Prevalence and spatial distribution of Coxiella burnetii seropositivity in northern Australian beef cattle adjusted for diagnostic test uncertainty.

Q fever is a zoonotic disease caused by infection with Coxiella burnetii transmitted from animals including, but not limited to, cattle, sheep and goats. The infection in cattle is typically sub-clinical with some evidence suggesting associated reproductive loss. There is currently limited data on the true prevalence and distribution of coxiellosis in beef cattle across northern Australia. During this study, 2,012 sera samples from beef cattle managed on commercial farms located in Queensland and the Northern Territory were tested using an indirect immunofluorescent assay (IFA) for serological evidence of IgG antibodies against C. burnetii. Bayesian latent class models were used to estimate the true prevalence, adjusted for diagnostic test sensitivity and specificity and incorporating the hierarchical structure of the cattle within farms and regions. In this study, cattle in the Northern Territory had lower estimated true prevalence than cattle within most regions of Queensland with the exception of south-east Queensland. Results from this study have described the geographic distribution and estimated the true prevalence of antibodies to C. burnetii in a sample of extensively managed beef cattle located across the tropical grazing regions of northern Australia.

Effects of topical treatment of cannabidiol extract in a unique manuka factor 5 manuka honey carrier on second intention wound healing on equine distal limb wounds: a preliminary study.

OBJECTIVE: Evaluate the effect of topical 1% cannabidiol on second intention wound healing in distal limb wounds of horses. DESIGN: Experimental. ANIMALS: Six Standardbred horses. METHODS: A total of five 2.5 cm × 2.5 cm full thickness skin wounds were created on the dorsomedial aspect of the metacarpi of 6 horses. Wounds were contaminated with faeces on the day of wound creation. Each wound was then assigned to a treatment group; compounded 1% cannabidiol in unique manuka factor (UMF) 5 manuka honey, UMF 5 manuka honey, UMF 20 manuka honey or saline. Each treatment was applied topically daily for a total of 42 days. Legs were bandaged and bandages were changed, daily, for 13 days postoperatively. Digital photographs of each wound were taken on day 1 then weekly for 6 weeks. Wound size, daily healing rate and total time to healing were recorded and compared statistically. RESULTS: Irrespective of the treatment, wounds did not retract as expected in the first 7 days after wound creation. There was no difference in wound area, daily healing rate, days to complete healing between treatment groups. CONCLUSIONS: This preliminary study failed to demonstrate any difference in wound healing variables between treatment groups in this model of second intention wound healing. This was unexpected due to the established effects of UMF 20 manuka honey on wound healing using the same model. This may be due to systemic effects of cannabidiol and study design. Further research into the use of cannabidiol in equine wounds is warranted.

The large-scale capture of eastern grey kangaroos (Macropus giganteus) and red kangaroos (Osphranter rufus) and its application to a population management project.

OBJECTIVE: A large-scale capture method was developed to enable sterilisation of a macropod population in western Sydney from 2005 to 2018. METHODS: Until March 2007, free ranging eastern grey kangaroos and red kangaroos were herded into purpose-built 15 m diameter capture yards (CYs) for darting with a projectile syringe. From March 2007 onwards, animals were free-range darted in large areas without herding. Kangaroos were darted with 1.33-5.10 mg/kg tiletamine/zolazepam and 0.01-0.02 mg/kg medetomidine, ± 0.03 mg/kg acepromazine. Deaths were monitored. Population counts were performed annually. RESULTS: There were 5825 capture events involving 3963 kangaroos. Over 85% of all captures occurred from 2005 to 2008. Of all reported deaths (n = 523), 135 were attributed to ill health. Musculoskeletal injuries incurred during capture were the main project-related cause of death (n = 116). Post capture myopathy was uncommonly diagnosed following capture (n = 19). CONCLUSION: The herding and capture method enabled a large number of kangaroos to be mobilised and captured with low mortality rates, and the use of CYs resulted in fewer capture-related injuries and deaths than free-range capture. The drug doses and combinations used for darting were safe and effective, and the capture technique was successfully applied to a population management project.

Comparison of conventional radiography and computed tomography as aids in the diagnosis of osteomyelitis in 11 foals.

BACKGROUND: Conventional radiography is currently the most common imaging modality used by veterinarians investigating foals with suspected osteomyelitis. Emerging evidence in adult horses and humans suggests computed tomography (CT) is a superior modality for evaluation of osseous changes in general. This study aimed to evaluate the potential benefits of CT versus conventional radiography in cases of osteomyelitis in foals. METHODS: Cases of osteomyelitis in foals under 6 months of age admitted over a 6-year period at a single referral hospital that had both CT and conventional radiography images were retrieved. Case details and measurements of the largest area of bone lysis identified in two planes (lateromedial/sagittal and dorsopalmar/dorsal) were evaluated by three veterinarians with a range of experience. RESULTS: A significant difference regarding lesion size was seen on the lateromedial (LM) radiographic projections compared with the equivalent sagittal plane CT image. The LM radiographic evaluation resulted in a 37% underestimation of the area of the lesion. Additionally, use of the LM radiographic projections were 2.5-fold more variable in the measurement area compared with CT. In general, regardless of projection, CT produced more information regarding lesion area and, in some cases, detected osseous changes that were not evident on the radiographs. CLINICAL RELEVANCE: LM radiographic projections are less reliable and commonly result in an under-appreciation of lesion size and extent. CT detected lesions that were difficult or impossible to identify on radiographs and may allow improved treatment planning.

Effect of reducing inspired oxygen concentration on oxygenation parameters during general anaesthesia in horses in lateral or dorsal recumbency.

OBJECTIVE: To compare the effects of two concentrations of oxygen delivered to the anaesthetic breathing circuit on oxygenation in mechanically ventilated horses anaesthetised with isoflurane and positioned in dorsal or lateral recumbency. METHODS: Selected respiratory parameters and blood lactate were measured and oxygenation indices calculated, before and during general anaesthesia, in 24 laterally or dorsally recumbent horses. Horses were randomly assigned to receive 100% or 60% oxygen during anaesthesia. All horses were anaesthetised using the same protocol and intermittent positive pressure ventilation (IPPV) was commenced immediately following anaesthetic induction and endotracheal intubation. Arterial blood gas analysis was performed and oxygenation indices calculated before premedication, immediately after induction, at 10 and 45 min after the commencement of mechanical ventilation, and in recovery. RESULTS: During anaesthesia, the arterial partial pressure of oxygen was adequate in all horses, regardless of position of recumbency or the concentration of oxygen provided. At 10 and 45 min after commencing IPPV, the arterial partial pressure of oxygen was lower in horses in dorsal recumbency compared with those in lateral recumbency, irrespective of the concentration of oxygen supplied. Based on oxygenation indices, pulmonary function during general anaesthesia in horses placed in dorsal recumbency was more compromised than in horses in lateral recumbency, irrespective of the concentration of oxygen provided. CONCLUSION: During general anaesthesia, using oxygen at a concentration of 60% instead of 100% maintains adequate arterial oxygenation in horses in dorsal or lateral recumbency. However, it will not reduce pulmonary function abnormalities induced by anaesthesia and recumbency.

Comparison of the effects of topical application of UMF20 and UMF5 manuka honey with a generic multifloral honey on wound healing variables in an uncontaminated surgical equine distal limb wound model.

OBJECTIVE: To compare the effect of application of manuka honey with unique manuka factor (UMF) 5 or 20 with a generic multifloral honey on equine wound healing variables. METHODS: Two full-thickness skin wounds (2.5 × 2.5 cm) were created on the metatarsus of both hindlimbs of eight Standardbred horses. The wounds on each horse were assigned to 1 of 4 treatments: UMF20 (UMF20) and UMF5 (UMF5) manuka honey; generic multifloral honey (GH); and a saline control. Bandages were changed daily for 12 days, after which treatment was stopped and the bandages were removed. Wound area was measured on day 1, then weekly until day 42. Overall wound healing rate (cm2 /day) and time to complete healing were recorded. RESULTS: There was no difference in wound area for any of the treatments on any measurement day except for day 21, where the mean wound area for wounds treated with UMF20 was smaller than the mean wound area for the UMF5-treated wounds (P = 0.031). There was no difference in mean (± SE) overall healing rate (cm2 /day) among the treatment groups. There were differences in mean (± SE) days to complete healing. Wounds treated with UMF20 healed faster than wounds treated with GH (P = 0.02) and control wounds (P = 0.01). CONCLUSIONS: Treatment of wounds with UMF20 reduced overall wound healing time compared with wounds treated with GH and control wounds. However, using this model the difference in the overall time to complete healing was small.

A pilot study comparing the effect of orally administered esomeprazole and omeprazole on gastric fluid pH in horses.

AIMS To compare the efficacy of an enteric coated esomeprazole paste with an enteric coated omeprazole paste to increase gastric pH after oral administration in horses. METHODS Nine adult Standardbred horses were randomly assigned to three groups, each containing three horses, for a study comprising three phases of 10 days, with an 18-day washout period between each phase. In each phase, three horses received either 0.5 mg/kg esomeprazole, 1 mg/kg omeprazole or a placebo, as an oral paste, once daily for 10 days (Days 0-9). Over the course of study all horses received all three treatments. Gastric fluid samples were collected using a gastroscope on Days 1, 3, 5, 8 and 10, with food and water withheld for 16 hours prior to collection of samples. The pH of all samples was measured immediately after collection. RESULTS Mean pH (3.38; SD 1.75) of the gastric fluid samples in the horses that received the placebo was lower than in the horses that received esomeprazole (6.28; SD 1.75) or omeprazole (6.13; SD 1.75) (p<0.001). There was no difference in the mean pH between horses receiving esomeprazole and those receiving omeprazole (p=0.56). CONCLUSIONS AND CLINICAL RELEVANCE Under these study conditions, esomeprazole paste was equally as effective as omeprazole paste in increasing gastric pH in horses. Enteric coated esomeprazole, may be a therapeutic alternative to omeprazole for the prevention of gastric ulcers in horses.

Effect of Manuka honey gel on the transforming growth factor ß1 and ß3 concentrations, bacterial counts and histomorphology of contaminated full-thickness skin wounds in equine distal limbs.

OBJECTIVE: To investigate the effect of 66% Manuka honey gel on the concentrations of transforming growth factor (TGF)-ß1 and TGF-ß3, bacterial counts and histomorphology during healing of contaminated equine distal limb wounds. METHODS: In this experimental study of 10 Standardbred horses, five full-thickness skin wounds (2 × 1.5 cm) were created on one metacarpus and six similar wounds were created on the contralateral metacarpus. Wounds were assigned to three groups: non-contaminated control wounds; contaminated control wounds; contaminated wounds treated daily with 1 mL Manuka honey gel topically for 10 days. For the contaminated wounds, faeces were applied for 24 h after wound creation. In five horses wounds were bandaged and in the other five horses wounds were left without a bandage. Biopsies were taken on days 1, 2, 7 and 10 after wounding to evaluate the effects of Manuka honey gel, wound contamination and bandaging on TGF-ß1 and TGF-ß3 concentrations, aerobic and anaerobic bacterial counts, and histomorphology. RESULTS: Manuka honey gel had no significant effect on TGF-ß1 and TGF-ß3 concentrations or wound bacterial counts. Manuka honey gel decreased wound inflammation (days 7, 10), increased angiogenesis (days 2, 7, 10), increased fibrosis and collagen organisation (day 7) and increased epithelial hyperplasia (days 7, 10). CONCLUSIONS: Treatment with Manuka honey gel resulted in a more organised granulation tissue bed early in wound repair, which may contribute to enhanced healing of equine distal limb wounds.

The urticating setae of Ochrogaster lunifer, an Australian processionary caterpillar of veterinary importance.

The bag-shelter moth, Ochrogaster lunifer Herrich-Schaffer (Lepidoptera: Notodontidae), is associated with a condition called equine amnionitis and fetal loss (EAFL) on horse farms in Australia. Setal fragments from O. lunifer larvae have been identified in the placentas of experimentally aborted fetuses and their dams, and in clinical abortions. The gregarious larvae build silken nests in which large numbers cohabit over spring, summer and autumn. The final instars disperse to pupation sites in the ground where they overwinter. Field-collected O. lunifer larvae, their nests and nearby soil were examined using light and electron microscopy to identify setae likely to cause EAFL and to determine where and how many were present. Microtrichia, barbed hairs and true setae were found on the exoskeletons of the larvae. True setae matching the majority of setal fragments described from equine tissue were found on third to eighth instar larvae or exuviae. The number of true setae increased with the age of the larva; eighth instars carried around 2.0-2.5 million true setae. The exuvia of the pre-pupal instar was incorporated into the pupal chamber. The major sources of setae are likely to be nests, dispersing pre-pupal larvae and their exuviae, and pupal chambers.

Effect of activated protein C in second intention healing of equine distal limb wounds: a preliminary study.

OBJECTIVE: To investigate the effect of activated protein C (APC) on second intention healing of distal limb wounds in horses. METHODS: In this experimental study of eight Standardbred geldings, six full-thickness skin wounds (2 × 1.5 cm) were created on one metacarpus (biopsy limb) and five similar wounds were created on the contralateral metacarpus (photographed limb). Three wounds on the biopsy limb were treated topically with 190 µg APC on days 1, 3, 6 and 9, while the remaining three wounds were untreated (control). One treated and one control wound were biopsied on days 4, 7 and 11 for histopathology. Wounds on the photographed limb were treated with either 66% Manuka honey gel, a commercial antibiotic ointment (bacitracin-neomycin-polymixin B ointment; BNP) or petrolatum daily throughout healing, treated on days 1,3,6 and 9 with 190 µg APC or left untreated. These wounds were digitally photographed and the wound area measured on day 1, then weekly until day 49. Overall time to healing was recorded. RESULTS: There was no effect of APC on wound size, the rate of healing or the overall time to heal. However, compared with control wounds, histological scoring demonstrated enhanced epithelialisation (day 4) and angiogenesis (day 11). Wound healing variables for wounds treated with APC, Manuka honey gel and control wounds were not different and the variables for wounds treated with BNP and petrolatum demonstrated delayed healing. CONCLUSION: The improvements in histological scores in APC-treated wounds suggest further study into the effect of APC on second intention wound healing in horses is warranted.

Risk factors for mortality in cattle during live export from Australia by sea.

OBJECTIVE: This study investigated mortality trends and risk factors for death for cattle exported live from Australia by sea. METHODS: Mortality data for all voyages from Australia to all destinations between 1995 and 2012 were analysed retrospectively. Daily mortality trends were assessed for 20 long-haul voyages from Australia to the Middle East and to the Russian Federation between 2010 and 2012. RESULTS: The overall voyage mortality percentage was 0.17% across the 13 million cattle exported on 6447 voyages. Mortality rates decreased significantly after 2000 and stabilised at low levels from 2003. The mortality rate for voyages to the Middle East and north Africa (0.44%) was significantly higher than for voyages to south-east Europe (0.28%), north-east Asia (0.12%) and south-east Asia (0.09%). Cattle exported from ports in southern Australia carried a higher mortality risk than those exported from northern ports for both long- and short-haul voyages. The daily mortality rate on long-haul voyages peaked at 3-4 weeks post-departure, although there was a smaller peak at 1-2 weeks. CONCLUSION: The marked reduction in mortality rate since 2000 is related to a number of factors, including industry initiatives, government legislation and market demand, that have resulted in changes to both the selection of cattle for export and the management of cattle prior to and during voyages. Routine collection of animal performance data, combined with NLIS records and use of methods described here, have the potential to contribute to more effective management of mortality risks across the export chain.

Major complications and risk factors associated with surgical correction of congenital medial patellar luxation in 124 dogs.

Dogs treated for congenital medial patellar luxation were reviewed for the purpose of determining the incidence of postoperative major complications requiring surgical revision and the risk factors for their occurrence. Major complications occurred in 18.5% of the patellar luxation stabilization procedures with implant associated complications being the most frequent, patellar reluxation the second, and tibial tuberosity avulsion the third most common major complication. Other complications included patellar ligament rupture and trochlear wedge displacement. When recession trochleoplasty was performed in addition to tibial tuberosity transposition, a 5.1-fold reduction in the rate of patellar reluxation was observed. Release of the cranial belly of the sartorius muscle further reduced the incidence of patellar reluxation, while patella alta (pre- or postoperative) and patellar luxation grade were not found to influence the rate of reluxation. Tibial tuberosity avulsion was 11.1-times more likely when using a single Kirschner wire to stabilize a transposition, compared with two Kirschner wires. Independent to the number of Kirschner wires used, the more caudodistally the Kirschner wires were directed, the higher the risk for tibial tuberosity avulsion. Tension bands were used in 24.4% of the transpositions with no tuberosity avulsion occurring in stifles stabilized with a tension band. Overall, grade 1 luxations had a significantly lower incidence of major complications than other grades, while body weight, age, sex, and bilateral patellar stabilization were not associated with risk of major complication development.

Processionary caterpillar setae and equine fetal loss: 1. Histopathology of experimentally exposed pregnant mares.

Six pregnant Standardbred mares aged between 6 and 14 years were gavaged with 50 g or 100 g of suspended emulsified whole Processionary caterpillars (Ochrogaster lunifer) for 5 days during 2 experiments undertaken to study the etiology of equine amnionitis and fetal loss (EAFL). The 6 treated mares and 1 untreated mare were between 128 and 252 days gestation. Mare 1 (untreated) was euthanized on day 5 of the treatment period, while the treated mares were euthanized on days 2, 4, 8, 10, 12, and 24 days from their first treatment. Caterpillar setae were not found in the untreated mare. Setal fragments were present in all regions of the gastrointestinal tracts in all treated mares, the uteri and mesenteric lymph nodes of 5 mares, and the liver of 4 mares. Acute gastroenteritis of varying severity was present in all treated mares, and 5 of 6 mares had acute colitis and endometritis. Focal hyperplastic serositis was found in the duodenum, cecum, dorsal colon, and uteri of various mares occasionally with embedded setal fragments. Setal invasion of the mucosa evoked a range of lesions including superficial erosion to deep ulceration. Inflammation in deeper tissues ranged from unapparent to neutrophilic (microabscesses), eosinophilic, or mononuclear (microgranulomas). The finding of setal fragments within the uterus of experimental mares suggests that direct migration of setal fragments acting as a bacterial vector is a likely mechanism for the bacterial abortions that characterize equine amnionitis and fetal loss.

Processionary caterpillar setae and equine fetal loss: 2. Histopathology of the fetal-placental unit from experimentally exposed mares.

Pregnant mares were experimentally exposed to whole caterpillar or exoskeleton of the Processionary caterpillar (Ochrogaster lunifer) via gavage. Tissues were collected from resulting abortions and near or full-term pregnancies consisting of 13 aborted fetuses, 3 fetuses from treated euthanized mares, membranes of 5 foals, and organs from 3 foals. Three control membranes and 1 control fetus and membranes were examined. Caterpillar setal fragments were present in the allantochorion of the 3 fetuses from the euthanized mares and 11 of 12 aborted fetuses (92%) embedded in the chorion (villi or stroma) or allantois (vasculature or stroma). Placental locations of fragments ranged from the cervical pole region to the body encompassing the umbilical insertion and pregnant horn. Numbers in each fetus ranged from 1 to 7 fragments. Setae were present in the allantochorion from 2 to 22 days after the initial treatment. Acute to chronic active inflammation was present in all aborted fetuses, all euthanized fetuses, and within at least 1 tissue level (chorion, allantois, umbilical cord, or amnion) of the membranes from full-term foals. Amnionitis, funisitis, and allantoitis were present in 95% of the examined membranes. Pneumonia was present in 95% of the specimens, and bacteria were present histologically in 90.5% of the specimens with or without accompanying inflammation. The rapid migration of setae within 2 days after mare exposure suggests that direct setal migration into the fetal membranes is a likely initiating factor for equine amnionitis and fetal loss (EAFL).

Bacteria isolated from field cases of equine amnionitis and fetal loss.

BACKGROUND: A series of unusual abortions occurred in Thoroughbred and Quarterhorse mares in the Hunter Valley region of New South Wales from mid-March to November 2004. The initial link between early cases was the microbiological culture of atypical environmental coryneforms from the stomach contents and/or lungs of fetuses aborted on different properties. METHODS: The unique pathologic lesions were described with a case definition and the term 'equine amnionitis and fetal loss' (EAFL) was established. RESULTS: The causal factor was the ingestion of the processionary caterpillar (Ochrogaster lunifer). Bacteria from the Actinomycetales order were isolated from 40% of the combined suspect and confirmed EAFL cases and included Microbacterium arborescens, Cellulomonas sp., Arthrobacter spp. and Cellulosimicrobium sp. Other bacteria isolated included various Gram-negative bacilli and Gram-positive cocci. CONCLUSIONS: Although the predominant type of bacteria isolated from EAFL was environmental coryneforms, it is important to note that a variety of bacteria were associated with the characteristic histopathological changes outlined by the case definition. This highlights the importance of histopathology on both fetal membranes and fetuses, as well as culture to confirm EAFL and to exclude other possible causes of abortion.

Exposure of mares to processionary caterpillars (Ochrogaster lunifer) in early pregnancy: an additional dimension to equine amnionitis and fetal loss.

REASONS FOR PERFORMING STUDY: Equine amnionitis and fetal loss (EAFL) is an unusual form of abortion in mid- to late-gestation mares, first identified in Australia in 2004. It has been shown that both whole processionary caterpillars (Ochrogaster lunifer) and their shed exoskeletons can induce abortion in mares during midgestation. These abortions exhibited gross pathology and bacteriology results consistent with field cases of EAFL. OBJECTIVES: To determine whether exposure of mares to the shed exoskeletons of processionary caterpillars can induce abortion in the preplacentation (<35 days' gestation) and early placentation (45-60 days) stages of pregnancy. STUDY DESIGN: In vivo experimental study. METHODS: Mares less than 35 days' gestation and between 45 and 60 days' gestation were exposed to a slurry of shed processionary caterpillar exoskeletons by nasogastric intubation. Mares were monitored by clinical examination daily. Transrectal ultrasonography was performed daily (control and treated preplacentation mares, treated early placentation mares) or every second day (control early placentation mares). Uterine swabs were collected from mares that aborted. All live foals underwent a clinical examination. Placentas were examined, with sampling for bacteriology and histopathology if appropriate. RESULTS: Abortions occurred in treated mares in both experiments without signs of impending abortion. One mare aborted in the embryonic stage experiment and 2 in the early placentation experiment. Embryonic and fetal death was detected on transrectal ultrasonography prior to abortion. In the early placentation experiment, one foal was born 5 weeks preterm and was very small, with laxity of the tendons in all limbs. Enteric or environmental bacteria, consistent with EAFL, were isolated from the mares that aborted. Focal mucoid placentitis lesions were present on the placentas of 2 treated mares, one from each experiment. CONCLUSIONS AND POTENTIAL RELEVANCE: Processionary caterpillar exposure may be associated with EAFL-related embryonic and early fetal loss in mares. Processionary caterpillars may also play a role in the occurrence of focal mucoid placentitis.

Clinical evaluation of alfaxalone as an anaesthetic induction agent in cats less than 12 weeks of age.

OBJECTIVE: To assess the clinical suitability of alfaxalone as an anaesthetic induction and maintenance agent for kittens aged less than 12 weeks. MATERIALS AND METHODS: The study group comprised 34 kittens aged less than 12 weeks that were presented for surgical desexing. They were aged by dentition, examined and weighed prior to premedication with acepromazine, atropine and morphine. At 20-30 min after premedication, animals were anaesthetised with intravenous alfaxalone administered to effect, using a target maximum expected dose of 5 mg/kg. All cats were intubated: 25 were maintained with isoflurane in oxygen administered with a non-rebreathing circuit and 8 were maintained by supplemental intravenous administration of alfaxalone. Subjective measures of anaesthetic quality and vital signs were recorded from enrolment to recovery. Cats receiving supplemental alfaxalone for maintenance were evaluated for time to first supplemental dose and the total dose of supplemental alfaxalone (mg/kg/h). Descriptive and comparative statistics were used to analyse and present collected data. RESULTS: The mean (± SD) dose of alfaxalone for induction was 4.7 ± 0.5 mg/kg body weight. Subjective measures of anaesthetic quality indicated acceptable induction, maintenance and recovery standards. Measured cardiovascular and respiratory parameters were well maintained. CONCLUSION: Alfaxalone in 2-hydroxypropyl-beta-cyclodextrin (Alfaxan®) is a suitable injectable anaesthetic induction agent for juvenile cats aged less than 12 weeks requiring anaesthesia. Maintenance of anaesthesia with supplemental doses of alfaxalone may be a suitable alternative in kittens when the use of inhalant anaesthetic maintenance is not feasible.

Effects of intra-articular sodium pentosan polysulfate and glucosamine on the cytology, total protein concentration and viscosity of synovial fluid in horses.

OBJECTIVE: Evaluate synovial fluid cytology, total protein concentration and viscosity after intra-articular administration of combined pentosan polysulfate and glucosamine in horses. DESIGN: Ten adult Standardbred horses had each carpal joint (n = 20) randomly assigned to one of two treatments: control (5 mL saline) or treated (pentosan polysulfate and glucosamine). All horses received an intra-articular injection every 7 days for 3 weeks and synovial fluid samples were collected on days 1 (baseline), 2, 3, 7, 8, 9, 14, 15, 16 and 21. Synovial fluid variables measured included total protein concentration, total nucleated cell count, red blood cell count, the neutrophil, lymphocyte, mononuclear cell and eosinophil percentages, and viscosity. RESULTS: Following injection, the total nucleated cell count increased in the synovial fluid samples from both groups. Values were significantly higher in treated joints on days 2, 3, 15 and 16. Red blood cell counts were low and no differences were seen between treated and control joints. Total protein concentrations and neutrophil percentages increased in both groups after injection, but decreased towards normal ranges within 7 days. Total protein concentration was significantly higher in treated joints on days 1, 3, 8, 9 and 15. Percentages of neutrophils were higher in treated joints on day 2, but significantly lower on days 8 and 15. Viscosity was significantly higher in treated joints on day 2 only. CONCLUSIONS: Intra-articular administration of combined pentosan polysulfate and glucosamine causes a mild inflammatory synovitis that is not substantially different to that elicited by injection of a similar volume of saline and so we conclude that these drugs are safe to use in the horse.

Effects of collecting serial tracheal aspirate and bronchoalveolar lavage samples on the cytological findings of subsequent fluid samples in healthy Standardbred horses.

OBJECTIVE: To evaluate the effect of collecting serial tracheal aspirate (TA) and bronchoalveolar lavage (BAL) samples on the cytological findings of subsequent fluid samples obtained from horses without clinical signs of respiratory disease. STUDY DESIGN: Experimental. STUDY POPULATION: Six healthy Standardbred horses. METHODS: Endoscopically-guided TA samples, and BAL samples collected using the blind field technique were obtained from the six horses on days 1, 2, 3, 4, 5, 12, and 17. On day 17, horses were sampled three times: at baseline and at 2.5 h and 4 h apart. The differential cytology of the fluid samples collected at each time point was expressed as percentages and compared statistically. RESULTS: There was a significant increase in neutrophil percentage in the TA samples taken at day 17 (at 2.5 h but not at 4 h apart). There was no significant change in the neutrophil percentages in the TA samples when repeated samples were taken ≥ 24 h apart. There was no significant change in the neutrophil percentages in the BAL fluid at any collection point. There were inconsistent changes in the percentages of lymphocytes and macrophages in the BAL fluid over time, but these remained within normal reference ranges and were considered clinically insignificant. CONCLUSIONS: Serial TA and BAL samples can be taken at 24 h intervals without affecting the cytological findings of subsequent fluid samples collected using the techniques described.

Equine amnionitis and fetal loss: mare abortion following experimental exposure to Processionary caterpillars (Ochrogaster lunifer).

REASONS FOR PERFORMING STUDY: In Australia, there have been recent reports of unusual abortions in mid- to late-gestation mares. These were clinically distinct from other recognised causes of pregnancy loss and the term 'equine amnionitis and fetal loss' (EAFL) was adopted to describe this syndrome. Initial investigations concluded that possible causal factors included the presence on affected stud farms of Processionary caterpillars (Ochrogaster lunifer). OBJECTIVES: To determine if exposure of pregnant mares to Processionary caterpillars or their shed exoskeletons can induce EAFL. METHODS: Processionary caterpillars and their shed exoskeletons were collected and stored frozen. Mid-gestation mares were dosed with a slurry of caterpillars or shed exoskeleton by nasogastric intubation. Their clinical responses and times to abortion were recorded. All aborted fetuses were autopsied and samples taken for bacteriological and virological culture and histopathology. RESULTS: Intubating mares in mid-pregnancy with preparations of either whole Processionary caterpillars or shed caterpillar exoskeletons induced abortion with few impending clinical signs. The gross pathological and bacteriological findings of the aborted fetuses were similar to those observed in field cases of EAFL. POTENTIAL RELEVANCE: Possible exposure to Processionary caterpillars should be considered when examining cases of fetal loss in the mare. The present results provide a starting point to further explore the aetiology and pathogenesis of EAFL.