Amelia Goddard

Experimental Reproduction of Severe Bluetongue in Sheep

Sheep inoculated with a virulent South African strain of bluetongue (BT) virus serotype 4 developed severe clinical signs and lesions characteristic of fulminant BT, including coronitis, hemorrhage and ulceration of the mucosal lining of the oral cavity and forestomaches, hemorrhage in the wall of the pulmonary artery, and focally extensive necrosis of skeletal muscle, especially of the neck. At necropsy, up to 14 days after infection, the infected sheep exhibited striking pulmonary edema, edema of the subcutaneous tissues and fascial planes of the head and neck, and pleural and pericardial effusion of varying severity. A reliable model for experimental reproduction of fulminant BT in sheep will facilitate future studies to better characterize the pathogenesis of this disease, particularly as it regards the mechanisms responsible for the increased vascular permeability that characterizes BT and related orbiviral diseases such as African horse sickness.

Prognostic Usefulness of Blood Leukocyte Changes in Canine Parvoviral Enteritis

Background: Despite treatment, many dogs still die of complications related to canine parvoviral (CPV) enteritis. Effective prognostication would be beneficial in managing this disease. Hypothesis: We hypothesize that the occurrence of leukocytopenias at admission and at 24 and 48 hours after admission, and changes in absolute leukocyte counts over time, could be used to predict outcome. Animals: Sixty‐two puppies with confirmed CPV. Methods: A prospective study was performed. CBC was performed daily until discharge or death (in which case a postmortem examination was performed). Results: Of the nonsurvivors (10/62; 16%), 9 died because of complications of the disease and 1 was euthanized because of a poor prognosis. There was a statistical significant difference in the occurrence of leukocytopenias between groups at 24 and 48 hours postadmission. The survivors showed a significant increase over time in certain leukocyte types (specifically lymphocytes) compared with values at admission. The positive predictive value for survivors was high. Nonsurvivors had marked thymic and lymphoid atrophy and marked bone marrow hypocellularity. Conclusion: An accurate prognosis could be obtained at 24 hours after admission by evaluating the change in total leukocyte, band neutrophil, lymphocyte, monocyte, and eosinophil counts.

Assessment of renal dysfunction using urinary markers in canine babesiosis caused by Babesia rossi

Renal damage is deemed a common, yet poorly documented, complication in canine babesiosis. Serum urea and creatinine are insensitive and non-specific markers of early renal dysfunction and their measurements are influenced by hemolysis caused by babesiosis. Therefore, the aim of this study was to use urinary markers to assess the localization and degree of renal dysfunction in dogs with Babesia rossi infection. Urinary immunoglobulin G (uIgG) and urinary C-reactive protein (uCRP) were measured as markers for glomerular dysfunction, while urinary retinol-binding protein (uRBP) was used as a marker for tubular dysfunction. Eighteen dogs presenting with uncomplicated babesiosis were included and compared with eight clinically healthy dogs. Previously validated commercial ELISA kits were used for the measurement of uIgG, uCRP, and uRBP. Results were related to urinary creatinine concentrations (c). Dogs with babesiosis had significantly higher concentrations of all three measured urinary markers compared to healthy dogs. Except for urinary protein/c ratio (UPC), routine urinary and serum markers for renal function (urine specific gravity (USG), serum urea and creatinine (sCr)) were not significantly different between dogs with babesiosis and healthy dogs. All three urinary markers were positively correlated with each other and with UPC. The data supports the presence of both glomerular and tubular dysfunction in dogs suffering from uncomplicated B. rossi infection. Urinary markers were superior to USG, serum urea and creatinine concentrations for the early detection of renal dysfunction in dogs with babesiosis.

Achieving population-level immunity to rabies in free-roaming dogs in Africa and Asia

Canine rabies can be effectively controlled by vaccination with readily available, high-quality vaccines. These vaccines should provide protection from challenge in healthy dogs, for the claimed period, for duration of immunity, which is often two or three years. It has been suggested that, in free-roaming dog populations where rabies is endemic, vaccine-induced protection may be compromised by immuno-suppression through malnutrition, infection and other stressors. This may reduce the proportion of dogs that seroconvert to the vaccine during vaccination campaigns and the duration of immunity of those dogs that seroconvert. Vaccination coverage may also be limited through insufficient vaccine delivery during vaccination campaigns and the loss of vaccinated individuals from populations through demographic processes. This is the first longitudinal study to evaluate temporal variations in rabies vaccine-induced serological responses, and factors associated with these variations, at the individual level in previously unvaccinated free-roaming dog populations. Individual-level serological and health-based data were collected from three cohorts of dogs in regions where rabies is endemic, one in South Africa and two in Indonesia. We found that the vast majority of dogs seroconverted to the vaccine; however, there was considerable variation in titres, partly attributable to illness and lactation at the time of vaccination. Furthermore, >70% of the dogs were vaccinated through community engagement and door-to-door vaccine delivery, even in Indonesia where the majority of the dogs needed to be caught by net on successive occasions for repeat blood sampling and vaccination. This demonstrates the feasibility of achieving population-level immunity in free-roaming dog populations in rabies-endemic regions. However, attrition of immune individuals through demographic processes and waning immunity necessitates repeat vaccination of populations within at least two years to ensure communities are protected from rabies. These findings support annual mass vaccination campaigns as the most effective means to control canine rabies.

Serum C‐Reactive Protein Concentration in Benign and Malignant Canine Spirocercosis

BACKGROUND Spirocerca lupi is a nematode of canids that forms a nodule in the esophagus that can undergo neoplastic transformation. C-reactive protein (CRP) is a major acute phase protein in the dog that has been used for treatment, monitoring, and prognostication in inflammatory and neoplastic disease. HYPOTHESIS/OBJECTIVES The objectives of this study were to determine if serum CRP concentration (1) is increased in canine spirocercosis, (2) can be used to determine neoplastic transformation, and (3) can be used to monitor response to treatment in benign spirocercosis. ANIMALS Forty-two dogs naturally infected with S. lupi and 21 control dogs. METHODS A retrospective study was performed. The infected cases were divided into benign (n = 28) or malignant (n = 14) spirocercosis. CRP was performed on all of the spirocercosis and control cases at presentation. Statistical analysis was done by the one-way analysis of variance and Students t-test. RESULTS The mean CRP concentration in the benign cases was 60.4 ± 48.0 mg/L and that of the malignant cases was 76.5 ± 44.8 mg/L; both values were significantly higher (P < .001) than those of the control group where the mean was 13.4 ± 17.9 mg/L. The mean CRP concentration for the convalescent sera in the benign group was lower than the pretreatment concentrations (P= .01). CONCLUSION AND CLINICAL IMPORTANCE CRP cannot be used to differentiate between benign and malignant spirocercosis. There is a decrease in CRP concentration in dogs with benign spirocercosis once treatment has commenced. Serial CRP measurement can be used to monitor response to treatment in benign spirocercosis.

Excessive Pro-Inflammatory Serum Cytokine Concentrations in Virulent Canine Babesiosis.

Babesia rossi infection causes a severe inflammatory response in the dog, which is the result of the balance between pro- and anti-inflammatory cytokine secretion. The aim of this study was to determine whether changes in cytokine concentrations were present in dogs with babesiosis and whether it was associated with disease outcome. Ninety-seven dogs naturally infected with B. rossi were studied and fifteen healthy dogs were included as controls. Diagnosis of babesiosis was confirmed by polymerase chain reaction and reverse line blot. Blood samples were collected from the jugular vein at admission, prior to any treatment. Cytokine concentrations were assessed using a canine-specific multiplex assay on an automated analyser. Serum concentrations of interleukin (IL)-2, IL-6, IL-8, IL-10, IL-18, granulocyte-macrophage colony stimulating factor (GM-CSF) and monocyte chemotactic protein-1 (MCP-1) were measured. Twelve of the Babesia-infected dogs died (12%) and 85 survived (88%). Babesia-infected dogs were also divided into those that presented within 48 hours from displaying clinical signs, and those that presented more than 48 hours after displaying clinical signs. Cytokine concentrations were compared between the different groups using the Mann-Whitney U test. IL-10 and MCP-1 concentrations were significantly elevated for the Babesia-infected dogs compared to the healthy controls. In contrast, the IL-8 concentration was significantly decreased in the Babesia-infected dogs compared to the controls. Concentrations of IL-6 and MCP-1 were significantly increased in the non-survivors compared to the survivors. Concentrations for IL-2, IL-6, IL-18 and GM-CSF were significantly higher in those cases that presented during the more acute stage of the disease. These findings suggest that a mixed cytokine response is present in dogs with babesiosis caused by B. rossi, and that an excessive pro-inflammatory response may result in a poor outcome.

Clinicopathologic abnormalities associated with snake envenomation in domestic animals

Envenomation of domestic animals by snakes occurs frequently in certain geographic areas. However, reports describing clinical signs, clinicopathologic abnormalities, therapeutic approaches, and outcomes are sparse. This review summarizes various snake families, venom types associated with harmful snakes, and the significant hematologic, hemostatic, and biochemical abnormalities associated with envenomation. Hematologic abnormalities include RBC membrane abnormalities, hemolysis, hemoconcentration, leukogram changes, and platelet abnormalities, specifically thrombocytopenia. Coagulopathies associated with snake envenomation are well described in human medicine, and many studies have demonstrated properties of venoms that lead to both procoagulation and anticoagulation. As expected, similar abnormalities have been described in domestic animals. Biochemical abnormalities are associated with the effects of venom on tissues such as liver, skeletal and cardiac muscle, vascular endothelium, and kidney as well as effects on protein components and cholesterol. This comprehensive review of clinicopathologic abnormalities associated with envenomation and their relationships to characterized venom constituents should be useful both in the diagnosis and management of envenomation and should serve as a foundation for future research in this field.

Myocardial injury in dogs with snake envenomation and its relation to systemic inflammation

OBJECTIVE To investigate the presence of myocardial injury in dogs hospitalized for snake envenomation and to examine its relationship with systemic inflammation. DESIGN Prospective case-control study. SETTING University teaching hospital and small animal referral hospital. ANIMALS Dogs naturally envenomed by the European viper (Vipera berus; n = 24), African puff adder (Bitis arietans; n = 5), or snouted cobra (Naja annulifera; n = 9). INTERVENTIONS Blood was collected from dogs envenomed by V. berus at admission, 12-24 hours postadmission, and 5-10 days postadmission. Blood was collected from dogs envenomed by B. arietans or N. annulifera at admission, and 12, 24, and 36 hours postadmission. MEASUREMENTS AND MAIN RESULTS Concentrations of cardiac troponin I (cTnI), a marker of myocardial injury, and C-reactive protein (CRP), a marker of systemic inflammation, were measured in each blood sample. Evidence of myocardial injury was found in 58% of dogs envenomed by V. berus at one or more time points. A significant correlation between cTnI and CRP concentrations was found at all time points. Evidence of myocardial injury was found in 80% of dogs envenomed by B. arietans at one or more time points; however, no correlation was found between cTnI and CRP concentrations. Evidence of myocardial injury was found in 67% of dogs envenomed by N. annulifera at one or more time points. A significant correlation between cTnI and CRP concentrations was found at admission, but not at other time points. CONCLUSIONS Myocardial injury frequently occurred in dogs with snake envenomation. While the degree of systemic inflammation was significantly correlated with degree of myocardial injury in V. berus envenomation at all time points, this was not the case in dogs envenomed by N. annulifera or B. arietans. This could be due to differences in the toxic substances of the snake venoms or to differences in the cytokines induced by the venom toxins.

Influence of Disease Process and Duration on Acute Phase Proteins in Serum and Peritoneal Fluid of Horses with Colic

Background The acute phase proteins (APP) serum amyloid A (SAA), haptoglobin, and fibrinogen are valuable blood biomarkers in equine inflammatory diseases, but knowledge of factors influencing their concentrations in blood and peritoneal fluid (PF) of horses with colic is needed. Objectives The objective of this study was to investigate the influence of demographics (age, sex, breed), disease process (simple obstruction, strangulating obstruction, inflammatory), disease location, disease duration, hypovolemia, and admission hospital on concentrations of APP, lactate and white blood cell counts (WBC) in horses with colic admitted to 2 referral hospitals. Animals The study included 367 horses with colic admitted at 2 referral hospitals. Methods Prospective multicenter observational study of clinical data, as well as blood and PF biomarkers. Associations between biomarker concentrations and clinical variables were analyzed using multivariate linear regression analysis. Results Increasing pre‐admission duration of colic was associated with increased concentrations of APP in blood and PF. Blood concentrations of SAA and fibrinogen were associated with disease process (inflammatory, strangulations, simple obstructions) in more colic duration groups (5–12 and >24 hours) than any of the other biomarkers. No relevant associations between demographic factors, hospital, or hydration status and the measured biomarkers were found. Conclusions and Clinical Importance In horses with colic, concentrations of APP are associated mainly with disease process and duration of colic and may thus be used for assessment of disease independently of demographic or geographic factors. Serum amyloid A may be a diagnostic marker for use in colic differential diagnosis, but further evaluation is needed.

Mortality in virulent canine babesiosis is associated with a consumptive coagulopathy

The inflammatory response to infection can activate the coagulation system via complex interactions. If uncontrolled, this may lead to a consumptive coagulopathy, a major risk factor for a poor clinical outcome. This prospective observational study was conducted to determine whether consumptive coagulopathy in dogs with Babesia rossi infection is related to mortality. Seventy-two client-owned dogs diagnosed with canine babesiosis were included. Diagnosis was confirmed by polymerase chain reaction and reverse line blot and dogs co-infected with Babesia vogeli or Ehrlichia canis were excluded. Blood samples were collected at admission. Coagulation factor-, antithrombin (AT)-, and protein C (PC)-activity, prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen and D-dimer concentrations were measured. The mortality rate was 18% (13/72 dogs) and the median activities of all the coagulation factors were significantly lower in the non-survivors compared to the survivors. Median PT and aPTT were significantly longer in the non-survivors compared to the survivors. Median AT activity was not significantly different but median PC activity was significantly decreased in the non-survivors. Median D-dimer concentrations were significantly higher in non-survivors compared to survivors. This study showed that dogs that died from B. rossi infection had a more severe consumptive coagulopathy compared to survivors, characterized by procoagulant activation, inhibitor consumption, and increased fibrinolytic activity.