The Impact of Population, Contact, and Spatial Heterogeneity on Epidemic Model Predictions.

Our objective was to evaluate the effect that complexity in the form of different levels of spatial, population, and contact heterogeneity has in the predictions of a mechanistic epidemic model. A model that simulates the spatiotemporal spread of infectious diseases between animal populations was developed. Sixteen scenarios of foot-and-mouth disease infection in cattle were analyzed, involving combinations of the following factors: multiple production-types (PT) with heterogeneous contact and population structure versus single PT, random versus actual spatial distribution of population units, high versus low infectivity, and no vaccination versus preemptive vaccination. The epidemic size and duration was larger for scenarios with multiple PT versus single PT. Ignoring the actual unit locations did not affect the epidemic size in scenarios with multiple PT/high infectivity, but resulted in smaller epidemic sizes in scenarios using multiple PT/low infectivity. In conclusion, when modeling fast-spreading epidemics, knowing the actual locations of population units may not be as relevant as collecting information on population and contact heterogeneity. In contrast, both population and spatial heterogeneity might be important to model slower spreading epidemic diseases. Our findings can be used to inform data collection and modeling efforts to inform health policy and planning.

Validation of Single and Pooled Manure Drag Swabs for the Detection of Salmonella Serovar Enteritidis in Commercial Poultry Houses.

Single swabs (cultured individually) are currently used in the Food and Drug Administration (FDA) official method for sampling the environment of commercial laying hens for the detection of Salmonella enterica ssp. serovar Enteritidis (Salmonella Enteritidis). The FDA has also granted provisional acceptance of the National Poultry Improvement Plan's (NPIP) Salmonella isolation and identification methodology for samples taken from table-egg layer flock environments. The NPIP method, as with the FDA method, requires single-swab culturing for the environmental sampling of laying houses for Salmonella Enteritidis. The FDA culture protocol requires a multistep culture enrichment broth, and it is more labor intensive than the NPIP culture protocol, which requires a single enrichment broth. The main objective of this study was to compare the FDA single-swab culturing protocol with that of the NPIP culturing protocol but using a four-swab pool scheme. Single and multi-laboratory testing of replicate manure drag swab sets (n  =  525 and 672, respectively) collected from a Salmonella Enteritidis-free commercial poultry flock was performed by artificially contaminating swabs with either Salmonella Enteritidis phage type 4, 8, or 13a at one of two inoculation levels: low, x¯  = 2.5 CFU (range 2.5-2.7), or medium, x¯  = 10.0 CFU (range 7.5-12). For each replicate, a single swab (inoculated), sets of two swabs (one inoculated and one uninoculated), and sets of four swabs (one inoculated and three uninoculated), testing was conducted using the FDA or NPIP culture method. For swabs inoculated with phage type 8, the NPIP method was more efficient (P < 0.05) for all swab sets at both inoculation levels than the reference method. The single swabs in the NPIP method were significantly (P < 0.05) better than four-pool swabs in detecting Salmonella Enteritidis at the lower inoculation level. In the collaborative study (n  =  13 labs) using Salmonella Enteritidis phage type 13a inoculated swabs, there was no significant difference (P > 0.05) between the FDA method (single swabs) and the pooled NPIP method (four-pool swabs). The study concludes that the pooled NPIP method is not significantly different from the FDA method for the detection of Salmonella Enteritidis in drag swabs in commercial poultry laying houses. Consequently based on the FDA's Salmonella Enteritidis rule for equivalency of different methods, the pooled NPIP method should be considered equivalent. Furthermore, the pooled NPIP method was more efficient and cost effective.

Effects of oral powder electrolyte administration on packed cell volume, plasma chemistry parameters, and incidence of colic in horses participating in a 6-day 162-km trail ride.

This study evaluated the effects of administering oral powder electrolytes on packed cell volume (PCV), plasma chemistry parameters, and incidence of colic in horses participating on a 6-day 162-km trail ride in which water was not offered ad libitum. Twenty-three horses received grain with powder electrolytes daily while 19 control horses received grain only. Horses were ridden approximately 32 km a day at a walk or trot. Packed cell volume and plasma chemistry parameters were analyzed daily. Episodes of colic were diagnosed and treated by a veterinarian unaware of treatment group allocation. Blood parameters and incidence of colic were compared between treatment groups. Electrolyte administration did not alter PCV or plasma chemistry parameters compared to controls. The incidence of colic was significantly higher in treated horses (P = 0.05). Oral powder electrolytes did not enhance hydration status or electrolyte homeostasis and may be associated with colic in horses participating on long distance trail rides similar to this model.

Effets de l'administration d'électrolytes en poudre oraux sur le volume d'hématocrite, les paramètres chimiques du plasma et l'incidence des coliques chez des chevaux participant à une randonnée de 162 km d'une durée de 6 jours. Cette étude a évalué les effets de l'administration d'électrolytes en poudre oraux sur la valeur d'hématocrite (VH), les paramètres chimiques du plasma et l'incidence de coliques chez des chevaux participant à une randonnée de 162 km d'une durée de 6 jours où l'eau n'était pas offerte ad libitum. Vingt-trois chevaux ont reçu du grain avec des électrolytes en poudre tandis que 19 chevaux témoins ont reçu du grain seulement. Les chevaux ont transporté un cavalier pendant environ 32 km par jour au pas de marche ou au trot. La valeur d'hématocrite et les paramètres chimiques du plasma ont été analysés tous les jours. Des épisodes de coliques ont été diagnostiqués et traités par un vétérinaire qui n'était pas informé de l'allocation au groupe de traitement. Les paramètres sanguins et l'incidence de coliques ont été comparés entre les groupes de traitement. L'administration des électrolytes n'a pas modifié la VH ni les paramètres chimiques du plasma par rapport aux témoins. L'incidence de coliques était significativement supérieure chez les chevaux traités (P = 0,05). Les électrolytes en poudre oraux n'ont pas amélioré l'état d'hydratation ni l'homéostasie des électrolytes et peuvent être associés à des coliques chez les chevaux participant à des randonnées de longue distance semblables à ce modèle.(Traduit par Isabelle Vallières).

Autonomy in the obstetrician/gynecologist-patient relationship as a predictor of patient satisfaction.

A considerable amount of recent medical research focuses on factors involving patient satisfaction. This study attempts to examine the role of autonomy in the gynecologist-patient relationship as it relates to patient satisfaction. Fifty-five patients at a women's clinic completed measures assessing autonomy preference (API) before the medical visit and patient-perceived autonomy support (HCCQ) and patient satisfaction (MISS) after the visit. Analyses revealed patients prefer a more equal level of decision making with their doctor (a medium level of autonomy) when asked general questions about medical decisions but preferred less autonomy when presented with actual scenarios. Results show a significant relationship between scenario-based autonomy preference level and visit satisfaction for both satisfaction measures. A significant relationship between perceived autonomy support and visit satisfaction was also found for both satisfaction measures. The findings of this study suggest autonomy is important to the gynecologist-patient relationship and worthy of future study.

Epidemiologic characterization of Colorado backyard bird flocks.

Backyard gallinaceous bird flocks may play an important role in the spread of infectious diseases within poultry populations as well as the transmission of zoonotic diseases to humans. An epidemiologic characterization was conducted of Colorado backyard flocks to gather information on general flock characteristics, human movement of birds, human-bird interaction, biosecurity practices, and flock health. Our results suggest that backyard poultry flocks in Colorado are small-sized flocks (68.6% of flocks had < 50 birds); consist primarily of layer chickens (85.49% of flocks), show chickens (32.18% of flocks), and waterfowl (34.07% of flocks); and are primarily owned for food (meat or egg) production for the family (86.44%) or as pet or hobby birds (42.27%). The backyard flock environment may promote bird-to-bird transmission as well as bird-to-human transmission of infectious disease. Birds are primarily housed with free access to the outside (96.85%), and many are moved from the home premises (46.06% within 1 yr). Human contact with backyard flocks is high, biosecurity practices are minimal, and bird health is negatively impacted by increased movement events. Increased knowledge of backyard bird characteristics and associated management practices can provide guidelines for the development of measures to decrease disease transmission between bird populations, decrease disease transmission from birds to humans, and increase the overall health of backyard birds.

In vitro motions of the medial and lateral proximal sesamoid bones under mid-stance load conditions are consistent with racehorse fracture configurations.

Proximal sesamoid bone (PSB) fractures in racehorses are likely fatigue fractures that occur due to repetitive loads and stress remodeling. The loading circumstances that may induce damage in the PSBs are not well understood. The goal of this study was to determine in three-dimensions, PSB motions relative to the opposing metacarpal condyle during simulated mid-stance loads. Seven equine cadaveric forelimbs were axially loaded in a material testing system to simulate standing and mid-stance walk, trot, and gallop load conditions (1.8-10.5 kN). Joint angles were determined by tracking the positions of bone-fixed kinematic markers. Internal-external rotation, abduction-adduction, and flexion-extension of each PSB relative to the third metacarpal condyle were compared between loads and between PSBs using an ANOVA with Tukey-Kramer post hoc tests for pairwise comparisons. The medial PSB rotated externally and the lateral PSB apex abducted during limb loading. Medial PSB external rotation was significantly greater at the gallop load condition than at the walk or trot load conditions. The medial and lateral PSB motions observed in this study are consistent with location of fatigue damage and fracture configurations frequently seen in medial and lateral PSBs from Thoroughbred racehorses. Specifically, medial PSB external rotation is consistent with the development of an abaxial subchondral medial PSB lesion that is reported in association with medial PSB transverse fracture and lateral PSB abduction is consistent with axial longitudinal fracture of the lateral PSB.

Biosecurity and bird movement practices in upland game bird facilities in the United States.

Since 1996, the emergence of Asian-origin highly pathogenic avian influenza subtype H5N1 has spurred great concern for the global poultry industry. In the United States, there is concern over the potential of a foreign avian disease incursion into the country. Noncommercial poultry operations, such as upland game bird facilities in the United States, may serve as a potential source of avian disease introduction to other bird populations including the commercial poultry industry, backyard flocks, or wildlife. In order to evaluate how to prevent disease transmission from these facilities to other populations, we examined biosecurity practices and bird movement within the upland game bird industry in the United States. Persons that held a current permit to keep, breed, or release upland game birds were surveyed for information on biosecurity practices, flock and release environments, and bird movement parameters. Biosecurity practices vary greatly among permit holders. Many facilities allow for interaction between wild birds and pen-reared birds, and there is regular long-distance movement of live adult birds among facilities. Results suggest that upland game bird facilities should be targeted for biosecurity education and disease surveillance efforts.

Histologic evaluation of the immediate effects of diamond burr debridement in experimental superficial corneal wounds in dogs.

PURPOSE: To evaluate the corneal changes immediately after diamond burr debridement of superficial corneal wounds in dogs. Spontaneous chronic corneal epithelial defects (SCCEDs) are the most common form of canine recurrent corneal ulcers. The diamond burr has been used in the management of corneal lesions in humans since 1983. Recently, it has been successfully used in the treatment of SCCEDs in dogs; however, little has been documented as to its mechanism of action. METHODS: Five adult female research dogs euthanized for reasons unrelated to the study were included, providing 10 normal eyes. An excimer laser spatula was used for epithelial removal after delineation with an 8 mm punch biopsy trephine. Diamond burr debridement was performed for 30 and 45 s in five eyes each (groups 1 and 2 respectively). The procedure was performed on the ventral half of the experimental defect as well as ventral normal cornea, immediately after euthanasia, and prior to enucleation. Samples were processed routinely for histologic evaluation and stained with periodic acid-Schiff. RESULTS: No stromal defects could be identified under light microscopy. In experimental corneal wounds, multi-focal areas remained covered by the epithelial basement membrane (BM) after diamond burr treatment in both groups (group 1 = 48% ± 16SD, group 2 = 26% ± 12SD). Removal of BM on group 2 was significantly higher than group 1 (P < 0.05). CONCLUSIONS : The diamond burr allows a safe method of debridement and does not create defects beyond the epithelial BM in corneal wounds in normal dogs. Evaluation of the diamond burr debridement in cases of SCCEDs is warranted.

Evaluation of the ocular penetration of topical alpha-luminol (Galavit®/GVT®).

PURPOSE: Oxidative stress plays a major role in the pathogenesis of many neurodegenerative diseases. It has also been implicated as part of the pathogenic mechanisms in the development of glaucoma. Alpha-luminol has shown profound anti-inflammatory and antioxidant effects in both experimental animal and human clinical studies. The purpose of this pilot study was to investigate for the first time the ocular penetration of topical alpha-luminol. METHODS: Nine animals were divided into three treated groups (three animals each; one drop OU/n = 18), each group receiving a different concentration of the eyedrop (0.5%, 1.5%, 2.5%). Aqueous humor and peripheral blood samples were obtained from each rabbit at three different timepoints (20 min, 4 h and 12 h). Samples were analyzed by means of high performance liquid chromatography and mass spectrometry; median values were compared. RESULTS: Alpha-luminol was found in the aqueous humor in all treated groups at all timepoints. At the 2nd and 3rd timepoints (4 h and 12 h), aqueous humor levels decreased significantly (P < 0.05) for two of the three dosages tested and it was not detectable in some eyes. The highest aqueous humor concentration of the drug was 272 ng/mL after 20 min (0.0217% of one drop, 2.5% group). Alpha-luminol was found in the vitreous in two animals, one in the 1.5% and another in the 2.5% group (16.4 and 21.5 ng/mL, respectively), at 12 h. CONCLUSIONS: Topically administered alpha-luminol readily penetrates into the anterior chamber and can penetrate into the vitreous chamber. Further investigation is warranted to better understand the intraocular pharmacokinetics of alpha-luminol.

Precision of repeated, Doppler-derived indirect blood pressure measurements in conscious psittacine birds.

Although the use of indirect methods for measuring blood pressure has become commonplace in dogs and cats, it is uncertain whether these methods can be extended to avian species with any proven accuracy or precision. To evaluate the precision of indirect blood pressure measurement in conscious psittacine birds by the Doppler flow method, 25 psittacine birds, weighing between 230 and 1263 g and representing 17 commonly kept species, were examined. Birds were manually restrained, and indirect blood pressure measurements were obtained by placing a cuff around the limb proximal to a Doppler ultrasonic flow detector held over either the basilic or cranial tibial artery. Three sets of 3 measurements were obtained from each wing and leg site, with cuff size and site based on pilot study data identifying the selection criteria of cuff placement with the least variance among repeated measurements. A mixed-effects linear regression analysis was performed to evaluate the differences among mean blood pressure measurements in the individual bird, obtained from the wing versus leg site as well as from 3 different cuff placements at each site. Results showed variation attributable to the limb was not significant. However, blood pressure measurements varied significantly between cuff placements on the same limb from the same bird and among individual birds. The precision of these indirect blood pressure measurements was poor. From these results, the meaning and value of Doppler-derived indirect blood pressure measurements obtained in psittacine birds remains in question, warranting further research.

Physical examination, serum biochemical, and coagulation abnormalities, treatments, and outcomes for dogs with toxicosis from α-amanitin-containing mushrooms: 59 cases (2006-2019).

OBJECTIVE: To report history, physical examination findings, clinicopathologic abnormalities, treatments, and outcomes of dogs with confirmed α-amanitin toxicosis resulting from ingestion of α-amanitin-containing mushrooms, and to report whether any differences were significant between survivors and nonsurvivors. ANIMALS: 59 dogs. PROCEDURES: Medical records of all dogs with confirmed α-amanitin toxicosis presented to a northern California emergency and specialty veterinary hospital between January 2006 and July 2019 were reviewed for signalment; body weight; history; physical examination findings including rectal temperature at presentation; results of serum biochemical analyses, coagulation tests, and a test for the detection of α-amanitin in urine; treatments; and outcomes. Differences for each were compared between survivors and nonsurvivors. RESULTS: Among the 59 dogs, 36 were < 1 year of age; 56 had variable clinical signs that included vomiting, diarrhea, anorexia, and weakness or lethargy; and 22 had rectal temperatures > 39.2°C (102.5°F) at presentation. Cases were seen throughout the calendar year. At presentation, alanine aminotransferase activity was mildly to markedly increased in 97% of dogs, hypoglycemia was noted in 78%, and coagulation times were prolonged in 91%. Most dogs that rapidly decompensated died; however, 13 dogs survived to hospital discharge and completely recovered. CONCLUSIONS AND CLINICAL RELEVANCE: Ability to recognize dogs with α-amanitin toxicosis on the basis of clinical signs, physical examination findings, and clinicopathologic test results is essential because mushroom ingestion is rarely observed and immediate treatment is necessary. Dogs that have marked hypoglycemia or coagulopathy may have a poor prognosis.

Characteristics of complete tibial fractures in California racehorses.

BACKGROUND: Tibial fractures cause ~3% of racehorse deaths. Pre-existing stress fractures have been associated with multiple racing and training fractures, but not complete tibial fractures. OBJECTIVES: To describe racehorse tibial fractures and compare signalment and exercise histories of affected and control racehorses. STUDY DESIGN: Retrospective analysis of necropsy reports. METHODS: Racehorses that had a complete tibial fracture (1990-2018) were retrospectively reviewed. Signalment and exercise histories of affected horses were compared to 1) racehorses that died because of non-tibial musculoskeletal injuries or 2) non-musculoskeletal cause and 3) age, sex, event-matched control racehorses. Tibial fracture prevalence was described relative to California racehorses that had at least one official work or race. Age, sex and limb distributions were compared between affected and control horses (Chi-square, Fisher's Exact test). Exercise history data were reduced to counts and rates of official high speed works, races and layups (periods without an official high speed work or race >60 days). Variables were compared among groups using matched logistic regression (P ≤ .05). RESULTS: Tibial fractures in 115 horses (97% unilateral; 50% left, 47% right) occurred most commonly during training (68%) and in 2- to 3-year-old horses (73%). Fractures were predominantly comminuted (93%), diaphyseal (44%) and oblique (40%). Of 61 cases examined for callus, 64% had periosteal callus associated with fracture, most commonly in proximal (65%) and distal diaphyseal (27%) locations. Of 28 racehorses with known exercise history, 57% never raced and 36% had a layup. Affected horses had fewer official-timed works and events (official high speed works and races), number of active days and accumulated less distance in events and works (P < .05) than control horses. MAIN LIMITATIONS: Retrospective review of necropsy reports by multiple pathologists over 28 years. CONCLUSIONS: Tibial fractures were associated with pre-existing stress fracture early in career. Most fractures were associated with proximolateral stress fractures.

Development, application, and validation of a survey for infectious disease control practices at equine boarding facilities.

OBJECTIVE: To develop a questionnaire for self-assessment of biosecurity practices at equine boarding facilities and to evaluate infectious disease control practices in these facilities in Colorado. DESIGN: Cross-sectional study. SAMPLE POPULATION: 64 equine boarding facilities in Colorado. PROCEDURES: Survey questions were rated according to importance for prevention and containment of equine infectious diseases. Point values (range, 0 to 20) were assigned for possible responses, with greater values given for optimal infection control methods. Questionnaires were mailed to equine boarding facilities in Colorado advertised on the World Wide Web. Survey responses were compared with assessments made by a member of the research team during visits to 30 randomly selected facilities. Agreement among results was analyzed via a kappa test and rated as poor, fair, moderate, substantial, or nearly perfect. RESULTS: Survey responses were received for 64 of 163 (39%) equine boarding facilities. Scores ranged from 106 to 402 points (maximum possible score, 418). Most facilities received better scores for movement and housing of equids than for other sections of the survey. Respondents at 24 of 48 (50%) facilities that routinely received new equids reported isolation of new arrivals. Agreement between self-assessment by survey respondents and evaluation by a member of the research team was determined to be fair to substantial. CONCLUSIONS AND CLINICAL RELEVANCE: Most equine boarding facilities have opportunities to improve measures for prevention or containment of contagious diseases (eg, isolation of newly arrived equids and use of written health management protocols). Most self-assessments of infection control practices were accurate.

Fatal intestinal inflammatory lesions in equids in California: 710 cases (1990-2013).

OBJECTIVE: To determine incidences and underlying causes of fatal intestinal inflammatory lesions (FIILs) and demographic characteristics of affected equids necropsied at any of the California Animal Health and Food Safety Laboratory facilities between January 1, 1990, and April 16, 2013. ANIMALS: 710 equids with FIILs, including colitis, duodenitis, enteritis, enterocolitis, enteropathy, enterotyphlitis, gastritis, gastroenteritis, ileitis, jejunitis, typhlitis, or typhlocolitis, alone or in combination. PROCEDURES: The medical records were reviewed, and data collected included animal age, sex, geographic origin, necropsy submission date, and breed, purpose, or characteristic of use. Descriptive statistics were compiled and reported as numbers and percentages. RESULTS: Colitis (323/710 [45.5%]), enteritis (146/710 [20.6%]), and typhlocolitis (138/710 [19.4%]) were the most common FIILs, and the underlying cause of most FIILs was categorized as either undetermined (465/710 [65.5%]) or bacterial (167/710 [23.5%]). The most common bacteria responsible for FIILs were Clostridium spp and Salmonella spp. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that the underlying cause for most FIILs could not be identified; however, when it was identified, it was most commonly bacterial and typically Clostridium spp or Salmonella spp, which could be useful information for practitioners when evaluating and managing horses and other equids with intestinal distress. In addition, results underscored the need for improved diagnostic procedures and strategies to determine underlying causes of FIILs in equids. Knowledge of the most common FIILs and their underlying causes may help in diagnosing and mitigating intestinal disease in equids.

Equine dental and skeletal fluorosis induced by well water consumption.

Two horses that consumed well water with high fluoride content exhibited clinical signs of chronic dental and skeletal fluoride toxicosis and were later euthanized and autopsied. Both horses had degenerative disease of multiple joints and multiple dental defects. Elevated fluoride concentrations were found in bone and tooth samples of both horses, well water, and feed. Microscopically, abnormalities were noted in bone and tooth samples, and consisted mostly of foci of cement necrosis and hypercementosis. Horses exhibiting bilateral, highly symmetrical dental and/or skeletal lesions, with chronic lameness, should be evaluated for the possible presence of fluoride toxicosis.

Data-Driven Network Modeling as a Framework to Evaluate the Transmission of Piscine Myocarditis Virus (PMCV) in the Irish Farmed Atlantic Salmon Population and the Impact of Different Mitigation Measures.

Cardiomyopathy syndrome (CMS) is a severe cardiac disease of Atlantic salmon caused by the piscine myocarditis virus (PMCV), which was first reported in Ireland in 2012. In this paper, we describe the use of data-driven network modeling as a framework to evaluate the transmission of PMCV in the Irish farmed Atlantic salmon population and the impact of different mitigation measures. Input data included live fish movement data from 2009 to 2017, population dynamics events and the spatial location of the farms. With these inputs, we fitted a network-based stochastic infection spread model. After assumed initial introduction of the agent in 2009, our results indicate that it took 5 years to reach a between-farm prevalence of 100% in late 2014, with older fish being most affected. Local spread accounted for only a small proportion of new infections, being more important for sustained infection in a given area. Spread via movement of subclinically infected fish was most important for explaining the observed countrywide spread of the agent. Of the targeted intervention strategies evaluated, the most effective were those that target those fish farms in Ireland that can be considered the most connected, based on the number of farm-to-farm linkages in a specific time period through outward fish movements. The application of these interventions in a proactive way (before the first reported outbreak of the disease in 2012), assuming an active testing of fish consignments to and from the top 8 ranked farms in terms of outward fish movement, would have yielded the most protection for the Irish salmon farming industry. Using this approach, the between-farm PMCV prevalence never exceeded 20% throughout the simulation time (as opposed to the simulated 100% when no interventions are applied). We argue that the Irish salmon farming industry would benefit from this approach in the future, as it would help in early detection and prevention of the spread of viral agents currently exotic to the country.

Relationship between herd size and annual prevalence of and primary antimicrobial treatments for common diseases on dairy operations in the United States.

Dairy operations in states representing 86% of the United States' national dairy herd were surveyed regarding the occurrence of common dairy diseases or disorders (digestive, respiratory, gastrointestinal, lameness, mastitis, navel infection) in specified production groups (weaned heifers, unweaned heifers, adult cows), and the most common antimicrobial preparation used to treat these conditions. Within disease and production group, disease frequency and characteristics of primary antimicrobial (drug class, availability, spectrum of activity, extra-label usage, withdrawal times) were compared among herd sizes (30-99, 100-499, and >/=500 cows) using chi-square or t-tests that accounted for the sampling design. The most common diseases were mastitis and lameness in cows, and gastrointestinal disease in unweaned calves, affecting 16, 11, and 15% of the target populations, respectively. Herd-level disease prevalence tended to increase as herd size increased, whereas within-herd prevalence tended to decrease as herd size increased. Broad-spectrum antimicrobials were selected as primary treatments by a majority of operations for nearly all diseases surveyed. When treating gastrointestinal disease, navel infection, or reproductive disorders, a majority of operations selected primary treatments not specifically labeled for that condition. Selection of over-the-counter preparations tended to decrease as herd size increased, whereas selection of broad-spectrum preparations tended to increase with herd size.

Lead contamination in backyard chicken layer flocks in California.

Backyard layer chickens may be exposed to a variety of metals in the environment, including lead. The potential public health concerns associated with lead exposure prompted us to systematically screen liver samples from backyard layers submitted to the diagnostic laboratory to estimate the prevalence of lead exposure. Over a period of 1 y, we tested 1,476 chicken livers, of which 45 were found to have lead concentrations of 0.9-41 µg/g. The lead-positive cases were investigated by follow-up questions to the bird owners on the environment, general management of the flock, and egg consumption of family members. Lead concentrations in 14 pooled egg samples were determined, and a conservative estimate of daily exposure of family members to lead was made based on egg consumption. In some cases, estimated daily lead intake exceeded the recommended limits for lead consumption in children. Analysis of feed, water, and environmental samples did not identify a source of exposure in most cases. Only 34% of owners of lead-positive birds submitted eggs or environmental samples, indicating a lack of interest or financial concerns. In most cases, neither the case history nor postmortem findings were indicative of lead intoxication; without systematically testing all birds, some cases could have been missed. Our study highlights the need for backyard chicken owners, veterinarians, and public health personnel to be aware of the risk of lead exposure and undertake preventive and surveillance measures.

Pharmacokinetics of a Long-lasting, Highly Concentrated Buprenorphine Solution after Subcutaneous Administration in Rhesus Macaques (Macaca mulatta).

Opioids are essential for use in rhesus macaques (Macaca mulatta) that require multimodal analgesia or those unable to receive NSAID as part of their pain management plan. The current opioid epidemic has universally limited the availability of these vital analgesics, compelling clinicians to investigate other options including novel opioid formulations. A commercially available injectable, long-lasting, highly concentrated buprenorphine solution (HCBS) provides therapeutic plasma concentrations lasting 24 h after a single dose in cats ( Felis catus). We hypothesized that this same HCBS would achieve therapeutic concentrations (≥0.1 ng/mL) for at least 24 h in rhesus macaques. In the current study, 6 healthy, adult rhesus macaques were included in a randomized, 2-period, 2-treatment crossover study. The low dose (0.24 mg/kg SC) achieved a peak plasma concentration of 19.1 ± 5.68 ng/mL at 0.308 ± 0.077 h, with an AUC of 236.4 ± 22.5 h/ng/mL and terminal elimination half-life of 19.6 ± 4.02 h; for the high dose (0.72 mg/kg SC), these parameters were 65.2 ± 14.7 ng/mL, 0.034 ± 0.004 h, 641.3 ± 79.4 h/ng/mL, and 20.6 ± 2.30 h, respectively. The mean plasma concentrations for the low and high doses in rhesus macaques significantly exceeded the therapeutic threshold for 48 and 72 h, respectively. One macaque showed mild somnolence at both doses, and another showed mild pruritus at both doses. These findings show that subcutaneous administration of HCBS provides prolonged and long-lasting therapeutic plasma levels for 48 to 72 h dosing without problematic adverse effects and thus represents a potential new analgesic alternative.

Prevalence of serum antibodies against Bartonella species in the serum of cats with or without uveitis.

Bartonella henselae has been implicated as a causative agent of chronic uveitis in people and in some cats. The objective of this study was to determine whether Bartonella species seroprevalence or titer magnitude varies among cats with uveitis, cats without ocular diseases recorded and healthy cats, while controlling for age and risk of flea exposure based on state of residence. There was no difference in seroprevalence rates or titer magnitude between cats with uveitis and cats with non-ocular diseases. Healthy cats were more likely to be seropositive for Bartonella species than cats with uveitis. The median Bartonella species titer was 1:64 for all groups, although healthy cats were more likely to have higher titers than cats with uveitis and cats with non-ocular disease. The results suggest that serum antibody tests alone cannot be used to document clinical uveitis associated with Bartonella species infection.