by Babesia canis rossi

This prospective, cross-sectional, observational study was designed to determine the association between the hormones of the pituitary-adrenal and pituitary-thyroid axes and outcome in dogs with naturally occurring Babesia canis rossi babesiosis. Ninety-five dogs with canine babesiosis were studied and blood samples were obtained from the jugular vein in each dog prior to treatment at admission to hospital. Serum cortisol, adrenocorticotrophic hormone (ACTH), thyroxine, free thyroxine and thyrotropin (TSH) concentrations were measured. Diagnosis was confirmed by polymerase chain reaction and reverse line blot and dogs infected with Babesia canis vogeli or Ehrlichia canis were excluded. Three outcomes were defined: hospitalization with subsequent death (n=7); hospitalization followed by recovery (n=56); and treatment as an outpatient (n=32). Serum cortisol and ACTH concentrations were significantly higher in the dogs that died, compared to hospitalized dogs that survived and compared to dogs treated as outpatients. Serum T4 and free T4 concentrations were significantly lower in the dogs that died, compared to the hospitalized dogs that survived and compared to dogs treated as outpatients. Serum TSH concentrations were not significantly different between any of the groups. Mortality was significantly associated with high cortisol and high ACTH concentrations and with low T4 and fT4 concentrations in dogs suffering from B. canis rossi babesiosis.     

Babesia canis canis and Babesia canis vogeli clinicopathological findings and DNA detection by means of PCR-RFLP in blood from Italian dogs suspected of tick-borne disease

The aims of this study were to determine the presence of Babesia spp. in blood samples from Italian dogs with clinical signs compatible with tick-borne diseases by means of PCR-restriction fragment length polymorphism (RFLP) and describe the clinicopathological findings of dogs with Babesia infection. We evaluated the majority of canine babesiosis cases by means of clinical history, physical examination, hematological, biochemical, serum electrophoresis, urinalysis and hemostatic tests. Forty-five out of 164 canine blood samples studied were positive to Babesia PCR-RFLP with the following results: Babesia canis canis (n=34) and Babesia canis vogeli (n=11). The majority of B. c. canis infections were detected in Northern Italy (29.1%; 30/103). B. c. vogeli cases were detected mainly in Central and Southern Italy (16.3%; 10/61). Only one B. c. vogeli was detected in Northern Italy (0.9%; 1/103). Three positive samples to B. c. canis and four positive samples to B. c. vogeli were selected for sequencing of a fragment of the 18S rRNA gene (410bp) for further molecular characterization. The sequence obtained from all seven dogs was 99/100% homologous to sequences from B. c. canis and B. c. vogeli, respectively, present in GenBank. Sixty-two percent of dogs infected with B. c. canis had recently travelled on a hunting trip to East European countries. The main acute clinical signs were dehydration, apathy, anorexia and fever. The majority of dogs infected with B. c. canis presented at initial clinical examination mild to severe thrombocytopenia, hyperfibrinogenemia, mild to moderate normocytic-normochromic non-regenerative anemia, hemolysis and neutropenia. The urinalysis showed hemoglobinuria in 13/19 dogs suggesting intravascular hemolysis. Dogs with B. c. canis infection had high levels of C-reactive protein. Hypoalbuminemia was present in 17/26 dogs. The 11 cases of B. c. vogeli infection did not present a homogenous clinicopathological pattern. B. c. vogeli infections were observed in young dogs causing hemolytic anemia and in adult/old does that frequently presented predisposing factors such as splenectomy or immunocompromised conditions. In conclusion, this study demonstrates the presence of B. c. canis and B. c. vogeli in Italian sick dogs and differences in clinicopathological pattern in these two species of B. canis.     

First evidence and molecular characterization of Babesia vogeli in naturally infected dogs and Rhipicephalus sanguineus ticks in southern France

Babesiosis is an emerging tick-borne disease of animals and humans caused by intraerythrocytic protozoa of the genera Babesia and Theileria. In France canine babesiosis has a high prevalence with Babesia canis thought to be the main aetiological agent of the disease. Babesia vogeli has already been reported to occur in Europe and in other countries around the Mediterranean Sea. The tick Rhipicephalus sanguineus, the main known vector of B. vogeli, occurs in southern France. However, only one case of a B. vogeli infected dog has been reported to date in France. To gain further insight into the prevalence of Babesia and Theileria infections in dogs and ticks of the R. sanguineus complex, a study was conducted in a veterinary practice in the south of France from January to September 2010. Twelve bloods from dogs and 36 R. sanguineus ticks were analyzed using PCR and sequencing. For the analysis of ticks, a new primer was designed to specifically amplify the B. vogeli 18S rRNA gene. Four dogs (33.3%) and 8 ticks (22.2%) were found to be infected with B. vogeli. This approach has thus revealed for the first time a cluster of cases of canine babesiosis caused by B. vogeli in France and highlights the need to systematically screen for pathogens potentially responsible for canine babesiosis at the species level using suitable molecular tools.     

The epidemiology of canine Babesia infections in Zambia

This study of 1196 dogs over a period of 18 months determined the seasonal infection patterns of canine babesiosis in Lusaka, the capital city of Zambia. The work also describes a retrospective study of the prevalence of canine babesiosis in laboratory clinical blood samples submitted to the University of Zambia, School of Veterinary Medicine for routine haematological examination from the year 1994 to 2009. A cross-sectional study was also performed to determine the levels of Babesia in a low-income society (during the dry season and the wet season of the year), where 361 samples were collected from dogs presented for mass rabies vaccination campaigns. Morphology of the Babesia indicated that all were of the large-sized Babesia canis infection. Babesia-positive dogs had significantly higher rectal temperatures than negative ones, and dogs younger than 1 year were more likely to be Babesia positive followed by those between 2 and 5 years old. Seasonal trends indicate two peaks, one in the rainy season (November-March) and another in the cold dry season (June/July). Monthly prevalence rates of Babesia ranged from 0% to 2.4% in natural populations and from 0% to 28.6% in laboratory specimens. This study shows that Zambia has lower Babesia prevalence than reported in other African countries.     

Metabolic and electrolyte disturbances in acute canine babesiosis.

Arterial blood pH, PCO2, bicarbonate, base excess/deficit, and lactate, as well as serum sodium, potassium, and chloride were measured in clinically normal dogs and in dogs with acute canine babesiosis. Metabolic acidosis developed in dogs with fatal as well as nonfatal Babesia canis infection. In the fatal group, the acidosis was uncompensated; among survivors, base deficit and blood lactate were significantly lower, and pH, PCO2, and bicarbonate values were significantly higher. Serum potassium values were significantly lower, and serum chloride values were significantly higher in dogs with acute babesiosis than in clinically normal dogs. The shock resulting from acute canine babesiosis is best viewed as anemic shock. Treatment should include an alkalizing agent, a blood transfusion, fluid therapy, and a babesicidal drug.     

Plasma insulin concentrations in hypoglycaemic dogs with Babesia canis rossi infection

Hypoglycaemia has been identified as a life-threatening metabolic complication in almost 20% of severely ill dogs suffering from babesiosis due to Babesia canis rossi infection, and has been correlated with mortality. Hyperinsulinaemia as a result of inappropriate insulin secretion may precipitate hypoglycaemia, and has been suggested as a possible cause of hypoglycaemia in human and murine malaria. This prospective, cross-sectional, observational study, including 94 dogs with naturally occurring virulent babesiosis, sought to identify the presence of inappropriate insulin secretion in hypoglycaemic canine babesiosis. Pre-treatment jugular blood samples were collected for simultaneous determination of plasma glucose and insulin concentrations. Animals were retrospectively divided into three groups: hypoglycaemic (BG<3.3 mmol/L; n=16), normoglycaemic (BG 3.3-5.5 mmol/L; n=62), and hyperglycaemic (BG>5.5 mmol/L; n=16). The median insulin concentrations for the hypoglycaemic, normoglycaemic, and hyperglycaemic groups were 10.7 pmol/L, 10.7 pmol/L, and 21.7 pmol/L, respectively. Statistical analysis revealed no significant difference in insulin concentration between the three groups. Additionally, the median insulin concentration in the hypoglycaemic and normoglycaemic groups was below the detection limit of the assay, suggesting that insulin secretion was appropriately low (i.e. undetectable) in these cases. Only two dogs had inappropriately elevated insulin concentrations. One of these dogs was hypoglycaemic. We conclude that hyperinsulinaemia is an infrequent cause of hypoglycaemia in virulent canine babesiosis. Other causes of hypoglycaemia, such as increased glucose consumption, depletion of hepatic glycogen stores, and hepatic dysfunction with impaired gluconeogenesis, are speculated to play more important roles in the pathophysiology of hypoglycaemia in canine babesiosis.     

Serum concentration of some acute phase proteins in naturally occurring canine babesiosis: a preliminary study

BACKGROUND: Serum concentrations of acute phase proteins can provide valuable diagnostic information in the detection, prognosis, or monitoring of disease. Information available on the acute phase response in naturally occurring canine babesiosis is limited. OBJECTIVE: The purpose of this investigation was to retrospectively evaluate serum concentrations of haptoglobin, C-reactive protein, and ceruloplasmin in dogs naturally infected with Babesia canis. METHODS: Haptoglobin, C-reactive protein, and ceruloplasmin concentrations were measured in serum samples from dogs with uncomplicated (n = 6) and complicated (n = 1) babesiosis and compared with 6 healthy dogs. RESULTS: Serum C-reactive protein and ceruloplasmin concentrations were significantly higher in dogs with babesiosis; however, serum haptoglobin concentration was significantly lower compared with control dogs (P <.01). CONCLUSIONS: Results of this study suggest that acute phase protein concentrations could be beneficial in the diagnosis and determination of the severity of babesiosis in dogs.     

The response of the pituitary-adrenal and pituitary-thyroidal axes to the plasma glucose perturbations in Babesia canis rossi babesiosis

This prospective, cross-sectional, interventional study was designed to determine the association between the hormones of the pituitary-adrenal and pituitary-thyroid axes and other clinical parameters with the blood glucose perturbations in dogs with naturally occurring Babesia canis rossi babesiosis. Thirty-six dogs with canine babesiosis were studied. Blood samples were obtained from the jugular vein in each dog prior to treatment at admission to hospital and serum endogenous adrenocorticotrophic hormone (ACTH), pre-ACTH cortisol, thyroxine, free thyroxine and TSH concentrations were measured. Immediately thereafter each dog was injected intravenously with 5 microg/kg of ACTH (tetracosactrin). A 2nd blood sample was taken 1 hour later for serum post-ACTH cortisol measurement. Three patient groups were recruited: hypoglycaemic dogs (glucose < 3.3 mmol/l, n = 12); normoglycaemic dogs (glucose 3.3-5.5 mmol/l, n = 12); hyperglycaemic dogs (glucose > 5.5 mmol/l, n = 12). Basal and post-ACTH serum cortisol concentrations were significantly higher in hypoglycaemic dogs, whereas body temperature, serum thyroxine and free thyroxine were significantly lower in hypoglycaemic dogs. Haematocrit was significantly lower in both hypo-and hyperglycaemic dogs compared with normoglycaemic dogs. Low blood glucose concentrations were significantly associated with high basal and post-ACTH cortisol concentrations and with low serum thyroxine and free thyroxine concentrations in dogs suffering from B. canis rossi babesiosis.     

An investigation into some causes of canine diarrhoea in Ibadan

Between October 1975 and March 1976, fourteen dogs of the 308 examined in the small animal clinic of the University of Ibadan were diarrhoeic while eight dogs from two experimental groups housed within the university and kept at a distance of about 1.5 km from the small animal clinic also had diarrhoea. The most common condition associated with diarrhoea in dogs in Ibadan was intestinal parasitism caused mainly by Ancylostoma caninum (six cases) Isospora canis (five cases) and Dipylidium caninum (one case). The other causes of diarrhoea were canine distemper, bacterial enteritis, canine babesiosis, traumatic gastroenteritis and eosinophilic gastroenteritis.