Clinical Lameness Research Articles

Field trials and tribulations: mortality, morbidity and liveweight following multivalent clostridial and Pasteurella vaccination of lambs on six English commercial sheep flocks

Objective: This field trial aimed to assess the effect of a multivalent clostridial and Pasteurella vaccine (Heptavac P Plus, MSD Animal Health, 2015), administered to lambs at two different time points, on lamb mortality (primary outcome), morbidity and growth rates (secondary outcomes) as compared to unvaccinated lambs.
 Background: This veterinary practice-based study was motivated by a knowledge gap identified during flock health planning activities and engagement between veterinarians and commercial sheep producers in a regional knowledge exchange programme in South West England. Common queries to the veterinary practice from sheep producers during summer to autumn 2012 included the value and timing of vaccinations to prevent disease associated with pasteurellosis. Discussions between veterinarians and consultants working in preventive sheep flock health planning stimulated a scientific literature search, which highlighted the lack of published data on field vaccine testing of Pasteurella components under British sheep commercial farming systems, and a lack of strong evidence in order to inform practical questions regarding the optimal timing of vaccinations aimed at preventing lamb mortalities in the pre-, peri- and post-weaning periods.
 Evidentiary value: A field vaccine trial was conducted on six commercial sheep flocks in South West England. From April 2013, across the six farms a total of 900 twin-born lambs (Ovis aries) were systematically randomly allocated into 1. unvaccinated, 2. early- (6 to 8-week-old) or 3. late- (18 to 20-week-old) vaccination groups. The study provides evidence to support recommendations for sheep producers regarding risks for clostridial disease in fully unvaccinated sheep flocks, supports the benefits of preventive ewe vaccination, and indicates that pre-weaning vaccination of lambs may be beneficial for reducing peri- and post-weaning losses on some flocks. The study highlights the challenges of identifying the reasons for mortality in grazing lambs, and provides new evidence to support the need for early intervention and treatment of ocular lesions in young lambs, in order to reduce their negative impact on lamb performance.
 Methods. During the 6-month trial, lambs were assessed for ocular lesions, orf lesions, clinical respiratory disease, lameness, diarrhoea, and ear tag losses. Monthly liveweights (kg) and mortalities were recorded. Lambs were removed from the study when they reached producer-defined finishing objectives, ≥46 kg liveweight or when they died.
 Results: Overall, low levels of mortality and disease outcomes were observed in both control and vaccinated lambs. A mortality rate of 33 deaths per 1000 lambs at-risk, 0.8% lameness (95% CI 0.6–1.1), 1.7% diarrhoea (95% CI 1.4–2.2), 3% ocular disease (including ocular discharge and/or entropion) (95% CI 2.2–3.2), and 2.6% orf lesions (95% CI 2.2–3.1) were recorded over the trial period. A higher proportion of mortalities occurred in unvaccinated or partially vaccinated lambs (n=23; 76.7%), as compared to trial lambs that had received a primary vaccine course (n=7; 13.3%). A small proportion of mortalities (n=3; 10.0%) occurred in lambs whose vaccination status could not be confirmed No clinical signs of respiratory disease were recorded during veterinary or producer assessments of control or vaccinated trial lambs. Mixed-effects models found significant between-farm and time differences in liveweights (p<0.001) but no significant effect of vaccination status on lamb growth rates. A dramatic decrease in lamb growth rates across all farms coincided with the weaning period – this was also the period in the study were the majority of grazing lamb mortalities were identified in flocks that routinely vaccinated their ewes against clostridial disease and pastuerellosis.
 Conclusion: A clear trend was found with fewer mortalities occurring in lambs that received a multivalent clostridial and Pastuerella spp. vaccination course compared to unvaccinated lambs. The reasons behind mortalities in grazing lambs were not diagnosed given the low submission of carcases for veterinary necropsy examination that was attributed to carcase scavenging and decomposition. No significant effects of vaccination were found on lamb growth rates or clinical outcomes. However, a secondary finding was the significant negative effect of ocular conditions (including discharge and entropion) on growth rates of lambs aged 6 weeks and over – supporting the need for early recognition and intervention in order to reduce animal welfare and production impacts.
 Application: We highlight study findings, field experiences and discuss some of the practical challenges and considerations in design and conduct of field vaccine trials used to inform evidence-based veterinary practice. The study will be of interest to veterinary surgeons, sheep producers, flock health and agricultural consultants, pharmaceutical agencies and advisors, researchers and those engaged in applied studies in animal health and welfare, veterinary epidemiology, preventive health management researchers, and participants and advisors in field vaccine trial design and development.
 

Laser-structured spike surface shows great bone integrative properties despite infection in vivo.

Implant associated infections can result in devastating consequences for patients. One major cause is the formation of bacterial biofilms, which result in increased resistance against antimicrobial therapeutics. A reduction of implant associated infections can be achieved by functionalization of implant surfaces. The generation of three dimensional surface structures by femtosecond laser ablation is one method to fabricate bacterial repellent large scaled surfaces without altering the material chemical composition. The challenge is to reduce bacterial growth while improving cellular ongrowth. For this purpose, spike structures were created as small as possible by used fabrication method on cubic Ti90/Al6/V4-rods and their effectiveness against bacterial colonization was compared to unstructured Ti90/Al6/V4-rods. Rods were implanted in the rat tibia and infected intraoperatively with 103 CFU of Staphylococcus aureus. Besides clinical behaviour and lameness, the vital bacterial biomass, morphological appearance and the volume of eukaryotic cells were determined on the implant surface after 21 days. Bone alterations were examined by radiological and histological techniques. Unexpectedly, the laser-structured implants did not show a lower bacterial load on the implant surface and less severe infection related bone and tissue alterations compared to the group without structuring. Simultaneously, a better bony integration and a higher cellular colonization with eukaryotic cells was detected on the laser-structured implants. These findings don't support the previous in vitro results. Nevertheless, the strong integration into the bone is a powerful argument for further surface modifications focussing on the improvement of the antibacterial effect. Additionally, our results underline the need for in vivo testing of new materials prior to clinical use.

Übersicht zu Zusammenhängen zwischen Änderungen der Bewegungsintensität und Ketose bei Milchkühen

With a prevalence of up to 43 % subclinical ketosis is one of the most common diseases in dairy cows in their transition period. In itself, this may cause subsequent diseases such as clinical ketosis or lameness. Therefore, monitoring of animals in this stage is of importance. In addition to the measurement of β-hydroxybutyrate or acetoacetate in blood, milk, and urine as well as the observation of the animals, computer-assisted systems are suitable means of monitoring. Information such as animal identification and activity data are recorded on a data logger and transmitted to a computer. A change in activity may be an indication of an underlying disease days before the onset of additional clinical signs. In cases of ketosis, a decrease in activity may be observed 5 days before the clinical diagnosis is made. Thus, these data are a valuable contribution in monitoring the cattle herd's health status for both the farmer and the veterinarian. Activity measurement may also be employed for the detection of a beginning lameness. In the presence of lameness, the individual's activity decreases and periods of lying are longer. Activity measurement via transponder as a part of the herd monitoring provides important information on lameness prevalence in the herd. In the presence of a lameness a visual assessment should additionally be made. Lameness scores (Locomotion score, Gait score) have been developed for this purpose and add to determining the lameness status of the herd. This way the animals are divided into different lameness classes. Based on this classification those individuals in need of claw trimming or further treatment may be identified leading to amelioration or prevention of secondary diseases. Due to lameness and subsequent reduction of activity and feed intake, the animals may develop subclinical or clinical ketosis. Therefore, under consideration of both animal welfare and economic factors early disease detection and prophylaxis is desirable and should be a main objective of herd monitoring.

The association between collagen and bone biomarkers and radiographic osteoarthritis in the distal tarsal joints of horses.

Osteoarthritis (OA) of the distal intertarsal (DIT) and tarsometatarsal (TMT) joints occurs commonly. Synovial fluid (SF) biomarkers of collagen and bone turnover have potential clinical value. To measure SF biomarker concentrations from DIT and TMT joints in adult horses and determine if they correlate with radiographic OA severity and are higher in joints with radiographic OA compared to controls. Cross-sectional. Radiographic OA of DIT and TMT joints was evaluated from adult horses (5-35years old). Overall radiographic scores divided horses into those with mild or moderate radiographic OA (16 joints from 9 horses) or controls (13 joints from 9 horses). Direct biomarkers of OA (Carboxypropeptide of type II collagen=CPII, carboxy-neoepitope of type II collagen exposed after collagenase-cleavage=C2C, Bone alkaline phosphatase=BAP and Chondroitin sulfate epitope=CS846) were measured via ELISA and CPII/C2C was calculated. Biomarkers were correlated with radiographic findings and concentrations from those with radiographic OA to control joints and were compared. Concentrations of CPII (R=0.84, P<0.001), C2C (R=0.69, P<0.001) and BAP (R=0.41, P=0.03) as well as CPII/C2C (R=0.69, P<0.001) values positively correlated with overall radiographic scores. Adjusted means±s.d., after controlling for age, for CPII (P<0.001), C2C (P<0.001), CPII/C2C (P=0.004) and BAP (P=0.05) were significantly higher in DIT and TMT joints with radiographic OA (CPII: 2174.45±1064.01; C2C: 233.52±51.187; CPII/C2C: 9.01±4.09; BAP: 21.98±15.34) compared to controls (CPII: 594.53±463.05; C2C: 153.12±48.95; CPII/C2C: 3.96±2.38; BAP: 12.76±3.61). CPII (P<0.001), C2C (P=0.001) and CPII/C2C (P=0.001) were significantly higher with moderate radiographic OA (CPII: 2444.61±772.78; C2C: 248.90±44.94; CPII/C2C: 9.47±2.97) compared to controls (CPII: 658.38±417.36; C2C: 156.49±47.61; CPII/C2C: 4.15±2.04), with CPII also showing significantly higher concentrations (P=0.04) with mild radiographic OA compared (1515.00±584.95) to controls (658.38±417.36). There were no differences in CS846 concentrations between radiographic OA and control joints. Age positively correlated with CPII (R=0.48, P=0.01) and C2C (R=0.44, P=0.02) concentrations. Radiographic OA was assessed, not clinical lameness. Controls were not age-matched to those with spontaneous radiographic OA. There is an association between collagen (CPII, C2C and CPII/C2C) and bone (BAP) biomarkers and radiographic OA in the distal tarsal joints of horses.

Wooden Breast Syndrome in Gastrocnemius Muscle of Roaster Chickens Leading to Muscle-Tendon Rupture and Leg Condemnation

Rupture of the gastrocnemius tendon is a costly challenge for the poultry industry due to bird culling from clinical lameness and leg condemnations at the processing plant. In this case, a broiler chicken producer experienced a dramatic increase in leg condemnations at processing, coinciding with a temporary increase in processing age and weight (from 62 days at 10.25 pounds or 4.66 kg to 67 days at 11 pounds or 5 kg body weight). Gross lesions in the condemned limbs included acute rupture of the gastrocnemius tendon with corresponding hemorrhage and edema. Histologic analysis, however, revealed that the “tendon rupture” observed grossly was in fact due to rupture of the gastrocnemius muscle at the myotendinous junction. The myopathic lesions, as well as the venous inflammation (phlebitis) and lipid infiltrates, observed in the affected tissues were consistent with wooden breast syndrome (WBS), which more typically manifests in the pectoral (breast) muscle. WBS in breast muscle and meat is well recognized as a significant problem in the poultry industry due to economic losses from breast meat condemnation. This report demonstrates that the negative bird health effects and economic impact of WBS are likely far greater than previously understood. Moving forward, WBS myopathy and vasculopathy must now also be considered as a potential cause for clinical lameness, gastrocnemius muscle-tendon rupture, and economic losses from leg condemnation in broiler chickens, particularly in birds raised to roaster weights.

A placebo-controlled study comparing the efficacy of intra-articular injections of hyaluronic acid and a novel hyaluronic acid-platelet-rich plasma conjugate in a canine model of osteoarthritis

BackgroundThe objective of this study was to assess the efficacy of intra-articular injections of hyaluronic acid (HA) and a novel, on-site conjugate of HA with autologous fibrinogen in platelet-rich plasma (HA-PRP) in a canine model of osteoarthritis (OA)MethodsTwelve beagle dogs underwent a unilateral resection of the cranial cruciate ligament (CrCL) of the stifle joint. Clinical and radiographic signs of OA were confirmed in all dogs 8 weeks following CrCL resection and prior to treatment. The dogs were randomized into three groups: saline (n = 4), HA (n = 4), and HA-PRP (n = 4). Each dog received intra-articular injections of the respective substance into the affected joint at pre-determined time points. The dogs were assessed for adverse effects for 3 days after each injection and for lameness, pain, range of motion, kinetics, and radiographic OA severity prior to treatment and 3 months after injection. OA severity as determined by radiographic examination was not significantly different among the groups at any time point. The dogs were then humanely euthanatized and the stifle joint assessed by gross and histological examinations.ResultsDogs treated with four weekly injections of HA or two biweekly injections of HA-PRP were significantly (p < 0.05) better than dogs treated with four weekly injections of saline at 2-, 4-, and 12-week time points based on a comfortable range of motion (CROM) and clinical lameness score. Gait analysis measuring symmetry and weight distribution on pressure sensor walkway showed significantly (p < 0.05) improved limb function for dogs treated with HA and HA-PRP compared with dogs treated with saline yet with better clinical outcome for the HA-PRP-treated group at 12 and 20 weeks follow-up. Gross and histological analysis of synovium and articular cartilage demonstrated significant (p < 0.05) improvement by both treatments groups compared to controls. There was however significantly (p < 0.05) less damage to the cartilage in the HA-PRP group compared to the HA-treated group.ConclusionsThese data suggest that while injection of HA and HA-PRP may be sufficient for short-term amelioration of the symptoms associated with OA, treatment with HA-PRP conjugates may be superior, providing significantly better long-term cartilage preservation.

The use of surface electromyography for quantification of changes in biceps femoris and triceps brachii muscle activity during induced forelimb and hindlimb lameness

Background: Movement asymmetry during lameness has been extensively studied using quantitative gait analysis, but limited information exists about adaptive muscle activity occurring during lameness. Objectives: To investigate whether asymmetric muscle activity occurs in superficial pelvic and thoracic limb muscles before and after induced forelimb (FL) and hindlimb (HL) lameness using surface electromyography (sEMG). Study Design: Experimental. Methods: sEMG sensors were attached bilaterally above Biceps Femoris (BF) and Triceps Brachii (TB) in a preliminary sample of five clinically non-lame horses. sEMG and 3D-kinematic data were collected during in-hand trot. FL and HL lameness (2-3/5 AAEP) were induced on separate days using a modified horseshoe, with baseline data initially collected each day. To quantify lameness, MinDiff was calculated from poll (HDMin) and pelvis (PDMin) vertical displacement for FL and HL lameness, respectively. Raw sEMG signals were DC-offset removed, high-pass filtered, and full-wave rectified. Integrated EMG (iEMG) was calculated using stride duration as the temporal domain. iEMG from each horse were normalised to the maximum observed value of individual muscles in the baseline condition. The difference between right and left iEMG values for each muscle were calculated for each stride to quantify muscle asymmetry (iEMGDiff). Repeated measures ANOVA compared iEMGDiff data for each muscle between conditions (baseline, induced FL and HL lameness). Results: Absolute mean±sd for HDMin (61.6±27.1) and PDMin (16.0±9.1) were congruent with the degree of induced lameness. Mean±sd baseline iEMGDiff was 14.2±5.7 across both muscles. BFiEMGDiff was significantly greater than baseline (15.2±6.9 vs. 80.9±46.1, p<0.05, pn2=0.704) during HL lameness and TBiEMGDiff during FL lameness (10.0±1.7 vs. 40.7±18.7, p<0.05, pn2=0.754). Main Limitations: Clinical lameness cases must confirm findings. Conclusions: FL and HL lameness cause differential increases in iEMG asymmetry in TB and BF. sEMG symmetry parameters could help understand neuromuscular adaptations to lameness and could compliment kinematic methods for objective lameness evaluation.

Association of lameness and mastitis with return-to-service oestrus detection in the dairy cow

Oestrus detection is an important part of maintaining efficient reproductive performance in dairy herds. Both lameness and mastitis are common diseases of dairy cows that may impact oestrus detection. A...

Effect of meloxicam treatment on movement asymmetry in riding horses in training.

Quantitative gait analysis has revealed that a large proportion of horses in training, perceived as free from lameness by their owners, show movement asymmetries of equal magnitude to horses with mild clinical lameness. Whether these movement asymmetries are related to orthopaedic pain and/or pathology has yet to be further investigated. Therefore, the objective of this study was to determine whether movement asymmetries in riding horses in training are affected by anti-inflammatory treatment with meloxicam. In a crossover design, horses were treated with meloxicam or placebo for four days respectively, with a 14–16 day washout period between treatments. Objective movement analysis utilising body mounted accelerometers was performed on a hard and a soft surface before and on day four of each treatment. A trial mean was calculated for the differences between the two vertical displacement minima and maxima of head (HDmin, HDmax) and pelvis (PDmin, PDmax) per stride. Horses (n = 66) with trial mean asymmetries greater than 6 mm for HDmin or HDmax, or more than 3 mm for PDmin or PDmax, at baseline were included. The difference before and after each treatment in the measured movement asymmetry was assessed with linear mixed models. Treatment with meloxicam did not significantly affect the movement asymmetry in any of the models applied (all p>0.30). These results raise new questions: are the movement asymmetries in riding horses in training simply expressions of biological variation or are they related to pain/dysfunction that is non-responsive to meloxicam treatment?

Clinical outcomes and complications of pancarpal arthrodesis stabilised with 3.5 mm/2.7 mm locking compression plates with internal additional fixation in 12 dogs

ABSTRACTAimsTo report the clinical outcomes and complications after the use of 3.5 mm/2.7 mm locking compression plates (LCP) with additional internal fixation for pancarpal arthrodesis (PCA) in dogs.MethodsThis was a retrospective study using medical records from a single orthopaedic referral hospital between December 2015 and April 2018. The inclusion criteria were the use of a dorsally applied LCP for PCA in dogs with a minimum follow-up period of 12 months. Additional crossed 2.7 or 3.5 mm cortical screws or Kirschner wires were placed in all limbs to further stabilise the joints. A light dressing without external coaptation was applied postoperatively to all limbs. Postoperative lameness assessment was recorded at the last clinical evaluation.ResultsTwelve dogs with 13 arthrodesed limbs were included, with carpal hyperextension injury being the most common indication for surgery (4/13; 31%). One dog was recorded with a minor complication, which was a metacarpal fracture distal to the bone plate. Major complications were observed in 4/13 (31%) limbs, with surgical site infection being recorded in all four limbs and screw loosening in one limb. No implant failure was reported. At the final clinical evaluation (43–437 days after surgery), none or mechanical lameness was recorded in 9/13 (69%) limbs, mild lameness in 3/13 (23%) limbs, and moderate lameness in one 1/13 (8%) limb.Conclusions and clinical relevanceLocking plate and screw fixation with additional internal fixation resulted in comparable complication and infection rates in canine PCA to previous published studies using hybrid dynamic compression plates. No implant failure was reported for any of the limbs despite the use of a light dressing without external coaptation.

Administration of enrofloxacin during late pregnancy failed to induce lesions in the resulting newborn foals.

A recent study demonstrated that enrofloxacin and ciprofloxacin cross the equine placenta without causing gross cartilage or tendon lesions in the 9-month fetus; however, long-term effects of in utero fluoroquinolone exposure remain unknown. To assess effects of fetal exposure to enrofloxacin on the resulting foal's cartilage and tendon strength. Healthy mares at 280days' gestation were allocated into four groups: untreated (n=5), therapeutic treatment (7.5mg/kg enrofloxacin, PO×14days, n=6), supratherapeutic treatment (15mg/kg, PO×14days, n=6) and no mare treatment with treatment of the foals post-partum (n=2). Mares were allowed to carry pregnancy to term, and foals were maintained on pasture for 5weeks. After that foals were euthanized, and their articular cartilage and extensor and flexor tendons were examined macroscopically and histologically for lesions. Tendon strength was tested by loading until failure. Administration of enrofloxacin at recommended doses in late gestation did not result in cartilaginous lesions or clinical lameness in any foal by 5weeks old. Tensile strength was greater in hind tendons than front tendons, but no difference was found between foals born from treated and control mares. Expectedly, osteochondral changes were present both in foals born from enrofloxacin-treated mares and in negative control foals with no apparent association with fluoroquinolone treatment during pregnancy. Only one time point in gestation was evaluated, and mares treated in the study were healthy at time of treatment. Additionally, it is possible that the assessments performed herein were not sensitive enough to detect subtle or functional changes in the articular cartilage. Further studies are needed to determine if enrofloxacin administration during late pregnancy potentiates osteochondral alterations in the first year of life. While this study did not assess other stages of gestation or long-term foal outcomes, short-term administration of enrofloxacin to late gestation mares did not result in macroscopic or microscopic lesions in the resulting foals by 5weeks of age.

Lameness and lying behavior in grazing dairy cows

Lameness is a serious welfare issue for dairy cows. To date, the majority of studies have focused on its effect on health and behavior at the herd level. The objectives of this study were to identify (1) between-cow and (2) within-cow changes in lying behavior associated with consistent and changing lameness status in grazing dairy cows. Previous studies of lying behavior in grazing dairy cows have not considered the effect of precipitation, so a third aim was to determine the effect of precipitation on lying behavior. A total of 252 dairy cows from 6 pasture-based farms in southern Brazil were gait scored weekly to assess lameness using a 5-point scale [1-5, numerical rating score (NRS)] for 4 consecutive weeks. Cows were considered to have consistent lameness if they were scored as lame (NRS ≥3) on each of the 4 visits and considered to have a changing lameness status if scored as being nonlame (NRS <3) on at least 1 of the 4 visits. Cows classified as having a changing lameness status were further classified as developed, recovered, or inconsistent. Lying behavior (daily lying time, mean lying bout duration, and daily number of lying bouts) was recorded continuously for 3 wk using leg-mounted accelerometers. Cow-level variables included parity, days in milk, and body condition score. Regional precipitation and temperature were recorded hourly. Because only 1 primiparous cow was identified as lame at each of the 4 visits, the between-cow analysis of lameness was run on multiparous cows only. The overall prevalence of clinical lameness on the first visit was 39%, with development and recovery rates of 16 and 10% over the 4 visits, respectively. The between-cow effect of consistent lameness status on daily lying time and number of lying bouts was dependent on precipitation; consistently lame cows had reduced lying time and lying bouts on days with rain compared with days without rain. There was no within-cow effect of changing lameness status on any of the lying behaviors. Precipitation was associated with decreased daily lying time, increased mean lying bout duration, and decreased daily number of lying bouts. The results of this research provide the first evidence that the effect of consistent lameness status on lying behavior is associated with rainfall in grazing dairy cows. Future work measuring lying behavior of grazing dairy cows should include precipitation as a covariate.

Lateral Radial Head Subluxation as a Complication Following Proximal Ulnar Osteotomy or Ostectomy in Eight Dogs.

The aim of this study was to report the complication of lateral radial head subluxation following proximal ulnar osteotomy (PUOO) or proximal ulnar ostectomy (PUOE) in eight dogs. Case records and diagnostic imaging of dogs developing lateral radial head subluxation following PUOO (n = 7) or PUOE (n = 2) were retrospectively reviewed. Information pertaining to clinical history, signalment, presenting condition, lameness grade, diagnostic imaging and initial surgery details, postoperative complications and their management were retrieved. Outcomes were established from subsequent clinical histories or telephone interviews with referring veterinarians. Comparison was made to a single-centre cohort without lateral radial head subluxation following PUOO or PUOE. Eight dogs (median age: 9.5 months [range: 6 months-6 years], median weight 7.7 kg [range: 5-28 kg]) were included. Six dogs had a PUOO performed; five dogs had unilateral surgery and one had bilateral surgery. Two dogs had unilateral PUOE surgery. Median time to diagnosis of lateral radial head subluxation following surgery was 6.5 weeks (range: 2-20 weeks). Five of the eight dogs had surgical revision of lateral radial head subluxation. Resolution of lateral radial head subluxation was achieved in four dogs, with three achieving acceptable to good mobility. One dog had poor postoperative mobility. A fifth dog remained lame after revision surgery failure. Three dogs did not have revision surgery; two underwent limb amputation and one dog remained lame as revision surgery was declined. Lateral radial head subluxation is a potentially severe postoperative complication following PUOO or PUOE.

Diagnosis of subclinical ketosis in dairy cows

Ketosis is a common disease in high producing dairy cows during the early lactation period. Subclinical ketosis (SCK) and periparturient diseases considerably account for economic and welfare losses in dairy cows. Subclinical ketosis poses an increased risk of production-related diseases such as clinical ketosis, displaced abomasum, retained placenta, lameness, mastitis and metritis. Production efficiency decreases (lower milk production, poor fertility, and increased culling rates), which results in economic losses. Increased concentrations of circulating ketone bodies, predominantly ?-hydroxybutyrate (BHB), without the presence of clinical signs of ketosis are considered as SCK. It is characterized by increased levels of ketone bodies in the blood, urine and milk. The gold standard test for ketosis is blood BHB. This ketone body is more stable in blood than acetone or acetoacetate. The most commonly used cut-points for subclinical ketosis are 1.2 mmol/L or 1.4 mmol/L for BHB in the blood. Clinical ketosis generally involves much higher levels of BHB, about 3.0 mmol/L or more. Usually, detection of SCK is carried out by testing ketone body concentrations in blood, urine and milk. A variety of laboratory and cowside tests are available for monitoring ketosis in dairy herds. But no cowside test has perfect sensitivity and specificity compared to blood BHB as the gold standard test. The aim of this review is to overview diagnostic tests for SCK in dairy cows, including laboratory and cowside tests.

The first detection of the sequence of bacteria from the Simkaniaceae family in surface waters in Poland.

One of the most common reasons for horse lameness is subchondral bone cysts (SBCs), which are especially evident in young horse athletes. It is believed that SBC development is strongly associated with an individual's bone growth and/or bone microstructure impairment. Current methods of SBC treatment include pharmacological treatment or surgical procedures which may allow the bone within the cyst to rebuild and be restored to properly developed bone tissue. Thus, we propose filling the SBCs with a 3D complex of alginate hydrogel and autologous adipose derived mesenchymal stem cells (ASCs). We have observed at the in vitro level, that this hydrogel complex induces osteogenic and chondrogenic differentiation potential through the upregulation of bone morphogenetic protein, osteopontin, collagen type I and aggrecan mRNA levels. Moreover, we detected the creation of a 3D extracellular matrix (EM). To investigate the complex in vivo, we chose 8 horses of varying age suffering from SBC, which resulted in lameness, to undergo experimental surgery. We documented the horses' clinical appearance, lameness and radiographic appearance, to determine that there was clinical improvement in 87.75% of the patients (n=7, out of 8 horses) 6 months postoperatively and 100% (n=8, out of 8 horses) a year after surgery. These results are promising for the potential of this procedure to become the standard in SBC treatment.

Generation of an equine biobank to be used for Functional Annotation of Animal Genomes project.

The Functional Annotation of Animal Genomes (FAANG) project aims to identify genomic regulatory elements in both sexes across multiple stages of development in domesticated animals. This study represents the first stage of the FAANG project for the horse, Equus caballus. A biobank of 80 tissue samples, two cell lines and six body fluids was created from two adult Thoroughbred mares. Ante-mortem assessments included full physical examinations, lameness, ophthalmologic and neurologic evaluations. Complete blood counts and serum biochemistries were also performed. At necropsy, in addition to tissue samples, aliquots of serum, ethylenediaminetetraacetic acid (EDTA) plasma, heparinized plasma, cerebrospinal fluid, synovial fluid, urine and microbiome samples from all regions of the gastrointestinal and urogenital tracts were collected. Epidermal keratinocytes and dermal fibroblasts were cultured from skin samples. All tissues were grossly and histologically evaluated by a board-certified veterinary pathologist. The results of the clinical and pathological evaluations identified subclinical eosinophilic and lymphocytic infiltration throughout the length of the gastrointestinal tract as well as a mild clinical lameness in both animals. Each sample was cryo-preserved in multiple ways, and nuclei were extracted from selected tissues. These samples represent the first published systemically healthy equine-specific biobank with extensive clinical phenotyping ante- and post-mortem. The tissues in the biobank are intended for community-wide use in the functional annotation of the equine genome. The use of the biobank will improve the quality of the reference annotation and allow all equine researchers to elucidate unknown genomic and epigenomic causes of disease.

Effect of tetramethyl thiuram disulfide (thiram) in relation to tibial dyschondroplasia in chickens.

Tetramethyl thiuram disulfide (thiram) is one of the important pesticides, which is extensively used in agriculture, but if it is combined with the cell membrane, then it causes membrane damage, bone morphogenic inactivation, and inhibited angiogenesis. Thiram has been considered a common cause of tibial dyschondrolplasia (TD) in various avian species, because it becomes the part of feed due to environmental contamination and its overuse in agriculture as pesticides or fungicide. However, there is no systematic study on the changes of the correlation indexes with toxic effect of the thiram in chickens. Therefore, we evaluated the toxic effects of thiram on growth performance of chickens, viscera organ index, pathological changes in tissue, and gene expression associated with osteoblast differentiation, vascularization, and tibial bone development. For this study, 1-day chickens (n = 300) were randomly distributed into two equal groups, control group (normal basal diet) and thiram group (adding thiram 40mg/kg in basal diet). The result presented that thiram group chickens were looking unhealthy, lazy, and showing clinical symptoms like lameness. Thiram treatment significantly reduced the performance of chickens, liver index, and tibial length compared with control group. The toxic effect of thiram increased the visceral organ index (spleen and cardiac), tibia index, and TD severity considerably. It also increased serum Ca2+ and P3+ concentration and decreased tibial density compared to control chickens but the difference was not significant. Histopathology of tibia and liver showed that there were severe lesions due to toxic effect of thiram. Furthermore, HIF-1α and VEGF antibody localizations were increased and WNT4 localization was reduced significantly in immunohistochemical analysis. This systemic study of toxic effects of thiram in chicken concluded that thiram reduced the growth performance of chickens through decreasing liver index, whereas increasing kidney, cardiac, and spleen index, and induced TD by changing the expressions of VEGF, HIF-1α, and WNT4.

Evaluation of Mastitis Impact on Lameness and Digital Lesions in Dairy Cows

AbstractObjective: This current study was done to find any correlation between clinical mastitis and lameness occurrence and incidence in dairy farms.Design: This prospective field trial was done on a case control study basis. Cows were divided into two mastitis and control group and lameness recorded and compared in both groups.Procedures: This current study was done during 9 month in a dairy herd with 800 milking cows. The mastitis scoring system was based on the International Dairy Federation definitions of mastitis severity from one to three. All cows were trimmed two times annually and also high locomotion score, lame and long toe cows referred for possible inspection and treatment. Records of sole ulcer (SU), white line disease (WLD), Toe Ulcer (TU), heel erosion (HE), digital dermatitis (DD) and interdigital necrobacillosis (INB) were assessed in this study. Data of the lesions up to three month after occurrence of mastitis was followed. 543 cows affected with mastitis were allocated to treatment and the same amount of the cows that didn’t show any mastitis during past three month allocated to control group.Results: Occurrence of mastitis reduce incidence of digital dermatitis significantly. Lameness except digital dermatitis were higher in mastitis group than control group (P<0.05).Conclusion and Clinical Relevance: Mastitis can play a role in occurrence of claw horn lesions (CHL) and any control program of lameness in the herds with high incidence of CHL should precede with control program of other predisposing or causative factors of this condition. Mastitis besides other infectious causes as a predisposing factor can play a significant role on lameness.

Subchondral bone cyst surgical treatment using the application of stem progenitor cells combined with alginate hydrogel in small joints in horses.

One of the most common reasons for horse lameness is subchondral bone cysts (SBCs), which are especially evident in young horse athletes. It is believed that SBC development is strongly associated with an individual's bone growth and/or bone microstructure impairment. Current methods of SBC treatment include pharmacological treatment or surgical procedures which may allow the bone within the cyst to rebuild and be restored to properly developed bone tissue. Thus, we propose filling the SBCs with a 3D complex of alginate hydrogel and autologous adipose derived mesenchymal stem cells (ASCs). We have observed at the in vitro level, that this hydrogel complex induces osteogenic and chondrogenic differentiation potential through the upregulation of bone morphogenetic protein, osteopontin, collagen type I and aggrecan mRNA levels. Moreover, we detected the creation of a 3D extracellular matrix (EM). To investigate the complex in vivo, we chose 8 horses of varying age suffering from SBC, which resulted in lameness, to undergo experimental surgery. We documented the horses' clinical appearance, lameness and radiographic appearance, to determine that there was clinical improvement in 87.75% of the patients (n=7, out of 8 horses) 6 months postoperatively and 100% (n=8, out of 8 horses) a year after surgery. These results are promising for the potential of this procedure to become the standard in SBC treatment.

Development of an equine carpal groove model to study early changes in osteoarthritis - a pilot study

Purpose: The cartilage groove model has been shown to be an effective model for investigation of early degenerative joint changes in various animal models, including recently in the equine metacarpophalangeal (MCP) joint. In this pilot study, we investigated: 1) if the groove model induces comparable cartilage degeneration in the equine middle carpal as in the MCP joint and 2) if a modified method for disrupting the collagen network without tissue loss, in combination with loading, also leads to cartilage degeneration. Methods: In two adult Shetland ponies, the dorsal aspect of the condyles of the third metacarpal bone (MCP joint) and the proximal surface of the radial facet of the third carpal bone (middle carpal joint) were grooved as described in the literature, using a hooked arthroscopic probe with a sharpened tip (“blunt grooves”). In the contra-lateral limb, grooves were made with a surgical mini blade that was clamped in a custom-made device (“sharp grooves”). After two weeks of box rest, the ponies were subjected to an eight-week training protocol on a treadmill. Clinical lameness was evaluated weekly. Synovial fluid was collected from the middle carpal joint before surgery and at two and 10 weeks postoperatively for analysis of glycosaminoglycan (GAG) levels and matrix metalloproteinase (MMP) activity. At 10 weeks, ponies were euthanized and osteochondral samples harvested for macroscopic, histologic and gene expression analysis of matrix components. Additionally, “fresh” grooves were made in the MCP and middle carpal joints of cadaver limbs to compare the microscopic appearance of grooves with and without a period of in vivo loading. Results: After 6-8 weeks post-operatively, regular stumbling and mild lameness were observed in both ponies during training. Macroscopically, grooves made by both techniques could be identified and adjacent tissue was affected, mainly in the carpal joints. Safranin-O stained histology sections clearly showed degenerative changes for cartilage with blunt grooves (i.e., loss of staining, fibrillation and cell clustering around the lesions), whereas only very mild changes were observed in cartilage with sharp grooves (Fig.1). Microscopy scores in both blunt and sharp grooved joints were higher at 10 weeks (12.4 and 7.3, respectively) compared with grooved cadaver joints (5.5 and 3.0) according to the OARSI equine microscopic grading system. Synovial fluid GAG concentrations dropped dramatically at two weeks after surgery, whereas MMP activity showed a clear increase. However, at 10 weeks, both markers returned to approximately baseline levels (Fig. 2). Carpal cartilage showed an upregulation of collagen 2, aggrecan and COMP, particularly where blunt grooves were made (Fig. 3). Conclusions: The groove model can be used in the equine carpus for the induction of cartilage degeneration. Contrary to the current paradigm, only disruption of the collagen network seemed not to lead to cartilage degeneration within 10 weeks after surgery. This would imply a crucial role for tissue loss. Synovial fluid GAG concentration and MMP activity do not seem to be sensitive markers once the initial inflammatory reaction has disappeared. A more extensive “omics-approach” could provide a better reflection of subtle changes in joint homeostasis in this early stage of degenerative joint changes. Confirmation in a larger number of animals is necessary, as is research on the long-term fate of the sharp lesions.