Cases Of Laminitis Research Articles

Neutrophil extracellular traps and active myeloperoxidase concentrate in lamellar tissue of equids with naturally occurring laminitis

Laminitis is a pathology of the equine digit ultimately leading to a failure of the dermo-epidermal interface. Neutrophil activation is recognized as a major factor in SIRS-associated laminitis and has recently been described in induced endocrinopathic laminitis evidenced by the presence of myeloperoxidase (MPO). Neutrophil extracellular traps (NET) are released with neutrophil activation. This study aimed to investigate the presence and activity of MPO and NET in the lamellar tissue of equids presented with naturally occurring laminitis. Samples of lamellar tissue of five horses and five donkeys presented with laminitis, as well as eight control horses without laminitis, were collected. Lamellar tissue extracts were submitted to ELISA and specific immuno-extraction followed by enzymatic detection (SIEFED) assays to confirm the presence and activity of both MPO and NET. Lamellar sections were also immunohistopathologically stained for MPO and NET. Analysis of lamellar tissue extracts revealed that laminitis cases had significantly higher levels of total MPO concentration, MPO activity, and NET-bound MPO activity in comparison to control horses. Moreover, a strong correlation was identified between the activity of NET-bound MPO and the total MPO activity, which suggests that MPO activity partly originates from NET-bound MPO. Immunohistochemical staining showed that MPO and NET labelling in laminitis cases was moderate to marked, primarily in the epidermis and in inflammatory infiltrates containing neutrophils, while labelling in control horses was minimal. This article constitutes the first indication of the presence and activity of NET-bound MPO in the lamellar tissue of horses and donkeys with naturally occurring laminitis. Targeting these substances may provide new treatment possibilities for this debilitating disease.

Predictors of laminitis development in a cohort of nonlaminitic ponies.

Quantifying risk factors for laminitis development requires improvement. To identify the most useful physical examination, metabolic and management factors to predict laminitis development in client-owned, nonlaminitic ponies. Prospective cohort study. Physical examination, metabolic and management data were collected from a pony cohort 6 monthly for up to 4years. Ponies were monitored for the development of laminitis. Metabolic data included basal plasma concentrations of ACTH ([ACTH]), adiponectin ([adiponectin]), triglycerides and glucose. Serum insulin concentrations ([insulin]) were measured in the unfasted basal state ([insulin]T0) and 60minutes ([insulin]T60) after administration of corn syrup (0.3ml/kg). Separate multivariable Cox proportional-hazards models were developed for physical, management/signalment and metabolic data and later combined into two final models. Low-, medium- and high-laminitis risk categories were defined based on basal or T60 [insulin]. Overall, 374 ponies (age 5-32years) and 891 pony-years were included in the main analysis. Laminitis incidence (95% confidence interval (CI)) was 4.8 (3.5-6.5) cases/100 pony-years. Laminitis development was associated with numerous univariable factors. Significant (P<.05) factors retained in the final multivariable models included [insulin]T0, [insulin]T60, [adiponectin] and divergent hoof growth. [ACTH] was not independently associated with laminitis. Based on [Insulin]T0, low- (<21.6 µIU/ml), medium- (21.6-45.2 µIU/ml) and high-risk (>45.2µIU/ml) categories encompassed 70, 20 and 10% of the population and had estimated 4-year laminitis incidences (95%CI) of 6 (2-9)%, 22 (10-33)% and 69 (48-82)% respectively. Based on [Insulin]T60 the low- (<53.4µIU/ml), medium- (53.4-153µIU/ml) and high-risk (≥153µIU/ml) categories comprised 60, 30 and 10% of the population and had estimated 4-year laminitis incidences (95%CI) of 3 (0-6)%, 20 (10-29)% and 73 (52-84)% respectively. Results may not apply to different insulin assays, geographical regions, breeds or management types. [Insulin]T0 or [insulin]T60 best quantify the risk of future laminitis development in nonlaminitic ponies.

Translating research into practice: Adoption of endocrine diagnostic testing in cases of equine laminitis

Research demonstrating insulin’s causal role in endocrinopathic laminitis has greatly advanced understanding of equine laminitis. However, the degree to which this knowledge has been translated into clinical practice has not been assessed. This two-part study aimed to investigate veterinary surgeons’ current diagnostic approach to laminitis, whether this had changed over time, and the impact of diagnosing an endocrinopathy on laminitis case management and outcome. Two cross-sectional online surveys of equine veterinary surgeons working within the UK were undertaken.The first study population comprised 141 veterinary surgeons, who had graduated a median of 8 years previously. Overall, 83.6% of respondents (n = 117/140) had changed their diagnostic approach to laminitis since graduating, primarily through increasing use of endocrine testing (88.7%; n = 86/97). Ninety-nine percent (n = 140/141) performed endocrine diagnostic test(s) for some or all laminitis cases at initial and/or subsequent examinations. The second study had 120 participating veterinary surgeons, ≥76% of whom considered diagnosing underlying endocrine diseases greatly influenced their laminitis case management. Where an endocrinopathy was identified, 75.0% (n = 90/120) considered that client communication regarding laminitis was facilitated, and ≥67% considered that treating the endocrinopathy was effective in reducing laminitis recurrence. This study demonstrates successful translation of research knowledge into equine practice, with the vast majority of veterinary surgeons adopting endocrine diagnostic testing within their routine approach to laminitis cases. Respondents perceived that this change in diagnostic approach has resulted in improvements in several non-clinical and clinical healthcare outcomes, including client communication and reduction in recurrent laminitis episodes.

A Retrospective Study of Mortality Causes in Arabian Horses

This study aims to describe the causes of death in Arabian horses at Al Wathba, in Abu Dhabi (United Arab Emirates) during 2018-2019. This study was conducted in a cohort of all Arabian horses that died. Data was collected retrospectively and only those horses with a full necropsy report available were included in the study. The carcass and all internal organs of each horse were examined and representative samples of tissues with abnormalities were collected in 10% neutral buffered formalin and processed for histopathological examination. A descriptive statistical analysis was performed. A total of 25 Arabian horses were examined post-mortem. Out of them, 35% were females. In general, colic occurred specifically at a higher frequency (80%), cases of collapse and sudden death during exercise and races occurred in 8%, cases of perinatal death in 8% and one case of laminitis (4%). The annual mortality in relation to the estimated population was 1% approximately. In conclusion, we identified and described the causes of death in Arabian horses in Al Wathba, Abu Dhabi, UAE during the period 2018-2019. In summary, a pathology of the digestive system specifically acute abdominal crisis (colic) is the main cause of death in Arabian horses, with 80%; other causes of mortality with a low incidence were in order collapse and sudden death during exercise and races, perinatal death and laminitis. These results allow establishing risk prevention measures of mortality in horses for specific activities like handling, feeding, training and races

A "modified Obel" method for the severity scoring of (endocrinopathic) equine laminitis.

BackgroundLaminitis is a common equine disease characterized by foot pain, and is commonly diagnosed using a five-grade Obel system developed in 1948 using sepsis-related cases. However, endocrinopathic laminitis is now the most common form of the disease and clinical signs may be mild, or spread across two Obel grades. This paper describes a modified method which assigns scores to discreet clinical signs, providing a wider scale suitable for use in a research setting.MethodsThe “modified Obel” method was developed using an iterative process. First, a prototype method was developed during the detailed observation of 37 ponies undergoing a laminitis induction experiment. The final method was refined and validated using video footage taken during the induction study and from a clinical trial of naturally occurring endocrinopathic laminitis cases. The Obel method was deconstructed and key laminitis signs were evaluated to develop a three-stage, five criteria method that employs a severity scale of 0–12. Veterinarians (n = 28) were recruited to watch and assess 15 video recordings of cases of varying severity, using the Obel and “modified Obel” methods. The inter-observer agreement (reproducibility) was determined using Kendall’s coefficient of concordance (Kendall W) and Krippendorf’s alpha reliability coefficient. A total of 14 veterinarians repeated the exercise 2–4 weeks after their original assessment, to determine intra-observer agreement (repeatability), assessed using a weighted kappa statistic (kw). Agreement between methods was calculated by converting all “modified Obel” scores to Obel grades and calculating the mean and distribution of the differences.ResultsThe “modified Obel” and Obel methods showed excellent and similar inter-observer agreement based on the Kendall W value (0.87, P < 0.001 vs. 0.85, P < 0.001) and Krippendorf’s alpha (95% CI) value (0.83 [0.53–0.90] vs. 0.77 [0.55–0.85]). Based on the kw value, the “modified Obel” method also had substantial repeatability, although slightly less than the Obel method, (0.80 vs. 0.91). Excellent agreement between the methods was found, with the mean difference (95% CI), comparing the Obel grade, with the “modified Obel” score converted to an Obel grade, being −0.12 (−0.19 to −0.06) grades. The Obel and converted “modified Obel” grades were identical 62% of the time (259/420) and a difference of one grade (higher or lower) occurred in 35% of cases (148/420).ConclusionBoth methods show excellent agreement, reproducibility and repeatability when used to diagnose endocrinopathic laminitis. The “modified Obel” method is a three-step examination process for severity-scoring of endocrinopathic laminitis, initially proposed for use within a research setting. When using the modified method a diagnosis of laminitis also requires clinical acumen. The allocation of scores for specific clinical signs should be particularly useful in research trials monitoring laminitis recovery.

Incidence and risk factors for recurrence of endocrinopathic laminitis in horses.

BackgroundEndocrinopathic laminitis is common in horses and ponies, but the recurrence rate of the disease is poorly defined.ObjectivesTo determine the incidence of, and risk factors for, the recurrence of endocrinopathic laminitis.AnimalsPrivately owned horses and ponies with acute laminitis (n = 317, of which 276 cases with endocrinopathic laminitis were followed up to study completion).MethodsThis prospective cohort study collected data on veterinary‐diagnosed cases of acute laminitis for 2 years. Each case was classified on acceptance to the study as endocrinopathic or non‐endocrinopathic using data collected in a questionnaire completed by the animal's veterinarian. Follow‐up data were collected at regular intervals to determine whether the laminitis recurred in the 2‐year period after diagnosis.ResultsThe recurrence rate for endocrinopathic laminitis was 34.1%. The risk of recurrence during the 2‐year study period increased with basal, fasted serum insulin concentration (P ≤ .05), with the probability of recurrence increasing markedly as the insulin concentration increased beyond the normal range (0‐20 μIU/mL) to over the threshold for normal (up to approximately 45 μIU/mL). Being previously diagnosed with laminitis (before the study; P = .05) was also a risk factor for recurrent laminitis. Cases with a higher Obel grade of laminitis were likely (P = .05) to recur sooner.Conclusions and clinical importanceKnowing that hyperinsulinemia and being previously diagnosed with laminitis are significant risk factors for recurrence will enable clinicians to proactively address these factors, thereby potentially reducing the risk of recurrence of laminitis.

Detection of endoplasmic reticulum stress and the unfolded protein response in naturally-occurring endocrinopathic equine laminitis

BackgroundLaminitis is often associated with endocrinopathies that cause hyperinsulinemia and is also induced experimentally by hyperinsulinemia, suggesting that insulin initiates laminitis pathogenesis. Hyperinsulinemia is expected to activate pro-growth and anabolic signaling pathways. We hypothesize that chronic over-stimulation of these pathways in lamellar tissue results in endoplasmic reticulum stress, contributing to tissue pathology, as it does in human metabolic diseases. We tested this hypothesis by asking whether lamellar tissue from horses with naturally-occurring endocrinopathic laminitis showed expression of protein markers of endoplasmic reticulum stress.ResultsThree markers of endoplasmic reticulum stress, spliced XBP1, Grp78/BiP and Grp94, were upregulated 2.5–9.5 fold in lamellar tissues of moderately to severely laminitic front limbs (n = 12) compared to levels in controls (n = 6–7) measured by immunoblotting and densitometry. Comparing expression levels between laminitic front limbs and less affected hind limbs from the same horses (paired samples from 7 to 8 individual horses) demonstrated significantly higher expression for both spliced XBP1 and Grp78/BiP in the laminitic front limbs, and a similar trend for Grp94. Expression levels of the 3 markers were minimal in all samples of the control (n = 6–7) or hind limb groups (n = 7–8). Immunofluorescent localizations were used to identify cell types expressing high levels of Grp78/BiP, as an indicator of endoplasmic reticulum stress. Grp78/BiP expression was highly elevated in suprabasal epidermal keratinocytes and only observed in laminitic front limbs (10/12 laminitic samples, compared to 0/7 in sections from the hind limbs and 0/5 of controls).ConclusionsThese data demonstrate that the endoplasmic reticulum stress pathway is active in naturally occurring cases of laminitis and is most active within a subset of epidermal keratinocytes. These data provide the rationale for further study of endoplasmic reticulum stress in experimental models of laminitis and the links between laminitis and human diseases sharing activation of this stress pathway. Pharmacological options to manipulate the endoplasmic reticulum stress pathway under investigation for human disease could be applicable to laminitis treatment and prevention should this pathway prove to be a driver of disease progression.

Pain management for laminitis in the horse

SummaryThe inability to control pain is the most common reason for cessation of treatment and euthanasia in cases of laminitis, yet pain also serves a unique protective function in these cases, particularly in the acute phase when lamellar integrity is weakened. Successful analgesia requires an understanding of the disease pathophysiology, the sources of pain in laminitis, methods of serial pain evaluation, and methods of analgesia including systemic and regional techniques. This review discusses the approach to analgesia including detail of traditional and novel analgesic medications and techniques with specific reference to the laminitis case.

Equine Laminitis: A retrospective study of 55 cases (2000-2004)

Laminitis is a common equine disease. In order to have a good prognosis, prompt therapy is essential. Fifty-five cases of equine laminitis, that were treated in the Clinic of Surgery, School of Veterinary Medicine, were included in this study. More specifically, the clinical presentation and the diagnostic approach are described and the therapeutic protocol is evaluated. At the same time, the literature is reviewed as far as the epidemiology, the pathogenesis, the clinical signs, the diagnosis and the treatment is concerned. It is worth mentioning that several therapeutic protocols have been put forward for the treatment of laminitis, perhaps due to the fact that its pathogenesis is still under dispute. Prolonged rest, frog support, cols hosing of the feet, severe diet, administration of antibiotics and non-steroidal anti-inflammatory drug were the key points of the protocol of this study that led to extremely good results for the majority of the cases.

The oral glucose test predicts laminitis risk in ponies fed a diet high in nonstructural carbohydrates

The aim of this study was to investigate the relationship between laminitis development in ponies and insulin/glucose concentrations in response to the oral glucose test (OGT) and a dietary challenge high in nonstructural carbohydrates (NSCs). After undergoing an OGT (1 g dextrose/kg BW in feed), 37 ponies with 2-h serum insulin concentrations ranging from 22 to 1,133 μIU/mL were subjected to a diet challenge period (DCP), consuming 12 g NSC/kg BW/d for up to 18 d. Insulin and glucose responses were measured on day 2 of the DCP. Clinical laminitis was diagnosed by blinded experts and confirmed radiographically. Basal ACTH levels and clinical signs were assessed to investigate concurrent putative pituitary pars intermedia dysfunction (PPID). The diet induced Obel grade 1 or 2 laminitis in 14 ponies (38%). The ponies that developed laminitis had higher maximum concentrations of blood glucose (P = 0.04) and serum insulin (P = 0.02) in response to the diet. The geometric mean (95% CI) blood glucose concentration for laminitis cases was 14.9 (12.9–17.2) mM, compared to 10.7 (9.2–12.5) mM for ponies who did not develop laminitis. Similarly, the geometric mean (95% CI) for serum insulin was 396 (301–520) μIU/mL for laminitis cases, compared to 216 (148–316) μIU/mL for ponies who did not develop laminitis. Laminitis incidence was likewise associated with insulin concentrations measured during the OGT. Laminitis occurred at frequencies of 0% (0/7) if postdextrose insulin (μIU/mL) was <50; 35% (8/23) if insulin was 50 to 195; and 86% (6/7) if insulin was >195 μIU/mL. Basal ACTH concentrations were above seasonally accepted reference ranges in 16/37 ponies, and 8 of these animals (50%) developed laminitis. This included all 5 ponies in the study that had clinical signs of PPID (100%). In contrast, hyperinsulinemia and laminitis occurred in only 3/11 ponies (27%) with elevated ACTH concentrations and no clinical signs of PPID (P = 0.009). Thus, laminitis occurrence was associated with higher glucose and insulin responses to both the OGT and challenge diet, and the frequency of laminitis can be predicted based on insulin and glucose hyperresponsiveness to these oral carbohydrate challenges.

Assessment of horse owners' ability to recognise equine laminitis: A cross-sectional study of 93 veterinary diagnosed cases in Great Britain.

Use of owner-reported data could further epidemiological knowledge of equine laminitis. However, owner recognition of laminitis has not previously been assessed. The primary objective was to establish whether cases of owner-suspected laminitis would be confirmed as laminitis by the attending veterinary surgeon. Secondary objectives were to compare owner- and veterinary-reported information from veterinary-confirmed cases of equine laminitis. Cross-sectional study. Twenty-five British veterinary practices were invited to submit laminitis reporting forms (LRFs) for active laminitis cases attended between January 2014 and October 2015; detailing 27 clinical signs, 5 underlying conditions and 7 risk factors associated with laminitis. Owners were invited to independently complete a modified LRF if reason for the veterinary visit was suspicion of laminitis. Differences between paired veterinary and owner LRFs, and between cases where owners did and did not recognise laminitis, were assessed using McNemar's and Fisher's Exact tests, respectively. Veterinary LRFs were received for 93 veterinary-diagnosed laminitis cases. All 51 owner-suspected cases were confirmed by veterinary diagnosis, with the remaining 42 (45.2%) not recognised as laminitis by owners. Undefined lameness, foot abscesses, colic and stiffness were common reasons for owner-requested veterinary visits in owner-unrecognised cases. 'Divergent growth rings' (prevalence difference: +27.3%, P=0.01) and 'breed type' (prevalence difference: +21.2%, P=0.04) were more commonly reported by veterinary surgeons in owner-recognised compared to owner-unrecognised cases. 'Difficulty turning', 'shifting weight' and risk factor 'body condition' were more frequently reported by veterinary surgeons whilst 'increased hoof temperature' was reported more frequently by owners. The limited clinical data restricted statistical inferences regarding the secondary objectives. All owner-suspected laminitis cases were confirmed upon veterinary examination, showing validity for the inclusion of owner-reported cases in future epidemiological studies. However, failure of laminitis recognition by owners highlights further need for evidence-based education to ensure early disease detection.

Collaboration as a Key Feature of Equine Evidence-Based Research: A Laminitis Case Study

&lt;p&gt;&lt;strong&gt;Abstract&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;It is widely believed that laminitis poses a threat to the health and welfare of all Equidae; however, there is a paucity of evidence-based research on fundamental aspects of the disease, including how commonly it occurs, its clinical presentation and those animals at greatest risk. Following generous funding from World Horse Welfare, we have produced a programme of work over the last eight years to improve the evidence base regarding the epidemiology of laminitis. This began with systematic reviews regarding the frequency of [1], and risk factors for [2], naturally-occurring laminitis which informed the planning and conduct of prospective veterinary practice-level cohort and nested case-control studies of veterinary-diag­nosed laminitis in British horses. Laminitis research tools, disease frequency estimates [3], potential novel modifiable risk factors [4] and guidelines for the differential diagnosis of laminitis [5] have all resulted from these now published, peer-reviewed studies. Ongoing work gathers further information on owner-report­ed laminitis cases by means of a prospective individual animal-level cohort study design, implemented through the use of web-based data collection (www.careaboutlaminitis.org.uk).&lt;/p&gt;&lt;p&gt;Each step of the generation of this evidence-based data has demanded high levels of collaborative effort between charitable bodies, epidemiologists, information technology consultants, public relation officers, laminitis researchers, veterinary practitioners and horse owners. This talk will outline the methods we used to gather evidence-based data in the equine field, highlight the challenges and lessons we have learnt, and emphasise the crucial role the veterinary practitioner can play in both providing and using such evidence-based data.&lt;/p&gt;&lt;br /&gt; &lt;img src="https://www.veterinaryevidence.org/rcvskmod/icons/oa-icon.jpg" alt="Open Access" /&gt;

Using the Horse Grimace Scale (HGS) to Assess Pain Associated with Acute Laminitis in Horses (Equus caballus).

Simple SummaryAcute laminitis is a common equine disease characterized by intense foot pain. This work aimed to investigate whether the Horse Grimace Scale (HGS), a facial-expression-based pain coding system, can be usefully applied to assess pain associated with acute laminitis in horses at rest. Ten horses, referred as acute laminitis cases with no prior treatment, were assessed at the admission and at seven days after the initial evaluation and treatment. The authors found that the Horse Grimace Scale is a potentially effective method to assess pain associated with acute laminitis in horses at rest, as horses showing high HGS scores also exhibited higher Obel scores, and veterinarians classified them in a more severe painful state. Acute laminitis is a common equine disease characterized by intense foot pain, both acutely and chronically. The Obel grading system is the most widely accepted method for describing the severity of laminitis by equine practitioners, however this method requires movement (walk and trot) of the horse, causing further intense pain. The recently developed Horse Grimace Scale (HGS), a facial-expression-based pain coding system, may offer a more effective means of assessing the pain associated with acute laminitis. The aims of this study were: to investigate whether HGS can be usefully applied to assess pain associated with acute laminitis in horses at rest, and to examine if scoring HGS using videos produced similar results as those obtained from still images. Ten horses, referred as acute laminitis cases with no prior treatment, were included in the study. Each horse was assessed using the Obel and HGS (from images and videos) scales: at the admission (before any treatment) and at seven days after the initial evaluation and treatment. The results of this study suggest that HGS is a potentially effective method to assess pain associated with acute laminitis in horses at rest, as horses showing high HGS scores also exhibited higher Obel scores and veterinarians classified them in a more severe painful state. Furthermore, the inter-observer reliability of the HGS total score was good for both still images and video evaluation. There was no significant difference in HGS total scores between the still images and videos, suggesting that there is a possibility of applying the HGS in clinical practice, by observing the horse for a short time. However, further validation studies are needed prior to applying the HGS in a clinical setting.

Decision-tree analysis of clinical data to aid diagnostic reasoning for equine laminitis: a cross-sectional study

The objective of this cross-sectional study was to compare the prevalence of selected clinical signs in laminitis cases and non-laminitic but lame controls to evaluate their capability to discriminate laminitis...

Laminitis: Risk Factors and Outcome in a Group of Danish Horses

Recent systematic reviews have highlighted the lack of quality information with respect to the epidemiology of equine laminitis. The objectives of this study were to identify in Denmark, the risk factors for new (i.e., not believed to have suffered from laminitis previously) cases of laminitis (NL) and to look at the outcome and incidence of repeated episodes of laminitis in these animals as well as those which had previously suffered an episode of laminitis (i.e., chronic cases) over the following 12 months. Information was obtained from 110 veterinary diagnosed cases of laminitis (69 new and 41 chronic) and 80 control animals (the next nonlaminitic horse/pony seen by that participating practice). All animals were followed for up to 1 year. Univariable and multivariable conditional logistic regression was conducted for the NL case-control pairs. Variables were retained within the final multivariable models if the likelihood ratio P value was <.05. There was no association between sex or gender and laminitis. A recent change of grass, being on what was considered high-quality grass and being a cold-blooded type, <149 cm (i.e., Shetland, Fell, Welsh, or Dartmoor pony, Icelandic horse, Norwegian fjords, or a mix of these breeds) were all significant risk factors for laminitis. Although cresty neck score and body condition score were significantly associated with NL at the univariable screening stage, they were found to be confounders of breed and each other during the multivariable model building process. Other factors such as weight and estimated starch intake were not found to be significant. Thirty-three percent of all the laminitis cases had been humanely destroyed within 12 months of diagnosis, mainly for laminitis-associated reasons, compared with only 7.5% of the controls (none for laminitis associated reasons). This study confirms the importance of grass turnout and breed on laminitis risk. Horses in work at the time of diagnosis as well as those diagnosed in the winter and spring were more likely to be humanely destroyed within the next 12 months than those not in work or diagnosed in the autumn and summer.

Clinical Research Abstracts of the British Equine Veterinary Association Congress 2015.

In cases of laminitis, an increased muscle force or contracture of the deep digital flexor muscle (DDFM) is suggested, but evidence-based research is lacking. To test if the DDFM of laminitic equines shows an increased muscle force detectable by needle-EMG including Interference Pattern Analysis (IPA). Cross-sectional study. Three groups consisted of Group 0 (control): 6 Royal Dutch Sport horses, 3 Shetland ponies and one Welsh pony (healthy, sound adults, mean ± s.d. weight 411 ± 217 kg). Group 1: 3 Royal Dutch Sport horses, one Friesian, one Haflinger, one Icelandic horse, 2 Welsh ponies, one miniature Appaloosa and 6 Shetland ponies (adults, mean ± s.d. weight 310 ± 172 kg) suffering from acute or chronic laminitis. EMG measurements including firing frequency (F) and IPA parameters Turns/Second (T), Amplitude/Turn (M) and Ratio M/T (R) were performed. ANOVA was used to analyse data. P values of P<0.05 were considered significant. Mean ± s.d. F of Group 0 and Group 1 was 53 ± 11 and 72 ± 21 Hz, mean ± s.d. T was 112 ± 57 and 106 ± 42, mean ± s.d. M was 284 ± 51 and 254 ± 38 μV and mean ± s.d. R was 0.39 ± 0.17 and 0.42 ± 0.16%, respectively. The firing frequency of Group 1 was significantly higher compared to Group 0 (P = 0.02), whereas other differences were not significant. In human medicine, an increased firing frequency is a characteristic of increased muscle force [1,2]. Thus, the increased firing frequency of the DDFM in case of laminitis suggests an elevated muscle force. As all parameters show a high variance, a repeated study including a larger test group is advised. Ethical animal research: Data collection from controls was approved by the Animal Welfare Committee of Utrecht University, approval number 2008.III.07.061 and 2013.III.01.012. Clinical cases were privately owned and written owner consent was obtained. None. Competing interests: None declared.

Informed Hypothetico‐Deductive Reasoning Based on Clinical Signs for Diagnosis of Equine Laminitis Using Decision Tree Analysis

Reasons for performing studyEffective diagnosis of equine laminitis is necessary to allow prompt instigation of palliative and therapeutic treatments, yet there has been limited work regarding diagnostic accuracy.ObjectivesTo compare the prevalence of clinical signs in laminitis and non‐laminitis lamenesses to evaluate the capabilities of discrimination for differential diagnosis.Study designAnalytical epidemiological study.MethodsVeterinary practitioners completed a pre‐designed checklist of laminitis‐associated clinical signs identified by literature review, for equine lameness of any origin. A case was defined as a horse/pony with veterinary‐diagnosed, clinically apparent laminitis, attended by a participating practitioner. Associations between clinical signs and case/control status were tested by logistic regression with adjusted odds ratios and 95% confidence intervals, with veterinary practice as a fixed effect, and Wald P‐value calculated. Multivariable analysis using graphical classification tree‐based statistical models allowed comprehension of the prevalence in the data associated with particular clusters of clinical signs.ResultsData were collected for 588 laminitis cases and 201 non‐laminitis lamenesses. The overall prevalence of specific clinical signs ranged from 2.7% for ‘sole prolapse’ to 85.0% for ‘lame at trot’. Differences in prevalence ranged from −14.1% for ‘lame at trot’ (more common in controls) to +71.9% for ‘short stilted gait at walk’ (more common in cases). Five clinical signs had a difference in prevalence of greater than +50%: ‘reluctance to walk’, ‘short, stilted gait at walk’, ‘difficulty turning’, ‘shifting weight’ and ‘increased digital pulse’. Bilateral forelimb lameness was the best discriminator (92% of animals with this clinical sign had laminitis). The additional presence of increased digital pulses improved this to 99%. Flat/convex sole, shifting weight and short stilted gait at walk were also useful discriminators.ConclusionsThis is the first study to provide information aiding diagnostic hypothetico‐deductive reasoning based on clinical signs to differentially diagnose laminitis from other lamenesses.Ethical animal research: Ethical approval obtained from Royal Veterinary College. Owners gave informed consent for their horses' inclusion in the study. Sources of funding: Project funded by World Horse Welfare. C.E. Wylie currently funded by The Margaret Giffen Charitable Trust. Competing interests: None declared.

Quantitative assessment of the equine hoof using digital radiography and magnetic resonance imaging.

Evaluation of laminitis cases relies on radiographic measurements of the equine foot. Reference values have not been established for all layers of the foot. To establish normal hoof wall and sole measurements using digital radiography (DR) and magnetic resonance imaging (MRI) and to document tissue components present in the dorsal hoof wall and solar layers seen on DR. Prospective observational case-control study. Digital radiography and MRI were performed on 50 cadaver front feet from 25 horses subjected to euthanasia for nonlameness-related reasons. Four observers measured hoof wall (dorsal, lateral and medial) and sole thickness (sagittal, lateral and medial) using DR and magnetic resonance images. One observer repeated the measurements 3 times. Inter- and intraobserver correlation was assessed. Digital radiography and MRI measurements for the normal hoof wall and sole were established. Inter- and intraobserver pairwise Pearson's correlation for DR (r>0.98) and MRI measurements (r>0.99) was excellent. Based on MRI, the less radiopaque layer on DR is comprised of the stratum lamellatum and stratum reticulare. Normal DR and MRI measurements for the hoof wall and sole were established. On DR images, the less radiopaque layer of the foot observed corresponds to the critical tissues injured in laminitis, the strata lamellatum and reticulare. These reference measurements may be used by the clinician to detect soft-tissue changes in the laminitic equine foot and provide a foundation for future research determining changes in these measurements in horses with laminitis.

Pathology of Natural Cases of Equine Endocrinopathic Laminitis Associated With Hyperinsulinemia.

Laminitis in equids is a clinical syndrome usually associated with systemic disease. Endocrinopathies recently have been recognized as the most common cause of laminitis, with hyperinsulinemia playing a key role. Descriptions of laminitis-associated lesions have been confusing due to the wide range of experimental models used, failure of adequate clinical documentation for naturally occurring cases, lack of separate analysis of inflammatory and endocrinopathic laminitis, and uncertainty regarding normal morphological variation of lamellae. In this study, lamellar morphology and pathology were described in 14 laminitic horses and ponies that had hyperinsulinemia (>20 mIU/l), with reference to 25 age- and breed-matched controls. The type and severity of lesions noted had no correlation with reported clinical duration and in at least some cases must have preceded it. Lesions were largely localized abaxially within the lamellar tissue and included apoptotic cell death, as well as lamellar fusion, hyperplasia, and partial replacement with aberrant keratin containing nucleated debris and proteinaceous lakes. The lesions resulted in irregular margins between the inner horn and the lamellar tissue. Acute separation originated from the abaxial region, with minimal associated inflammation. Axially, epidermal lamellar tapering was the most frequent morphological observation. The lesions in these chronic cases of laminitis were similar to those described in some inflammatory laminitis models and contained features seen in developmental phases of hyperinsulinemic models. These findings support the theory that repeated episodes of subclinical laminitis occur prior to clinical presentation. In addition, the pathology does not include extensive basement membrane failure seen in some inflammatory models.

‘Riding the Rollercoaster’: Veterinary Experiences of Managing Laminitis in Practice

Reasons for performing studyLittle is reported about the successes and challenges experienced by veterinary surgeons while managing cases of laminitis. Such information could enhance the effectiveness of communication of management and preventive health strategies for laminitis.ObjectivesTo explore veterinary surgeons’ experiences of dealing with laminitis and examine how veterinary–client communication influences the treatment and management of cases.Study designFocus group discussions conducted among first‐opinion equine veterinary surgeons.MethodsFirst‐opinion ambulatory veterinary practices from Cheshire (n = 15), Lancashire (n = 14) and the Rutland region (n = 14) were identified. Letters of invitation were sent and all practices were telephoned to invite veterinary surgeons to participate in the study. Key questions relating to laminitis were explored within semi‐structured focus group discussions: veterinary perceptions of laminitis information, reasons for horse‐owners’ seeking veterinary advice, veterinary perceptions of horse‐owners’ knowledge, attitudes and practices, situations where the advice of other professionals may be sought. All discussions were recorded and transcribed verbatim. A thematic analysis was conducted using NVivo software.ResultsThree focus group discussions were held with veterinary surgeons with a range of experience; 2 in the North West (9 vets) and one in Rutland (4 vets). Emerging themes relating to veterinary surgeons’ experience of dealing with laminitis included; veterinary–client communication, challenges faced by vets, managing clients perceptions and expectations, client recognition and management of laminitis, feeding and obesity management, issues of compliance, causes of laminitis, strategies to prevent laminitis, diagnosing, treating and prognosticating in laminitis cases, sources of veterinary information and collaboration with other professionals.ConclusionsThe findings illustrate key features of the veterinary–client relationship in supporting owners through the variable course of this disease. This study demonstrates the complexity of issues that veterinary surgeons may encounter when managing cases of laminitis and communicating healthcare messages to the client.Ethical animal research: This project was approved by the University of Liverpool Ethics for Research Committee. Sources of funding: The authors gratefully acknowledge support and funding from the BVA Animal Welfare Foundation charitable trust. Competing interests: None.