Rhodococcus equi occipital bone osteomyelitis, septic arthritis and meningitis in a neurological foal

Less Typical Courses of Rhodococcus equi Infections in Foals

This article aims to present several interesting and less typical courses of Rhodococcus equi infections in foals, collected during the 2019-2021 foaling seasons in some Polish studs. The study was conducted by the Division of Veterinary Epidemiology and Economics, Warsaw University of Life Sciences-SGGW, and concentrated on ultrasonographic contribution to diagnostics and treatment of the disease. Among many standard cases of rhodococcal pneumonia, some rare ones occurred. The aforementioned issues include the potential contribution of rhodococcal infection to a grave outcome in a prematurely born filly, lost as a yearling, so-called "extrapulmonary disorders" (EPD), a hypothesis of inherited immunodeficiency with grave outcome in a breeding dam line from one stud, and macrolide-induced anhidrosis. The main benefit of this report would be to supplement the general picture of clinical rhodococcosis.

Occipital condyle defects assessed by radiography or CT can be a normal finding in foals

Age of complete ossification of equine occipital condyles has not been published. Consequently, clinical significance of occipital condyle defects on radiographs or CT scans of young horses remains unknown. The goals of this single-center, retrospective, cross-sectional study were to characterize incidental occipital condyle defects and to define the age of complete ossification. The margin of occipital condyles was classified as regular or with defect(s). Analyses were made on 121 horses, including 106 radiographic and 19 CT studies showing the occipital condyles of horses less than 5 years of age obtained over 6 years in a referral hospital. Neurological signs and outcome were not associated with occipital defects. Horses with regular occipital condyles on radiographs had a median age of 974 days (median interquartile range = 707) compared with 47 days (interquartile range = 106) in the defect group. The odds of finding radiographically regular occipital condyles were 2.6% higher for each additional day of age (P = .011, 95% CI, 0.6-4.7%). In the CT group, univariate analyses demonstrated a significant effect of age on the aspect of occipital condyles (P = .016). Horses with regular occipital condyles were older (median age = 881 days; interquartile range = 1054) than horses with a defect (median age = 109 days, interquartile range = 318). All horses above 156 days (5.1 months) of age and 550 days (18.1 months) of age had regular occipital condyles on radiographic and CT images, respectively. This study describes occipital condyle defects as a potential normal finding in young horses and provides guidelines for interpretation of the occipital condyle ossification process.

Current Trends in Understanding and Managing Equine Rhodococcosis

The aim of this review was to summarize studies on equine rhodococcosis over the last decade. For many years Rhodococcus equi has remained one of the major health challenges in the equine breeding industry worldwide. Recently, many novel approaches and ideas have been described and some of them were initially implemented into the clinical practice. This study reviews a variety of new information about neonatal susceptibility, clinical appearance, considered and applied diagnostic procedures and treatment alternatives, factors limiting accurate prognosis, ideas regarding environmental management and prophylaxis considerations. Although multiple research were conducted, the main problems such as high morbidity and mortality, a lack of reliable prevention strategies and treatment limitations are still unresolved and require further scientific effort.

Alterations in the fecal microbiota of patients with spinal cord injury

Objectives

Spinal cord injury (SCI) is associated with severe autonomic dysfunction. Patients with SCI often suffer from a lack of central nervous system control over the gastrointestinal system. Therefore, we hypothesized that patients with SCI would cause intestinal flora imbalance. We investigated alterations in the fecal microbiome in a group of patients with SCI.

Methods

Microbial communities in the feces of 23 patients and 23 healthy controls were investigated using high-throughput Illumina Miseq sequencing targeting the V3-V4 region of the 16S ribosomal RNA (rRNA) gene. The relative abundances between the fecal microbiota at the genus level in patients with SCI and healthy individuals were determined using cluster analysis.

Results

The structure and quantity of fecal microbiota differed significantly between patients with SCI and healthy controls, but the richness and diversity were not significantly different. A two-dimensional heatmap showed that the relative abundances of forty-five operational taxonomic units (OTUs) were significantly enriched either in SCI or healthy samples. Among these, 18 OTUs were more abundant in healthy controls than in patients with SCI, and 27 OTUs were more abundant in the SCI group than in healthy controls.

Conclusion

Our study showed that patients with SCI exhibited microbiome dysbiosis.

Arthroscopic approach and intra-articular anatomy of the equine atlanto-occipital joint

OBJECTIVE

To develop arthroscopic approaches to the atlanto-occipital (A-O) and describe associated arthroscopic anatomy.

STUDY DESIGN

Experimental ex vivo study and clinical case report.

ANIMALS

Ten equine cadaver joints and 1 clinical case.

METHODS

CT arthrograms of 8 A-O joints were performed to determine the placement of an arthroscopic portal. Arthroscopy was performed via dorsal and/or ventral approaches (dorsal or ventral to the longissimus capitis tendon) in 10 cadaveric A-O joints and the A-O joint of a 2-week-old foal with septic arthritis. Accessible cartilage was debrided in 3 cadaver joints. Accessibility and risks were assessed by review of arthroscopic images, postoperative necropsy, and computed tomography (CT).

RESULTS

Dorsal and ventral outpouchings of the A-O joint were identified with CT. Arthroscopy of the dorsal pouch provided access to 50% of the dorsocranial occipital condyle and 15% of the dorsocranial atlas articular surfaces. Joint distension caused displacement of the dura. Dura perforation occurred with a blind dorsal approach in 2 of 5 joints. Dura perforation did not occur after ultrasonography-guided approaches. Arthroscopic debridement of septic arthritis and osteomyelitis was successful in 1 clinical case.

CONCLUSION

Approaches to the A-O joint were determined from CT examinations. The cranial aspect of the dorsal pouch of the A-O joint was accessed via arthroscopic triangulation in all horses of this study. Ultrasound-guided joint access prevented perforation of vital structures, including the spinal canal.

CLINICAL SIGNIFICANCE

Advanced imaging improves the diagnosis of A-O joint pathology. Descriptions of arthroscopic anatomy and accessibility provide important information for surgical intervention.

Comparison of conventional radiography and computed tomography as aids in the diagnosis of osteomyelitis in 11 foals

BACKGROUND

Conventional radiography is currently the most common imaging modality used by veterinarians investigating foals with suspected osteomyelitis. Emerging evidence in adult horses and humans suggests computed tomography (CT) is a superior modality for evaluation of osseous changes in general. This study aimed to evaluate the potential benefits of CT versus conventional radiography in cases of osteomyelitis in foals.

METHODS

Cases of osteomyelitis in foals under 6 months of age admitted over a 6-year period at a single referral hospital that had both CT and conventional radiography images were retrieved. Case details and measurements of the largest area of bone lysis identified in two planes (lateromedial/sagittal and dorsopalmar/dorsal) were evaluated by three veterinarians with a range of experience.

RESULTS

A significant difference regarding lesion size was seen on the lateromedial (LM) radiographic projections compared with the equivalent sagittal plane CT image. The LM radiographic evaluation resulted in a 37% underestimation of the area of the lesion. Additionally, use of the LM radiographic projections were 2.5-fold more variable in the measurement area compared with CT. In general, regardless of projection, CT produced more information regarding lesion area and, in some cases, detected osseous changes that were not evident on the radiographs.

CLINICAL RELEVANCE

LM radiographic projections are less reliable and commonly result in an under-appreciation of lesion size and extent. CT detected lesions that were difficult or impossible to identify on radiographs and may allow improved treatment planning.

Magnetic resonance imaging characteristics of equine head disorders: 84 cases (2000-2013)

The equine head is an anatomically complex area, therefore advanced tomographic imaging techniques, such as computed tomography or magnetic resonance imaging (MRI), are often required for diagnosis and treatment planning. The purpose of this multicenter retrospective study was to describe MRI characteristics for a large sample of horses with head disorders. Horses imaged over a period of 13 years were recruited. Eighty-four horses met the inclusion criteria, having neurological (n = 65), sinonasal (n = 14), and soft tissue (n = 5) disorders. Magnetic resonance imaging accurately depicted the anatomy and allowed identification of the primary lesion and associated changes. There were good correlations between MRI findings and intraoperative or postmortem results. Magnetic resonance imaging showed the exact localization of the lesions, their size, and relation to surrounding structures. However, in the neurological group, there were 45 horses with no MRI abnormalities, 29 of which had a history of recurrent seizures, related to cryptogenic epilepsy. Magnetic resonance imaging was otherwise a valuable diagnostic tool, and can be used for studying a broad range of head disorders using either low-field or high-field magnets.

Ultrasonographic findings in 38 horses with septic arthritis/tenosynovitis

Septic arthritis/tenosynovitis in the horse can have life-threatening consequences. The purpose of this cross-sectional retrospective study was to describe ultrasound characteristics of septic arthritis/tenosynovitis in a group of horses. Diagnosis of septic arthritis/tenosynovitis was based on historical and clinical findings as well as the results of the synovial fluid analysis and/or positive synovial culture. Ultrasonographic findings recorded were degree of joint/sheath effusion, degree of synovial membrane thickening, echogenicity of the synovial fluid, and presence of hyperechogenic spots and fibrinous loculations. Ultrasonographic findings were tested for dependence on the cause of sepsis, time between admission and beginning of clinical signs, and the white blood cell counts in the synovial fluid. Thirty-eight horses with confirmed septic arthritis/tenosynovitis of 43 joints/sheaths were included. Degree of effusion was marked in 81.4% of cases, mild in 16.3%, and absent in 2.3%. Synovial thickening was mild in 30.9% of cases and moderate/severe in 69.1%. Synovial fluid was anechogenic in 45.2% of cases and echogenic in 54.8%. Hyperechogenic spots were identified in 32.5% of structures and fibrinous loculations in 64.3%. Relationships between the degree of synovial effusion, degree of the synovial thickening, presence of fibrinous loculations, and the time between admission and beginning of clinical signs were identified, as well as between the presence of fibrinous loculations and the cause of sepsis (P ≤ 0.05). Findings indicated that ultrasonographic findings of septic arthritis/tenosynovitis may vary in horses, and may be influenced by time between admission and beginning of clinical signs.