Concentrations of Selected Adipocytokines in the Blood Plasma in Proximal Suspensory Desmopathy of Horses, with a Focus on Their Physical Activity-A Pilot Study.

Chronic tendon and ligament diseases are commonly encountered in both athletic humans and animals, especially horses. Distal limb diseases, including suspensory ligament (SL) pathology due to anatomical, histological, and biomechanical properties, can be considered a model for tendon and ligament pathologies in humans. The appropriate selection of therapy is often crucial in optimising the healing process. One decisive factor influencing the possibility of returning to pre-disease training levels appears to be the utilisation of physical activity, including controlled movement, during the rehabilitation process. In the pathogenesis of musculoskeletal diseases and rehabilitation, adipocytokines play diverse roles. However, it is unclear what significance they hold in horses and in specific disease entities as well as the consequences of their mutual interactions. Recent studies indicate that in the pathogenesis of diseases with varied aetiologies in humans, their value varies at different stages, resulting in a diverse response to treatment. The results of this study demonstrate lower resistin concentrations in the venous blood plasma of horses with proximal suspensory desmopathy (PSD), while higher levels were observed in regularly trained and paddocked animals. The horses investigated in this study showed higher concentrations of resistin and IL-8, particularly in paddocked horses as well as in the working group of horses. The results suggest that these concentrations, including resistin in blood plasma, may be clinically significant. This attempt to explore the aetiopathogenesis of the processes occurring in the area of the proximal attachment of the suspensory ligament may optimise the procedures for the treatment and rehabilitation of horses.

Standing low-field MRI of the equine proximal metacarpal/metatarsal region is considered useful for diagnosing primary bone pathology and makes a positive contribution to case management: A prospective survey study.

High-field MRI of the proximal metacarpal/metatarsal region has been associated with great diagnostic potential and clinical reports of standing low-field MRI of the forelimb suggest the same. To better understand diagnostic outcomes with standing low-field MRI of the proximal suspensory region, a prospective survey study was conducted and users of a widely available system questioned on their experience, operating procedures, and interpretation of standing low-field MRI findings. Response data included scores on a modified Likert scale from which weighted ratings were calculated for statistical analyses. Depending on the question, responses were obtained from 17 to 29 of the 38 invited facilities. Users indicated that standing low-field MRI was most frequently performed in the face of equivocal diagnostic findings; compared to Sports horses, general purpose riding horses were thought less likely to have detectable abnormalities and standing low-field MRI was rated most useful for the detection of primary bone pathology in the proximal metacarpal region. Standing low-field MRI signal change involving both the suspensory ligament and adjacent bone concurrently was rated most relevant and abnormalities solely affecting the muscle/adipose tissue bundles least relevant for diagnosing suspensory ligament injury. Transverse scans and in decreasing order T1-weighted gradient echo, short-tau inversion recovery FSE, T2*-weighted gradient echo, and T2-weighted FSE sequences were most frequently acquired and judged most useful by the majority of users experienced in imaging of the target area. This survey supports the relevant impact of standing low-field MRI on clinical case management, particularly in the context of imaging the proximal metacarpal region.

Intermediate patellar ligament desmopathy often occurs in conjunction with other stifle abnormalities.

Intermediate patellar ligament (IPL) desmopathy is a relatively uncommon injury previously reported to have a poor prognosis for return to athletic activity. There is little documentation of the clinical and ultrasonographic features, clinical significance, and outcome for return to work following IPL injury in horses. The aim of this retrospective descriptive study was to describe the clinical and ultrasonographic features of IPL desmopathy, its association with other injuries of the stifle, and outcome for return to work following injury. Forty-two stifles with an ultrasound diagnosis of IPL desmopathy over a 5-year time period were included. Data regarding signalment, clinical presentation, diagnostic imaging findings, treatment, and outcome are described. Intermediate patellar ligament desmopathy occurred most commonly in the midbody (35/42; 83%) of the ligament and lesions were predominantly hypoechoic discrete tears (31/42; 74%) that were obliquely oriented in a craniolateral to caudomedial direction (28/42; 67%). Rarely (1/42; 2%) was IPL desmopathy the only ultrasonographic abnormality detected. Of 13 horses that underwent recheck ultrasound examination, the majority (11/42; 85%) either did not improve or worsened ultrasonographically. Despite this, of 25 horses with long-term follow-up, 23 (92%) returned to work, 16 at the same level or higher. A variety of treatments were utilized. The clinical significance of IPL desmopathy is difficult to determine because it is usually found in conjunction with other stifle abnormalities. Although IPL desmopathy rarely shows ultrasonographic improvement over time, prognosis can be good for return to work.

IMAGING DIAGNOSIS-RADIOGRAPHY AND COMPUTED TOMOGRAPHY OF RADIOULNAR ISCHEMIC NECROSIS IN A JACK RUSSELL TERRIER.

A 7-year-old Jack Russell Terrier with a history of minor trauma was presented for lameness of the left forelimb. Radiography and computed tomography demonstrated a localized radioulnar osteolytic lesion with cortical bone loss and enthesiophytes. Based on results of diagnostic imaging and histopathological examination, the final diagnosis was radioulnar ischemic necrosis (RUIN), complicated by pathologic fracture. A rare disorder of unknown etiology, RUIN may be secondary to tearing of the interosseous ligament and potential ischemia. It should be differentiated from neoplastic or fungal disease. To the authors´ knowledge, this is the first canine case report describing RUIN.

Accuracy of low-field magnetic resonance imaging versus radiography for guiding injection of equine distal interphalangeal joint collateral ligaments.

Desmopathy of the distal interphalangeal joint collateral ligament is a common cause of lameness in the horse and carries a variable prognosis for soundness. Intralesional treatment has been proposed for improving outcome; however, limited reports describe methods for injecting this ligament. The purpose of this study was to compare accuracy of low-field magnetic resonance imaging (MRI) vs. radiography for injecting the collateral ligament of the distal interphalangeal joint. Equine cadaver digit pairs (n = 10) were divided by random assignment to injection of the ligament by either technique. An observer unaware of injection technique determined injection success based on postinjection MRI and/or gross sections acquired from the proximal, middle, and distal portions of the ligament. McNemar's test was performed to determine statistical difference between injection techniques, the number of injection attempts, and injection of the medial or lateral collateral ligament. Magnetic resonance imaging guided injection was successful more frequently than radiographic-guided injection based on postinjection MRI (24 of 30 vs. 9 of 30; P = 0.0006) and gross sections (26 of 30 vs. 13 of 30; P = 0.0008). At each level of the ligament (proximal, middle, and distal), MRI-guided injection resulted in more successful injections than radiographic guidance. Statistical significance occurred at the proximal aspect of the collateral ligament based on postinjection MRI (P = 0.0143) and the middle portion of the ligament based on gross sections (P = 0.0253). Findings supported future testing of standing, low-field MRI as a technique for delivering intralesional regenerative therapy in live horses with desmopathy of these collateral ligaments.

Concurrent radiological and ultrasonographical findings in the forelimb proximal sesamoid bones and adjacent suspensory ligament branches in yearling and 2-year-old Thoroughbred sales horses.

BACKGROUND: Changes in the proximal sesamoid bones (sesamoids) and the insertional region of the adjacent suspensory ligament branch (branch) are of particular importance in young Thoroughbreds sold at public auction. Little is known about the prevalence of concurrent ultrasonographical branch change, relative to the various grades of radiological sesamoid appearance. OBJECTIVE: To examine the existence of concurrent radiological and ultrasonographical findings in individual sesamoid-branch units in sales horses; to determine whether there are any radiological findings that are consistently accompanied by a particular degree of insertional branch change, and to provide practical recommendations as to when suspensory branch ultrasonography may be warranted in a sales environment. STUDY DESIGN: Prospective cohort study using an enrolled sample. METHODS: Horses were enrolled with consignor permission from a large Thoroughbred yearling sale and five 2-year-old Thoroughbred sales the following year. Data from the radiological evaluation of forelimb sesamoids and the ultrasonographical examination of the adjacent forelimb suspensory branches were described. RESULTS: A total of 2204 yearling forelimb sesamoid-branch units and 1336 2-year-old forelimb sesamoid-branch units were included, from 551 sales yearlings and 334 sales 2-year-olds. The proportion of yearling sesamoids with grade ≤1 vascular channels that had adjacent grade ≥2 fibrillar branch change was 1.2%. The same proportion for 2-year-olds was 3.8%, with medial forelimb sesamoids with grade 1 vascular channels overrepresented in 2-year-olds in this category. In yearlings, 31% of sesamoids with grade 2 vascular channels had adjacent grade ≥2 fibrillar branch change and 59% of sesamoids with grade 3 vascular channels had adjacent grade ≥2 fibrillar branch change. In 2-year-olds, 47% of sesamoids with grade 2 vascular channels had adjacent grade ≥2 fibrillar branch change and 67% of sesamoids with grade 3 vascular channels had the same. Only one yearling sesamoid and one 2-year-old sesamoid with radiological abaxial concavity had grade ≥2 fibrillar branch change. MAIN LIMITATIONS: Hindlimbs were not included. Clinical examinations were not performed and the status of any past or present inflammatory process at the sesamoid-branch enthesis could not be inferred from radiographs and ultrasonographic images alone. CONCLUSIONS: The existence and prevalence of concurrent radiological and ultrasonographical findings in the proximal sesamoid bones and adjacent suspensory ligament branches in yearling and 2-year-old Thoroughbred sales horses has been established. General recommendations have been made for selective branch ultrasonography on the basis of radiological sesamoid appearance. The results support a separate aetiology for radiological sesamoid abaxial concavity that does not primarily involve the suspensory branch insertion.

The prognosis for return to athletic function for Thoroughbred racehorses in Hong Kong with injuries to the palmaroproximal aspect of the metacarpus diagnosed using low-field magnetic resonance imaging.

OBJECTIVE: To evaluate and compare the prognosis for Thoroughbred racehorses to return to galloping and racing with injuries to the palmaroproximal metacarpus diagnosed with MRI. ANIMALS: 29 flat racing Thoroughbreds at the Hong Kong Jockey Club that underwent MRI between 2014 and 2022. METHODS: Clinical, radiographic, ultrasonographic, and MRI reports were collected from veterinary clinical records, and these were combined with training and racing data. Horses were categorized on the basis of MRI diagnosis: (1) proximal suspensory ligament (PSL) involvement only, (2) PSL and concurrent proximal third metacarpal (MC3) bone involvement, and (3) proximal MC3 bone involvement only. The following were compared for prognosis for return to athletic function: return to galloping or racing, and reinjury. RESULTS: Overall, the prognosis for return to athletic function was fair, with 92% (22/24; P = .53) and 67% (16/24; P = .73) of horses returning to galloping and racing, respectively. There was a relatively low reinjury rate, with 18% (4/22) of horses reinjuring. Horses with concurrent injury to both the PSL and proximal MC3 bone (Category 2) took longer to return to gallop (median, 116; IQR, 100.5 to 160), when compared with horses having only PSL injury (median, 69; IQR, 43 to 80; P = .04). Of the 4 horses that reinjured, 3 (75%) were horses in Category 2. CLINICAL RELEVANCE: The findings from this study suggest that injuries involving both PSL and proximal MC3 bone concurrently require a longer rehabilitation period than those with PSL involvement alone.

Percutaneous ultrasonic debridement of equine tendinopathy and desmopathy: A report of 10 cases.

Background: Tendinopathy and desmopathy are significant causes of morbidity in horses. Aim: To evaluate the use of percutaneous ultrasonic debridement (PUD) as a treatment for chronic tendinopathy and desmopathy in the horse. Methods: Eight adult horses with 10 affected limbs presented for lameness, ranging from 60-700 days postinjury. Diagnostic ultrasound identified the following: suspensory branch desmitis (n = 1), suspensory body desmitis (n = 2), Achilles tendinopathy (n = 1), desmitis of the accessory ligament of the deep digital flexor (DDF) tendon (n = 1), DDF tendinopathy (n = 2), and superficial digital flexor tendinopathy (n = 3). All horses had demonstrated lameness ranging from grade 1 to 4 [American Association of Equine Practitioners (AAEP) scale], with a mean pretreatment grade of 2.7. All horses underwent PUD using the Tenex Health TX® System. Results: Follow-up results were available from 6 to 41 months (mean, 23.2 months). Follow-up ultrasound imaging demonstrated improvement in fiber alignment and architectural change in all cases. All horses had a reduction in lameness from the treated tendon or ligament (AAEP grade 0-1; mean AAEP grade, 0.2) following a single treatment; lameness completely resolved in 8 of 10 treated limbs. No adverse events occurred in any case. No horses in this study developed a recurrence of their original lesion. Conclusion: Horses in this study demonstrated improvement following the PUD procedure. The procedure was well-tolerated and safe. Removal of tendinopathic scar tissue with PUD resulted in a return to function and without recurrence of the original lesion in all horses.

Application of the Ridden Horse Pain Ethogram to 150 Horses with Musculoskeletal Pain before and after Diagnostic Anaesthesia.

The Ridden Horse Pain Ethogram (RHpE) was developed to facilitate the recognition of musculoskeletal pain. The aim of this study was to document changes in RHpE scores before and after diagnostic anaesthesia was performed to alleviate pain ± when the saddle was changed. One hundred and fifty horses underwent ridden exercise as part of an investigation of poor performance. The RHpE was applied before and after the interventions. Fifty-two (34.7%) horses exhibited a bilaterally symmetrical short step length and/or restricted hindlimb impulsion and engagement. Fifty-three (35.3%) horses had episodic lameness; only forty-five (30.0%) horses were continuously lame. The median maximum lameness grade when ridden was 2/8 (interquartile range [IQR]: 0-3; range: 0-4). Fifty-six (37.3%) horses had an ill-fitting saddle, which was considered likely to influence performance. The median RHpE scores after the interventions (2/24 [IQR: 1-3, range: 0-12]) were significantly lower than before the interventions (9/24 [IQR: 8-11, range: 2-15]) (Wilcoxon signed-rank z = 10.6, p < 0.001). There was no correlation between the RHpE score and maximum lameness grade before diagnostic anaesthesia (Spearman's rho = 0.09, p = 0.262). It was concluded that the absence of overt lameness does not preclude primary musculoskeletal pain. Gait quality and performance can be improved by diagnostic anaesthesia, with substantial reductions in RHpE scores.

Incidence of Patellar Desmopathy in the Modified Maquet Technique with and without PRGF.

Patellar desmopathy can lead to desmitis, discomfort, and lameness. In the traditional MMT, a pin is used for the fixation of the fragment of the osteotomized tibia to the implant and the tibial diaphysis; this pin needs to be placed below the insertion of the patellar ligament to avoid damaging it. Considering the differences between TTA and MMT, the authors consider it important to determine the incidence of patellar desmopathy in the MMT. This is a prospective study that enrolled 53 owned dogs that underwent MMT and were followed up by a complete examination and radiograph controls to establish the patellar tendon thickening and the presence of clinical desmitis. The PRGF were administrated to 29 of those patients, in order to determine if PRGF's action could decrease ligament desmitis. The conclusions in this study were that the desmopathy produced by the MMT is similar to that generated by the TTA if the pin is carefully placed; in addition, the PRGF did not decrease the inflammation and the thickening of the ligament.

Magnetic resonance imaging and histopathological evaluation of equine oblique sesamoidean ligaments.

BACKGROUND: Pathology involving the oblique sesamoidean ligaments (OSLs) is commonly diagnosed during magnetic resonance imaging (MRI) of the equine distal limb. Presence of striations within the ligament and magic angle artefact can result in an incorrect diagnosis of pathological change. No studies have been performed using histopathology, the gold standard, to corroborate their imaging diagnosis. OBJECTIVES: (a) To determine which MRI characteristics are associated with normal vs abnormal OSLs and (b) to evaluate the ability of MRI to correctly identify abnormal vs normal oblique sesamoidean ligaments using histopathology as the gold standard. STUDY DESIGN: Observational, cross-sectional study. METHODS: Cadaver limbs (n = 77) were obtained from horses (n = 21) subjected to euthanasia at the hospital. MRI and histopathology was performed on each of the limbs. MRI scoring was performed for multiple MRI characteristics, and each limb was deemed normal or abnormal. Histopathology scoring was performed to give an overall score of normal or abnormal. Mixed model logistic regression was performed to evaluate which MRI characteristics were associated with normal vs abnormal OSLs using backwards elimination and a significance level of <0.1. Sensitivity and specificity were also calculated. RESULTS: The sensitivity and specificity of MRI to correctly identify abnormal OSLs was 81% (95% CI 54%-96%) and 90% (95% CI 79%-96%) respectively. Based on logistic regression, increased cross-sectional area at the origin (OR: 26.77, 95% CI 1.1-4640, P = .07), increased ligament hyperintensity (OR: 9.59, 95% CI 1.23-155; P = .04) and reduction in striations (increased hypointensity score) (OR: 7.8, 95% CI 0.72-218, P = .07) were associated with abnormal OSL. MAIN LIMITATIONS: Lameness exam was not performed on any of the horses prior to euthanasia. Findings can only be applied to chronic, degenerative changes, rather than an acute injury. CONCLUSIONS: Increased cross-sectional area and changes in the signal intensity are associated with pathology within the OSLs. Medial to lateral size asymmetry and striation pattern variation can occur in histologically normal OSLs and should be interpreted with caution if other signs of pathology are absent.

Subclinical Ultrasonographic Abnormalities of the Suspensory Ligament Branches Are Common in Elite Showjumping Warmblood Horses.

Background: There is limited information concerning the ultrasonographic appearance of suspensory ligament branches (SLB) in sports horses. Publications exist on clinical injuries that lead to loss of training days and retirement, but not on the appearance of SLBs in high level showjumping Warmbloods. Objectives: To demonstrate the prevalence of subclinical SLB abnormalities in regularly competing high-level showjumpers; to grade each branch 0-3; compare forelimb vs. hindlimb and medial vs. lateral SLBs; subjectively assess periligamentous fibrosis; measure cross sectional area (CSA) and to gather competition follow-up data. Study Design: Prospective cross-sectional study using ultrasonograms. Methods: Sixty elite showjumping Warmbloods without recent history or clinical signs of SLB desmopathy were examined ultrasonographically. Eight static images of each SLB were acquired in transverse and longitudinal sections, anonymised and stored. Images were then assessed and graded by two experienced blinded clinicians based on a published ordinal scale (grade 0-3). A branch score was assigned based on the most severe grade of any image slice in each branch series. SLB cross-sectional area measurement was obtained from each SLB using the transverse image proximal to insertion. Results: The frequency of grade 2 (moderate) ultrasonographic abnormalities was high. Combined data showed a prevalence of 58% (554/960) grade 2 SLBs. Interobserver agreement was good (kappa = 0.65). Periligamentous fibrosis was over represented in hindlimbs (64%). Combined observer data showed there was no statistical difference in branch scores based on limb or laterality. Follow-up over 12 months revealed only two horses were excluded from competition due to SLB injury. Main Limitations: Sample size was small. Images were obtained in static mode, limbs were not clipped of hair, lameness evaluation was under FEI veterinary inspection and not performed by the authors and follow-up evaluation was from FEI competition records and communication only, and was limited to 1 year. Conclusions: Regularly competing elite showjumping Warmbloods have a high prevalence of subclinical SLB ultrasongraphic abnormalities, which may not contribute to causing lameness, poor-performance or be viewed entirely negatively at prepurchase examination. Judicious interpretation of moderate severity SLB abnormalities is advised due the low incidence of clinical injury demonstrated during the 1 year follow-up.

Equine suspensory ligament and tendon explants cultured with platelet-rich gel supernatants release different anti-inflammatory and anabolic mediators.

The aim of this study was to evaluate the release of pro- and anti-inflammatory as well as anabolic mediators stimulated by a leukocyte-reduced platelet-rich gel supernatant (Lr-PRGS) and a leukocyte-reduced plasma supernatant (Lr-PL) at two concentrations (25 and 50%) on normal equine suspensory ligament explants (SLEs) and tendon explants (TEs). SLEs and TEs from six horses were independently incubated for 48 h with Lr-PRGS and Lr-PL at concentrations of 25 and 50%, respectively. Samples were collected from the incubated tissues at 1 h and 48 h, which were employed for ELISA determination of interleukin 1 beta (IL-1ß), tumor necrosis factor alpha (TNF-α), IL-4, IL-1 receptor antagonist (IL-1ra), platelet-derived growth factor isoform BB (PDGF-BB), transforming growth factor beta-1 (TGF-ß1, and hyaluronic acid (HA). Overall, 50% Lr-PRGS induced significantly less IL-1ß release than the other hemoderivatives in both tissues. At 48 h, both Lr-PRGS and 25% Lr-PL induced significantly higher TNF-α concentrations in SLEs when compared to TEs, whereas both Lr-PRGS concentrations induced significantly higher IL-4 concentrations in SLEs in comparison to TEs. IL-1ra release was not different between tissues. However, this cytokine was significantly higher in tissue explants cultured with both Lr-PRGS concentrations. HA concentration was lower in tissue explants cultured with all hemoderivatives at two concentrations when compared to the control group. The positive effects observed for ligaments and tendons treated with Lr-PRGS may be mediated by the inhibition of IL-1ß release of and increased release of IL-4 and IL-1ra. Furthermore, PDGF-BB could be a polypeptide responsible for mediating the release of anti-inflammatory cytokines in SLEs and TEs incubated with Lr-PRGS.

Ultrasonographic appearance of normal and injured lateral patellar ligaments in the equine stifle.

REASONS FOR PERFORMING STUDY: Ultrasound is widely used in horses with stifle lameness, yet limited information is available regarding the appearance of normal and injured lateral patellar ligaments (LPL). OBJECTIVES: To map the normal ultrasonographic appearance of the LPL. To describe the clinical and ultrasonographic features of LPL injuries. STUDY DESIGN: Descriptive study of healthy horses and retrospective case series. METHODS: Twelve horses without stifle lameness underwent ultrasonographic examination of bilateral LPLs and ultrasonographic features were recorded. Eighteen horses with LPL injury were identified from 1999 to 2011. RESULTS: The normal LPL changes in appearance from origin to insertion. It shows ill-defined margins at the patella, becomes flattened and bilobed over the lateral trochlear ridge, is oval-triangular shaped with variable echogenicity and fibre pattern distal to the LTR, and becomes tapered with striations at the tibial insertion. LPL injury was identified in 18 horses of multiple breeds and uses. All injuries were acute, and 12 had wounds. Eleven horses were severely lame (grade 4-5/5). Ultrasonographic lesions were severe in 78% of cases. The mid to insertional portion of the LPL was most often affected. Radiography showed fractures of the tibial tuberosity (n = 6), patella (n = 4) and lateral trochlear ridge (n = 1). Fractures involved LPL attachments in 9 horses. Five were treated for osteomyelitis and one for synovial sepsis. Recheck ultrasound in 4 horses showed minimal to no change in the appearance of LPL injuries. Nine horses returned to riding, one continued as a broodmare, 2 were retired, one became a broodmare, 2 were lost to follow-up and 3 were subjected to euthanasia owing to concurrent injuries. CONCLUSION: Normal variations in shape, echogenicity and fibre pattern of the LPL are important considerations to prevent false positive diagnoses during ultrasonography. LPL injuries were often severe and associated with craniolateral stifle trauma. Prognosis varied from good to guarded in horses without additional severe injuries.

Desmopatia degenerativa em equinos: métodos de diagnóstico em animais vivos / Equine degenerative desmopathy: diagnostic methods in live animals

A desmopatia degenerativa (DD) possui caráter sistêmico e manifesta-se por acúmulos de proteoglicanos (PG) na matriz extracelular (MEC) de tecidos que contenham colágeno. Este estudo teve o objetivo de diagnosticar equinos suspeitos de serem acometidos por DD, em um plantel de animais de raça nacional, segundo o ângulo da articulação metatarsofalangiana (AMF) e a presença de acúmulos de PG em amostras de ligamento da nuca (LN). Analisaram-se 123 equinos clinicamente sadios e somente três (2,7 por cento) deles, segundo o ângulo AMF < 146(0), foram considerados suspeitos. Não houve diferença significativa entre os grupos. Quinze éguas foram submetidas ao exame do ângulo da AMF e à biópsia do LN, das quais sete (47,7 por cento) foram consideradas suspeitas, segundo ângulo da AMF, enquanto seis (40 por cento) apresentaram acúmulos de PG. Foram encontrados acúmulos de PG em três (20 por cento) éguas não suspeitas. Um animal suspeito não apresentou alterações histológicas compatíveis de DD.

The prevalence of degenerative desmopathy (DD) was studied in equines of national breeds, according to the metatarsophalangeal joint angle (MPA) and the presence of accumulation of proteoglycans (PG) in samples of nucal ligament (NL) from live animals, according to their age. One hundred twenty three clinically healthy horses were used. Only three (2.7 percent), that had their angle rate MPA<146º were considered suspect, with no significant difference between groups. Fifteen mares were subjected to examination of the angle of the MPA and biopsy of NL as well had reduction of the MPA angle, and six (40 percent) showed accumulation of PG. Accumulation of PG was found in three (20 percent) not suspected mares. A suspected animal showed no histological changes compatible to DD.