Genomic hybrid capture assay to detect Borrelia burgdorferi: an application to diagnose neuroborreliosis in horses.

Antemortem diagnosis of neuroborreliosis in horses has been hindered by both the low sensitivity of PCR testing for Borrelia burgdorferi in CSF and the low specificity of serum:CSF ELISA ratios used to determine intrathecal antibody production against the bacterium. PCR testing of the CSF of an adult horse with acute neurologic disease for the B. burgdorferi flagellin gene was negative. However, we enriched B. burgdorferi DNA through nucleic acid hybrid capture, followed by next-generation sequencing, and identified B. burgdorferi in the CSF of the horse, confirming a diagnosis of neuroborreliosis.

Serological survey for antibody to Encephalitozoon cuniculi in horses in the USA.

Encephalitozoon cuniculi is an obligate intracellular microsporidian parasite that can result in clinical and subclinical infection in many species. In the present study, a serological survey was conducted using samples from 105 horses in the state of New Jersey; 49 of the samples were obtained from clinically abnormal animals. Five or 4.8% of 105 serum samples were found to demonstrate reactivity by ELISA with titers of 1:64 to 1:1,024. One of the samples was obtained from a clinically normal horse. Clinical signs and diagnoses from the other animals included lameness, colic, osteochondritis dissecans, and fever. All clinical issues were resolved with hospitalization and treatment without the institution of E. cuniculi-focused therapy. This is the first report on the detection of E. cuniculi antibodies in horses in the USA.

Assessment of serum amyloid A testing of horses and its clinical application in a specialized equine practice.

OBJECTIVE: To compare serum amyloid A (SAA) concentration, plasma fibrinogen concentration, total WBC count, and serum albumin-to-globulin concentration ratio (A:G ratio) in clinically normal (CN) and clinically abnormal (CA) horses. DESIGN: Prospective cohort study. ANIMALS: 111 CN horses and 101 CA horses hospitalized at a specialty clinical practice. PROCEDURES: Shortly after admission, a blood sample (20 mL) was collected from each horse for a CBC, serum protein electrophoresis, and determination of plasma fibrinogen concentration; SAA concentration was assessed with a previously validated immunoturbidometric assay. Similar testing of a subset of CA horses was conducted at various points during treatment. RESULTS: Total WBC count, A:G ratio, and SAA concentration were determined for all 212 horses; data regarding plasma fibrinogen concentration were available for 127 horses (of which 47 were CN and 80 were CA). Median SAA concentration, total WBC count, and plasma fibrinogen concentration and mean A:G ratio differed significantly between CN horses and CA horses. Correlations between these variables were poor to weak. For discrimination of CN horses from CA horses, the SAA assay had sensitivity of 53% and specificity of 94% (diagnostic accuracy, 75%); for the other assessments, accuracy ranged from 59% to 62%. Repeated assessment of SAA concentration in some CA horses revealed a gradual return to normal concentrations. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that assessment of SAA concentration can provide valuable information regarding the clinical state of horses and may be more useful for patient monitoring and as a prognostic indicator than are traditional markers of inflammation.

Multinodular pulmonary fibrosis in five horses.

CASE DESCRIPTION: 5 horses were evaluated because of decreased appetite, weight loss, fever, cough, tachypnea, and respiratory distress. CLINICAL FINDINGS: Tachycardia, tachypnea, increased respiratory effort, lethargy, fever, poor body condition, and nasal discharge were detected in various combinations on initial physical examination. Evaluation of the lower portion of the respiratory tract via radiography and ultrasonography revealed a severe nodular interstitial pattern. Histologic examination of lung tissue revealed interstitial expansion of alveolar parenchyma with collagen, intraluminal accumulation of neutrophils and macrophages within the alveoli, and occasional intranuclear inclusion bodies within alveolar macrophages. Equine herpesvirus type 5 was detected in samples of lung tissue, bronchoalveolar lavage fluid, or both via polymerase chain reaction assay in all cases. A diagnosis of equine multinodular pulmonary fibrosis (EMPF) was established. TREATMENT AND OUTCOME: Horses were provided supportive treatment and were administered a variety of medications including corticosteroids and acyclovir. Two horses survived and returned to their previous level of activity. Three horses were euthanized because of either deterioration of clinical condition (n=2) or failure to improve within 4 weeks of initiation of treatment (1). CLINICAL RELEVANCE: EMPF should be considered as a differential diagnosis for adult horses with interstitial pneumonia and should be suspected on the basis of characteristic radiographic, ultrasonographic, and histopathologic findings. Equine herpesvirus type 5 is found in association with EMPF; although the exact pathogenic role this virus plays in EMPF is unknown, equine herpesvirus type 5 may be an etiologic agent or cofactor in the development of EMPF.

Application of PCR and Reverse Line Blot Hybridization to Detect Arthropod 1 Transmitted Haemopathogens in Horses Presented at a Referral Veterinary Facility in 2 New Jersey, USA

Equine granulocytic ehrlichiosis is a tick-borne zoonotic disease caused by the 36 intracellular bacterium Anaplasma phagocytophilum. This disease has been well 37 documented in California, USA and sporadic cases have been recorded in New Jersey 38 and other states. Equine piroplasmosis is a reportable disease in the United States with 39 the most recent outbreak reported in Florida in 2008. In order to detect these diseases in 40 an area of low prevalence, two PCRs followed by a reverse line blot (RLB) hybridization 41 process were performed on DNA extracted from blood of 133 horses presented at a large 42 equine referral clinic in New Jersey. One PCR amplified the 16S rRNA gene for 43 Anaplasma/ Ehrlichia and gene and the other the 18S rRNA gene for Theileria/Babesia. 44 Amplified products were applied to a membrane to which oligonucleotide probes for equine granulocytic ehrlichiosis (Anaplasma phagocytophilum) and equine piroplasmosis 46 (Theileria equi and Babesia caballi) were covalently attached. Two horses were positive 47 for Anaplasma phagocytophilum .This is the first published record of A phagocytophilum 48 DNA to be detected in horses in the United States using the reverse line blot 49 hybridization process. This technique is useful for large scale epidemiological screening 50 and detection of several tick-transmitted haemopathogens simultaneously in animals with 51 vague clinical signs of disease.

Effects of a polymerized ultrapurified bovine hemoglobin blood substitute administered to ponies with normovolemic anemia.

The development of ultrapurified hemoglobin-based oxygen carriers has eliminated many problems associated with whole-blood transfusions in other species. We hypothesized that the administration of polymerized ultrapurified bovine hemoglobin (PUBH) would result in improved hemodynamic parameters in ponies with normovolemic anemia without adverse effects on renal function or coagulation times. Normovolemic anemia was induced in 6 healthy adult ponies. Over a 3-day period, at least 45 mL/kg of whole blood was withdrawn from each pony until a target PCV of <12% was attained. Plasma was separated from the red blood cells via centrifugation and readministered to the ponies on each day. After the final plasma transfusion, 15 mL/kg of hetastarch (control, n = 6) or 15 mL/kg of PUBH (treatment, n = 6) was administered at 10 mL/kg/h IV. Administration of PUBH at a rate of 10 mL/kg/h was not associated with any adverse effects in 5 of the 6 ponies. One pony experienced an anaphylactoid reaction during infusion of PUBH. The reaction, characterized by intense pruritus, tachycardia, and tachypnea resolved shortly after stopping the infusion. Ponies receiving PUBH had significantly lower cardiac indices (P = .03) and heart rates (P = .002) than control animals. A significantly greater increase in central venous pressure was observed in the PUBH group compared to the hetastarch group (P = .02). No adverse renal or coagulation effects were observed with PUBH infusion. These results suggest that PUBH improves hemodynamics and oxygen transport parameters in horses experiencing normovolemic anemia. Patients should be monitored closely during infusion for any adverse reactions.