A technique for creating critical-size defects in the metatarsus of sheep for use in investigation of healing of long-bone defects

OBJECTIVE: To develop a technique for use in investigation of healing of long-bone defects by creation of a critical-size defect in the left metarsal III and IV bone (metatarsus) of sheep. ANIMALS: 18 healthy adult sheep. PROCEDURE: Sheep were allocated to 4 groups (3, 3, 5, and 7 sheep in groups 1 to 4, respectively). An ostectomy with various segmental length-to-diaphyseal diameter ratios (0.5, 1.0, 2.0, and 2.0 for groups 1 to 4, respectively) was performed on the left metatarsus of each sheep. The defect was left empty in sheep of groups 1, 2, and 3, whereas the defect was filled with a massive corticocancellous bone autograft in sheep of group 4. RESULTS: All sheep tolerated the surgical procedure well and were able to use the affected limb the day after surgery. Radiographic and histologic examinations conducted 16 weeks after surgery revealed nonunion in all sheep of groups 1, 2, and 3, whereas consistent bone healing with abundant bone formation was observed in all sheep of group 4. CONCLUSIONS AND CLINICAL RELEVANCE: Analysis of these findings suggests that the sheep metatarsal model is a critical-size defect model with low morbidity. It should allow the assessment of new technologies for bone regeneration in conditions closely mimicking the clinical setting. IMPACT FOR HUMAN MEDICINE: Use of this technique in sheep should be of benefit for the preclinical study of osteoconductive, osteoinductive, or osteogenic biomaterials for use in humans.     

Comparison of digital and optical hand-held refractometers for the measurement of feline urine specific gravity

Measuring urine specific gravity (USG) is an important component of urine analysis as it evaluates renal concentrating capability. The objective of this study was to quantify the difference in USG values between a hand-held optical analogue refractometer and a cat-specific digital instrument. Urine samples from 55 cats were assessed. There was a statistically significant difference between these two refractometers (P<0.001), with the optical refractometer (mean USG=1.031) consistently reading higher than the digital refractometer (mean USG=1.027). Results for a random subset of the samples (n=10) were compared with urine osmolality and both the optical and digital instruments demonstrated excellent correlation. While an accurate USG reading is important, it is unlikely that the statistical significance between the two instruments is clinically significant and, therefore, unlikely to result in a change in patient evaluation or treatment plans. While both the digital and optimal refractometers are highly correlated to the urine osmolality, making both devices valid for assessment of USG in clinical practice, this digital device is easier to read and eliminates the variability of subjective interpretation.     

Hemorrhagic and necrotizing hepatitis associated with administration of a modified live canine adenovirus-2 vaccine in a maned wolf (Chrysocyon brachyurus)

A 15-yr-old, female, maned wolf (Chrysocyon brachyurus) was euthanized after presenting semicomatose with severe, uncontrolled frank hemorrhage from her rectum 6 days following a routine physical examination and vaccination. Histopathology indicated severe hemorrhagic and necrotizing hepatitis with intranuclear basophilic inclusion bodies in the liver that were thought to be consistent with adenoviral infection. Further classification by polymerase chain reaction, immunohistochemical staining, virus isolation, and electron microscopy confirmed the etiologic agent to be canine adenovirus-2. A representative sample of the vaccine that had been used was submitted and sequenced along with the virus isolated from the maned wolf. The sequencing of the etiologic agent that had been isolated from the maned wolf was determined to be the same as the strain of virus used in the production of the modified live vaccine that had been administered 6 days prior to death. From this information, the diagnosis of vaccine-induced adenoviral hepatitis was made. This is the first confirmed case of vaccine-induced canine adenoviral hepatitis in a maned wolf.     

An analysis of an early-warning system to reduce abortions in dairy cattle in Denmark incorporating both financial and epidemiologic aspects

Emergency preparedness relies on the ability to detect patterns in rare incidents in an early stage of an outbreak in order to implement relevant actions. Early warning of an abortion storm as a result of infection with a notifiable disease, e.g. brucellosis, bovine viral diarrhea (BVD) or infectious bovine rhinotracheitis (IBR), is a significant surveillance tool. This study used data from 507 large Danish dairy herds. A modified two-stage method for detecting an unusual increase in the abortion incidence was applied to the data. An alarm was considered true if an abortion were detected in the month following the alarm month, otherwise false. The total number of abortions that could potentially be avoided if effective action were taken ranged from 769 (22.9%) to 10 (0.3%), as the number of abortions required to set the alarm increased from 1 to 6. The vast majority of abortions could, however, not be predicted, much less prevented, given this early-warning system. The false to true alarm ratio was reduced when the number of abortions that set the alarm increased. The financial scenarios evaluated demonstrated that the value of an abortion, the cost of responding to an alarm and the efficiency of the actions are important for decision making when reporting an alarm. The presented model can readily be extended to other disease problems and multiple-time periods.     

Evaluation of surrogate markers for passive transfer of immunity in kittens

OBJECTIVE: To identify surrogate markers of passive transfer of immunity in kittens. DESIGN: Prospective clinical trial. ANIMALS: 55 kittens from 12 specific-pathogen-free queens. PROCEDURE: Kittens were allocated at birth into colostrum-fed (n = 27) and colostrum-deprived (28) groups. Blood was collected at birth and on days 1, 2, 4, 7, 14, 28, and 56. Serum samples were analyzed for activities of alkaline phosphatase (ALP), alanine aminotransferase, aspartate aminotransferase, creatine kinase, lactate dehydrogenase, gamma-glutamyltransferase, amylase, and lipase and for concentrations of albumin, total protein, bilirubin, urea nitrogen, creatinine, cholesterol, glucose, calcium, phosphorus, and triglycerides by use of an automated analyzer. Total serum solids concentrations were estimated by use of refractometry. Serum IgG concentrations were quantified by use of radial immunodiffusion. RESULTS: All kittens were agammaglobulinemic at birth. Colostrum-fed kittens had significantly higher IgG concentrations than did colostrum-deprived kittens from 1 though 28 days of age. Transient significant differences in serum biochemical variables between the colostrum-deprived and colostrum-fed groups were substantially resolved by day 4. Passive transfer of immunity could be reliably determined at 1 day of age and to a lesser extent at 2 days of age only by measurement of serum activity of ALP. CONCLUSIONS AND CLINICAL RELEVANCE: Adequacy of passive transfer in kittens initially correlated with serum activity of ALP, but quantification of serum IgG concentration was necessary after 2 days of age.     

Raccoonpox in a Canadian cat

Poxvirus infections affecting the skin of cats are extremely rare in North America, in contrast to Europe where cowpox virus is well recognized as an accidental pathogen in cats that hunt small rodents. The virus or viruses responsible for the anecdotal cases in North America have never been characterized. This paper reports a case of raccoonpox infection in a Canadian cat. Biopsy of the initial ulcerative lesion on the forepaw revealed ballooning degeneration of surface and follicular keratinoctyes. Infected cells contained large eosinophilic type A inclusions. Electron microscopic examination revealed virions of an orthopoxvirus, subsequently identified as raccoonpox by polymerase chain reaction and gene sequencing. The cat made a full recovery.     

Pharmacokinetics and pharmacodynamics of pantoprazole in clinically normal neonatal foals

REASONS FOR PERFORMING STUDY: Proton pump inhibitors (PPIs) are a mainstay of treatment for acid-related ulceration in man and horses. Currently, only an oral preparation of omeprazole is approved for use in horses in the USA. Intravenous administration of a PPI would provide a useful therapeutic alternative for those foals in which oral medication is not feasible. OBJECTIVE: To investigate the pharmacokinetics and pharmacodynamics of pantoprazole following i.v. or intragastric administration in healthy neonatal foals. METHODS: Seven healthy foals age 6-12 days at the start of the study were evaluated. Treatments included no drug administration, i.v. pantoprazole (1.5 mg/kg bwt) and intragastric pantoprazole (1.5 mg/kg bwt). Intragastric pH was recorded for 24 h after drug administration for pharmacodynamic evaluation. Plasma pantoprazole concentrations were measured using high-performance liquid chromatography. RESULTS: Plasma concentrations of pantoprazole were detectable at the 5 min sampling point following i.v. or intragastric administration. Bioavailability of intragastric-administered pantoprazole was 41%. Baseline mean hourly pH was 1.5-6.1. There was a statistically significant increase in mean hourly pH relative to untreated foals 2-24 h after i.v. or intragastric pantoprazole administration. CONCLUSIONS: Based on these data, i.v. or intragastric administration of pantoprazole results in a significant, prolonged increase in intragastric pH. POTENTIAL RELEVANCE: The i.v. formulation of pantoprazole may provide a clinically useful alternative means of acid suppression in foals unable to tolerate enteral administration of a PPI, such as those with pyloric outflow obstruction.     

The development of methods for immunophenotypic and lymphocyte function analyzes for assessment of Southern sea otter (Enhydra lutris nereis) health

The Southern sea otter (Enhydra lutris nereis) is listed as threatened under the Endangered Species Act. The population began a pattern of slow decline in 1995. The decline was attributed to high adult mortality rates with infectious disease being the major cause of death. Multiple pathogens were implicated in these deaths including opportunistic pathogens such as Coccidiodes immitis and Toxoplasma sp. These findings suggested that the immunological health of mature animals in this population might be compromised. The primary goal of this study was to establish techniques for assessing phenotypic and functional baseline data for peripheral blood mononuclear cells (PBMC) in free-ranging sea otters. Standard total and differential white blood cell counts were augmented by emumeration of T and B lymphocyte subsets. Lymphocyte function was determined by both mitogen-induced proliferation and expression of IL-2 receptors. In addition to establishing normal ranges for adult animals, age-related changes were identified in B lymphocyte numbers and cell-surface density of major histocompatability complex class II (MHC II) proteins. The predominant lymphocyte subpopulation in Southern sea otters is the T lymphocyte. Substantial variation among individual animals was observed within the B lymphocyte population both in cell number and density of MHC II expression. Pups had greater numbers of T and B lymphocyte, as well as, greater MHC II expression on B lymphocytes than adults. Mitogen-induced proliferation of peripheral blood mononuclear cells (PBMC) was variable among individual animals with no significant difference in cell response between age class and gender. Concanavalin (ConA) was a more effective mitogen in stimulating proliferation and interleukin (IL)-2 receptor expression than pokeweed. This data can be used to augment routine hematology profiles and aid in the identification of animals with immunologic perturbations.     

Salmonella enterica serovar Kentucky recovered from human clinical cases in Maryland,USA (2011–2015)

Salmonella Kentucky is among the most frequently isolated S. enterica serovars from food animals in the United States. Recent research on isolates recovered from these animals suggests there may be geographic and host specificity signatures associated with S. Kentucky strains. However, the sources and genomic features of human clinical S. Kentucky isolated in the United States remain poorly described. To investigate the characteristics of clinical S. Kentucky and the possible sources of these infections, the genomes of all S. Kentucky isolates recovered from human clinical cases in the State of Maryland between 2011 and 2015 (n = 12) were sequenced and compared to a database of 525 previously sequenced S. Kentucky genomes representing 12 sequence types (ST) collected from multiple sources on several continents. Of the 12 human clinical S. Kentucky isolates from Maryland, nine were ST198, two were ST152, and one was ST314. Forty‐one per cent of isolates were recovered from patients reporting recent international travel and 58% of isolates encoded genomic characteristics similar to those originating outside of the United States. Of the five isolates not associated with international travel, three encoded antibiotic resistance genes conferring resistance to tetracycline or aminoglycosides, while two others only encoded the cryptic aac(6′)‐Iaa gene. Five isolates recovered from individuals with international travel histories (ST198) and two for which travel was not recorded (ST198) encoded genes conferring resistance to between 4 and 7 classes of antibiotics. Seven ST198 genomes encoded the Salmonella Genomic Island 1 and substitutions in the gyrA and parC genes known to confer resistance to ciprofloxacin. Case report data on food consumption and travel were, for the most part, consistent with the inferred S. Kentucky phylogeny. Results of this study indicate that the majority of S. Kentucky infections in Maryland are caused by ST198 which may originate outside of North America.