Grade IV gastric ulceration, pyloric aplasia, and an ectopic duodenal papilla in a 13-year-old Quarter Horse gelding evaluated for recurrent colic.

OBJECTIVE: The objective of this Case Report was to describe the clinical manifestation and postmortem findings of a horse evaluated for recurrent colic diagnosed with pyloric aplasia and an ectopic duodenal papilla. ANIMAL: 13-year-old Quarter Horse gelding. CLINICAL PRESENTATION, PROGRESSION, AND PROCEDURES: The horse was presented to a referral center for signs of colic that were unresponsive to management on the farm. No abnormalities were noted on rectal palpation; however, upon passage of a nasogastric tube, 31 L of net gastric reflux was obtained. Gastroscopy noted grade IV squamous ulceration and moderate glandular ulceration, severe gastric dilatation, an abnormally positioned gastric outflow tract, and an ectopic duodenal papilla leaking bile-like fluid directly into the stomach. TREATMENT AND OUTCOME: The horse was initially treated with gastroprotectants, promotility agents, and dietary modifications. Following treatment failure and repeated episodes of colic with increasing severity, the horse was euthanized and a necropsy performed. At necropsy, it was confirmed that the aboral aspect of the stomach formed a dilated pouch and continued directly into the proximal duodenum with no discernible pyloric sphincter. The area of the pylorus was delineated by a faint indentation. The ectopic duodenal papilla was traced to the liver. CLINICAL RELEVANCE: Congenital gastric abnormalities, even in adult horses, should be considered as differential diagnoses when investigating horses presenting with a history of chronic colic. Neither pyloric aplasia nor an ectopic duodenal papilla have been described in the equine literature, and this Case Report raises awareness of the presence of such malformations and their manifestations.

Fasting horses perioperatively decreases manure production and increases time to manure output postoperatively: a controlled randomized trial.

OBJECTIVE: To compare 3 perioperative feeding regimens and their effect on anesthetic complications, manure output, and colic proportion in healthy horses. METHODS: 45 horses presenting for elective orthopedic procedures were randomly assigned to 1 of 3 groups: not fasted (NF; continuous access to hay perioperatively), fasted muzzled (FM; 10-hour preoperative fast with slow refeeding postoperatively and muzzle placement), or fasted not muzzled (FNM; same as FM without muzzle placement). Anesthetic protocol was standardized. Outcomes compared between groups included anesthesia time, arterial oxygenation, duration of hypotension, perioperative manure output, time to first passage of manure postoperatively, pain scores, and colic proportion. Comparisons were made with a mixed model and Fisher exact test with statistical significance considered at P ≤ .05. RESULTS: No differences were seen in pain scores, oxygenation, hypotension, or colic between groups. Groups FM and FNM had a significantly greater mean reduction in postoperative manure weight (-81% and -70%; P = .003) and number of manure piles (-63% and -55%; P = .005) compared to group NF (-39% and -22%; P < .001; weight and piles, respectively). Mean ± SD minutes to passage of manure postoperatively was significantly shorter in group NF (238 ± 13 minutes) than groups FM (502 ± 174 minutes; P < .001) and FNM (444 ± 171 minutes; P = .003). CLINICAL RELEVANCE: Horses with continuous access to hay prior to and following recovery from anesthesia passed more manure and passed manure sooner after surgery than their fasted counterparts without detrimental effect on anesthetic parameters and postoperative complications. Continuous access to hay perioperatively supports manure production in healthy horses without increase in anesthetic complications.

Subchondral bone sequestrum formation in the proximal intra-articular and osteochondral region of the third metatarsal bone of an Appaloosa mare treated for septic arthritis.

OBJECTIVE: To raise awareness of the potential for intra-articular subchondral bone sequestrum formation secondary to a traumatic or septic process to enable more rapid identification of this uncommon but possible outcome in future cases. ANIMAL: A client-owned 12-year-old Appaloosa mare. CLINICAL PRESENTATION, PROGRESSION, AND PROCEDURES: The mare had a wound to the lateral aspect of the fourth metatarsal bone (MT4) that communicated with the distal tarsal joints. Radiographs revealed a displaced, comminuted fracture of MT4. TREATMENT AND OUTCOME: The horse underwent aggressive debridement of the wound and MT4 as well as, on 2 occasions, needle joint lavage. Systemic, regional, and IA antibiotic therapy was also performed together with a bone graft from the tuber coxae. The horse's comfort improved, and the wound appeared to be healing. Five weeks following discharge, the horse re-presented with a non-weight-bearing lameness and radiographs revealed marked osteomyelitis of the tarsometatarsal and distal intertarsal joints. Postmortem examination of the limb identified a sequestrum within the proximal articular surface of the third metatarsal bone. CLINICAL RELEVANCE: The present report highlights the importance of arthroscopic lavage to visualize the cartilage surface and the benefits of advanced imaging to detect associated changes within the bone earlier than conventional radiographs. To our knowledge, no reports exist of intra-articular subchondral bone sequestra in the tarsometatarsal joint in horses.

The use of radiofrequency in equine orthopedic surgery.

The use of radiofrequency energy (RFE) has become increasingly popular in equine orthopedic surgery in recent years, particularly for the debridement of cartilage lesions and soft tissue resection. However, despite considerable advancements in the technology, the safety and efficacy of RFE have continued to be questioned. While studies investigating the use of RFE for chondroplasty in the equine population are lacking, there is an abundance of research studies in the human literature assessing its effect on healthy chondrocytes, and researchers are seeking to develop guidelines to minimize collateral damage. This review article provides a concise and thorough summary of the current use of RFE in equine orthopedics, in addition to discussing the recent evidence surrounding its use for chondroplasty in both the human and equine populations.

An Unusual Cause of Femoral Nerve Paresis in a Horse: Disseminated B Cell Lymphoma With Plasmacytoid Differentiation and Direct Neuronal Invasion.

A 21-year-old Quarter Horse mare presented with a chronic, progressively worsening left pelvic limb lameness of 3 weeks duration. The initial examination identified a consistent lameness at a walk. Neurological examination showed sensory and gait abnormalities consistent with left femoral nerve dysfunction. The horse minimally advanced the leg cranially and had a shortened stride length at the walk. During the stance phase, the heels of the left hind foot did not contact the ground and the horse quickly took weight off of the limb. Diagnostic imaging (ultrasound and nuclear scintigraphy) examinations did not reveal a cause. Severe lymphocytosis was identified on complete blood cell count (69,600 cells /uL; reference range: 1,500-4,000 cells/uL), suggestive of lymphoma. Postmortem examination revealed focal swelling of the left femoral nerve. Multiple masses were found in the stomach, large colon, adrenal gland, mesentery, heart, and meninges. The entire left pelvic limb was dissected and did not reveal other causes of the gait deficit. Histologic evaluation of the left femoral nerve revealed disseminated intermediate cell size B cell lymphoma, with an immunophenotype suggestive of plasmacytoid differentiation. These lymphocytes infiltrated the femoral nerve at the location of the focal nerve swelling, in addition to other peripheral nerves. This case highlights a horse with an atypical diagnosis of femoral nerve paresis caused by direct neoplastic lymphocyte infiltration, deriving from disseminated B cell lymphoma with plasmacytoid differentiation (neurolymphomatosis). Though rare, disseminated lymphoma with direct nerve infiltration should be considered in horses with peripheral neuropathies.

Arthroscopic removal of osteochondral fragments located within the condylar fossa of the third metacarpus/metatarsus in Thoroughbred yearlings.

OBJECTIVE: To describe an arthroscopic technique for the removal of osteochondral fragments located within the condylar fossa of the third metacarpal/tarsal bone. STUDY DESIGN: Retrospective study. ANIMALS: Thoroughbred yearlings (n = 11). METHODS: Osteochondral fragments located within the condylar fossa of the third metacarpal/tarsal bone identified during presale radiographic examination were removed via arthroscopy, assisted with ultrasonography in select cases. Complete fragment removal was confirmed by intraoperative radiography. RESULTS: Fragments were successfully removed using rongeurs following dissection of soft tissue attachments using a bipolar radiofrequency probe. No postoperative complications occurred. CONCLUSIONS: An ipsilateral arthroscopic and instrument portal coupled with ultrasound assistance and a radiofrequency probe allowed for successful removal of fragments located within the condylar fossa of the third metacarpal/tarsal bone. The technique allowed for the removal of the unstable osteochondral fragment and associated physical debris. CLINICAL SIGNIFICANCE: The described surgical technique enables the removal of osteochondral fragments located within the condylar fossa of the third metacarpal/tarsal bone with minimal disruption to the surrounding soft tissues.

Globetrotting strangles: the unbridled national and international transmission of Streptococcus equi between horses.

The equine disease strangles, which is characterized by the formation of abscesses in the lymph nodes of the head and neck, is one of the most frequently diagnosed infectious diseases of horses around the world. The causal agent, Streptococcus equi subspecies equi, establishes a persistent infection in approximately 10 % of animals that recover from the acute disease. Such 'carrier' animals appear healthy and are rarely identified during routine veterinary examinations pre-purchase or transit, but can transmit S. equi to naïve animals initiating new episodes of disease. Here, we report the analysis and visualization of phylogenomic and epidemiological data for 670 isolates of S. equi recovered from 19 different countries using a new core-genome multilocus sequence typing (cgMLST) web bioresource. Genetic relationships among all 670 S. equi isolates were determined at high resolution, revealing national and international transmission events that drive this endemic disease in horse populations throughout the world. Our data argue for the recognition of the international importance of strangles by the Office International des Épizooties to highlight the health, welfare and economic cost of this disease. The Pathogenwatch cgMLST web bioresource described herein is available for tailored genomic analysis of populations of S. equi and its close relative S. equi subspecies zooepidemicus that are recovered from horses and other animals, including humans, throughout the world. This article contains data hosted by Microreact.

Radiographic Description of a Bone Exostosis Lesion on the Caudal Aspect of the Proximal Tibia in Three Thoroughbred Yearlings (2014-2019).

This manuscript describes exostosis lesions originating from the caudal aspect of the proximal tibia identified in three Thoroughbred yearlings as part of the routine review of presale radiographic images. These lesions are hypothesized to be osteochondromas. The identification of bony exostoses on the proximal tibia has not been reported before in current literature. As they have not been described, the future effect on performance or soundness is unknown. Although these cases were not lame at the time of detection, the future growth of the lesion and its impact on surrounding soft tissues is unknown.