Hoof wall masses removal in 30 standing sedated horses: Surgical technique, postoperative complications and long-term outcome.

OBJECTIVE: To describe the surgical technique for removal of hoof wall masses in horses under standing sedation (SS) and local anesthesia (LA), and to report complications and long-term outcome following surgery. STUDY DESIGN: Observational retrospective study. ANIMALS: Client-owned horses (n = 30). METHODS: Horses undergoing keratoma removal under SS and LA in a single equine hospital between August 2016 and July 2023 were included in the study. Signalment, affected foot, history of lameness and/or foot abscesses, degree of lameness on admission, imaging findings (radiography and magnetic resonance imaging [MRI] when available), location of the mass, surgical technique, remedial farriery, postoperative care, complications and outcome were recorded. Long-term follow-up information was obtained by telephone questionnaire. RESULTS: A total of 30 horses met the inclusion criteria. Duration of lameness ranged from 1 to 289 days (mean 90 days). The degree of lameness varied from absent to grade 4/5 (AAEP) (mean grade 3/5). All horses underwent preoperative radiographic examination and 14/30 underwent MRI. All horses underwent partial hoof wall resection. The surgery was performed safely in all cases. Postoperative complications included marked lameness in the early postoperative period in 3/30 horses and exuberant granulation tissue formation in 2/30 horses. Long-term (>6 months) follow-up information was available for 28 horses, and 26/28 horses returned to previous levels of exercise. Recurrence was suspected in 1/30 horses. CONCLUSIONS: The complication rate was lower than previously reported for keratoma removal under general anesthesia (GA). CLINICAL SIGNIFICANCE: Removal of hoof wall masses under SS and LA can be considered as an alternative to removal under GA.

Fetal rhabdomyoma in a Thoroughbred filly.

A newborn Thoroughbred filly presented with a large mass located on the ventro-rostral aspect of the mandible. The mass was surgically removed under general anaesthesia. Upon gross examination, the mass was well circumscribed with a heterogeneous lobulated appearance. The results of histopathology and immunohistochemistry were consistent with a diagnosis of congenital fetal rhabdomyoma. On follow-up at six months post-surgical excision, no abnormalities were noted on clinical examination.

Outcome of tenoscopically guided palmar/plantar annular ligament desmotomy for the treatment of palmar/plantar annular ligament constriction without concurrent intrathecal soft-tissue injury in a UK horse population.

OBJECTIVE: To determine the outcome of tenoscopically guided palmar/plantar annular ligament (PAL) desmotomy to treat PAL constriction without concurrent intrathecal soft-tissue injury, notably of the digital flexor tendons and manica flexoria. STUDY DESIGN: Retrospective multicenter cohort study. ANIMALS: Sixty-five horses. METHODS: Horses from four UK equine hospitals, with digital flexor tendon sheath (DFTS) tenosynovitis, which underwent tenoscopically guided PAL desmotomy for treatment of PAL constriction between 2017 and 2022 were included. All horses had lameness isolated to the DFTS/PAL, and PAL constriction was diagnosed tenoscopically when there was difficulty maneuvering the endoscope into or through the fetlock canal. Horses with tearing of the digital flexor tendons and/or manica flexoria, or any other intrathecal pathology, were excluded. Follow up was via structured telephone questionnaire. RESULTS: Follow up (median 25 months) was available for 61 horses with cobs and ponies predominating. Forty-two returned to their previous level of work, or a higher level, postoperatively and 50 owners were satisfied with the outcome of surgery. Eleven horses returned to lower level exercise, and six were retired/euthanized as they did not regain soundness. Fifty-two horses achieved soundness (median 3 months postoperatively). CONCLUSION: Tenoscopically guided PAL desmotomy for the treatment of PAL constriction in the absence of intrathecal soft tissue injury had a good prognosis for return to previous levels of exercise in a UK horse population. CLINICAL SIGNIFICANCE: The prognosis for horses undergoing tenoscopically guided PAL desmotomy to treat PAL constriction in the absence of intrathecal injury is better than previously described. Cobs and ponies seem to be predisposed to PAL constriction in agreement with the previous literature.

Evaluation of peritoneal l-lactate concentration in horses in the early post-partum period.

BACKGROUND: Peritoneal fluid lactate concentration is an important diagnostic tool in horses with abdominal pain. Information on peritoneal lactate concentrations is lacking following parturition in the mare. OBJECTIVES: To compare blood and peritoneal lactate concentrations in a population of mares within 36 h post-partum, report a normal reference range and identify any impact of retained foetal membranes (RFMs). METHODS: This is a retrospective study evaluating healthy mares from which blood and peritoneal samples had been obtained within 36 h of parturition. Exclusion criteria included signs of abdominal pain within this period. Data was interrogated for normality using a Shapiro-Wilk test. Wilcoxon signed-rank test and Bland-Altman analysis were used to compare blood and peritoneal lactate concentrations. Linear regression was used to compare age and breed data with peritoneal lactate concentrations. Significance was defined as p < 0.05. RESULTS: Forty mares met the inclusion criteria. Mean age was 12.6 ± 4.1 years, and most mares were multiparous (65%). Peritoneal lactate ((1.2 (IQR = 0.9-1.6) mmol/L) was increased compared to blood lactate concentration (0.7 (IQR = 0-1.1)mmol/L; p < 0.001). Plasma total protein (TP) concentrations were 68 (IQR = 64-74) g/L and peritoneal protein concentrations 8 (IQR = 4-9.7) g/L. Six mares developed RFM. The median fold-increase in peritoneal lactate concentration compared to blood lactate concentration was 0.9 (IQR: 0.01-1.7; range: 0-2.5). The reference range for peritoneal fluid lactate concentration was 0-2.5 mmol/L. CONCLUSION: Peritoneal lactate concentrations in healthy post-partum mares remained within the normal reference range and were not influenced by RFM or parturition. Increased peritoneal lactate in this group warrants further investigation.

Negative-Pressure Wound Therapy (NPWT) in Horses: A Scoping Review.

Obtaining a healthy wound environment that is conductive to healing in horses can be challenging. Negative-pressure wound therapy (NPWT) has been employed in humans to enhance wound healing for decades. The existing evidence for the effectiveness of NPWT remains uncertain in equine medicine. The aim of this review is to investigate NPWT applications and benefits in horses. A scoping review was performed according to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines for scoping reviews on three databases (PubMed, Web of Science-Thompson Reuters, and Wiley Online Library). Twenty-four manuscripts were considered. After removing duplicates, 17 papers underwent abstract screening. Of these, 16 + 1 (cited by others) were evaluated for eligibility according to PICOs, including no case reports/retrospective studies, four original articles, and three reviews. Fifteen manuscripts met the inclusion criteria. The focus of the articles was wound management; they included three reports of wounds communicating with synovial structures. Traumatic wounds and surgical-site infections are indications for NPWT. NPWT presents several advantages and few complications making it an attractive alternative to conventional wound management. However, randomized controlled trials should be performed to quantify the benefits and establish precise protocols in horses.

'First Case of Stiff-Horse Syndrome in United Kingdom'.

Stiff-person syndrome is a well-recognised disease in humans, whilst cases of stiff-horse syndrome (SHS) have been rarely reported in the veterinary medicine literature. SHS is a progressive immunomediated disorder of the central nervous system leading to a disturbance of gamma amino butyric acid transmission at the neuromuscular junction in which antibodies are produced against the enzyme glutamic acid decarboxylase. A 6 year-old Irish Sport Horse was presented for investigation of involuntary violent contraction of hindlimb and back muscles triggered by stress. The diagnosis of SHS was made after elevated anti-glutamic acid decarboxylase antibodies titres were detected in the horse's serum. Administration of oral corticosteroids (prednisolone 0.75 mg/kg bwt) resulted in resolution of the clinical signs. However, reoccurrence of clinical signs was observed after the dose of corticosteroids was reduced or the treatment discontinued. To the best of the authors' knowledge this is the first reported case of SHS in United Kingdom. Considering the potential implications on the horses' welfare, further investigation on SHS pathogenesis and treatment are warranted.

Diffusion of Radiodense Contrast Medium Following Perineural Injection of the Deep Branch of the Lateral Plantar Nerve Using Two Different Techniques in Horses: an In Vivo Study.

OBJECTIVES: This article evaluates and compares the diffusion pattern of radiopaque contrast medium following perineural analgesia of the deep branch of the lateral plantar nerve performed using two different techniques: weight-bearing or flexed. STUDY DESIGN: This was an in vivo experimental study. METHODS: Eight horses were enrolled. Perineural injection of the right and left deep branch lateral plantar nerves was performed with a weight-bearing or flexed technique, using radiopaque contrast medium (iohexol). Radiographic evaluation was performed after 5 (T5), 15 (T15) and 30 (T30) minutes. The diffusion of contrast medium was assessed independently by two blinded readers who analysed the extension of the main contrast medium bulk and the maximum diffusion of contrast medium in both proximal and distal directions. The effect of time and technique employed on contrast medium diffusion was assessed using two-way analysis of variance for repeated measures (p ≤ 0.05). RESULTS: There was no significant difference in the diffusion of the contrast medium between the two techniques at T15. However, at T30 the weight-bearing technique resulted in a significantly increased diffusion in the proximal direction (p = 0.02). In one case, belonging to the weight-bearing group, contrast medium was identified within the tarsal sheath. There was no evidence of contrast medium in the tarsometatarsal joint of any horse, regardless of the technique used. CONCLUSIONS: The two techniques resulted in a similar diffusion at T15. However, the use of a weight-bearing technique resulted in a significant increase in proximal contrast medium diffusion 30 minutes after injection.

An atypical presentation of leiomyosarcoma causing extremity compartment syndrome of the crural region in a Dutch Warmblood mare: a case report.

A 12-year-old Warmblood mare was presented with an acute onset left hindlimb lameness associated with generalised soft tissue swelling of the entire limb and medial saphenous vein (MSV) thrombophlebitis. A presumptive diagnosis of extremity compartment syndrome (ECS) was made. Due to the clinical deterioration, emergency fasciotomy of the crural fascia and biopsy was performed. Histological and immunohistochemical examination of the samples confirmed a diagnosis of leiomyosarcoma likely originating from the tunica media of the MSV. This report is the first to describe an unique combination of ECS and thrombophlebitis associated with a leiomyosarcoma in a horse.

Standing thyroidectomy in 10 horses.

OBJECTIVE: To describe a surgical technique for thyroidectomy in horses with thyroid neoplasia under standing sedation and local anesthesia. STUDY DESIGN: Retrospective study. ANIMALS: Client-owned horses (n = 10). METHODS: Medical records of horses with a history of thyroid enlargement were included in the study if thyroid gland enlargement was treated surgically via hemi- or bilateral thyroidectomy, with the horse standing and sedated. Data derived from follow-up clinical examination, performance level, recurrence, and cosmetic outcome were evaluated. RESULTS: Thyroid enlargement was unilateral in 8 and bilateral in 2 horses. Histopathological findings included adenomas (5/10), adenocarcinomas (2/10), cystic hyperplasia (2/10), and C-cell adenoma (1/10). No major complications were encountered during or after surgery. All horses resumed their previous level of exercise within 6 weeks. Recurrence was diagnosed in 1 horse, 7 months after excision, and a second surgery was required. Recurrent laryngeal nerve neuropathy and seroma formation subsequent to surgery were not recorded in any of the cases. CONCLUSION: Thyroidectomy can safely be performed with the horse standing and sedated with local anesthesia. CLINICAL RELEVANCE: Performing standing thyroidectomy does not increase intraoperative or postoperative complications and could be considered for horses with thyroid enlargement amenable to surgery.