Increased ILC3s associated with higher levels of IL-1ß aggravates inflammatory arthritis in mice lacking phagocytic NADPH oxidase.

The role of redox regulation in immune-mediated arthritis has been previously described. However, the relationship between innate immune cells, including innate lymphoid cells (ILCs) and phagocyte-derived ROS, in this process remains unclear. Here, we characterize ILCs and measure the IL-1 family cytokines along with other cytokines relevant to ILC functions and development in serum-induced arthritic joints in wild type and phagocytic NADPH oxidase (NOX2)-deficient Ncf1-/- mice. We found more severe serum-induced joint inflammation and increased NCR+ ILC3s in inflamed joints of Ncf1-/- mice. Furthermore, in vitro stimulation with IL-1ß on Tbet+ ILC1s from joints facilitated their differentiation into ROR-γt+ ILC3s. Moreover, treatment with IL-1 antagonists effectively lowered the proportions of NCR+ ILC3s and IL-17A producing ILC3s in Ncf1-/- arthritic mice and ameliorated the joint inflammation. These results suggest that NOX2 is an essential regulator of ILC transdifferentiation and may mediate this process in a redox-dependent manner through IL-1ß production in the inflammatory joint. Our findings shed important light on the role of ILCs in the initiation and progression in tissue inflammation and delineate a novel innate immune cell-mediated pathogenic mechanism through which redox regulation may determine the direction of immune responses in joints.

Distinct Roles of Interferon Alpha and Beta in Controlling Chikungunya Virus Replication and Modulating Neutrophil-Mediated Inflammation.

Type I interferons (IFNs) are key mediators of the innate immune response. Although members of this family of cytokines signal through a single shared receptor, biochemical and functional variation exists in response to different IFN subtypes. While previous work has demonstrated that type I IFNs are essential to control infection by chikungunya virus (CHIKV), a globally emerging alphavirus, the contributions of individual IFN subtypes remain undefined. To address this question, we evaluated CHIKV pathogenesis in mice lacking IFN-ß (IFN-ß knockout [IFN-ß-KO] mice or mice treated with an IFN-ß-blocking antibody) or IFN-α (IFN regulatory factor 7 knockout [IRF7-KO] mice or mice treated with a pan-IFN-α-blocking antibody). Mice lacking either IFN-α or IFN-ß developed severe clinical disease following infection with CHIKV, with a marked increase in foot swelling compared to wild-type mice. Virological analysis revealed that mice lacking IFN-α sustained elevated infection in the infected ankle and in distant tissues. In contrast, IFN-ß-KO mice displayed minimal differences in viral burdens within the ankle or at distal sites and instead had an altered cellular immune response. Mice lacking IFN-ß had increased neutrophil infiltration into musculoskeletal tissues, and depletion of neutrophils in IFN-ß-KO but not IRF7-KO mice mitigated musculoskeletal disease caused by CHIKV. Our findings suggest disparate roles for the IFN subtypes during CHIKV infection, with IFN-α limiting early viral replication and dissemination and IFN-ß modulating neutrophil-mediated inflammation.IMPORTANCE Type I interferons (IFNs) possess a range of biological activity and protect against a number of viruses, including alphaviruses. Despite signaling through a shared receptor, there are established biochemical and functional differences among the IFN subtypes. The significance of our research is in demonstrating that IFN-α and IFN-ß both have protective roles during acute chikungunya virus (CHIKV) infection but do so by distinct mechanisms. IFN-α limits CHIKV replication and dissemination, whereas IFN-ß protects from CHIKV pathogenesis by limiting inflammation mediated by neutrophils. Our findings support the premise that the IFN subtypes have distinct biological activities in the antiviral response.

Histologically validated scoring system for the assessment of hock burn in broilers.

The assessment of bird-based welfare indicators plays an important role in the evaluation of bird welfare. The aim of the study was to histologically validate a visual scoring system for hock burn in broilers and to detect threshold values of a visual score to define welfare-relevant alterations in terms of mild lesions or ulcers of the hock. We collected 200 hocks of 39- to 42-day-old Ross 308 broilers after the slaughter process. Each hock was scored visually ("macro scores" 0-4) and evaluated histologically ("micro scores" 0-3), with high scores representing more severe lesions. Although we found a tendency for higher micro scores with increasing macro scores, an exact allocation of macro to micro scores was not possible. For example, macro score 1 could represent micro scores 1, 2 and 3, whereas macro scores 3 and 4 always represented micro score 3 (ulcer). The conditional probability of certain micro scores for given macro scores was estimated using a multinomial logistic regression model. Ulcer showed the highest probability at macro score 1, whereas mild lesions were not found to have an estimated highest probability at any macro score. The depth of inflammation of hock burn lesions increased with increasing macro scores up to macro score 3 with an average depth of 1019 µm. Visually more severe and deeper lesions were also histologically rated with higher scores. Thus, considering limitations, the herein validated macroscopic assessment scheme for hock burn allows an estimation of histological alterations in hocks of broilers.RESEARCH HIGHLIGHTS Histological validation of a visual assessment scheme for hock burn in broilers.Tendency for higher micro scores with increasing macro scores.Estimation of histological score via macro score possible with limitations.Histological depth of inflammation increased with an increasing macro score.

Short communication: Accuracy of estimation of lameness, injury, and cleanliness prevalence by dairy farmers and veterinarians.

Lameness, injuries, and cleanliness are considered important indicators of dairy cow welfare, milk production, and milk quality. Previous research has identified that farmers globally underestimate the prevalence of these cow-based measurements, but no information on the perceptions of veterinarians is available. Because veterinarians are often perceived as the main providers of health advice on farms, the objective of the present study was to evaluate the relationship between the true prevalence of lameness, injury (hock, knee, neck), and cleanliness (udder, legs, flanks), and the estimated prevalence of these issues by farmers and their herd veterinarians. A cross-sectional study was conducted between February 2016 and July 2017. First, the farm owner and the herd veterinarian were asked to estimate the prevalence of lameness, of neck, knee and hock injuries, and of udder, leg, and flank cleanliness on the farm. The research team then visited the farm and scored all lactating cows in the herd for each measurement. Linear regression models were used to assess the relationship between the prevalence estimated by the veterinarians and the farmers, of each cow-based measurement, and the true prevalence on the farm. The 93 herds enrolled had a median of 55 milking cows and were housed in tiestall (90%) and freestall (10%) barns. Ten herd veterinarians participated and were involved with 2 to 22 enrolled farms each. A wide variation was detected in the true prevalence of the different cow-based measurements among herds (lameness: range = 19-72%, median = 36%; neck injuries: range = 0-65%, median = 14%; knee injuries: range = 0-44%, median = 12%; hock injuries: range = 0-57%, median = 25%; dirty udder: range = 0-55%, median 13%; dirty legs: range = 0-91%, median = 18%; and dirty flanks: range = 0-82%, median = 20%). For both veterinarians and farmers, the perception of each cow-based measurement prevalence increased incrementally as the herd's true prevalence increased. Overall, farmers and veterinarians underestimated cow-based measurements. Farmers and veterinarians more accurately estimated lameness prevalence in herds with higher prevalence than in herds with low prevalence, suggesting a better awareness of the issue on farms with lameness problems. Injuries were less accurately estimated in herds with higher injury prevalence compared with herds with lower prevalence, suggesting an opportunity for better knowledge transfer in this area.

Prevalence of hock, knee, and neck skin lesions and associated risk factors in dairy herds in the Maritime Provinces of Canada.

Skin lesions are commonly seen in dairy herds and have been associated with animal-, environmental-, and management factors. These lesions are not only a welfare concern, but they also affect profitability. Three areas on the cattle were examined for skin lesions: the hock, knee, and neck. Previous Canadian studies estimating the prevalence of lesions and the risk factors associated with them have not included the Maritime Provinces. In this study, 73 herds in the Maritime Provinces were chosen voluntarily to participate, with both tiestalls (n = 33) and freestalls (n = 40) represented. Within each herd, 67 to 90% of the lactating cows were selected and assessed for potential animal-, environmental-, and management-based risk factors. If producers were aware of the potential risk factors, this could help them reduce the prevalence in their herd. Leg lesions were scored on a 4-point scale (0-3) based on hair loss, swelling, and scabs, with a lesion defined as a score of 2 or 3 on at least 1 hock or knee. Necks were scored on a 3-point scale (0-2), with a lesion defined as score 2. For freestalls, the prevalence (95% confidence interval) of hock lesions was 39% (29-49%), knee lesions was 14% (11-18%), and neck lesions was 1% (<1-2%). Similarly, for tiestalls the prevalence (95% confidence interval) of hock lesions was 39% (33-46%), knee lesions was 17% (13-22%), and neck lesions was 5% (3-8%). Due to differences in management and methods of assessment between facility types, tiestalls and freestalls were analyzed separately. Due to dichotomization of cows as having a skin lesion or not, random-effects multivariable logistic regression was used to determine the risk factors for each lesion and facility type. Several environmental-based measurements, such as the stall base, type and dryness of bedding, and type of milking parlor, were associated with leg lesions. An environmental-based measurement that was associated with neck lesions was the design of the feed rail barrier in freestalls and the dimensions of the tie rail in tiestalls. Animal-based risk factors, such as stage of lactation, parity, and body condition, were also associated with all 3 types of lesions. This study showed that lesions to the hock, knee, and neck were common in the Maritime Provinces of Canada. Although differences were seen between facility types, in general, the results suggest that improving stall design and management and feed bunk design would help producers reduce the number of skin lesions seen in dairy cattle.

Prevalence of osteochondral lesions in the fetlock and hock joints of Standardbred horses that survived bacterial infection before 6 months of age.

BACKGROUND: Young Standardbred horses frequently develop fragments in joints. Some fragments represent osteochondrosis; others are considered developmental, but it is uncertain whether they result from preceding osteochondrosis. Osteochondrosis occurs as a consequence of failure of the cartilage canal blood supply and ischaemic chondronecrosis. In heritably predisposed foals, failure was associated with incorporation of vessels into bone. However, bacterial vascular failure was also recently documented in foals suffering spontaneous infections, proving that bacteria can cause osteochondral lesions in foals up to 150 days old. The aim was to determine prevalence of fetlock and hock lesions at screening age in Standardbred horses that survived infections before 6 months of age, and compare this to prevalence reported in the literature. METHODS: The material consisted of 28 Standardbred horses; 17 males and 11 females that presented and were diagnosed clinically with bacterial infections from 1 to 150 days of age (average: 41.3 days). A screening set of 8 radiographic projections was available from all 28 horses at 7-85 months of age (average: 23.6 months). Lesion prevalence was compared to three previously reported Standardbred cohorts. RESULTS: Osteochondral lesions were detected in one or more joints of 19/28 horses (67.9%); in the fetlock joint of 14/28 horses (50%) and the hock joint of 11/28 horses (39.3%). These prevalences were ≥ 2 x higher than the corresponding prevalences in the comparison cohorts, and statistically significantly so in 5:6 comparisons (p-values from < 0.00001 to 0.01). In the sepsis cohort, there were an average of 2.3 affected joints and 2.5 lesions per affected horse, whereas there in the one comparable literature cohort were an average of 1.5 affected joints and 1.7 lesions per affected horse. CONCLUSIONS: Standardbred horses that survived bacterial infections before 6 months of age had more osteochondral lesions than literature comparison cohorts at screening age. The implication was that some of the lesions in this group were caused by bacteria. It may become necessary to develop methods for differentiating between acquired, septic and aseptic, heritably predisposed lesions.

High field magnetic resonance imaging contributes to diagnosis of equine distal tarsus and proximal metatarsus lesions: 103 horses.

Injury of the distal tarsus and proximal metatarsus commonly causes lameness. Magnetic resonance imaging (MRI) allows concurrent assessment of both the distal tarsal joints and suspensory ligament origin, and aids identification of lesions that may otherwise go undetected by other modalities. In this retrospective observational study, the medical records of a veterinary imaging center were searched for MRI exams of the distal tarsus and proximal metatarsus for the years 2012 through 2014. Studies for 125 limbs of 103 horses were identified and retrospectively evaluated by two board-certified veterinary radiologists. Soft tissue and osseous changes were characterized and graded by degree of severity. The patients' signalment, lameness severity, and results of diagnostic analgesia were recorded. Osteoarthritic changes of the distal intertarsal and tarsometatarsal joints were the most common findings. Other findings included bone marrow lesions, degenerative changes of the small cuboidal bones, subchondral cystic lesions, and intertarsal desmopathy. Suspensory ligament desmopathy was found in 53% of limbs. Fourty-seven percent of limbs that responded to analgesia of the proximal suspensory ligament had more severe lesions in the distal tarsus. Bone marrow lesions of the third tarsal bone were the only MRI finding that correlated with grade of lameness in patients for which lameness grade was reported. The grade of lameness has a poor correlation with the severity of lesions found on MRI. The findings support the use of MRI for simultaneous evaluation of the proximal metatarsus and distal tarsus, particularly given the difficulty of lesion localization with diagnostic analgesia.

Anterior wrist and medial malleolus: the optimal sites for tissue selection in electric death through hand-to-foot circuit pathway.

Specific morphological changes may be absent in some cases of electrocution shocked by the voltage of 220 V or lower. In this study, we attempted to demonstrate that the anterior wrist and medial malleolus were the optimal sites with promising and significant changes in electric death through the hand-to-foot circuit pathway. We established an electric shock rat model and observed histopathologic changes in the anterior wrist and medial malleolus. The results showed that the current intensities in the left anterior wrist and right medial malleolus were remarkably higher than those in the other sites, and the nuclei long/short (L/S) axis ratios of the arterial endotheliocyte and the skeletal muscle cell in these two areas were significantly higher than those in other parts of the body. These findings suggested that the anterior wrist and/or medial malleolus soft tissues as the narrowest parts of the limbs could be used as promising and useful sites for the assessment of electrical shock death, especially in forensic pathologic evaluation.

High dietary biotin levels affect the footpad and hock health of broiler chickens reared at different stocking densities and litter conditions.

Responses to stocking density (SD), dietary biotin concentration and litter condition were evaluated on 2016 Ross 308 male broilers in the fattening period (day 22-day 42). The birds were placed in 48 pens with either dry or wet litter to simulate the final stocking density of 30 kg (12 broilers/m2 ; normal stocking density, NSD) and 40 kg (16 broilers/m2 ; high stocking density, HSD) of body weight (BW)/m2 floor space. A corn-soybean meal-based diet was supplemented with biotin to provide a normal (NB; 155 µg/kg) or high (HB, 1521 µg/kg) level of dietary biotin. There were six repetitions per treatment. The inappropriate moisture content of litter associated with HSD was avoided (p < 0.05) by good management (SD difference: dry litter, 6.65% vs. wet litter, 13.23%; 42 days), which made it advantageous (p < 0.01) for footpad (SD difference: dry litter, 0.118 vs. wet litter, 0.312; weekly average value) and hock health (SD difference: dry litter, 0.090 vs. wet litter, 0.303; weekly average value) of HSD birds, but not (p > 0.05) for growth and processing yield. In HSD, the biotin effect (gains, FCR) was significantly higher (p < 0.01) than in NSD. The similar response of HSD birds to supplemental biotin was observed (p < 0.05) for lesion scores of footpad and hock in particularly finishing chickens, and a significant interaction (p < 0.01) among stocking density, biotin supplementation and litter condition existed from 35 to 42 days of age. Taken together, increasing dietary biotin improves the performance and well-being of broiler chickens stocked at high densities in litter-independent and litter-dependent manners respectively.

Surgical Management of Osteochondrosis in Foals.

Osteochondrosis is common in young, athletic horses. Some lesions respond to conservative therapy. Surgical management is the mainstay of treatment. Arthroscopic debridement is useful in the femoropatellar joint, tarsocrural joint, fetlock joint, and shoulder joint. Debridement is associated with good outcomes, except in the shoulder joint. Osteochondrosis lesions in the elbow may be difficult to access arthroscopically, thereby transosseous debridement. Surgical management of subchondral cystic lesions of the medial femoral condyle consists of debridement, debridement with grafting, transcondylar screws, and intralesional corticosteroid injection. Surgical management is indicated with lameness and persistent effusion, and in many horses intended for athletic use.

Berberis aristata Ameliorates Adjuvant-Induced Arthritis by Inhibition of NF-κB and Activating Nuclear Factor-E2-related Factor 2/hem Oxygenase (HO)-1 Signaling Pathway.

The present study was carried out to investigate the anti-arthritic activity of Berberis aristata hydroalcoholic extract (BAHE) in formaldehyde-induced arthritis and adjuvant-induced arthritis (AIA) model. Arthritis was induced by administration of either formaldehyde (2% v/v) or CFA into the subplantar surface of the hind paw of the animal. In formaldehyde-induced arthritis and AIA, treatment of BAHE at doses 50, 100 and 200 mg/kg orally significantly decreased joint inflammation as evidenced by decrease in joint diameter and reduced inflammatory cell infiltration in histopathological examination. BAHE treatment demonstrated dose-dependent improvement in the redox status of synovium (decrease in GSH, MDA, and NO levels and increase in SOD and CAT activities). The beneficial effect of BAHE was substantiated with decreased expression of inflammatory markers such as IL-1ß, IL-6, TNF-R1, and VEGF by immunohistochemistry analysis in AIA model. BAHE increased HO-1/Nrf-2 and suppressed NF-κB mRNA and protein expression in adjuvant immunized joint. Additionally, BAHE abrogated degrading enzymes, as there was decreased protein expression of MMP-3 and -9 in AIA. In conclusion, we demonstrated the anti-arthritic activity of Berberis aristata hydroalcoholic extract via the mechanism of inhibition of NF-κB and activation of Nrf-2/HO-1.

Isolation of digital dermatitis treponemes from cattle hock skin lesions.

BACKGROUND: Bovine hock lesions present a serious welfare and production issue on dairy farms worldwide. Current theories suggest that trauma is an important factor in the formation of hock lesions, although infection may also play a role in increasing their severity and duration. HYPOTHESIS: Digital dermatitis (DD) lesions in dairy cows are strongly associated with specific treponeme bacteria which are opportunistic invaders of other skin regions. Hock lesions were tested to ascertain if they too contained treponemes. ANIMALS: Swab and tissue samples were taken from hock lesions from two farms in South West England. METHODS: Hock lesions were classified into two categories: open lesions, which were often bleeding and ulcerated, or were encrusted; and closed lesions, which were classified as hair loss with no skin breakage. PCR assays and bacterial isolation were used to detect treponemes in hock lesions. RESULTS: All three phylogroups of digital dermatitis treponemes were detectable and isolated from open hock lesions only, with closed lesions showing no evidence of treponeme infection, either by PCR or bacterial culture. When analysed by 16S rRNA gene sequencing, the cultured treponeme DNA showed complete homology or was very similar to that found in foot lesions. Additionally, skin swabs from near the open hock wounds were also positive by PCR assay and isolation for the DD treponemes. CONCLUSIONS AND CLINICAL IMPORTANCE: Identification of the contribution of these infectious agents will allow for more optimal treatments to be developed that reduce the prevalence and healing times of both hock and DD lesions.

Capsaicin-sensitive sensory nerves exert complex regulatory functions in the serum-transfer mouse model of autoimmune arthritis.

OBJECTIVE: The K/BxN serum-transfer arthritis is a widely-used translational mouse model of rheumatoid arthritis, in which the immunological components have thoroughly been investigated. In contrast, little is known about the role of sensory neural factors and the complexity of neuro-immune interactions. Therefore, we analyzed the involvement of capsaicin-sensitive peptidergic sensory nerves in autoantibody-induced arthritis with integrative methodology. METHODS: Arthritogenic K/BxN or control serum was injected to non-pretreated mice or resiniferatoxin (RTX)-pretreated animals where capsaicin-sensitive nerves were inactivated. Edema, touch sensitivity, noxious heat threshold, joint function, body weight and clinical arthritis severity scores were determined repeatedly throughout two weeks. Micro-CT and in vivo optical imaging to determine matrix-metalloproteinase (MMP) and neutrophil-derived myeloperoxidase (MPO) activities, semiquantitative histopathological scoring and radioimmunoassay to measure somatostatin in the joint homogenates were also performed. RESULTS: In RTX-pretreated mice, the autoantibody-induced joint swelling, arthritis severity score, MMP and MPO activities, as well as histopathological alterations were significantly greater compared to non-pretreated animals. Self-control quantification of the bone mass revealed decreased values in intact female mice, but significantly greater arthritis-induced pathological bone formation after RTX-pretreatment. In contrast, mechanical hyperalgesia from day 10 was smaller after inactivating capsaicin-sensitive afferents. Although thermal hyperalgesia did not develop, noxious heat threshold was significantly higher following RTX pretreatment. Somatostatin-like immunoreactivity elevated in the tibiotarsal joints in non-pretreated, which was significantly less in RTX-pretreated mice. CONCLUSIONS: Although capsaicin-sensitive sensory nerves mediate mechanical hyperalgesia in the later phase of autoantibody-induced chronic arthritis, they play important anti-inflammatory roles at least partially through somatostatin release.

Multiple tarsal luxations in 2 Holstein heifers.

Two Holstein heifers were referred for non-weight bearing lameness. The physical examination and radiographic findings were diagnostic of tarsal luxation. Treatment and outcome are reported. A closed reduction was successfully performed in 1 heifer. The second animal was euthanized after attempts to reduce and stabilize the joint.

Luxations multiples du tarse chez 2 taures Holstein. Deux taures Holstein ont été référées pour boiterie de non-appuie. L'examen physique et les radiographies étaient diagnostiques d'une luxation du tarse. Les traitements et pronostic sont décrits. Une réduction fermée a été possible sur une taure et l'autre a été euthanasiée après l'échec de la réduction.(Traduit par les auteurs).

Osteochondral lesions in distal tarsal joints of Icelandic horses reveal strong associations between hyaline and calcified cartilage abnormalities.

Osteochondral lesions in the joints of the distal tarsal region of young Icelandic horses provide a natural model for the early stages of osteoarthritis (OA) in low-motion joints. We describe and characterise mineralised and non-mineralised osteochondral lesions in left distal tarsal region joint specimens from twenty-two 30 ±1 month-old Icelandic horses. Combinations of confocal scanning light microscopy, backscattered electron scanning electron microscopy (including, importantly, iodine staining) and three-dimensional microcomputed tomography were used on specimens obtained with guidance from clinical imaging. Lesion-types were described and classified into groups according to morphological features. Their locations in the hyaline articular cartilage (HAC), articular calcified cartilage (ACC), subchondral bone (SCB) and the joint margin tissues were identified and their frequency in the joints recorded. Associations and correlations between lesion-types were investigated for centrodistal joints only. In centrodistal joints the lesion-types HAC chondrocyte loss, HAC fibrillation, HAC central chondrocyte clusters, ACC arrest and ACC advance had significant associations and strong correlations. These lesion-types had moderate to high frequency in centrodistal joints but low frequencies in tarsometatarsal and talocalcaneal-centroquartal joints. Joint margin lesion-types had no significant associations with other lesion-types in the centrodistal joints but high frequency in both the centrodistal and tarsometatarsal joints. The frequency of SCB lesion-types in all joints was low. Hypermineralised infill phase lesion-types were detected. Our results emphasise close associations between HAC and ACC lesions in equine centrodistal joints and the importance of ACC lesions in the development of OA in low-motion compression-loaded equine joints.

Prevalence of and factors associated with hock, knee, and neck injuries on dairy cows in freestall housing in Canada.

Injuries are a widespread problem in the dairy industry. The objective of this study was to determine the prevalence of and explore the animal-based and environmental factors associated with hock, knee, and neck injuries on dairy cows in freestall housing in Ontario and Alberta, Canada. Freestall dairy farms in the provinces of Ontario (n=40) and Alberta (n=50) were visited for cross-sectional data collection. A purposive sample of 40 lactating Holstein cows was selected for detailed observation on each farm. Cows were scored for hock, knee, and neck injuries on a 3- or 4-point scale, combining the attributes of hair loss, broken skin, and swelling and with a higher score indicating a more severe injury. The highest hock and highest knee score were used in the analysis. Animal-based and environmental measures were taken to explore which factors were associated with injury. Overall, the prevalence of cows with at least one hock, knee, and neck injury was 47, 24, and 9%, respectively. Lame cows had a greater odds of hock injury [odds ratio (OR)=1.46] than nonlame cows, whereas cows with fewer days in milk (DIM) had reduced odds of hock injury compared with those >120 DIM (OR=0.47, 0.64, and 0.81 for <50, 50-82, and 83-120 DIM, respectively). The odds of hock injury was lower on sand (OR=0.07) and concrete (OR=0.44) stall bases in comparison to mattresses. Conversely, the odds of knee injury was greater on concrete (OR=3.19) stall bases compared with mattresses. Cows in parity 1 (OR=0.45 and 0.27 for knee and neck injury, respectively) and 2 (OR=0.49 and 0.40 for knee and neck injury, respectively) had lower odds of knee and neck injury compared with cows in parity 4+. Low feed rail heights increased the odds of neck injury (OR=76.71 for rails between 128 and 140 cm and OR=43.82 for rails ≤128 cm). The odds of knee injury was greater on farms where any cows were observed slipping or falling when moving into the holding area for milking (OR=2.69) and lower on farms with rubber flooring in the alley along the feed bunk compared with bare concrete floors (OR=0.19). These results demonstrate that individual animal characteristics, as well as barn design and animal management, are associated with hock, knee, and neck injuries. These data can help to guide investigations into causes and prevention of injuries.

Clinical and diagnostic imaging characteristics of lateral digital flexor tendinitis within the tarsal sheath in four horses.

Lateral digital flexor tendonitis is a rarely reported cause of hind limb lameness in performance horses. The purpose of this retrospective study was to describe clinical and diagnostic imaging findings for a group of horses with lateral digital flexor tendinitis within the tarsal sheath. Equine cases with a diagnosis of lateral digital flexor tendonitis and magnetic resonance imaging (MRI) studies of the affected region were retrieved from North Carolina University's medical record database. Recorded data for included horses were signalment; findings from history, physical examination, lameness examination, and all diagnostic imaging studies; treatment administered; and outcome. Four horses met inclusion criteria. Lameness was mild/moderate in severity and insidious in onset in all patients. Responses to flexion tests were variable. All horses showed positive improvement(70­90%) in lameness after tarsal sheath analgesia. Radiographic, scintigraphic, and ultrasonographic findings were inconclusive. For all horses, MRI characteristics included increased T2, PD, and STIR signal intensity within the lateral digital flexor tendon in the area of the tarsal sheath. Tarsal sheath effusion was slight in three horses, and mild/moderate in one horse. With medical treatment, two horses were sound at 6-month follow up, one horse was sound at 1-year followup, and one horse had a slight persistent lameness (grade 1/5) at 9-month followup. Findings supported the use of MRI for diagnosing lateral digital flexor tendonitis within the tarsal sheath in horses. Affected horses may have a good prognosis for return to athletic performance following appropriate medical treatment.

Fast- and slower-growing broilers respond similarly to a reduction in stocking density with regard to gait, hock burn, skin lesions, cleanliness, and performance.

There is an increasing trend toward broiler production systems with higher welfare requirements. Breed and stocking density are considered key factors for broiler welfare that are often specified as criteria for such higher welfare systems. However, it remains unknown how slower-growing broilers respond to a reduction in stocking density with regard to their welfare and performance, and whether this response differs from fast-growing broilers. Therefore, we compared fast- (F) and slower-growing broilers (S) housed at 4 different stocking densities (24, 30, 36, and 42 kg/m2, based on slaughter weight) and measured their welfare scores (i.e., gait, footpad dermatitis, hock burn, skin lesions and cleanliness), litter quality and performance. The experiment had a 2 × 4 factorial design with 4 replicates (pens) per treatment (32 pens in total). Thinning (15%) was done in a 50/50 male/female ratio at 38 (F) and 44 (S) d of age (estimated body weight of 2.2 kg). We hypothesized that breeds would respond differently to a reduction in stocking density. Contrary to our hypothesis, only one interaction between breed and stocking density was found on footpad dermatitis, indicating that fast- and slower-growing broilers generally showed similar responses to a reduction in stocking density. F broilers showed a steeper decline in the prevalence of footpad dermatitis with reducing stocking density compared to S broilers. Broilers housed at lower stocking densities (24 and/or 30 kg/m2) showed improved welfare measures, litter quality and performance compared to those housed at higher stocking densities (36 and/or 42 kg/m2). S broilers had better welfare scores (gait, footpad dermatitis and skin lesions), litter quality and lower performance compared to F broilers. In conclusion, reducing stocking density improved welfare of both F and S broilers, but more for F broilers in case of footpad dermatitis, and using S broilers improved welfare compared to F broilers. Reducing stocking density and using slower-growing broilers benefits broiler welfare, where combining both would further improve broiler welfare.

Cool perch availability improves the performance and welfare status of broiler chickens in hot weather.

A study was conducted to determine whether water-cooled perches would be preferred by commercial broilers exposed to a hot ambient environment, and subsequently, whether utilization of these perches would improve performance and the well-being of birds, beyond those provided by normal perches. Four hundred and thirty-two 14-d-old male chickens from a commercial fast-growing strain (Arbor Acres) were housed in the following conditions: 1) cool perches, 2) normal perches, and 3) control pens with no perches. The results showed that there was greater use of cool perches than normal perches for broiler chickens during summer (F1, 4=125, P=0.0004). Cool perches increased BW gain (F2, 6=5.44, P=0.0449) and breast (F2, 24=3.31, P=0.0539) and thigh muscle yields (F2, 24=6.29, P=0.0063), while decreasing abdominal fat deposition (F2, 24=7.57, P=0.0028), cooking loss (pectoralis major, F2, 24=3.30, P=0.0542; biceps femoris, F2, 24=3.42, P=0.0493), percentage of panting birds (F2, 6=102, P<0.0001), and scores of footpad (F2, 6=122, P<0.0001) and hock (F2, 6=68.2, P<0.0001) burn, and abdominal plumage condition (F2, 6=52.0, P=0.0002), particularly toward the end of the rearing period. In contrast, normal perches hardly affected growth performance, carcass composition, meat quality and behavioral patterns, and appeared to worsen the welfare status, including footpad and hock burns and abdominal plumage condition, due to a lower occupancy rate. Cool perches offer a thermoregulatory and performance advantage to broilers exposed to a hot environment and appear to be a management strategy for improving the production and well-being of commercial broilers.

Filarial tenosynovitis caused by Pelecitus species (Spirurida, Filarioidea, Onchocercidae) in the legs of a channel-billed toucan (Ramphastos vitellinus).

An adult channel-billed toucan (Ramphastos vitellinus), imported from Surinam, South America, 18 months earlier, was found dead in its cage. At necropsy, the hock joints were swollen bilaterally and had a reduced range of motion. Small curled worms were present in subcutaneous tissue around the joints, with edema and fibrin formation. These worms were classified as the filarioid nematode, Pelecitus species. Blood-borne microfilariae were seen in cytologic impression smears of the lung and the leg lesions.