Selenium deposition in an atypically disintegrated hoof wall in a Thoroughbred racehorse with alkali disease: Proof by energy-dispersive X-ray fluorescence analysis.

From summer 2018 to summer 2019, several Thoroughbred racehorses held at the Miho Training Centre of the Japan Racing Association inadvertently ingested excessive amounts of sodium selenite, resulting in typical chronic selenium (Se) poisoning - the so-called alkali disease. The typical abnormality was a hoof wall disorder with a circumferentially deep ring and/or transverse hoof wall cracks parallel to the coronet on all feet and appearing after excessive ingestion. One affected Thoroughbred male was unique in that all the hooves had a rough surface with a very fragile hoof wall, but no wall rings or transverse cracking. This horse was euthanized because of dysstasia due to the permanent foot pain associated with hoof wall deformities in the front feet. To detect Se deposition in the hooves, we used energy-dispersive X-ray fluorescence (EDXRF) analysis to measure the Se signal intensity of each lesion. Characteristic Se-kα signals were emitted from the areas of histologically damaged hoof wall at 33.76 ± 11.78 (mean ± SD) counts per second (cps)/mm2. In contrast, the signal from the uninjured proximal hoof wall was 1.43 ± 0.14 cps/mm2 and that from the uninjured distal hoof wall was 1.51 ± 0.23 cps/mm2. The much greater Se deposition in the injured hoof walls suggests that their disintegration was caused by alkali disease. These results indicate that atypical hoof wall abnormalities due to alkali disease can be diagnosed by EDXRF analysis.

Survey assessing foot trimmer involvement in managing lameness in UK beef cattle.

BACKGROUND: Cattle lameness is a significant welfare and economic problem facing the livestock industry. Published research has investigated foot trimming practices in dairy herds, but little is known about the practices in beef herds. Therefore, the objective of this study was to obtain information about the current practices of professional cattle foot trimmers concerning beef cattle within the UK. METHODS: An online survey comprising 16 questions was created using the Joint Information Systems Committee platform. The survey was open for 3 months. RESULTS: There was a significant difference (p < 0.05) between the proportions of dairy cattle and beef cattle receiving preventative foot trims. Digital dermatitis was the most commonly recorded cause of lameness when a lame beef animal was trimmed by the respondents, followed by white line disease. A thematic analysis of foot trimmers' opinions of barriers to engagement on beef farms is presented, in addition to their opinions on veterinary involvement with beef lameness. LIMITATIONS: Distribution bias may have affected the results, as the survey was distributed online with support from the Cattle Hoof Care Standards Board and the National Association of Cattle Hoof Trimmers. The percentage of foot trimmers not affiliated with either professional body is not known. CONCLUSION: Further research on the impact of lameness on suckler and finishing cattle, including investigations into preventative actions to reduce lameness in beef systems, is warranted.

Transcriptional responses consistent with perturbation in dermo-epidermal homeostasis in septic sole ulceration.

The aim of this study was to evaluate transcriptional changes in the sole epidermis and dermis of bovine claws with septic sole ulceration of the lateral claw. Assessment included changes in transcripts orchestrating epidermal homeostatic processes, including epidermal proliferation, differentiation, inflammation, and cell signaling. Sole epidermis and dermis samples were removed from region 4 of lesion-bearing lateral and lesion-free medial claws of pelvic limbs in multiparous, lactating Holstein cows. Control sole epidermis and dermis samples were obtained from region 4 of lateral claws of normal pelvic limbs. Transcript abundances were evaluated by real-time PCR, and relative expression analyzed by ANOVA. Relative to normal lateral claws, sole epidermis and dermis in ulcer-bearing claws exhibited downregulation of genes associated with growth factors, growth factor receptors, activator protein 1 (AP-1) and proto-oncogene (CMYC) transcription components, cell cycle elements, lateral cell-to-cell signaling elements, and structures of early and late keratinocyte differentiation. These changes were accompanied by upregulation of proinflammatory transcripts interleukin 1 α (IL1A), interleukin1 ß (IL1B), interleukin 1 receptor 1 (IL1R1), inducible nitric oxide synthase (NOS2), the inflammasome components NOD-like receptor protein 3 (NLRP3), pyrin and caspase recruitment domain (PYCARD), caspase-1 interleukin converting enzyme (CASPASE), the matrix metalloproteinases (MMP2 and MMP9), and the anti-inflammatory genes interleukin 1 receptor antagonist (IL1RN) and interleukin1 receptor 2 (IL1R2). Transcript abundance varied across epidermis and dermis from the ulcer center, margin, and epidermis and dermis adjacent to the lesion. Sole epidermis and dermis of lesion-free medial claws exhibited changes paralleling those in the adjacent lateral claws in an environment lacking inflammatory transcripts and downregulated IL1A, interleukin 18 (IL18), tumor necrosis factor α (TNFA), and NOS2. These data imply perturbations in signal pathways driving epidermal proliferation and differentiation are associated with, but not inevitably linked to epidermis and dermis inflammation. Further work is warranted to better define the role of crushing tissue injury, sepsis, metalloproteinase activity, and inflammation in sole ulceration.

Molecular evidence of sterile tissue damage during pathogenesis of the pododermatitis aseptica hemorrhagica circumscripta is associated with disturbed epidermal-dermal homeostasis.

Pododermatitis aseptica hemorrhagica circumscripta is associated with metalloproteinase 2 weakening of distal phalangeal suspensory structures and sinkage of the distal phalanx in the claw capsule. Pressure from the tuberculum flexorium on the sole epidermis and dermis produces hemorrhagic tissue injury and defective horn production appearing as yellow-red, softened claw horn in region 4 of the sole. A model of the MAPK/ERK signal cascade orchestrating epidermal-dermal homeostasis was employed to determine if sterile inflammatory responses are linked to disturbed signal transduction for epidermal homeostasis in sole epidermis and dermis. The objective was to assess shifts in target genes of inflammation, up- and downstream MAPK/ERK signal elements, and targeted genes supporting epidermal proliferation and differentiation. Sole epidermis and dermis were removed from lateral claws bearing lesions of PAHC, medial claws from the same limb and lateral claws from completely normal limbs of multiparous, lactating Holstein cows. The abundance levels of targeted transcripts were evaluated by real-time PCR. Lesion effects were assessed by ANOVA, and mean comparisons were performed with t-tests to assess variations between mean expression in ulcer-bearing or medial claw dermis and epidermis and completely normal lateral claw dermis and epidermis or between ulcer-bearing dermis and epidermis and medial claw dermis and epidermis. The lesions were sterile and showed losses across multiple growth factors, their receptors, several downstream AP1 transcription components, CMYC, multiple cell-cycle and terminal differentiation elements conducted by MAPK/ERK signals and ß 4, α 6, and collagen 17A hemidesmosome components. These losses coincided with increased cytokeratin 6, ß 1 integrin, proinflammatory metalloproteinases 2 and 9, IL1B and physiologic inhibitors of IL1B, the decoy receptor, and receptor antagonist. Medial claw epidermis and dermis from limbs with lateral claws bearing PAHC showed reductions in upstream MAPK/ERK signal elements and downstream targets that paralleled those in hemorrhagic lesions. Inhibitors of IL1B increased in the absence of real increases in inflammatory targets in the medial claw dermis and epidermis. Losses across multiple signal path elements and downstream targets were associated with negative effects on targeted transcripts supporting claw horn production and wound repair across lesion-bearing lateral claws and lesion-free medial claw dermis and epidermis. It was unclear if the sterile inflammation was causative or a consequence of these perturbations.

Measuring hoof horn haemorrhage in heifers: A history.

Understanding the aetiology and pathogenesis of claw-horn disease (CHD) is essential for developing prevention/treatment programmes. Haemorrhages in the hoof horn (i.e. white line/sole haemorrhages) are an important part of the pathogenesis of CHD, being precursors to and predictors of lesions such as white-line disease and sole ulcer. Understanding haemorrhage development can provide useful information about the aetiology and pathogenesis of CHD. The development of hoof horn haemorrhages is best studied in cattle without previous claw-horn damage, as previous history of damage can markedly alter the hoof's response to stressors. Since the early 1990s, many prospective studies of the risk factors associated with CHD have been undertaken in late pregnant and early lactation heifers, which have a low risk of having had CHD but which are exposed to the same risk factors as lactating cows. Those studies have used a range of methods to assess hoof horn haemorrhages, with the principal focus, particularly initially (but also more recently), being on measuring lesion severity. However, as the science developed it became clear that measuring lesion extent was also important and that combining severity and extent in a single measure was the best approach to assess hoof horn haemorrhages. Studies of hoof horn haemorrhage in heifers have significantly increased our understanding of CHD, demonstrating the importance of housing and the relative lack of importance of post-calving nutrition. Most importantly, they have shown the importance of parturition as a risk factor for CHD, and how parturition interacts with other risk factors to accentuate their effect. The use of such studies has decreased in recent years, despite recent research showing that we still have much to learn from prospective studies of hoof horn haemorrhages in heifers.

Penetrating wood foreign bodies (stob) of the coronary band in horses: 15 cases.

OBJECTIVE: To retrospectively report the historical and clinical findings, diagnostics, treatment, and outcome of horses with penetrating wood foreign bodies (PWFBs) of the coronary band. ANIMALS: 15 client-owned horses. CLINICAL PRESENTATION: Horses had varying degrees of lameness and soft tissue swelling of the coronary band and pastern region. A defect in the coronary band was identified, but the actual wood foreign body was not always readily visualized. RESULTS: Medical records of horses diagnosed with PWFBs of the coronary band between 2004 and 2023 were reviewed. Information retrieved from the medical records included history, signalment, diagnostics, treatment, and outcome. Thirteen of 15 horses that sustained a PWFB to the coronary band were participating in foxhunting. Penetrating wood foreign bodies occurred more frequently near the central axis or toe region (11/15) and more commonly in the forelimbs (11/15). Removal of PWFBs can be performed with the horse standing and sedated with regional anesthesia. Complete removal of the PWFB required partial removal of the adjacent hoof wall. CLINICAL RELEVANCE: Penetrating wood foreign bodies occurred in the coronary band and lodged distally in the hoof wall of horses. Foxhunting may be a risk factor for this type of injury. Penetrating wood foreign bodies occurred most commonly in the front feet, near the central axis of the coronary band. Complete removal of the PWFB required removing a section of the adjacent hoof wall. The prognosis for return to the previous level of activity following treatment was favorable.

Surgical excision of P3 fragments in 86 declawed cats: case series (2013-2023).

CASE SERIES SUMMARY: This case series describes the clinical findings and surgical intervention of 86 declawed cats; 52 from a shelter or rescue and 34 owned cats. Historical reports from owners and shelter staff included house-soiling, biting behavior, repelling behavior, barbering, lameness, chronic digit infection and nail regrowth. All the cats had fragments of the third phalanx (P3) of varying sizes diagnosed on radiographs. Pathology visible on examination included digital subcutaneous swelling, ecchymosis, malaligned digital pads, ulcerations, exudate, tendon contracture, nail regrowth and callusing. Surgery was pursued in these cases to remove the P3 fragments, relieve tendon contracture and reposition the digital pads with an anchoring suture. Gross findings intraoperatively included fragmented growth of cornified and non-cornified nail tissue, osteophytes on the surface of the second phalanx, deep digital flexor tendon calcification, and both bacterial and sterile exudate. The most common complication 14 days postoperatively was mild (14%) to moderate (1%) lameness. All historical parameters recorded improved in both populations of cats (house-soiling, biting behavior, repelling behavior, barbering, lameness, tendon contracture and chronic digit infection). Postoperatively, 1/47 cats exhibited continued malalignment of two digital pads and there were no reports of long-term postoperative lameness. RELEVANCE AND NOVEL INFORMATION: Two methods of declawing cats are detailed in the veterinary literature, including partial amputation of P3 and disarticulation of the entire P3 bone. The novel information in this report includes historical and clinical signs of declawed cats with P3 fragments, intraoperative gross pathology, surgical intervention and the postoperative follow-up results.

Partial herd hoof trimming results in a higher economic net benefit than whole herd hoof trimming in dairy herds.

Sole ulcers, a common cause of lameness is the costliest non-infectious foot lesion in dairy cows and one of the most prevalent non-infectious foot lesions in freestall housing systems. Costs associated with sole ulcers are treatment costs, plus increased labor and decreased productivity and fertility. Routine hoof trimming is part of a strategy to manage sole ulcers. However, hoof trimming strategies differ among farms. The two most frequently applied strategies are: 1) partial herd hoof trimming with a 2-month interval between trims; and 2) whole herd hoof trimming at 6-month intervals. A Markov model was developed to investigate whether every 2 months partial herd hoof trimming or whole herd hoof trimming every 6 months was the most cost-effective strategy to avoid costs associated with sole ulcers. In this model, the net benefits for a 100-cow herd and the average productive life span of a dairy cow in intensive dairy systems of 3 years were evaluated. Partial herd hoof trimming was the most cost-effective strategy 100% of the time compared to whole herd hoof trimming, with a difference in 3-year net benefits of US$4,337 (95% CI: US$2,713-US$5,830). Based on sensitivity analyses, variables that were the sources of the biggest uncertainty in the model were herd size, the probability of being trimmed in a partial herd trim, and the prevalence of sole ulcers. To further investigate the impacts of herd size and of probability of being trimmed, various scenario analyses were conducted. With increasing herd size, the difference in net benefits in favor of partial herd hoof trimming increased even more. Scenario analyses about the probability of getting trimmed all indicated that targeted intervention increased the difference in net benefits in favor of partial herd hoof trimming. However, if the selection of cows to be trimmed in a partial herd trim was random, the whole herd hoof trimming strategy became cost-effective. Therefore, targeted selection and early intervention are necessary to decrease costs associated with sole ulcers.

Uncommon dermatologic manifestation (paronychia) in a cat with diabetes mellitus.

A 3.5-year-old male intact domestic short hair cat presented for a chronic wound and crusts over the claw and claw folds over several months. The cat was diagnosed with diabetes mellitus based on the presence of persistent hyperglycemia, glucosuria, and compatible clinical signs which consist of polyuria, polydipsia, polyphagia, and weight loss. Glipizide (Glucotrol XL, Pfizer, Indonesia) 2.5 mg orally twice daily was prescribed. By the seventeenth day, the patient's claws and skin around the paw had normalized and the abnormal claw sloughed off, revealing a normal claw underneath. Blood glucose, urinalysis and serum fructosamine were also normalized by the thirtieth day. The patient underwent diabetic remission, and the skin and claw lesions have remained in remission and not recurred since the treatment of the diabetes mellitus. This is the first report of a diabetic cat with dermatologic changes to the skin and claw regions. As the diabetes mellitus went into clinical remission, so too did the dermatologic manifestations, even without any specific dermatologic treatment.

Exploring the impact of high-energy diets on cattle: Insights into subacute rumen acidosis, insulin resistance, and hoof health.

Cattle lameness remains a significant concern, causing economic losses and compromising animal welfare. Claw horn lesions have been identified as a major cause of lameness in dairy cows, but their correlation with high-energy diets and ruminal acidosis remains unclear. Hence, the primary objective of this study was to assess the effects of a high-starch diet and a conventional diet on the rumen environment, acute-phase proteins, and metabolic alterations, with a particular focus on insulin resistance and the consequent implications for the histology of the hooves in Holstein steers. A total of 16 animals were divided into the high-starch (HS; 37% starch) and conventional (CON; 16.8% starch) groups. Glucose tolerance tests (GTT), blood analyses, rumen fluid analyses, and histological evaluations of the hoof tissue were conducted over a 102-d experimental period. The HS group showed a lower ruminal pH than the CON group, and with values indicating SARA. The plasma glucose and IGF-1 concentrations were higher in the HS group, suggesting an anabolic state. Both groups exhibited an increase in the insulin area under the curve (AUC) after the GTT on d 102. Histological analysis of the hooves showed a reduction in the length and width of the epidermal lamella in both groups. We found a significant negative correlation between the insulin AUC and the length and width of the epidermal lamella. Because both groups were similarly affected, the hypothesis that histological alterations were caused by the experimental diets still needs confirmation. Additionally, the development of SARA was not essential for the observed histological changes in the hoof. Further studies are warranted to thoroughly investigate the role of insulin and IGF-1 imbalances in claw health.

A scoring system for grading corkscrew claws in dairy cattle.

Corkscrew claw (CC) in dairy cattle is increasingly reported in dairy herds. CC is a progressive deformity of the claw capsule with uncertain aetiology and pathogenesis. Genetics and specific environmental factors are suspected of contributing to the development of this irreversible condition. CC has been found in lame cows; however, the cause and effect has not been established. To perform analysis of risk factors, treatment and pathogenesis, a definition of severity scores is called for. The aim of this study was to measure and analyse CC characteristics from photos of cows' feet to describe and evaluate a scoring system for CC. Width of the visible part of the axial wall, degree of contact between the toe and the floor and angle of the distal part of the abaxial wall as a proxy for the deviation of the abaxial wall was measured from 393 pictures of CC. Based on the measurements on the claws, the parameter "width of the axial wall" was chosen to define the scores. The parameter was divided into three intervals to define either mild CC 0.3-2.0 cm, moderate CC 2.1-3.5 cm or severe CC>3.5 cm and correlation between the parameters; level of contact between the toe and the floor and the angle of the distal abaxial wall was evaluated. There was a significant positive linear correlation between width of the axial wall and angle of the distal part of the abaxial wall (r=0.91), the wider the axial wall, the more the abaxial wall deviated in the distal part. As the width of the axial wall increased the toe increasingly lost contact with the floor, this association was significant for mild CC and moderate CC but not for severe CC. The Interobserver agreement of the CC Scoring system was tested by 30 claw trimmers each scoring 32 cadaver feet and by 2 trained observers on 28 photos of feet using Cohen´s weighted kappa and showed substantial to almost perfect agreement between untrained and trained observers, respectively.

Evaluation of potassium monopersulfate footbath solution for controlling digital dermatitis in lactating dairy cattle. A randomized clinical trial.

Our objective was to assess potassium monopersulfate as a disinfectant used in footbath to control digital dermatitis (DD) in dairy cows. We hypothesized that a potassium monopersulfate solution would control DD. A 180-day randomized negative controlled trial was conducted in a 265-Holstein free-stall facility. Throughout the trial, foot bathing was performed bi-weekly using a split (left vs. right feet) footbath: one tub filled with 1% potassium monopersulfate (treatment), the other with tap water (control). Digital dermatitis lesions were scored during trimming chute examinations of the unwashed hind heels every 90 days using the modified M-scoring system. Digital dermatitis lesions were re-categorized into four variables: 1) inactive; 2) active; 3) any; 4) inactive or absence of DD lesions. Three longitudinal outcomes were characterized: risks of 1) developing a DD lesion; 2) reactivating an inactive DD lesion; 3) development of an inactive or the absence of the DD lesion. A generalized linear model was used to compare the variables and longitudinal outcomes between treated and control groups. Prevalence of active DD lesions increased from 12.5% to 39.9% between days 0 and 90. This significant increase in prevalence justified the discontinuation of the study on day 90 for ethical reasons. There was no statistical difference between treated and control groups for the first outcome (RR: 1.0; 95% CI: 0.62, 1.7), the second outcome (RR: 1.0; 95% CI: 0.62,-1.7); or the third outcome (RR: 0.88; 95% CI: 0.37, 2.1). A 1% potassium monopersulfate footbath solution appears ineffective to control DD in this study.

Association between a genetic index for digital dermatitis resistance and the presence of digital dermatitis, heel horn erosion, and interdigital hyperplasia in Holstein cows.

Digital dermatitis (DD) is a polybacterial disease endemic to most UK dairy farms. It poses a major financial and welfare threat and is characterized by high incidence and recurrence rates. We aimed to investigate the association between the UK EBV for resistance to digital dermatitis, the digital dermatitis index (DDI), and the frequency of DD, heel horn erosion (HHE), and interdigital hyperplasia (IH) in a population of Holstein dairy cows. We enrolled and genotyped 2,352 cows from 4 farms in a prospective cohort study. Foot lesion records were recorded by veterinary surgeons for each animal at 4 time points during a production cycle, starting at approximately 2 mo before calving and ending in late lactation. Importantly, these records were not used in the calculation of the DDI. Lesion records were matched to the animal's own DDI (n = 2,101) and their sire's DDI (n = 1,812). Digital dermatitis index values in our study population ranged from -1.41 to +1.2 and were transformed to represent distance from the mean expressed in SD. The relationship between the DDI and the presence of DD was investigated using a logistic regression model, with farm, parity, and a farm-parity interaction fitted as covariates. A multivariable logistic regression model was fitted to evaluate the relationship between HHE and DDI with farm fitted as a covariate. Finally, a univariable logistic regression model with DDI as explanatory variable was used to investigate the relationship between IH and DDI. The odds ratio of an animal being affected by DD was 0.69 for 1 SD increase in the animal's DDI (95% CI = 0.63-0.76). The odds of HHE and IH were 0.69 (95% CI = 0.62-0.76) and 0.58 (95% CI = 0.49-0.68) respectively for 1 SD increase in DDI. The adjusted probability of DD was 32% (95% CI = 27-36%) for cows with mean DDI value of 0, while it was 24% (95% CI = 20-29%) in cows with a DDI value of +1. Sire DDI breeding values were standardized in the same way and then binned into terciles creating an ordinal variable representing bulls of high, medium, and low genetic merit for DD resistance. The daughters of low genetic merit bulls were at 2.05 (95% CI = 1.60-2.64), 1.96 (95% CI = 1.53-2.50), and 2.85 (95% CI = 1.64-5.16) times greater odds of being affected by DD, HHE, and IH, respectively, compared with the daughters of high genetic merit bulls. The results of this study highlight the potential of digital dermatitis genetic indexes to aid herd management of DD, and suggest that breeding for resistance to DD, alongside environmental and management control practices, could reduce the prevalence of the disease.

An abattoir study of the prevalence of foot lesions and claw measurements in water buffalo in Egypt.

BACKGROUND: Lameness has been associated with compromised animal welfare and reduced productivity in dairy cattle herds worldwide. However, little is known about the prevalence of claw lesions in the dairy buffalo population in Egypt. Furthermore, the optimum measurements for claw trimming in buffalo are unknown. A cross-sectional cadaver study was conducted where 135 pair buffalo hind feet were collected from 4 slaughterhouses and examined for the presence of claw lesions. The proportion and associated 95% confidence interval (CI) of each type of lesion were calculated. A separate set of healthy claws (n = 26) underwent ultrasonography (US) and computed tomography (CT). The agreement between US and CT measurements was assessed using Passing-Bablok regression and intraclass correlation coefficient. The CT measurements were used to calculate trimming recommendations. RESULTS: At least one lesion was identified in 242 claws (89.6%, 95% CI = 85.4-93.0). In healthy claws, poor to moderate agreement was identified between US and CT measurements which could be due a sample size of the study. The average ± standard deviation (SD) minimum recommended external wall length of the lateral and medial claws in heifers was 7.1 ± 0.36 cm and 7.5 ± 0.35 cm, respectively. The average ± SD minimum recommended external wall length in buffaloes over five years of age was 8.2 ± 0.27 cm and 8.4 ± 0.39 cm for the lateral and medial claws, respectively. CONCLUSIONS: The study found a high prevalence of claw lesions in buffalo in Egypt, the clinical significance of which requires further elucidation. Recommended measurements will help guide claw trimming in buffalo to minimise lesions.

Prolonged hyperinsulinemia increases the production of inflammatory cytokines in equine digital lamellae but not in striated muscle.

Hyperinsulinemia is the key feature of equine metabolic syndrome (EMS) which leads to debilitating sequelae. Hyperinsulinemia-associated laminitis (HAL) is one of the major sequelae of EMS, although the pathophysiological mechanisms are not well elucidated. Using an equine model, we hypothesized that expression of inflammatory markers would be increased in digital lamellae and striated muscle following prolonged hyperinsulinemia. Healthy Standardbred horses (5.4 ± 1.9 years) were alternately assigned to a prolonged euglycemic-hyperinsulinemic clamp (pEHC) or control group (n = 4 per group). Following a 48 h pEHC or a 48 h infusion of a balanced electrolyte solution (controls), biopsies were collected from digital lamellar tissue, skeletal muscle and cardiac muscle were obtained. All hyperinsulinemic horses developed laminitis regardless of previous health status at enrollment. Protein expression was quantified via Western blotting. A significant (P < 0.05) upregulation of the protein expression of heat shock protein 90 (HSP90), alpha 2 macroglobulin (A2M) and fibrinogen (α, ß isoforms), as well as inflammatory cytokines including interleukin-1ß were detected in digital lamellae following prolonged hyperinsulinemia. In contrast, protein expression of cytokines and acute phase proteins in heart and skeletal muscle was unchanged following hyperinsulinemia. Upregulation of inflammatory cytokines and acute phase proteins in digital lamellae during prolonged hyperinsulinemia may reveal potential biomarkers and novel therapeutic targets for equine endocrinopathic laminitis. Further, the lack of increase of inflammatory proteins and acute phase proteins in striated muscle following prolonged hyperinsulinemia may highlight potential anti-inflammatory and cardioprotective mechanisms in these insulin-sensitive tissues.

A prospective cohort study examining the association of claw anatomy and sole temperature with the development of claw horn disruption lesions in dairy cattle.

Foot characteristics have been linked to the development of sole lesions (sole hemorrhage and sole ulcers) and white line lesions, also known as claw horn disruption lesions (CHDL). The objective of this study was to examine the association of claw anatomy and sole temperature with the development of CHDL. A cohort of 2,352 cows was prospectively enrolled from 4 UK farms and assessed at 3 time points: before calving (T1-precalving), immediately after calving (T2-calving), and in early lactation. At each time point body condition score was recorded, a thermography image of each foot was taken for sole temperature measurement, the presence of CHDL was assessed by veterinary surgeons, and an ultrasound image was taken to retrospectively measure the digital cushion and sole horn thickness. Additionally, at the postcalving time point, foot angle and heel depth were recorded. Four multivariable logistic regression models were fit to separately examine the relationship of precalving and postcalving explanatory variables with the development of either white line lesions or sole lesions. Explanatory variables tested included digital cushion thickness, sole horn thickness, sole temperature, foot angle, and heel depth. Farm, parity, body condition score, and presence of lesion at the time of measurement were also included in the models. A thicker digital cushion shortly after calving was associated with decreased odds of cows developing sole lesions during early lactation (odds ratio [OR]: 0.74, 95% confidence interval [CI]: 0.65-0.84). No association was found between digital cushion thickness and development of white line lesions. Sole temperature after calving was associated with increased odds of the development of sole lesions (OR: 1.03, 95% CI: 1.02-1.05), and sole temperature before and after calving was associated with the development of white line lesions (T1-precalving OR: 1.04, 95% CI: 1.01-1.07; T2-calving OR: 0.96, 95% CI: 0.93-0.99). Neither foot angle nor heel depth was associated with the development of either lesion type. However, an increased sole horn thickness after calving reduced the odds of cows developing sole lesions during early lactation (OR: 0.88, 95% CI: 0.83-0.93), highlighting the importance of maintaining adequate sole horn when foot trimming. Before calving, animals with a lesion at the time of measurement and a thicker sole were more likely to develop a sole lesion (OR: 1.23, 95% CI: 1.09-1.40), compared with those without a sole lesion. The results presented here suggest that white line and sole lesions may have differing etiopathogenesis. Results also confirm the association between the thickness of the digital cushion and the development of sole lesions, highlight the association between sole horn thickness and sole lesions, and challenge the potential importance of foot angle and heel depth in the development of CHDL.

Routine hoof-trimming data provides insight into the occurrence of claw lesions in Holstein herds in the central region of South Africa.

Claw lesions in dairy cows contribute significantly to lameness, causing distress and discomfort for affected cows and raising welfare concerns. Despite increased awareness, lameness incidence continues to rise. Defining and recording claw traits are particularly problematic. In South Africa (SA), claw data is limited to paper-based records kept by private hoof trimmers. This research analysed claw-trimming data from five dairy farms over 6 years to examine the occurrence and recording of claw lesions in SA Holstein cattle. Lesion identification followed the Claw Lesion Identification in Dairy Cattle brochure. Among the recorded lesions, digital dermatitis (DD) had the highest prevalence (64.02%), followed by sole ulcers (SU; 8.59%), white line disease (WLD; 6.27%), and sole haemorrhage (SH; 4.28%), and most lesions occurred in the rear feet. Chi-square tests and correspondence analysis (CA) were employed to explore the relationships between lesions, feet, and housing. Results indicated that the prevalence of SU and SH showed high similarity for foot and lesion association, and that these were more highly associated with the rear feet. Additionally, the prevalence of DD and interdigital phlegmon were strongly associated, and closely associated with SU, and all these lesions were associated with both dirt lot and free-stall housing systems. CA further confirmed a close association between WLD and SH, and the prevalence of these lesions in the combination housing system. Results of this study highlight the complexity of lesion data and that specific associations between lesions could lead to simplifying the recording thereof. Consolidating the most informative claw lesions into categories will aid in the practical prevention, management, and treatment of lameness on-farm.

Transmission and lesion progression of treponeme-associated hoof disease in captive elk (Cervus canadensis).

Treponeme-associated hoof disease (TAHD) is a debilitating disease of free-ranging elk (Cervus canadensis) in the northwestern U.S. While treponemes are associated with lesions, the etiology and transmissibility between elk are unknown. Our objective was to determine whether the disease can be environmentally transmitted to captive elk. Four individually housed treatment elk and 2 control elk were challenged with soil mixed with inoculum prepared from free-ranging elk hooves from TAHD-positive elk or autoclaved hooves from normal elk, respectively. The inoculum for each group was applied to the interdigital space and added to pre-existing soil in each pen. Eight challenges were conducted at 1-4-week intervals and lesion development was assessed during a 138-day challenge period that was followed by a 170-day monitoring period to document lesion progression. All treatment elk, but no control elk, developed gross and histologic lesions consistent with TAHD. Treponema phylotypes similar to those in bovine digital dermatitis in cattle were detected using 16S rRNA gene amplicon sequencing from lesions in all treatment elk, but no control elk, during the challenge period. Lesions progressed from ulcerations in the interdigital space to extensive ulceration and underrunning of the hoof capsule by 35 and 173 days following the initial inoculation, respectively. Lameness in treatment elk was correlated with lesion development (R = 0.702, p≤0.001), and activity of infected elk was reduced during the challenge (p≤0.001) and monitoring periods (p = 0.004). Body condition was significantly lower in treatment than control elk 168 days following the initial inoculation (p = 0.05) and at each individual elk's study endpoint (p = 0.006). Three of 4 treatment elk were euthanized when they reached humane endpoints, and one elk recovered. These results provide direct evidence that TAHD is a transmissible infectious disease in elk. As such, actions that reduce transmission risk can support disease management and prevention.

Persistence of orthopaedic hoof blocks for the treatment of lame cattle kept permanently at pasture.

AIMS: To compare the retention by New Zealand dairy cows kept at pasture in a lame cow group, of three hoof block products commonly used in the remediation of lameness. METHODS: Sixty-seven farmer-presented Friesian and Friesian x Jersey dairy cows from a single herd in the Manawatu region (New Zealand) suffering from unilateral hind limb lameness attributable to a claw horn lesion (CHL) were randomly allocated to one of three treatments: foam block (FB), plastic shoe (PS) and a standard wooden block (WB). Blocks were applied to the contralateral healthy claw and checked daily by the farm staff (present/not present) and date of loss was recorded. Blocks were reassessed on Day 14 and Day 28 and then removed unless further elevation was indicated. Daily walking distances were calculated using a farm map and measurement software. Statistical analyses included a linear marginal model for distance walked until block loss and a Cox regression model for the relative hazard of a block being lost. RESULTS: Random allocation meant that differences between products in proportion used on left or right hind foot or lateral or medial claw were small. Mean distance walked/cow/day on farm tracks whilst the block was present was 0.32 (min 0.12, max 0.45) km/day; no biologically important difference between products in the mean distance walked was identified. Compared to PS, cows in the WB group were five times more likely to lose the block (HR = 4.8 (95% CI = 1.8-12.4)), while cows in the FB group were 9.5 times more likely to lose the block (HR = 9.5 (95% CI = 3.6-24.4)). CONCLUSIONS: In this study, PS were retained for much longer than either FB or WB. As cows were managed in a lame cow group for the study duration, walking distances were low and did not impact on the risk of block loss. More data are needed to define ideal block retention time. CLINICAL RELEVANCE: In cows with CHL the choice of block could be based on the type of lesion present and the expected re-epithelisation times.

Lameness recovery rates following treatment of dairy cattle with claw horn lameness in the Waikato region of New Zealand.

AIMS: To describe the time in days for lame dairy cows to recover after diagnosis and treatment of claw horn lameness, and to investigate whether cure rates differed between farms. METHODS: Five dairy farms in the Waikato region were conveniently enrolled into a descriptive epidemiological study. Three of these farms had dairy cattle enrolled over two consecutive seasons, while two farms enrolled for one year. Lame cattle diagnosed by the farmers were enrolled into the study if they had a lameness score (LS ≥ 2 on a 0-3 scale) and claw horn lesions. All enrolled animals were treated by a single veterinarian following a consistent methodology, and subsequently assessed for LS at a median frequency of 4 days from enrolment until they were sound (LS = 0). The times (days) taken for animals to become sound and non-lame (LS < 2) were reported for all animals, and Kaplan-Meier survival curves used to present the results. A Cox-proportional hazard model was used to assess if the hazard of soundness was associated with farm, age, breed, lesion, number of limbs involved, and LS at enrolment. RESULTS: A total of 241 lame cattle with claw horn lesions were enrolled across the five farms. White line disease was the predominant pain-causing lesion in 225 (93%) animals, and blocks were applied to 205 (85%) of enrolled animals. The overall median days from enrolment to becoming sound was 18 (95% CI = 14-21) days, and 7 (95% CI = 7-8) days to become non-lame. A difference in the hazards of lameness cure between farms was identified (p = 0.007), with median days to lameness cure between farms ranging from 11 to 21 days. No associations were identified between age, breed, limb, or LS at enrolment on the lameness cure rates. CONCLUSIONS: Treatment of claw horn lameness following industry-standard guidelines in dairy cattle on five New Zealand dairy farms resulted in rapid cure, although cure rates differed between farms. CLINICAL RELEVANCE: Following industry best-practice lameness treatment guidelines, including frequent use of blocks, can result in rapid lameness cure rates in New Zealand dairy cows. This study also suggests that management of lame cattle on pasture can positively benefit their welfare and recovery times. The reported cure rates provide veterinarians with benchmarks on the length of time after which a lame animal should be re-examined, and in the investigation of poor treatment response rates at the herd level.