Background: There is a concern that performing routine dental floats could result in adverse pregnancy outcomes in mares. There is a paucity of data on the effect of dentistry during pregnancy in domestic species. In women, dental prophylaxis is considered safe during pregnancy. Objectives: The objective of this study was to determine if routine dental floating was associated with adverse pregnancy outcomes in Thoroughbred broodmares. Study Design: Retrospective records analysis Methods: Clinical and farm records from 2013 to 2021 were utilized. Abortion, stillbirth and placentitis was modeled using SAS GLIMMIX procedure. Time of the dental procedure was categorized in two ways, occurring when the mares were 1) open or pregnant or 2) open, during the 1st trimester (0 – 114 days), the 2 nd trimester (115 – 228 days) or the 3 rd trimester (> 229 days) of pregnancy for separate models for each outcome. Significance was set at P < 0.05. Results: Both logistic regression models examining abortion found age of mare at the time of float remained significant, while trimester of dental procedure, farm and year float was performed were not significant. Both logistic regression models examining stillbirth found the age of the mare at the time of float remained significant, with location being significant in the first model (open or pregnant) and a tendency (0.10 > P > 0.05) in the second model (open, 1 st, 2 nd, or 3 rd trimester). Other variables in the models were not significant. Farm remained significant in both logistic models of placentitis, while age of mare at the time of float, trimester of dental float and year float was performed were not significant. Main Limitations: Not a controlled study. Conclusions: Floating a mare’s teeth during each trimester of pregnancy is a safe procedure.

Background: Betulinic acid, a natural pentacyclic triterpenoid, has been studied for its anti-inflammatory and anti-tumoural properties in various species. Recent in vitro and in vivo work has shown promise for treatment of equine skin tumours’ in horses. Objective: The objective of this study is to evaluate the safety and efficacy of a compounded 1% betulinic acid cream for the treatment of equine cutaneous melanoma and sarcoid in clinical cases. Study Design: Prospective randomized, blinded, placebo-controlled clinical trial. Methods: In select cases, biopsies were performed to confirm the diagnosis prior to enrolment. Photographs and measurements were obtained before and after the trial period. A compounded 1% betulinic acid or placebo cream was applied twice daily for 7 days, then once daily for 21 days. Owners completed a daily questionnaire to evaluate adverse reactions. Tumour volume was calculated based on width and length measurements using an established model. Mann-Whitney U tests were used to evaluate the change in tumour volume between groups. Results: A total of 37 horses completed the clinical trial, 16 horses with melanoma and 21 horses with sarcoid tumours. There were no significant differences in the change in tumour volume between treatment and placebo groups for either tumour type. The compounded cream was well tolerated. Main Limitations: This study was limited by owner subjectivity in application and questionnaires. Follow-up tumour measurements were not always performed by the same veterinarian. Conclusions: Based on this data, application of a compounded 1% betulinic acid cream was safe but did not result in a statically significant reduction in tumour volume for equine melanoma or sarcoid during a 30-day application period compared to a placebo. In general, tumour volume decreased in all groups and clinical trials evaluating the compound at twice daily application for an extended application period would be valuable.

Twelve suckling foals with nasal discharge, aged five to seven months, were treated in field conditions with the application of trimethoprim and sulfadiazine, anthelmintics and macrolids with rifamycins. Five days after clarithromycin with rifampin was administered, one foal died, and a second foal became colicky. The second foal underwent colic surgery and was then euthanised due to severe large colonic oedema. This finding was identical to that of the first non-survived foal. The following day, colic behaviour and colitis were present in additional two foals. These foals did not respond to anti-endotoxemic and supportive therapy, and when circulatory collapse with pleural effusion developed, they were euthanised. The remaining eight foals were diagnosed at the home stable with the same findings. Ultrasound confirmed massive oedema of the large colon, but with only slight changes in the lungs. All remaining foals were managed with transfaunation. Five of the foals improved within twelve hours, and the other three, those with the most severe colon oedema, were treated intensively at the clinic with antibiotics, repeated transfaunation and supportive care. The main symptoms of significant disturbance of the microbiome included colic, colon oedema and, in the worst-affected foals, final stage pleural effusion. Repeated transfaunation significantly improved the health status of the foals and halted the development of the symptoms displayed by the first four foals.

A five-year-old Oldenburg maiden mare presented for reproductive evaluation following several months, where the owner noticed the mare exhibiting irregular behavioral estrus. After an initial attempt to manage the mare with an estrus suppression medication, a more thorough investigation was performed, ultimately leading to the identification of several reproductive anatomical abnormalities and sex chromosome karyotyping, which allowed for the diagnosis of sex chromosome mosaicism. Based on a recent literature search, this is the first report of 64,XX/64,XY/63,XO mosaicism in a mare, where abnormal and irregular behavioral issues were the primary presenting sign. This report describes the clinical signs and diagnostic investigation that led to the eventual diagnosis and further discusses how such a common and seemingly innocuous presenting problem, can have a complex underlying etiology, with significant implications for the horse’s future working, and reproductive potential.

Medications selected to treat problems of pregnancy in the mare must be simultaneously safe for the mare, safe for the developing fetus, and able to penetrate the placental barrier. With consideration of these factors, the practitioner must determine when and for how long to administer therapy. Monitoring equine pregnancy can be challenging, owing to the size of the equine abdomen (precluding visualization of the entire fetoplacental unit), individual variation in appearance of the reproductive tract, and (typically) minimal clinical signs of pregnancy compromise until late in a disease process. This paper is an extension of an article originally prepared for the 2023 Proceedings of the American Association of Equine Practitioners, produced with permission.

This case report describes a Thoroughbred broodmare presented for colic and pyrexia. The mare had a history of repeated urinary tract infections, placentitis, abortion and endotoxaemia. A diagnosis of bilateral subcapsular renal haematoma was made by ultrasonography and standing laparoscopy and confirmed on post-mortem. Trauma, clotting disorder, and neoplasia were ruled out as a cause of the bleeding. However, histopathology revealed severe, diffuse, acute fibrinosuppurative tubulointerstitial nephritis with degeneration of vascular walls, suggesting that this has caused renal bleeding and development of subcapsular hematomas.

A 13-year-old Belgian jumping mare was presented with acute onset of severe left forelimb lameness after a jumping competition. Radiographic images showed the presence of periosteal new bone formation on the lateral radial eminence, while ultrasonographic images revealed a severe injury of the lateral collateral ligament of the elbow associated with severe proliferative synovitis of the humeroradial joint. The rehabilitation program consisted of hand walking for five weeks and progressive increase of controlled exercise duration for an additional 16 weeks. Therapeutic ultrasound and pulsed electromagnetic field were also applied. Repeated radiographic and ultrasonographic images after six weeks showed inactivity of the insertional pathology (smooth outline and homogenous radiopacity), marked improvement in the echogenicity and fibrillary pattern, reduction in size, resolution of the oedema, and joint distension. No signs of elbow osteoarthritis were detected. The horse retuned to its normal activity 22 weeks after the time of diagnosis. Injuries of the lateral collateral ligament of the elbow are rare and are frequently reported as traumatic and with poor prognosis. This case demonstrated that a severe lesion can result in a favorable prognosis for return to athletic activities with correct diagnosis and appropriate therapeutic multimodal approach.

Lymphoma in horses is uncommon and rarely diagnosed as the cause of ataxia in horses. This case report describes a two-year-old Standardbred cryptorchid colt who presented with acute onset of grade 3.5/5 ataxia. Due to the severity of the ataxia, a full neurologic examination could not be completed, and the colt was humanely euthanized. Post-mortem examination revealed multiple osteochondritis dissecans lesions in the cervical and lumbar spine. Initially this was thought to be the cause of the ataxia, however histopathology revealed multifocal areas where the spinal nerve roots and epidural surface of the dural mater of the meninges were surrounded or covered by plaques of neoplastic round cells which infiltrated the adipose tissue surrounding the spinal tissues. Atypical round cells similar to those observed in the spinal meningeal tissues were also found in the kidneys, lungs, liver, testes and one lymph node. Immunohistochemical staining of meningeal tissue samples revealed moderate to intense cytoplasmic/membranous immunoreactivity for CD20 and a diagnosis of multicentric diffuse large B cell lymphoma was made. Lymphoma should be included in the differential diagnoses for a horse presenting with ataxia and neurologic deficits

Background: Established or ongoing septic arthritis requiring repeated joint flushing remains a treatment challenge with a poor survival outcome aggravated by the necessicity of controlled antimicrobial usage. Objective: To describe the outcomes and survival rates of patients with synovial sepsis treated by lavage with a 0.05% chlorhexidine solution. Study design: Clinical retrospective observational study. Methods: Patients with synovial sepsis who underwent standing needle or arthroscopic lavage under general anaesthesia with a 0.05% chlorhexidine solution, followed by Lactate Ringer Solution (LRS). Complementary systemic and regional antibiotics were used. Short (6 months) and long term (>1 year) evolution were assessed. Results: 10 horses met the inclusion criteria. Affected joints included metacarpophalangeal joints (20%), tarso-crural joint (10%), radiocarpal and intercarpal joints (20%), distal interphalangeal joints and navicular bursa (30%), distal interphalangeal joints (20 %). Time from onset to referral ranged from 1-20 days, mean 8.3 days. Eighty percent of horses survived for more than one year. Four horses were retired to the field, three returned to a light level of work and one went back to full work. Main limitations: Retrospective study of a limited group of horses initially treated by different clinicians before referral, as such, first line treatment had differences between cases. Resolution was evaluated on clinical signs rather than clinical pathology of synovial fluid due to clinical decision or difficulty in obtaining samples. Conclusion: With this series of challenging synovial sepsis cases treated by lavage with a chlorhexidine solution we provide a treatment protocol, proof of clinical concept and report patient’s short and long-term clinical evolution. Short and long term post-operative lameness should be expected despite resolution of the septic arthritis. This treatment poses a novel option for challenging cases but should be regarded as a salvage procedure due to the possibility of long term mild lameness.

A three-year-old Warmblood filly presented with left forelimb lameness of two weeks duration with a discharging sinus over the lateral aspect of the mid-metacarpal region. The filly was diagnosed with a proximal, open, comminuted fracture of metacarpal IV (MCIV). Initial treatment with local debridement and systemic antimicrobial administration was unsuccessful, with the development of osteomyelitis which cultured a methicillin resistant Staphylococcus pseudointermedius. A subsequent segmental ostectomy was performed resulting in avulsion of proximal MCIV from metacarpal III post-operatively. Reduction and internal fixation of the displaced MCIV with cortical lag screws was performed, with immediate bone failure during recovery from general anaesthesia. The proximal MCIV was then removed under standing sedation and local anaesthesia. Subsequent development of osteoarthritis in the carpometacarpal and middle carpal joints was likely secondary to joint instability, but the horse was sound 12 months post-operatively. Despite the surgical complications in this case being previously described, there are no reports on the removal of metacarpal splint bones in the horse to the author’s knowledge. As the prognosis for this case is considered good for future athletic performance, proximal or complete MCIV resection could be considered as a possible treatment option in select cases.

Background: No safety study has been conducted regarding PRP usage in cervical facet joints Objectives: To determine whether intra- and/or peri-articular injections of PRP in cervical facet joints in the horse is safe. Study design: Prospective, multi-centre, safety study Methods: PRP was injected via ultrasound guidance into the cervical and/or cervicothoracic facet joints in horses with diagnosed cervical complaints. Data recorded for each case included: breed, sex, age, primary reason for treatment, list of which facet joints were injected, the volume of PRP injected, whether the PRP was injected intra-articular or peri-articular, gauge of needle used. Data was collected at three time points: prior to treatment, 48 hours after treatment and a minimum of 30 days after treatment. At each time point, owners/trainers were asked to assess the level of pain the horse was suffering on a 0-10 (no pain to worst) scale. At the final evaluation the owners/trainers were also asked if the treatment met their expectations on a 0-5 scale. Results: No adverse events were reported. The average pain scores prior to treatment, at 48 hours, and at 30 days were 3.8, 3.4 and 1.1 respectively (see Figure 2). At no point did any horse have an increase in their reported pain level. Main limitations: Since PRP is not classified as a drug it does not come with a label indicating items such as dosage or route of administration. Thus, methodologies will vary amongst veterinarians. Conclusions: PRP appears to be safe for cervical and/or cervicothoracic facet joint injections in the horse. Evidence for efficacy was also recorded by means of owner/trainer reporting that the injections overwhelmingly met their expectations.

The ventral and dorsal components of the ascending colon are adjoined by the ascending mesocolon, and few case reports have described congenital or acquired malformations of this structure. This case series reports the occurrence of large mesenteric rents of the ascending mesocolon ( Hernia mesocolica coli ascendentis) in 6 adult horses diagnosed during exploratory laparotomy. Based on the history of the patients, the rents were most likely acquired. The rents were mainly located directly adjacent to the left dorsal colon, and without affecting the intestinal blood supply. The size of the defect varied between 20 and 80 cm, and in 5/6 cases it was a subacute or chronic rupture with rounded edges. Two different types of intestinal displacements in relation to the rent were found, with either a localized torsion of the dorsal colon or herniation of the pelvic flexure through the rent. In all cases, the intestine could be repositioned, and the rent was sutured. Despite some minor postoperative complications, the short- and long-term outcome was excellent. It was hypothesised that recurrent colon displacements or trauma elicited by an intrauterine foal may have been the cause of the rent in some of the cases.

Background : Anthelmintic resistance in equine parasites is increasing. Frequent anthelmintic use accelerates selection for resistance. Objectives : Investigate how horse owners currently use anthelmintics to control intestinal parasites. Study design : Online survey. Methods: Questionnaire distributed via practices, equestrian organisations, etc., December 2021 to October 2022. Combination of multiple choice, Likert scale and free text questions. Descriptive / inferential statistics performed (Microsoft Excel and IBM SPSS). Results : 4232 useable responses. Owners of horses on livery yards less likely to make worming decisions compared to those on private properties (p<0.001); managers made decisions in 39.6% of horses on livery yards; 60.7% of owners sought worming advice from their veterinarian; 52.0% administered anthelmintics based on routine faecal egg counts (FECs) / tapeworm serology result; 30.0% routinely tested, but wormed at least once a year regardless of the results; 16.1% did not test, but wormed at least once a year. Owners were more likely to administer anthelmintics based on test results if they sought veterinary advice or were on a health programme (both p<0.001). Of those who routinely wormed, 54.9% wormed once a year; 45.1% wormed twice or more a year. Frequency of routine worming was higher if they didn’t routinely test (p<0.001); 88.9% simultaneously wormed all horses on the pasture. Moxidectin was the first choice for 82.2% of owners who routinely wormed at least once yearly. Routine FECs were performed by 84.7%, higher for those who sought veterinary advice (89.3%, p<0.001). Tapeworm ELISAs were utilised by 40.8%, higher for those on a health programme (68.1%; p<0.001); 58.5% routinely treated for tapeworms regardless of test results. Main Limitations : Selection bias. Conclusions : Owners apply moderately good diagnostic-led parasite control practices, but still common to regularly treat with anthelmintics (30.0% worming at least once a year regardless of the FEC results).

Background : Anthelmintic resistance in equine parasites is increasing. Pasture management is a vital component of parasite control, and is important to limit the development of resistance. Objectives : Investigate how horse owners use management procedures to control common intestinal parasites in horses. Study design : Online survey. Methods : Questionnaire distributed via practices, equestrian organisations, etc., December 2021 - October 2022. Combination of multiple choice, Likert scale and free text questions. Descriptive and inferential statistics performed in Microsoft Excel and IBM SPSS. Results : 4232 useable responses from the UK, predominantly England (85.4%). Premises included livery yards (45.7%) and private properties (51.1%). Most horses (70.4%) were aged 6-20 years. Over half (55.9%) were used for general riding/pleasure; 58.9% grazed with 1-3 other horses, while 20.7% grazed alone; 21.5% alternated or co-grazed with ruminants (significantly higher for horses grazing on private properties compared to horses grazing on livery yards; 73.3% of owners removed faeces from pastures (poo-picking), of which 86.4% removed faeces twice a week or more. Owners of horses pastured individually were significantly more likely to poo-pick (89.8%) than horses pastured in groups (68.9%); 77.1% of respondents rested pastures, but less than 5% for over 6 months. Only 5.1% of owners reported they had experienced illnesses related to worms in any horse (commonest clinical signs were colic and weight loss). Limitations : Selection bias. Conclusions : Results suggest a lack of understanding of the principles of non-chemical parasite control among many horse owners. Many owners (>25%) are not routinely poo-picking. Horses pastured alone or kept on a private property were significantly more likely to have their faeces regularly removed than thoses pastured in groups or kept on livery yards.

Sialolithiasis is an uncommon condition of the salivary gland in the horse, primarily affecting the parotid salivary duct. Clinical signs may include salivary stasis within the gland and potential progression to sialadenitis, facial draining tract, or a permanent fistula. A 19-year-old Warmblood gelding was referred with severe septic sialadenitis of the right parotid gland. A 4 cm sialolith was detected radiographically and removed surgically. Although surgery was uneventful and patency of the salivary duct was assessed intra-operatively, mild accumulation of saliva within the gland was noted one day later. A stenosis caudal to where the sialolith was lodged was diagnosed through contrast radiography. Balloon dilatation of the stenosis was attempted unsatisfactorily and a polyethylene catheter was placed and sutured to the oral mucosa to maintain the parotid empty. A week later, the oral portion of the catheter was chewed by the horse, preventing catheter removal without surgery. Subsequently, ultrasonographic and radiographic re-evaluations were performed routinely to assess the patency of the catheter or complications associated with long-term placement. After 1 year, no salivary stasis in the gland or complications were observed. This is the first description of successful long-term indwelling catheter placement to resolve stenosis of the salivary duct. This procedure offers a simple, economical, and safe option compared to more complicated or invasive techniques previously described in horses, with excellent functional and cosmetic results.

Insulin Resistance vs Dysregulation – A Distinction without a DifferenceEleanor M. Kellon, VMDEquine Cushing’s and Insulin Resistance Group, Inc.2307 Rural Road, Tempe, AZ 85282, USAdrkellon@gmail.comIn 2014, the term insulin dysregulation was introduced in an article by Frank and Tadros, published in EVE. It purported to cover all causes of “excessive insulin response to oral sugars, fasting hyperinsulinemia and insulin resistance” 1 . This was precipitated by interest in the enteroinsular axis and whether incretins might play a role in the excessive response to oral sugars, as well as decreased insulin clearance contributing to hyperinsulinemia. The paper also mentioned the stress response to illness, sepsis and injury as causing hyperinsulinemia but this is well recognized to be a physiological insulin resistance response to preserve glucose for critical tissues like heart and brain. Similarly, the hyperinsulinemia of pregnancy was recognized as a physiological response to allow ample access of the glucose to the fetus. The hyperinsulinemia of PPID is also recognized to be a combination of genetic predisposition and insulin resistance in response to the POMC hormones. This leaves only incretins and reduced insulin clearance as possible causes of hyperinsulinemia without insulin resistance.Higher insulin response to oral than intravenous glucose is a well recognized physiological response in all species, including the horse. Interest in incretins traces back to a 2001 study which determined higher insulin response to oral glucose than intravenous in both horses and Shetland ponies. There was one pony in the study with an exaggerated insulin response and higher GIP incretin (glucose-dependent insulinotropic polypeptide). However, that pony also had elevated absorption of glucose and insulinresistance status was unknown. In a 2016 study 2 , 31 ponies previously identified as hyperinsulinemic were evaluated to determine their active GLP-1 (glucagon-like peptide-1 incretin) and insulin responses to feeding glucose and compare that to the response to intravenous glucose. In phase one of the trial, 22 ponies determined to have hyperinsulinemic responses to oral feeding were subjected to a CGIT (combined insulin-glucose tolerance test). Only 15 of the 22 were determined to be IR by CGIT criteria. However, it has been shown that the diagnostic sensitivity of the insulin phase of CGIT is only 28.5%3 . In phase two, 9 other ponies were utilized. Those that had previously been identified as high responders to oral glucose were found to have the same insulin response to intravenous glucose as the normal ponies. However, they were also found to absorb more glucose orally than the normal ponies i.e., higher AUC glucose. AUC insulin following the oral tests was not correlated with AUC GIP but was correlated with AUC active GLP-1 while total GLP-1 did not change. Given the increased glucose absorption in those ponies, elevated GLP-1 is not an unexpected finding but rather was a normal and appropriate physiologic response to the enhanced glucose absorption, as was the higher insulin – not a dysregulation.Four studies since then have looked for a correlation between elevated levels of GLP-1 or GIP and a hyperinsulinemic response to oral carbohydrates in both normal and hyperinsulinemic horses but failed to find a significant difference. Most notably, one study 4 found the 75 minute insulin response to oral glucose was negatively correlated to GLP-1 and adiponectin levels were positively correlated to GLP-1, the exact opposite of what would be expected if exaggerated incretin responses could cause hyperinsulinemia without insulin resistance or could lead to insulin resistance.To further add to the confusion, both a GLP-1 mimetic and GLP-1 receptor antagonist have been reported to decrease the insulin response to a meal. Interestingly, in the case of the mimetic, the reduced insulin response was due to an increase in whole body insulin sensitivity, again directly contradicting the idea that incretins could cause hyperinsulinemia without there being insulin resistance.As for reduced insulin clearance, one study has documented reduced insulin clearance in horses with metabolic syndrome and hyperinsulinemia. This is a well-recognized component of human insulin resistance in metabolic syndrome and type 2 diabetes mellitus. The reduced insulin clearance helps spare the beta cells and compensate for cellular insulin resistance by maintaining higher circulating insulin levels and is thus an adaptive physiological response, not a dysregulation. There are no studies in any species documenting reduced insulin clearance without concurrent insulin resistance.In contrast, since the 2005 publication of insulin sensitivity quintiles using minimal model analysis of FSIGT (frequently sampled intravenous glucose tolerance test) data, over 40 articles have been formally published describing diagnosis of insulin resistance by intravenous response to glucose, insulin or their combination in various protocols, sometitmes with greater sensitivity than oral testing.It appears possible, but by no means proven, that some animals, particularly ponies, may over-absorb glucose, possibly under the influence of GLP-2, leading to exaggerated GLP-1 and insulin responses to meals and that this repeated exposure to high levels of insulin would lead to insulin resistance. However, even if this is shown to be true, it is not the insulin response that is dysregulated but rather glucose absorption. The GLP-1 and insulin responses to the enhanced glucose load are appropriate and physiological. The end result is likely insulin resistance from repeated exposure to high levels of insulin, as also described by Frank and Tadros, and could be considered an early stage of insulin resistance. They certainly wouldn’t be treated any differently than an animal with insulin resistance confirmed by intravenous testing.By creating an artificial distinction between horses and all other species with insulin resistance there is the potential to reduce interest in collaboration and funding. It also encourages avenues of research which are unlikely to ever benefit the horse or increase understanding of equine insulin resistance. The term insulin dysregulation should be abandoned as the other proposed mechanisms for hyperinsulemia have either not been proven, lead to insulin resistance or are known to be an inherent physiological response to insulin resistance.References:1. N. Frank and E.M. Tadros, Insulin dysregulation, Equine Vet J 46 (2014), pp. 103-112.2. M.A. de Laat, J.M. McGree and M.N. Sillence, Equine hyperinsulinemia: investigation of the enteroinsular axis during insulin dysregulation,Am J Physiol Endocrinol Metab 310 (2016), pp. E61-72.3. L.K. Dunbar, K.A. Mielnicki, K.A. Dembek, R.E. Toribio and T.A. Burns, Evaluation of Four Diagnostic Tests for Insulin Dysregulation in Adult Light-Breed Horses, J Vet Intern Med 30 (2016), pp. 885-891.4. N. Frank and D.M. Walsh, Repeatability of Oral Sugar Test Results, Glucagon-Like Peptide-1 Measurements, and Serum High-Molecular-Weight Adiponectin Concentrations in Horses, J Vet Intern Med 31 (2017), pp. 1178-1187.5. K.H. Treiber, D.S. Kronfeld, T.M. Hess, R.C. Boston and P.A. Harris, Use of proxies and reference quintiles obtained from minimal model analysis for determination of insulin sensitivity and pancreatic beta-cell responsiveness in horses, Am J Vet Res 66 (2005), pp. 2114-2121.

Background: Injury resulting in proliferative new bone formation on the dorsal aspect of the middle phalanx (P2) has been recognised by equine veterinarians and is generally referred to as capsulitis. Objectives: Describe the clinical features, treatment, and outcomes of this condition. Study Design: Case series (n=19) Methods: Clinical cases in which the horse presented for lameness and were diagnosed with acute formation of proliferative bone on the dorsal aspect of P2 were included in the study (cases collected from 2005-2022). Signalment, history, presenting clinical signs, diagnostics, treatments administered, and outcome were evaluated. Results: Horses presented with unilateral lameness that were all classified as either a moderate lameness at a trot (n=6), or a moderate to severe lameness at a walk (n=13). The presentation of lameness was recorded as acute in 15/19 horses and not reported in the remainder. Bone proliferation on the dorsal aspect of P2 was diagnosed on radiographic evaluation in all horses (as part of the inclusion criteria). In horses with sequential radiographs made from the time of acute presentation, the bone production developed rapidly over a period of a few weeks to 2 months. A variety of therapeutic options were implemented, and 13/19 (68%) of the cases were subject to humane euthanasia with only one horse returning to its previous athletic function. Milder cases were more likely to have better outcomes. Main Limitations: Small sample size. Conclusions: Acute new bone proliferation on the dorsal aspect of P2 may be associated with moderate to severe lameness and carries a poor prognosis for return to athletic performance and survival.

A recently castrated 4-year-old Selle Français gelding was presented for evaluation of a renal failure. Abdominal and transrectal ultrasonography revealed a large volume of anechoic free fluid within the peritoneal cavity with high creatinine concentration and a tear at the cranial pole of the bladder. Medical management was initiated for two days, then a standing laparoscopy was performed to close the defect using barbed suture. After a transient acute renal injury, the gelding recovered and was discharged from the hospital 13 days post-operatively. To our knowledge, this case is the first report using barbed sutures on the equine bladder.