Cavernous sinus syndrome in a Holstein bull.

A 13-month-old Holstein bull was presented for right-sided exophthalmos. Ophthalmologic examination noted that the animal was visual in both eyes, but that the right pupil was persistently dilated and very sluggish to constrict when stimulated with a bright light and that normal ocular motility was absent. Fundic examination of the right eye was normal as was a complete ophthalmologic examination of the left eye. Radiographs at presentation did not reveal the presence of sinusitis or other skull abnormalities. Initial treatment comprised intravenous antibiotics and anti-inflammatories for orbital inflammation over a 14-day period. There was no perceptible change in the appearance or neuro-ophthalmologic examination of the right eye during hospitalization. The animal was discharged to the owner's care, but 3 weeks later was found recumbent with unilateral strabismus of the left eye and a fixed right pupil. Due to the inability to rise and rapid deterioration, humane euthanasia was performed, and a full postmortem examination, preceded by a MRI, was performed that identified abscesses extending bilaterally through the round foramina obliterating the cavernous sinus region, as well as abscessation of the right mandible, right trigeminal neuritis, right-sided sinusitis, and right-sided otitis media. Cavernous sinus syndrome should be considered in cattle with a combination of exophthalmos and neuro-ophthalmologic abnormalities involving cranial nerves III, IV, V, and VI, whose branches are located within the cavernous sinus.

Equine neuroaxonal dystrophy/degenerative myeloencephalopathy in Gypsy Vanner horses.

BACKGROUND: Equine neuroaxonal dystrophy/degenerative myeloencephalopathy (eNAD/EDM) is a neurodegenerative disease that primarily affects young, genetically predisposed horses that are deficient in vitamin E. Equine NAD/EDM has not previously been documented in Gypsy Vanner horses (GVs). OBJECTIVES: To evaluate: (1) the clinical phenotype, blood vitamin E concentrations before and after supplementation and pedigree in a cohort of GV horses with a high prevalence of neurologic disease suspicious for eNAD/EDM and (2) to confirm eNAD/EDM in GVs through postmortem evaluation. ANIMALS: Twenty-six GVs from 1 farm in California and 2 cases from the Midwestern U.S. METHODS: Prospective observational study on Californian horses; all 26 GVs underwent neurologic examination. Pre-supplementation blood vitamin E concentration was assessed in 17- GVs. Twenty-three were supplemented orally with 10 IU/kg of liquid RRR-alpha-tocopherol once daily for 28 days. Vitamin E concentration was measured in 23 GVs after supplementation, of which 15 (65%) had pre-supplementation measurements. Two clinically affected GVs from California and the 2 Midwestern cases had necropsy confirmation of eNAD/EDM. RESULTS: Pre-supplementation blood vitamin E concentration was ≤2.0 µg/mL in 16/17 (94%) of GVs from California. Post-supplementation concentration varied, with a median of 3.39 µg/mL (range, 1.23-13.87 µg/mL), but only 12/23 (52%) were normal (≥3.0 µg/mL). Normalization of vitamin E was significantly associated with increasing age (P = .02). Euthanized horses (n = 4) had eNAD/EDM confirmed at necropsy. CONCLUSIONS AND CLINICAL IMPORTANCE: GVs could have a genetic predisposition to eNAD/EDM. Vitamin E supplementation should be considered and monitored in young GVs.

Prognostic indicators for survival of downer cattle treated using a flotation tank in a referral hospital: 190 cases (2000-2020).

BACKGROUND: Nonambulatory cattle present therapeutic challenges in addition to animal welfare concerns. Flotation therapy is a treatment option, but more information regarding prognostic indicators for survival is needed to guide use of this modality. HYPOTHESIS/OBJECTIVES: Evaluate historical and clinical variables assessed during hospitalization as prognostic indicators for survival in recumbent cattle undergoing flotation treatment in a referral hospital. ANIMALS: A total of 190 nonambulatory dairy cattle. METHODS: Retrospective case series. Medical records were analyzed from cattle undergoing flotation between 2000 and 2020. Univariable and multivariable logistic regression analyses were performed to assess the association of clinical variables with survival to discharge. RESULTS: Eighty-nine of 190 (47%) recumbent cattle survived to discharge. For each additional day of hospitalization, cattle were 1.10 (95% confidence interval [CI], 1.02, 1.21) times more likely to survive. Cattle unable to walk out of the tank after their first float session were 0.11 (95% CI, 0.04, 0.28) times less likely to survive compared to cattle that could and inappetent cattle were 0.22 (95% CI, 0.07, 0.63) times less likely to survive compared to cattle with normal appetites. Cattle diagnosed with coxofemoral luxation or toxemia were 0.11 (95% CI, 0.02, 0.65) and 0.16 (95% CI, 0.02, 0.90) times less likely to survive, respectively, compared to cattle with causes of recumbency that were undetermined. CONCLUSIONS AND CLINICAL IMPORTANCE: Walking out of the tank after the first float session, appetite, diagnosis, and days of hospitalization are associated with outcome in nonambulatory dairy cattle treated by flotation. These findings can be used to determine likely outcome and guide treatment, referral, or euthanasia decisions.

Resolution of tracheal collapse and stenosis without surgical intervention in two Holstein calves.

CASE DESCRIPTION: A 4-month-old 127.5-kg (280.5-lb) Holstein heifer calf (patient 1) and a 4-month-old 174-kg (382.8-lb) Holstein bull calf (patient 2) of high genetic value were examined because of signs of respiratory tract disease (dyspnea, wheezing, and coughing) of 2 and 3 months' duration, respectively, that did not respond to antimicrobial and anti-inflammatory treatment. Patient 1 was born with assistance owing to malpresentation and dystocia. The birth of patient 2 was unobserved. CLINICAL FINDINGS: For both calves, results of a physical examination, CBC, serum biochemical analysis, thoracic radiography and CT, and nasotracheal endoscopy led to the diagnosis of tracheal collapse and stenosis secondary to perinatal rib fractures. Neither calf had evidence of substantial lower airway disease. TREATMENT AND OUTCOME: Both calves were discharged from the hospital with the recommendation that they be individually housed in cool, well-ventilated stalls with no access to headlocks. The clinical signs abated, and surgical intervention was not pursued in either patient. Both patients grew as expected and achieved reproductive maturity, with patient 1 becoming an oocyte donor and patient 2 being purchased by a commercial bull stud company. Patient 1 was reevaluated at 21 months old, and patient 2 was reevaluated at 26 months old. Results of follow-up thoracic radiographic (patient 1) and nasotracheal endoscopic (both patients) examinations indicated an anatomically normal trachea with no evidence of collapse or stenosis. CLINICAL RELEVANCE: This report was the first to describe successful resolution of tracheal collapse and stenosis secondary to perinatal rib fracture in dairy calves without surgical intervention.

Surgical findings and outcome for dairy cattle with jejunal hemorrhage syndrome: 31 cases (2000-2007).

OBJECTIVE: To describe signalment; surgical findings; short-, medium-, and long-term outcome; and recurrence rate for cattle undergoing celiotomy because of jejunal hemorrhage syndrome (JHS) and to analyze risk factors associated with outcome and recurrence. DESIGN: Retrospective case series. ANIMALS: 31 dairy cattle with JHS. PROCEDURES: Medical records were analyzed. Follow-up information was obtained from owners of cattle surviving until discharge. RESULTS: 18 of 31 (58%) cattle undergoing celiotomy survived to initial discharge. Fifteen (48%) and 13 (42%) were alive 6 and 12 months after discharge, respectively. All 5 deaths within 12 months after discharge were attributed to JHS recurrence. Survival time was 12 to 85 months for the 13 long-term survivors. Six of 7 that died > 12 months after celiotomy did so for reasons unrelated to JHS. Recurrence rate among short-term survivors was 7 of 18; 1 of these survived long-term. A significant proportion of affected cattle were Brown Swiss, compared with proportions for other breeds. Manual massage of the bowel to break down clots was associated with a significantly higher short-term survival rate than was enterectomy or enterotomy. Medium- and long-term survival rate was higher in cattle referred 24 to 48 hours after onset of signs. Length of obstructing blood clots was not associated with outcome. Other factors were not significantly associated with recurrence. CONCLUSIONS AND CLINICAL RELEVANCE: Survival rates were higher than those in other reports. Prompt celiotomy and resolution by use of manual massage were associated with higher survival rates. In this population, JHS recurred in 7 of 18 short-term survivors.

The effect of foot-and-mouth disease vaccination on early pregnancy loss in beef heifers in Argentina.

The threat of Foot and Mouth Disease (FMD) in South America has global economic implications and retaining a FMD Free status under the World Organization for Animal Health (OIE) remains a top priority. In Argentina the Servicio Nacional de Sanidad y Calidad Agroalimentaria (SENASA), the national service of agri-food health and quality, requires cattle located in the Pampean region of the Salado River basin to receive two foot-and-mouth disease (FMD) vaccinations per year, which results in one vaccination coinciding with beef cattle breeding season. While the vaccination program remains necessary, there is a growing concern amongst food animal veterinarians, that the overlap of FMD vaccination with the first 35 days of the breeding season is associated with early pregnancy loss (EPL). To address this concern, a preliminary randomized controlled trial t study was conducted to investigate the risk ratio (RR) of EPL in vaccinated, pregnant Aberdeen Angus heifers. Initially (Day 0), 858 heifers underwent fixed time-AI (FTAI). Subsequently, on day 33, following pregnancy diagnosis by transrectal ultrasonography pregnant heifers (n = 311) were randomly allocated to two treatment groups. Group 1 (162 animals) received an inactivated oil emulsion FMD vaccine, and Group 2 (149 animals) received a saline injection (control). On day 51 (18 days post vaccination), pregnancy status was re-evaluated by ultrasonography. The initial pregnancy rate (PR) on Day 33 was 58% (498/858 animals). On Day 51 (18 days post vaccination), PR in Group 1 was 96.3% (156/162 animals), and in Group 2 (control) was 98.6% (147/149 animals). The EPL in Group 1 was 3.7% (6/162 animals) and in Group 2 was 1.3% (2/149 animals). The RR of EPL in Group 1, compared to Group 2, was 2.8 (95% confidence interval: 0.6-13, p-value: 0.20). With such a wide range in confidence intervals and a p value of 0.20 a larger prospective study would be necessary to establish an unequivocally statistically significant link between heifer vaccination 33 days post FTAI and an increased risk of EPL.

Characterization of equine P-selectin glycoprotein ligand-1 by using a specific monoclonal antibody.

P-selectin glycoprotein ligand (PSGL-1) is a widely distributed adhesion molecule that plays a critical role in regulating lymphocyte homing and leukocyte trafficking during inflammation. The lack of specific reagents for equine PSGL-1 (ePSGL-1) has prevented mechanistic studies regarding its function and regulation in the horse. We synthesized a ePSGL-1 peptide to generate a monoclonal antibody (mAb), ePL1. Using flow cytometry and Western blot, we showed that ePL1 binds specifically to ePSGL-1 in transfected mammalian cells. We also demonstrated that ePL1 binds to equine leukocytes and recognized a protein with molecular weight 165 and 280kDa under reducing and non-reducing condition, respectively, likely corresponding to ePSGL-1. Seventy percent of equine monocytes bound by both ePL1 and HECA-452, an antibody defining sLex-like carbohydrate epitope. Both ePL1 and HECA-452 recognized ePSGL-1 protein precipitated by equine P-selectin-IgG chimera. Neuraminidase treatment increased ePL1 binding and the molecular weight of ePSGL-1, O-sialoglycoprotein endopeptidase digestion and tyrosine mutation abolished ePL1 staining and recognition. The ePL1 specific binding epitope appears to be the polypeptide backbone of ePSGL-1 in the presence of tyrosine but the process is independent of sialylation modification. In conclusion, we provide evidence that this antibody can be used for cell surface staining and immune-blot analyses.

Cardiac isoenzymes in healthy Holstein calves and calves with experimentally induced endotoxemia.

This paper describes a controlled study designed to establish normal values for cardiac troponins I and T (cTnI and cTnT) and CK-MB mass in healthy newborn Holstein calves, and to compare values for cTnI, cTnT, CK-MB and total creatine kinase (CK) with age-matched calves experiencing experimentally induced endotoxemia. Nineteen healthy Holstein bull calves, 48 to 72 h of age were used. Baseline cTnI, cTnT, CK-MB and total CK measurements were obtained from control (n = 9) and experimental (n = 10) calves. Controls then received physiological saline and experimental calves received endotoxin (O55:B5 Escherichia coli LPS) intravenously after which cardiac biomarkers and total CK were measured at 3 h, 6 h, 12 h, and 24 h post-initiation of infusion. Measured values were analyzed and compared using analysis of variance (ANOVA) by repeated measure design, with statistical significance set at P < 0.05. The cardiac biomarker cTnT was not detected in any calf at any time point, and CK-MB was only detected in 5 of 95 samples. The cTnI was significantly increased compared to baseline and controls, 3 h post lipopolysaccharide (LPS) infusion. Total CK was significantly increased in LPS administered calves at 18 and 24 h post infusion. The mean, standard deviation, and range for cTnI in healthy controls were 0.023 ng/mL (s = 0.01), and 0.01 to 0.05 ng/mL, respectively. In conclusion, LPS administration was associated with rapid and significant increases in cTnI but CK-MB and cTnT were not detected in the plasma of healthy calves. Total CK values increased significantly following LPS administration. Biochemical evidence of myocardial injury occurs within 3 h following LPS administration to neonatal Holstein calves.

Salmonella in Dairy Cattle.

As an infectious, contagious pathogen, Salmonella is probably rivaled by only bovine viral diarrhea virus in its ability to cause clinical disease, such as enteritis, septicemia, pneumonia, and reproductive losses. The increasing prevalence of Salmonella, particularly Salmonella Dublin, on dairies presents new challenges to producers and veterinarians. No current discussion of bovine salmonellosis is complete without acknowledging the increasing public health concern. Increasing antimicrobial resistance among enteric pathogens brings the use of antimicrobials by veterinarians and producers under ever stricter scrutiny. This article provides a comprehensive review of Salmonella etiology, prevalence, pathogenesis, diagnostics, treatment, and control.

Cloning and functional characterization of recombinant equine P-selectin.

The recent molecular characterization and sequencing of equine P-selectin (ePsel), and its glycoprotein ligand, P-selectin glycoprotein ligand-1 (PSGL-1), have provided the tools for further investigation into their role in leukocyte trafficking. Here, we report the generation of a genetically engineered chimeric protein (ePsel-IgG) in which the equine P-selectin lectin and epithelial growth factor (EGF) domains were covalently linked to the equine IgG1 heavy chain constant region. The soluble ePsel-IgG was observed to bind to equine monocytes by confocal microscopy and flow cytometry. Furthermore, equine monocytes bound to immobilized ePsel-IgG in a time course and dose dependent manner. Not only did ePsel-IgG act as an adhesion molecule, it was also found to activate ERK1/2 kinase and induce IL-8 mRNA expression in equine monocytes. That all of the aforementioned ePsel-IgG-induced cell binding and cell signaling were abolished by the addition of EDTA, suggested that ePsel-IgG chimera mediated events occurred via the P-selectin ligand, PSGL-1. We were able to demonstrate that 78% of equine monocytes cross-reacted with anti-human HECA-452 antibody, which recognizes the sialy-Lewis X (sLex) epitope, a well-known carbohydrate binding site on human PSGL-1. Pre-incubation of equine PBMC with neuraminidase or O-sialoglycoprotein endopeptidase (OSGP) reduced ePsel-IgG monocyte binding to 36% or 60%, respectively. Taken together, these data suggest that there might be two ligand recognition sites on P-selectin, one of which recognizes sLex and another which recognizes P-selectin ligand core protein. The ePsel-IgG chimera can be a useful as a reagent for further studies on the role of equine P-selectin and signal transduction in inflammatory events in horse.

Identification by next-generation sequencing of Aichivirus B in a calf with enterocolitis and neurologic signs.

An 11-d-old Holstein bull calf was presented to the Veterinary Medical Teaching Hospital at the University of Wisconsin-Madison because of a 4-d history of diarrhea and persistent low-grade fever. Initial diagnosis was enteritis caused by Cryptosporidium and rotavirus. During hospitalization, the calf became stuporous and was only responsive to noxious stimuli, with hypotonia of all 4 limbs, tail, head, and neck. A cerebrospinal fluid analysis revealed xanthochromia, with marked lymphocytic pleocytosis, which was suggestive of viral meningitis and/or encephalitis. Aichivirus B, which belongs to the Kobuvirus genus, was tentatively identified in spinal fluid by next-generation DNA sequencing. This virus can affect a multitude of species, including humans and cattle, and has been isolated from both healthy and diarrheic individuals. However, to date, a possible connection with neurologic disease has not been described, to our knowledge.

Prognostic value of clinicopathologic variables obtained at admission and effect of antiendotoxin plasma on survival in septic and critically ill foals.

This prospective study compared survival rates of critically ill and septic foals receiving 1 of 2 different types of commercial equine plasma and analyzed admission variables as possible predictors of survival. Standardized clinical, hematologic, biochemical, and hemostatic admission data were collected and foals received either conventional commercially available hyperimmune equine plasma or equine plasma specifically rich in antiendotoxin antibodies in a double-blinded, coded fashion. Sepsis was defined as true bacteremia or sepsis score >11. Overall survival rate to discharge was 72% (49/68). Foals that were nonbacteremic and demonstrated a sepsis score of < or = 11 at admission had a 95% (18/19) survival rate. The survival rate to discharge for septic foals was 28/49 (57%), with truly bacteremic foals having a survival rate of 58% (14/24), whereas that for nonbacteremic, septic foals was 56% (14/25). Sensitivity and specificity for sepsis score >11 as a predictor of bacteremia were 74 and 52%, respectively. For the entire study population, a higher survival rate to discharge was documented for those foals receiving hyperimmune plasma rich in antiendotoxin antibodies (P = .012, odds ratio [OR] 6.763, 95% confidence interval [CI]: 1.311, 34.903). Administration of plasma rich in antiendotoxin antibodies also was associated with greater survival in septic foals (P = .019, OR 6.267, 95% CI: 1.186, 33.109). Statistical analyses demonstrated that, among 53 clinical and clinicopathologic admission variables, high sepsis score (P < .001), low measured IgG concentration (P = .01), high fibrinogen concentration (P = .018), low segmented neutrophil count (P = .028), and low total red blood cell numbers (P = .048) were the most significant predictors of overall mortality.

Defining colloid osmotic pressure and the relationship between blood proteins and colloid osmotic pressure in dairy cows and calves.

OBJECTIVE: To establish the reference interval for colloid osmotic pressure (COP) in neonatal and adult cattle and to investigate associations between COP and total protein, albumin, or globulin in the two populations sampled. DESIGN: Cross-sectional observational study. SETTING: Animals were sampled on commercial dairy farms in Southern Wisconsin, and samples were processed and analyzed in a clinical pathology laboratory at a university teaching hospital. ANIMALS: Forty adult lactating Holstein cows between 2 and 4 years of age and 40 healthy Holstein calves of both sexes between 2 and 7 days of age. INTERVENTIONS: Adult cows were sampled by coccygeal venipuncture into standard heparinized vacutainer tubes, calves were sampled by jugular venipuncture also into heparinized vacutainer tubes. MEASUREMENTS AND MAIN RESULTS: For adult cows, the mean COP was 22.52 mm Hg, with a standard deviation of 1.0. For calves, the mean COP was 19.6 mm Hg, with a standard deviation of 1.9. Good correlation was demonstrated in adults between COP and albumin concentrations (r(2) = 0.72) and between COP and both total protein concentration (r(2) = 0.74) and globulin (r(2) = 0.65) in calves. For adults, regression plots established best fit relationships of COP = 0.472 (albumin) + 6.49, whereas for calves, two regression equations could be described; COP = 0.305 (globulin) + 8.62, and 0.268 (total plasma protein) + 2.73. CONCLUSIONS: Suggested normal ranges (mean ± 2 standard deviations) for COP in adult lactating dairy cows and calves between 2 and 7 days of age were 21-25 mm Hg and 17-23 mm Hg, respectively.

Biochemical markers of cardiac injury in normal, surviving septic, or nonsurviving septic neonatal foals.

The cardiac biomarkers cardiac troponin T (cTnT) and I (cTnI) and the cardiac isoenzyme of creatine kinase (CKMB) are used extensively in human medicine to diagnose and provide valuable prognostic information in patients with ischemic, traumatic, and septic myocardial injury. We designed a study to establish normal values for these markers in healthy, neonatal foals and to compare them with values obtained from septic neonates in a referral hospital population. The 25th, 50th, 75th, and 95th percentiles for cTnI and CKMB in the healthy-foal population were 0.08, 0.14, 0.25, 0.49 ng/mL and 1.4, 2.3, 4.0, 7.4 ng/mL, respectively. The values obtained for cTnT were frequently (43/52 foals; 83%) below the lower limit of detection of the assay (0.009 ng/mL), but the median and range were 0.009 and 0.009-0.041 ng/mL, respectively. In the septic foal population, the 25th, 50th, 75th, and 95th percentile values for cTnI and CKMB were 0.05, 0.12, 0.22, and 1.10 ng/mL and 2.0, 4.4, 7.8, and 24 ng/mL, respectively. The values obtained for cTnT were less frequently below the lower limit of detection (23/38 foals; 60%) compared with the healthy foal population, and the median and range were 0.009 and 0.009-0.20 ng/mL, respectively. Significantly higher values were observed for cTnT and CKMB in septic foals compared with the healthy neonatal foal population, but there were no differences among septic foals in survivors compared with nonsurvivors. These findings suggest that myocardial injury occurs during septicemia in neonatal foals but that the injury is not associated with survival among septic foals.

Evaluation of cytotoxicity and antiviral activity of recombinant human interferon alfa-2a and recombinant human interferon alfa-B/D hybrid against bovine viral diarrhea virus, infectious bovine rhinotracheitis virus, and vesicular stomatitis virus in vitro.

OBJECTIVE: To evaluate cytotoxicity and antiviral activity of recombinant human interferon alfa-2a and recombinant human interferon alfa-B/D hybrid against cytopathic and noncytopathic bovine viral diarrhea virus (BVDV), infectious bovine rhinotracheitis virus (IBRV), and vesicular stomatitis virus (VSV) in vitro. SAMPLE POPULATION: Primary bovine testicular cells and Mardin Darby bovine kidney cells. PROCEDURES: To evaluate cytotoxicity, cells were added to serial dilutions of each interferon. To evaluate antiviral activity of each interferon, interferons were serially diluted 1:10, and tissue culture cells were added; virus was then added at 3 time points. Prevention of viral infection by interferon was defined as failure to induce cytopathologic effect for VSV, IBRV, and cytopathic BVDV and failure to detect virus immunohistochemically for cytopathic and noncytopathic BVDV. RESULTS: No evidence of cytotoxicity in either cell line was detected after incubation with interferon alfa-2a or interferon alfa-B/D. However, reduced growth rates of tissue culture cells were detected for each interferon when undiluted interferon was tested. Comparable and profound antiviral activities against cytopathic and noncytopathic BVDV were evident for each interferon. Interferon alfa-2a and interferon a-B/D had comparable antiviral activities against VSV. Neither interferon had antiviral activity against IBRV. CONCLUSIONS AND CLINICAL RELEVANCE: The safety and marked in vitro antiviral activity against noncytopathic BVDV, cytopathic BVDV, and VSV suggest that interferons alfa-2a and alfa-B/D may be useful for treatment of natural disease after infection with these viruses.

Evaluation of antiviral activity and toxicity of recombinant human interferon alfa-2a in calves persistently infected with type 1 bovine viral diarrhea virus.

OBJECTIVE: To evaluate antiviral activity and toxicity of recombinant human interferon alfa-2a in calves persistently infected with noncytopathic type 1 bovine viral diarrhea virus (BVDV). ANIMALS: 5 Holstein heifers, 4 to 12 months of age. PROCEDURES: Calves persistently infected with noncytopathic type 1 BVDV were treated with recombinant human interferon alfa-2a every other day for 12 weeks. Viral loads were measured during the treatment period and compared with pre- and post-treatment values. Complete physical examinations were performed weekly, and calves were observed daily for signs of systemic illness. Complete blood counts and serum biochemical analyses were performed before, during, and after the treatment period. Because calves developed anemia during the treatment period, bone marrow biopsy specimens were collected. Antirecombinant human interferon alfa-2a antibody concentrations in serum samples obtained before, during, and after the treatment period were measured by use of an ELISA. RESULTS: Recombinant human interferon alfa-2a had no antiviral activity against noncytopathic type 1 BVDV in persistently infected calves. All calves developed microcytic anemia during the treatment period that persisted for up to 13 weeks after cessation of treatment. Anti-interferon antibodies were detected during the treatment period and persisted for at least 2 weeks after cessation of treatment. CONCLUSIONS AND CLINICAL RELEVANCE: Because of lack of in vivo antiviral activity against BVDV, recombinant human interferon alfa-2a has little promise as a therapeutic agent for the treatment of BVDV infection, at least in persistently infected cattle. Furthermore, treatment was associated with adverse immunologic and hematologic effects.

Pneumothorax in dairy cattle: 30 cases (1990-2003).

OBJECTIVE: To evaluate the features, underlying causes, results of diagnostic testing, and treatment of pneumothorax in dairy cattle. DESIGN: Retrospective study. ANIMALS: 30 dairy cattle. PROCEDURE: Medical records of all cattle with a diagnosis of pneumonia were reviewed. For cattle with pneumothorax, information was obtained pertaining to signalment, anamnesis, diagnosis, treatment, and outcome. Survival data were compared between cattle with pneumonia with or without pneumothorax. RESULTS: Pneumothorax was associated with bronchopneumonia in 18 cattle, interstitial pneumonia in 7 cattle, pharyngeal or laryngeal trauma in 3 cattle, and neonatal respiratory distress in 2 calves. Bovine respiratory syncytial virus was the most commonly detected infectious agent. Eighteen of 30 (60%) cattle survived; 8 were euthanatized and 4 died. Survival rate was 81% for cattle with pneumonia without pneumothorax during the same time period. Pneumothorax was a significant risk factor for failure to survive to discharge from the hospital for cattle with underlying chronic bronchopneumonia. CONCLUSIONS AND CLINICAL RELEVANCE: Pneumothorax in dairy cattle appears to occur most commonly in association with chronic bronchopneumonia. Cattle of both sexes and all ages can be affected.

Plasma endotoxin concentration in horses: a methods study.

BACKGROUND: Accurate determination of plasma endotoxin concentration is critical for ex vivo and in vitro cellular and molecular studies of endotoxemia in horses. However, reports are conflicting with respect to anticoagulant, handling, and sample preparation. OBJECTIVE: The purpose of this study was to determine the effect of blood sample fraction and handling time on measurement of endotoxin concentration in horses. METHODS: Whole blood, anticoagulated with 3.8% (0.12 M) sodium citrate (9:1), was collected from 5 healthy horses. Whole blood (WB), platelet-rich plasma (PRP), and platelet-poor plasma (PPP) were spiked with endotoxin (2 EU/mL). Endotoxin-spiked WB samples were centrifuged immediately to generate PRP for measurement. Endotoxin concentration was subsequently measured by Limulus amebocyte assay at 0, 15, 30, 45, and 60 minutes. Assays were performed in triplicate and results were analyzed using Student's t-test, with significance set at P <.05. RESULTS: Mean endotoxin concentrations in 2 EU/mL-spiked WB were significantly different from those in PPP at all time points tested. Recovery of endotoxin in PRP generated from WB was significantly diminished after just 15 minutes. CONCLUSION: PRP generated from WB is significantly more reliable than PPP in determining endotoxin concentration ex vivo. Measurement of endotoxin in PRP generated from WB was significantly diminished after 15 min, identifying a time frame within which to process blood samples for endotoxin analysis.

Timely diagnosis of dairy calf respiratory disease using a standardized scoring system.

Respiratory disease of young dairy calves is a significant cause of morbidity, mortality, economic loss, and animal welfare concern but there is no gold standard diagnostic test for antemortem diagnosis. Clinical signs typically used to make a diagnosis of respiratory disease of calves are fever, cough, ocular or nasal discharge, abnormal breathing, and auscultation of abnormal lung sounds. Unfortunately, routine screening of calves for respiratory disease on the farm is rarely performed and until more comprehensive, practical and affordable respiratory disease-screening tools such as accelerometers, pedometers, appetite monitors, feed consumption detection systems, remote temperature recording devices, radiant heat detectors, electronic stethoscopes, and thoracic ultrasound are validated, timely diagnosis of respiratory disease can be facilitated using a standardized scoring system. We have developed a scoring system that attributes severity scores to each of four clinical parameters; rectal temperature, cough, nasal discharge, ocular discharge or ear position. A total respiratory score of five points or higher (provided that at least two abnormal parameters are observed) can be used to distinguish affected from unaffected calves. This can be applied as a screening tool twice-weekly to identify pre-weaned calves with respiratory disease thereby facilitating early detection. Coupled with effective treatment protocols, this scoring system will reduce post-weaning pneumonia, chronic pneumonia, and otitis media.