Differential effects of the venoms of Russell's viper and Indian cobra on human myoblasts.

Local tissue damage following snakebite envenoming remains a poorly researched area. To develop better strategies to treat snakebites, it is critical to understand the mechanisms through which venom toxins induce envenomation effects including local tissue damage. Here, we demonstrate how the venoms of two medically important Indian snakes (Russell's viper and cobra) affect human skeletal muscle using a cultured human myoblast cell line. The data suggest that both venoms affect the viability of myoblasts. Russell's viper venom reduced the total number of cells, their migration, and the area of focal adhesions. It also suppressed myogenic differentiation and induced muscle atrophy. While cobra venom decreased the viability, it did not largely affect cell migration and focal adhesions. Cobra venom affected the formation of myotubes and induced atrophy. Cobra venom-induced atrophy could not be reversed by small molecule inhibitors such as varespladib (a phospholipase A2 inhibitor) and prinomastat (a metalloprotease inhibitor), and soluble activin type IIb receptor (a molecule used to promote regeneration of skeletal muscle), although the antivenom (raised against the Indian 'Big Four' snakes) has attenuated the effects. However, all these molecules rescued the myotubes from Russell's viper venom-induced atrophy. This study demonstrates key steps in the muscle regeneration process that are affected by both Indian Russell's viper and cobra venoms and offers insights into the potential causes of clinical features displayed in envenomed victims. Further research is required to investigate the molecular mechanisms of venom-induced myotoxicity under in vivo settings and develop better therapies for snakebite-induced muscle damage.

Effect of Hypotension and Dobutamine on Gastrointestinal Microcirculations of Healthy, Anesthetized Horses.

Horses undergoing abdominal exploratory surgery are at risk of hypotension and hypoperfusion. Normal mean arterial pressure is used as a surrogate for adequate tissue perfusion. However, measures of systemic circulation may not be reflective of microcirculation. This study measured the mean arterial pressure, cardiac index, lactate, and four microcirculatory indices in six healthy, anesthetized adult horses undergoing elective laparotomies. The microcirculatory parameters were measured at three different sites along the gastrointestinal tract (oral mucosa, colonic serosa, and rectal mucosa) with dark-field microscopy. All macro- and microcirculatory parameters were obtained when the horses were normotensive, hypotensive, and when normotension returned following treatment with dobutamine. Hypotension was induced with increases in inhaled isoflurane. The horses successfully induced into hypotension did not demonstrate consistent, expected changes in systemic perfusion or microvascular perfusion parameters at any of the three measured gastrointestinal sites. Normotension was successfully restored with the use of dobutamine, while the systemic perfusion and microvascular perfusion parameters remained relatively unchanged. These findings suggest that the use of mean arterial pressure to make clinical decisions regarding perfusion may or may not be accurate.

Identifying key factors contributing to treatment costs for snakebite envenoming in private tertiary healthcare settings in Tamil Nadu, India.

BACKGROUND: India suffers ~58,000 annual deaths due to snakebites. The 'Big Four' snakes (Russell's viper, Indian cobra, common krait, and saw-scaled viper) that are responsible for most bites cause diverse clinical effects. Delayed treatment increases the risk of serious complications and treatment costs. Although government hospitals offer free treatment for snakebites in India, most patients opt for private healthcare, which is an out-of-pocket expense as they often lack health insurance coverage. This study aims to analyse snakebite treatment costs in private tertiary care hospitals in Tamil Nadu, India and identifies the key factors contributing to treatment costs. METHODOLOGY/PRINCIPAL FINDINGS: The treatment cost details for 913 snakebite victims were collected from 10 private tertiary care hospitals across Tamil Nadu. The data were classified into hospital, pharmacy, investigation, and laboratory costs, and analysed to determine various factors that contribute to the costs. The results demonstrate that the average treatment costs vary widely for different snakes. The hospital and pharmacy costs are higher than investigation and laboratory costs for all snakebites. Notably, Russell's viper bites cost significantly more than the bites from other snakes. Overall, the type of snake, nature of complications, specialist treatments required, and arrival time to hospitals were identified as some of the key factors for higher treatment costs. CONCLUSIONS/SIGNIFICANCE: These data demonstrate that ~80% of snakebite patients can be treated with INR 100,000 (~GBP 1000 or USD 1200) or less. This study emphasises the urgent need to improve rural medical care by providing appropriate training for healthcare professionals and essential resources to facilitate early assessment of patients, administer the initial dose of antivenom and refer the patients to tertiary care only when needed. Moreover, the outcome of this study forms a basis for developing appropriate policies to regulate snakebite treatment costs and provide affordable medical insurance for vulnerable communities.

Partial segmental thrombosis of the corpus cavernosum following Russell's viper bite.

Snakebite envenoming (SBE) is common in rural communities living in tropical regions that often have fragile and/or overwhelmed healthcare systems. The complex scenarios around SBE lead to a high number of deaths, disabilities, and long-term consequences in patients. Russell's viper (Daboia russelii) is one of the most medically important snake species in India, which causes devastating pathological conditions characterised by a wide range of clinical manifestations. This broad spectrum of symptoms requires additional therapeutic interventions beyond the classical antivenom administration. Hence, positive outcomes for patients affected by SBE can be achieved with a better understanding of previous experiences describing clinical manifestations and various therapeutic interventions including for rare and underreported conditions. Here, we report an SBE victim who developed partial segmental thrombosis in the corpus cavernosum following Russell's viper envenomation and its diagnostic and treatment approaches. The patients received 180 ml of antivenom to resolve the abnormalities in their haematological parameters. Despite antivenom treatment, they developed severe pain in their genital region, and subsequent ultrasound and magnetic resonance imaging confirmed segmental thrombosis in the corpus cavernosum, which required supportive measures. The treatment using low molecular weight heparin, rivaroxaban and non-steroidal anti-inflammatory drugs resolved segmental thrombosis. In conclusion, this case report exemplifies the development of a rare segmental thrombosis in corpus cavernosum and how the medical, scientific, and general community can benefit from documenting clinical manifestations, medically relevant insights into patient care and the management of underreported complications.

Indian Ornamental Tarantula (Poecilotheria regalis) Venom Affects Myoblast Function and Causes Skeletal Muscle Damage.

Envenomation by the Indian ornamental tarantula (Poecilotheria regalis) is medically relevant to humans, both in its native India and worldwide, where they are kept as pets. Muscle-related symptoms such as cramps and pain are commonly reported in humans following envenomation by this species. There is no specific treatment, including antivenom, for its envenomation. Moreover, the scientific knowledge of the impact of this venom on skeletal muscle function is highly limited. Therefore, we carried out this study to better understand the myotoxic properties of Poecilotheria regalis venom by determining its effects in cultured myoblasts and in the tibialis anterior muscle in mice. While there was no effect found on undifferentiated myoblasts, the venom affected differentiated multinucleated myotubes resulting in the reduction of fusion and atrophy of myotubes. Similarly, intramuscular administration of this venom in the tibialis anterior muscle in mice resulted in extensive muscle damage on day 5. However, by day 10, the regeneration was evident, and the regeneration process continued until day 20. Nevertheless, some tissue abnormalities including reduced dystrophin expression and microthrombi presence were observed on day 20. Overall, this study demonstrates the ability of this venom to induce significant muscle damage and affect its regeneration in the early stages. These data provide novel mechanistic insights into this venom-induced muscle damage and guide future studies to isolate and characterise individual toxic component(s) that induce muscle damage and their significance in developing better therapeutics.

Peripheral Arterial Thrombosis following Russell's Viper Bites.

Envenomings by Russell's viper ( Daboia russelii ), a species of high medical importance in India and other Asian countries, commonly result in hemorrhage, coagulopathies, necrosis, and acute kidney injury. Although bleeding complications are frequently reported following viper envenomings, thrombotic events occur rarely (reported only in coronary and carotid arteries) with serious consequences. For the first time, we report three serious cases of peripheral arterial thrombosis following Russell's viper bites and their diagnostic, clinical management, and mechanistic insights. These patients developed occlusive thrombi in their peripheral arteries and symptoms despite antivenom treatment. In addition to clinical features, computed tomography angiography was used to diagnose arterial thrombosis and ascertain its precise locations. They were treated using thrombectomy or amputation in one case that presented with gangrenous digits. Mechanistic insights into the pathology through investigations revealed the procoagulant actions of Russell's viper venom in standard clotting tests as well as in rotational thromboelastometry analysis. Notably, Russell's viper venom inhibited agonist-induced platelet activation. The procoagulant effects of Russell's viper venom were inhibited by a matrix metalloprotease inhibitor, marimastat, although a phospholipase A 2 inhibitor (varespladib) did not show any inhibitory effects. Russell's viper venom induced pulmonary thrombosis when injected intravenously in mice and thrombi in the microvasculature and affected skeletal muscle when administered locally. These data emphasize the significance of peripheral arterial thrombosis in snakebite victims and provide awareness, mechanisms, and robust strategies for clinicians to tackle this issue in patients.

Neutrophil-mediated erythrophagocytosis following Russell's viper (Daboia russelii) bite.

Snakebite envenomation is regarded as a high-priority neglected tropical disease by the World Health Organisation, as it results in significant loss of lives and permanent disabilities. Russell's viper is one of the important venomous snakes that causes morbidities, mortalities and disabilities in India. The clinical presentation of Russell's viper envenomation is characterised by local envenoming effects including tissue damage, venom-induced coagulopathy, neurotoxicity, and kidney injury. However, venom composition and its mechanisms of toxicity are highly variable even within snakes of the same species including Russell's viper. This variation in venom composition results in a broad range of clinical complications. Here, we present a previously undocumented case of neutrophil-mediated erythrophagocytosis in a healthy 28-year-old female following Russell's viper bite. Systemic envenomation effects and bleeding abnormalities in this patient were corrected by the administration of polyvalent antivenom. Two days later, the patient developed progressive swelling and ecchymosis in the bitten limb. Observed abnormal limits within blood testing were followed up by a peripheral blood smear where it was found that 30% of neutrophils had phagocytosed erythrocytes as they were found within the cytoplasm. The patient underwent a fasciotomy for compartmental syndrome and received packed red cells and a course of corticosteroids. Following this treatment, the patient made a full recovery. This case report outlines a previously undocumented pathological event induced by Russell's viper envenomation, guiding diagnosis and treatment. Clinicians' knowledge of the mechanisms of toxicity of Russell's viper envenomation and its clinical manifestations are essential for improving the treatment of snakebites to achieve positive outcomes.

Ashes to eye: A skilled snake handler's experience with ophthalmic envenomation.

With the continued growth of human populations, rural urbanisation and habitat degradation are on the rise, resulting in the displacement of native wildlife and an increase in human-wildlife conflicts. The presence of human habitation and waste often attracts rodents and thereby, snakes, leading to increased snake sightings in homes. To address this problem, snake handlers, who are volunteers that remove and relocate snakes away from human development areas, are called upon. However, snake removal is a high-risk task that poses a risk of envenomation, particularly when dealing with spitting snakes. Several cobra species have the ability to spit venom. If the venom enters a person's eye, it can result in ophthalmic envenomation, which can have serious consequences for their eyesight. Therefore, snake handlers should take precautions, wear suitable eye protection, and use appropriate tools to ensure their safety and that of the snake. In this case, an experienced snake handler was called to remove a spitting cobra, but they were ill-equipped. During the removal, the venom was sprayed across the handler's face, and some of it entered their eye, resulting in ophthalmic envenomation. The handler promptly irrigated their eye, but medical treatment was still necessary. This report highlights the risks and consequences of ophthalmic injury and the importance of wearing appropriate eye protection and taking due care when dealing with venomous species, particularly those that can spit venom. It serves as a reminder that accidents can happen at any time and experienced snake handlers are not exempt from the risks.

Rapid identification of bilateral adrenal and pituitary haemorrhages induced by Russell's viper envenomation results in positive patient outcome.

The clinical management of snakebite envenomation (SBE) is challenging in many tropical and subtropical regions of developing countries due to the complex clinical manifestations and inadequate medical infrastructure. Some venomous snakes, such as the Indian Russell's viper (Daboia russelii) cause a wide range of rare complications in addition to their classical envenomation effects. In general, these uncommon complications are often misdiagnosed or not treated promptly due to a lack of awareness about these conditions. Thus, it is critical to report such complications to draw the attention of the healthcare and research communities to improve the clinical management and scientific research of SBE, respectively. Here, we report bilateral adrenal and pituitary haemorrhages in an SBE patient following a bite by Russell's viper in India. The initial symptoms included gum bleeding, swelling, axillary lymphadenopathy and clotting abnormalities. Despite the administration of antivenom, the patient presented palpitation, nausea, and abdominal pain, which were not recovered by combinational therapy with epinephrine and dexamethasone. Further infusion of antivenom did not address these issues and the patient displayed persistent hypotension, hypoglycaemia and hyperkalaemia suggesting an adrenal crisis. Inadequate secretion of corticosteroids was confirmed by laboratory tests, and imaging investigations revealed haemorrhages in both the adrenal and pituitary glands. The patient made a full recovery after treatment with hydrocortisone and thyroxine. This report adds to the growing evidence of rare complications induced by Russell's viper envenomations and it provides relevant guidance to diagnose and treat such complications in SBE victims.

The Effectiveness of Antibiotics in Managing Bacterial Infections on Bite Sites following Snakebite Envenomation.

Snakebite envenomation (SBE) is a life-threatening medical emergency with a high mortality rate. Common secondary complications following SBE, such as wound infections, are significant due to their impact on worsening local tissue damage and causing systemic infection. Antivenoms are not effective to treat wound infections following SBE. Moreover, in several rural clinical settings, broad-spectrum antibiotics are often used without clear guidelines or based on limited laboratory data, resulting in undesirable side effects and exacerbated treatment costs. Therefore, robust antibiotic strategies should be developed to tackle this critical issue. Currently, there is limited information available on the bacterial profiles of SBE-induced infections and antibiotic susceptibility. Hence, it is essential to improve the knowledge of bacterial profiles and their antibiotic sensitivity in SBE victims to develop better treatment strategies. This study aimed to address this issue by examining the bacterial profiles of SBE victims with a specific focus on Russell's viper envenomation. The most frequently found bacteria in the bites of SBE victims were Staphylococcus aureus, Klebsiella sp., Escherichia coli, and Pseudomonas aeruginosa. Linezolid, clindamycin, colistin, meropenem, and amikacin were some of the most effective antibiotics for commonly grown bacteria in SBE victims. Similarly, ciprofloxacin, ampicillin, amoxiclave, cefixime, and tetracyclin were the least effective antibiotics for common bacteria found in the wound swabs of SBE victims. These data provide robust guidance for infection management following SBE and offer useful insights to aid in designing effective treatment protocols for SBE with serious wound infections in rural areas where laboratory facilities may not be readily available.

Russell's viper envenomation induces rectus sheath haematoma.

Snakebite envenomation causes systemic and local manifestations, which result from the individual or synergistic actions of multiple venom components. The pathological hallmarks of medically important venomous snakes such as the Indian Russell's viper (Daboia russelii) are well known. Envenomation by Russell's viper is typically characterised by coagulopathies, muscular damage, nephrotoxicity, and neurotoxicity. However, recent reports have revealed several unusual complications that provide a better understanding of Russell's viper envenomation effects. To further strengthen this, here, we report a case of Russell's viper bite that induced acute abdominal pain, which was intensified on day two and conservatively treated under medical supervision. Both Fothergill and Carnett signs were positive for this patient. An ultrasound imaging revealed a dissimilar dense mass, and the abdominal computed tomography scan confirmed rectus sheath haematoma. The clinical management involved the administration of polyvalent antivenom, packed red blood cells, fresh frozen plasma, and platelets. The patient recovered gradually and was discharged from the hospital eight days after the bite. Overall, this case presentation shares an uncommon experience and adds new insights into the complex series of rare pathological events associated with Russell's viper bites in India. The scientific documentation of relatively infrequent entities based on an ongoing living assessment of medical experiences, for example, this rectus sheath haematoma, constitutes valuable guidance for an adequate diagnosis and timely treatment. Essential awareness among clinicians and further research on understanding the molecular relationship between Russell's viper venom and rectus sheath haematoma will improve patient outcomes and understanding of this condition, respectively.

An Unnecessary Russell's Viper Bite on the Tongue Due to Live Snake Worship and Dangerous First Aid Emphasise the Urgent Need for Stringent Policies.

India suffers the highest incidence of snakebite envenomation (SBE) in the world. Rural communities within India and other countries have long-held cultural beliefs surrounding snakes and SBE treatments, with snake statues present in numerous Hindu temples. While most cultural beliefs are well respected and do not affect anyone, some people worship live venomous snakes without any safety precautions. Moreover, they practice various inappropriate first aid and traditional treatments that exacerbate SBE-induced complications. We report an unusual case of SBE on the tongue of a patient who was bitten while worshipping Russell's viper following the advice of an astrologer based on the appearance of a snake in the patient's dream. Following the bite, the tongue was deeply incised by the priest as a first aid to mitigate SBE-induced complications. The patient suffered profuse bleeding and swelling of the tongue resulting in difficulties in intubating them. The patient regained consciousness after antivenom administration, intranasal ventilation, and blood removal from the mouth. The tongue underwent extensive surgery to restore movement and function. This report advises caution to those undertaking the extremely risky practice of worshipping live snakes and emphasises the urgent need to develop and enforce policies to mitigate such actions and educate rural communities.

ALVAC-fIL2, a feline interleukin-2 immunomodulator, as a treatment for sarcoids in horses: A pilot study.

BACKGROUND: Sarcoid tumors are common in horses and may negatively impact the performance and value of the horse. No known treatment is reliably successful. HYPOTHESES/OBJECTIVES: To determine tolerability, overall response rate, time to response, and progression-free survival of horses with biopsy-confirmed or suspected sarcoids treated with ALVAC-fIL2. ANIMALS: Client-owned horses with measurable, presumed- or biopsy-confirmed sarcoid tumors. METHODS: Prospective pilot study. One milliliter of ALVAC-fIL2 was injected into 4 to 5 areas of the sarcoid(s) in each horse (week 0); this treatment was repeated in weeks 1, 3, and 7. Sarcoids were measured at each visit, and response to treatment was determined according to the Response Evaluation Criteria in Solid Tumors for dogs (v1.0). After the final treatment, horses were reassessed and sarcoids remeasured every 3 months until tumor progression or for a minimum of 1 year if progression was not documented. RESULTS: Fourteen horses were included. Tumor size decreased in 86% of the horses, and the median time to first response was 89 days (range, 34-406 days). Median time to best response was 211 days (range, 56-406 days), but 3 of the sarcoids still were decreasing in size at the time of final evaluation. The median progression-free interval was not reached. Adverse events were minimal and included transient focal inflammation in 2 horses. CONCLUSIONS AND CLINICAL IMPORTANCE: Intratumoral injection of ALVAC-fIL2 has promise as a well-tolerated and effective, tissue-sparing treatment for horses with sarcoid tumors.

Comparison of the oral and rectal mucosal and colonic serosal microcirculations of healthy, anesthetized horses.

The objectives of the study were to: i) determine baseline microvascular perfusion indices (MPI) and assess their repeatability in healthy horses under general anesthesia, and ii) compare the MPIs of 3 microvascular beds (oral mucosa, colonic serosa, and rectal mucosa). Healthy adult horses were anesthetized and sidestream dark field microscopy was used to collect video loops of the oral mucosa, rectal mucosa, and colonic serosa under normotensive conditions without cardiovascular support drugs; videos were later analyzed to produce MPIs. Baseline MPI values were determined for each site, which included the total vessel density (TVD), perfused vessel density (PVD), portion perfused vessels (PPV), and microcirculatory flow index (MFI). Differences in MPIs between microvascular beds were not statistically significant. Repeatability of the measurements varied for each MPI. In particular, the site of sampling had a profound effect on the repeatability of the PPV measurements and should be considered in future studies.

Les objectifs de cet étude étaient: i) de déterminer les indices de perfusion microvasculaires (IPM) de base et évaluer leur répétabilité chez les chevaux en bonne santé sous anesthésie générale, et ii) de comparer les IPMs de trois lits microvasculaires (muqueuse orale, séreuse du colon, et muqueuse rectale). Des chevaux adultes en bonne santé ont été anesthésiés et une unité de microscopie au champ sombre a été utilisée pour recueillir des boucles vidéo de la muqueuse buccale, de la muqueuse rectale, et de la séreuse du colon sous des conditions de tension artérielle normale. Les vidéos ont été analysées pour produire les IPMs, incluant la densité totale des vaisseaux, la densité des vaisseaux perfusés, la portion des vaisseaux perfusés, et l'index de flux microcirculaire. Pour chaque IPM, les différences entre les sites anatomiques n'étaient pas significatives statistiquement. La répétabilité des mesures variait pour chaque IPM. En particulier, le type de lit microvasculaire a une influence profonde sur la répétabilité des mesures.(Traduit par les auteurs).

Internal fixation of fractured ribs in neonatal foals with nylon cable tie using a modified technique.

Nylon cable tie has been shown to be an effective and economical method for fixing fractured ribs in the neonatal foal. This article describes a modification of the previously described technique. Under general anesthesia, the fractured ribs were exposed and a hole was drilled in the dorsal and ventral fragments. The fracture was not reduced, leaving the fragments overriding each other. The nylon cable tie was passed through the hole in the dorsal fragment from the external surface of the rib. The free end of the cable tie was then passed through the hole in the ventral fragment from the external surface of the rib and the tie was tightened. This technique was used in 4 neonatal foals with no complications. The modification of the original technique represents a method to minimize soft tissue trauma, implant failure, and complications.

Technique modifiée pour la fixation interne de fractures de côtes chez le poulain nouveau-né avec des attaches de câbles en nylon. Cet article décrit une technique pour réparer les fractures de côtes chez le poulain nouveau-né en utilisant des attaches de câbles en nylon. Sous anesthésie générale, une incision verticale a été faite et les côtes fracturées ont été exposées. Une mèche de perceuse a été utilisée pour faire des trous dans les fragments dorsaux et ventraux des côtes fracturées, approximativement 5 à 10 mm de la ligne de fracture. Le câble a été introduit dans le trou du fragment dorsal et ensuite dans le trou du fragment ventral. Les attaches de câbles ont été resserrées. Les fractures n'ont pas été réduites et les fragments dorsaux chevauchaient les fragments ventraux. Cette technique a été utilisée sans complications chez quatre poulains nouveau-nés.(Traduit par les auteurs).

Ex vivo equine medial tibial plateau contact pressure with an intact medial femoral condyle, with a medial femoral condylar defect, and after placement of a transcondylar screw through the condylar defect.

OBJECTIVE: To determine ex vivo contact data on the equine medial tibial plateau loaded by an intact medial femoral condyle (MFC), by an MFC with an osteochondral defect, and with a screw inserted in lag fashion through the MFC defect. STUDY DESIGN: Ex vivo experiment. ANIMALS: Stifles (n = 6). Horses (n = 4). METHODS: Stifle joints were axially loaded to 1800 N at 155°, 145°, and 130°, under 3 conditions: Intact, MFC with a 15 mm circular osteochondral defect, and with a transcondylar screw inserted in lag fashion through the defect. An electronic pressure sensor (Tekscan®) on the medial tibial plateau recorded contact area, force, peak pressure, and contact maps. Stress load (N/cm(2) ) was calculated for the entire medial plateau and in 3 sub-regions; cranial, caudal, and central. Significance was set at P ≤ .05. RESULTS: Flexion increased force, contact area, and stress load for all conditions. An MFC defect significantly reduced force at both flexion angles and contact area at 145°. The transcondylar screw returned force to intact values at 130° and reduced contact area in extension. Intact MFC contact maps revealed pressure peaks on the central cartilage at all angles and contact pressure and area expansion and caudal movement with flexion. Contact maps with an MFC defect amplified the caudal and abaxial pressure movement during flexion, and the screw did not further change them. CONCLUSIONS: Stifle flexion increases force, contact area, and stress load on the medial tibial plateau and is most pronounced caudally. An MFC defect alters load on the medial tibial plateau, and a transcondylar screw may reverse some of those changes.

Preliminary investigation of the treatment of equine medial femoral condylar subchondral cystic lesions with a transcondylar screw.

OBJECTIVE: To determine if medial femoral condylar (MFC) subchondral cystic lesions (SCL) causing lameness will demonstrate radiographic evidence of healing and lameness reduction after placement of a transcondylar screw in lag fashion. STUDY DESIGN: Retrospective case series. ANIMALS: Horses (n = 20) with lameness attributed to a MFC SCL. METHODS: A 4.5 mm screw was inserted in lag fashion across MFC SCL in horses with hindlimb lameness. Post-operative radiography and lameness examinations were performed at 30-60 day intervals after surgery for 120 days, and SCL radiographic area and lameness were graded. Treatment was considered successful if lameness was eliminated and the radiographic area of the SCL on a caudocranial projection decreased ≥ 50% by 120 days. RESULTS: Twenty-six limbs were treated. Nine horses (11 limbs) had autologous adjunctive biologics placed into the SCL. Lameness was reduced by 1-2 grades by 60 days after surgery in 18 horses and was eliminated in 15 horses by 120 days, at which time the SCL area had decreased ≥ 50% and work had resumed without lameness (mean follow-up, 12 months). Biologic therapies had no impact on treatment success. Treatment was less successful in horses >3 years of age. CONCLUSIONS: A MFC transcondylar screw decreases the area of a MFC SCL on craniocaudal radiographs and eliminates lameness in ∼ 75% of horses by 120 days. The simplicity and lack of specialized equipment required make this technique a useful option for the treatment of equine SCL causing lameness.

Comparison of 2 equine transfixation pin casts and the effects of pin removal.

OBJECTIVE: To (1) compare strain on the dorsal aspect of the proximal phalanx (P1) between 2 types of transfixation pin casts (TPC) and (2) evaluate the change in strain as the pins are removed. STUDY DESIGN: Experimental. ANIMALS: Equine cadaver forelimbs (n = 10 pair). METHODS: Each limb of a pair was assigned to 1 of 2 TPC constructs. Construct 1 consisted of a TPC with 2 positive profile, centrally threaded pins placed in the distal aspect of the third metacarpus (MC3) and construct 2 had 4 smooth Steinmann pins placed similarly. A strain gauge was mounted on P1 and axial compression (444.8-5337.9 N) applied. One forelimb of each pair was tested as a control with no construct in place. The 2 TPC groups were retested after removal of 1 proximal (n = 5 limbs) or distal (n = 5) pin from construct 1, and 2 proximal (n = 5) or distal (n = 5) pins from construct 2. Limb specimens were retested after all pins had been removed. RESULTS: There was a significant decrease in strain between both TPC constructs and the non-casted control at all loads except 444.8 N. There was no significant difference in strain reduction between the 2 TPC constructs. After proximal pin removal there was a 7% (construct 1) and 10% (construct 2) increase in strain. When distal pins were removed there was a 0.5% (construct 1) and 1% (construct 2) increase in strain. The difference between proximal and distal pin removal was only statistically different from each other at high loads. CONCLUSION: Both constructs provided equivalent reduction in strain. Removal of the proximal pin(s) increased the strain.

Effect of body position on intra-abdominal pressures and abdominal perfusion pressures measured at three sites in horses anesthetized with short-term total intravenous anesthesia.

OBJECTIVE: To assess effects of body position on direct measurements of intra-abdominal pressure (IAP) and abdominal perfusion pressure (APP) in horses anesthetized with total intravenous anesthesia (TIVA). ANIMALS: 9 healthy adult horses. PROCEDURES: Instrumentation in unsedated standing horses involved insertion of an arterial catheter for blood pressure measurements and 3 intraperitoneal cannulas (left flank, right flank, and ventral abdomen) for IAP measurements. Baseline values were measured for heart rate, respiratory rate, systolic arterial blood pressure, mean arterial blood pressure (MAP), diastolic arterial blood pressure, and IAP. Horses were medicated with xylazine, and pressures were measured again. Anesthesia was induced with ketamine-diazepam and maintained with a ketamine-guaifenesin infusion. Horses were positioned twice into left lateral recumbency, right lateral recumbency, or dorsal recumbency. Hemodynamic pressures and accessible abdominal pressures were measured for each recumbency position. The APP was calculated as MAP - IAP. Differences in IAP, MAP, APP and sedation (standing horses) or body position (anesthetized horses) were compared by means of repeated-measures ANOVA or paired t tests. RESULTS: Baseline hemodynamic and IAPs were not different after xylazine administration. Ventral abdomen IAP and MAP were lower for horses in dorsal recumbency than in right or left lateral recumbency. Ventral abdomen APP remained unchanged. For lateral recumbencies, flank IAP was lower and APP was higher than pressure measurements at the same sites during dorsal recumbency. CONCLUSIONS AND CLINICAL RELEVANCE: Body position affected IAP and APP in healthy anesthetized horses. These effects should be considered when developing IAP acquisition methods for use in horses with abdominal disease.