Treatment of chronic sinusitis in a horse with systemic and intra-sinus antimicrobials.

A 12-year-old Norwegian Fjord gelding was diagnosed with paranasal sinusitis as a post-operative complication of tooth repulsion surgery. The infection with inspissated purulent material persisted despite sinus trephination and lavage, and systemic antimicrobial therapy. Resolution occurred following infusion of a gelatin/penicillin mixture into the right rostral and caudal maxillary sinus.

Traitement de la sinusite chronique chez un cheval à l'aide d'antimicrobiens systémiques et dans les sinus. Une sinusite paranasale a été diagnostiquée chez un hongre Fjord âgé de 12 ans comme complication postopératoire d'une chirurgie pour la répulsion d'une dent. L'infection avec du matériel purulent épaissi a persisté malgré la trépanation et le lavage du sinus et une thérapie antimicrobienne systémique. La résorption s'est produite après l'infusion d'un mélange de gélatine et de pénicilline dans les sinus maxillaires rostral et caudal droits.(Traduit par Isabelle Vallières).

Acute pancreatitis following granulosa cell tumor removal in a mare.

Acute pancreatitis is a rare disease in horses and is often associated with gastrointestinal disorders. Accurate diagnosis is challenging due to the presence of nonspecific clinical signs. This case represents the first documentation of acute pancreatitis in a horse following surgery of the reproductive tract.

Pancréatite aiguë consécutive à l'enlèvement d'une tumeur de la granulosa chez une jument. La pancréatite aiguë est une maladie rare chez les chevaux et est souvent associée aux troubles gastro-intestinaux. Un diagnostic exact est difficile en raison de la présence de signes cliniques non spécifiques. Ce cas représente la première fois qu'une pancréatite aiguë est documentée chez un cheval après la chirurgie de l'appareil reproducteur.(Traduit par Isabelle Vallières).

Osteogenic potential of sorted equine mesenchymal stem cell subpopulations.

The objectives of this study were to use non-equilibrium gravitational field-flow fractionation (GrFFF), an immunotag-less method of sorting mesenchymal stem cells (MSCs), to sort equine muscle tissue-derived mesenchymal stem cells (MMSCs) and bone marrow-derived mesenchymal stem cells (BMSC) into subpopulations and to carry out assays in order to compare their osteogenic capabilities. Cells from 1 young adult horse were isolated from left semitendinosus muscle tissue and from bone marrow aspirates of the fourth and fifth sternebrae. Aliquots of 800 × 10(3) MSCs from each tissue source were sorted into 5 fractions using non-equilibrium GrFFF (GrFFF proprietary system). Pooled fractions were cultured and expanded for use in osteogenic assays, including flow cytometry, histochemistry, bone nodule assays, and real-time quantitative polymerase chain reaction (qPCR) for gene expression of osteocalcin (OCN), RUNX2, and osterix. Equine MMSCs and BMSCs were consistently sorted into 5 fractions that remained viable for use in further osteogenic assays. Statistical analysis confirmed strongly significant upregulation of OCN, RUNX2, and osterix for the BMSC fraction 4 with P < 0.00001. Flow cytometry revealed different cell size and granularity for BMSC fraction 4 and MMSC fraction 2 compared to unsorted controls and other fractions. Histochemisty and bone nodule assays revealed positive staining nodules without differences in average nodule area, perimeter, or stain intensity between tissues or fractions. As there are different subpopulations of MSCs with different osteogenic capacities within equine muscle- and bone marrow-derived sources, these differences must be taken into account when using equine stem cell therapy to induce bone healing in veterinary medicine.

Les objectifs de la présente étude étaient d'utiliser une méthode non-équilibrée de fractionnement par flot sous champs gravitationnel (GrFFF), une méthode sans marquage immunologique de séparation des cellules souches mésenchymateuses (MSCs), afin de séparer les cellules souches mésenchymateuses dérivées du tissu musculaire équin (MMSCs) et les cellules souches mésenchymateuses provenant de la moelle osseuse (BMSCs) en sous-populations et de réaliser des essais afin de comparer leurs capacités ostéogéniques. Des cellules provenant d'un jeune cheval adulte furent isolées du muscle semi-tendineux gauche et d'aspirations de la moelle osseuse de la quatrième et cinquième strernèbre. Des aliquotes de 800 × 103 MSCs provenant de chaque source de tissu furent séparés en 5 fractions par GrFFF non-équilibré (système breveté GrFFF). Des fractions regroupées ont été mises en culture afin de proliférer pour utilisation dans des essais ostéogéniques, incluant la cytométrie en flux, l'histochimie, des essais de nodules osseux, et l'amplification en chaine quantitative par la polymérase (qPCR) pour l'expression des gènes de l'ostéocalcine (OCN), RUNX2, et osterix. Les MMSCs et BMSCs équins étaient séparés de manière constante en 5 fractions qui demeuraient viables pour utilisation dans des essais ostéogéniques additionnels. Les analyses statistiques ont confirmé une régulation à la hausse très significative pour OCN, RUNX2 et osterix pour la fraction 4 des BMSC (P < 0,00001). La cytométrie en flux a révélé une taille et une granularité différente pour la fraction 4 des BMSCs et la fraction 2 des MMSCs comparativement aux témoins non-séparés et aux autres fractions. L'histochimie et les essais de nodules osseux ont révélé des nodules se colorant positivement sans différence pour les tissus ou les fractions dans la moyenne de la surface du nodule, du périmètre, ou de l'intensité de la coloration. Étant donné qu'il y a différentes sous-populations de MSCs avec différentes capacités ostéogéniques parmi les sources dérivées du muscle et de la moelle osseuse, ces différences doivent être prises en compte lors de l'utilisation thérapeutique en médecine vétérinaire des cellules souches pour induire la guérison osseuse.(Traduit par Docteur Serge Messier).

Application of a novel sorting system for equine mesenchymal stem cells (MSCs).

The objective of this study was to validate non-equilibrium gravitational field-flow fractionation (GrFFF), an immunotag-less method of sorting mesenchymal stem cells (MSCs) into subpopulations, for use with MSCs derived from equine muscle tissue, periosteal tissue, bone marrow, and adipose tissue. Cells were collected from 6 young, adult horses, postmortem. Cells were isolated from left semitendinosus muscle tissue, periosteal tissue from the distomedial aspect of the right tibia, bone marrow aspirates from the fourth and fifth sternebrae, and left supragluteal subcutaneous adipose tissue. Aliquots of 800 × 10(3) MSCs from each tissue source were separated and injected into a ribbon-like capillary device by continuous flow (GrFFF proprietary system). Cells were sorted into 6 fractions and absorbencies [optical density (OD)] were read. Six fractions from each of the 6 aliquots were then combined to provide pooled fractions that had adequate cell numbers to seed at equal concentrations into assays. Equine muscle tissue-derived, periosteal tissue-derived, bone marrow-derived, and adipose tissue-derived mesenchymal stem cells were consistently sorted into 6 fractions that remained viable for use in further assays. Fraction 1 had more cuboidal morphology in culture when compared to the other fractions. Statistical analysis of the fraction absorbencies (OD) revealed a P-value of < 0.05 when fractions 2 and 3 were compared to fractions 1, 4, 5, and 6. It was concluded that non-equilibrium GrFFF is a valid method for sorting equine muscle tissue-derived, periosteal tissue-derived, bone marrow-derived, and adipose tissue-derived mesenchymal stem cells into subpopulations that remain viable, thus securing its potential for use in equine stem cell applications and veterinary medicine.

L'objectif de la présente étude était de valider une méthode non-équilibrée de fractionnement par flot sous champs gravitationnel (GrFFF), une méthode sans marquage immunologique de séparation des cellules souches mésenchymateuses (MSCs) en sous-populations, pour utilisations avec des MSCs provenant de tissu musculaire, de tissu de périoste, de moelle osseuse, et de tissu adipeux de chevaux. Les cellules furent prélevées post-mortem à partir de six jeunes chevaux adultes. Les cellules furent isolées du muscle semi-tendineux gauche, du périoste de l'aspect disto-médial du tibia droit, d'aspirations de moelle osseuse de la quatrième et cinquième sternèbres, et du tissu adipeux sous-cutané de la région supra-glutéale gauche. Des aliquots de 800 × 103 MSCs de chaque tissu ont été séparés et injectés dans un appareil capillaire apparenté à un ruban par flot continu (système breveté GrFFF). Les cellules furent séparées en six fractions et les absorbances [densité optique (OD)] notées. Six fractions de chacun des six aliquots furent par la suite combinées afin de fournir des fractions poolées qui avaient des nombres adéquats de cellules pour ensemencer des concentrations égales dans les essais. Les MSCs provenant du tissu musculaire, du périoste, de la moelle osseuse, et du tissu adipeux étaient de manière constante séparées en six fractions qui sont demeurées viables pour utilisation dans des essais ultérieurs. La fraction 1 avait plus de cellules de morphologie cuboïde comparativement aux autres fractions. Les analyses statistiques des OD des fractions ont révélé une valeur de P < 0,05 lorsque les fractions 2 et 3 étaient comparées aux fractions 1, 4, 5, et 6. Il fut conclu que la méthode GrFFF non-équilibrée est une méthode valide pour séparer les MSCs équines dérivées des cellules musculaires, du périoste, de la moelle osseuse, et du tissu adipeux en sous-populations qui demeurent viables, assurant ainsi son potentiel pour utilisation en médecine vétérinaire et les applications avec les cellules souches équines.(Traduit par Docteur Serge Messier).

Unilateral notomelia in a newborn Holstein calf.

A 24-hour-old Holstein bull calf with notomelia was donated to the Atlantic Veterinary College. The extra limb was on the right side of the caudal neck adjacent to the withers. The limb was surgically removed under general anesthesia. The calf was adopted and discharged with no complications.

Notomélie unilatérale chez un veau Holstein nouveau-né. Un veau taureau Holstein âgé de 24 heures atteint de notomélie a été donné à l'Atlantic Veterinary College. Le membre supplémentaire se trouvait du côté droit du cou caudalement au garrot. Le membre a été enlevé par chirurgie sous anesthésie générale. Le veau a été adopté et a reçu son congé sans complications.(Traduit par Isabelle Vallières).

Characterization and osteogenic potential of equine muscle tissue- and periosteal tissue-derived mesenchymal stem cells in comparison with bone marrow- and adipose tissue-derived mesenchymal stem cells.

OBJECTIVE: To characterize equine muscle tissue- and periosteal tissue-derived cells as mesenchymal stem cells (MSCs) and assess their proliferation capacity and osteogenic potential in comparison with bone marrow- and adipose tissue-derived MSCs. SAMPLE: Tissues from 10 equine cadavers. PROCEDURES: Cells were isolated from left semitendinosus muscle tissue, periosteal tissue from the distomedial aspect of the right tibia, bone marrow aspirates from the fourth and fifth sternebrae, and adipose tissue from the left subcutaneous region. Mesenchymal stem cells were characterized on the basis of morphology, adherence to plastic, trilineage differentiation, and detection of stem cell surface markers via immunofluorescence and flow cytometry. Mesenchymal stem cells were tested for osteogenic potential with osteocalcin gene expression via real-time PCR assay. Mesenchymal stem cell cultures were counted at 24, 48, 72, and 96 hours to determine tissue-specific MSC proliferative capacity. RESULTS: Equine muscle tissue- and periosteal tissue-derived cells were characterized as MSCs on the basis of spindle-shaped morphology, adherence to plastic, trilineage differentiation, presence of CD44 and CD90 cell surface markers, and nearly complete absence of CD45 and CD34 cell surface markers. Muscle tissue-, periosteal tissue-, and adipose tissue-derived MSCs proliferated significantly faster than did bone marrow-derived MSCs at 72 and 96 hours. CONCLUSIONS AND CLINICAL RELEVANCE: Equine muscle and periosteum are sources of MSCs. Equine muscle- and periosteal-derived MSCs have osteogenic potential comparable to that of equine adipose- and bone marrow-derived MSCs, which could make them useful for tissue engineering applications in equine medicine.

Comparison of radiography and computed tomography to evaluate metacarpo/metatarsophalangeal joint pathology of paired limbs of thoroughbred racehorses with severe condylar fracture.

OBJECTIVE: To compare the orthogonal radiographic (OR) and computed tomographic (CT) appearance of paired Thoroughbred racehorse limbs with severe condylar fracture. STUDY DESIGN: In vitro study. SAMPLE POPULATION: Cadaveric paired limbs with severe condylar fracture (n=11 horses). METHODS: Four standard radiographic and multiple transverse CT images were obtained of the fractured and contralateral limbs centering on the metacarpo/metatarsophalangeal (fetlock) joints. Radiographs and CT images were graded by 4 raters, and interobserver agreement was calculated. Imaging evaluations were supplemented by fetlock joint dissection. A consensus description of actual injury and the detection accuracy of OR and CT for that injury was determined. Results- Rater agreement for OR and CT for most pathologic features was good or excellent. OR was similar to CT for the detection of condylar and diaphyseal third metacarpal and metatarsal (MC/MT3) fractures, diaphyseal fractures of the first phalanx (P1), and fracture location on the condyle. CT was superior to OR for detection of MC/MT3 proximal fissures and articular comminution, condylar small cracks and lucencies, and proximal sesamoid fractures. OR was superior to CT for detection of proximal P1 dorsal fractures. Both OR and CT were poor at detecting palmar/planter proximal P1 fractures and coalescing cracks in the subchondral bone of MC/MT3. CONCLUSIONS: CT is better than OR for detection of pathology in limbs with condylar fractures, but does not detect every pathologic feature. CLINICAL RELEVANCE: CT provides superior information of pathology in Thoroughbred racehorses with condylar fractures.

Scanning electron microscopic examination of third metacarpal/third metatarsal bone failure surfaces in thoroughbred racehorses with condylar fracture.

OBJECTIVE: To examine the fracture failure surfaces from Thoroughbred horses that had sustained a catastrophic condylar fracture. SAMPLE POPULATION: Bone specimens from the failure surface were obtained from 12 Thoroughbred racehorses with catastrophic injury and 2 non-racing horses with accidental long bone fracture. METHODS: Bone specimens from the failure surface of each fracture were incubated with gold microspheres to label microcracks before examination at x50 to x60,000 using scanning electron microscopy. Microcracking at the failure surface was assessed using a visual analog scale. RESULTS: Branching arrays or clusters of microcracks were seen over a range of magnifications in adapted subchondral bone in the distal end of the MC3/MT3 bone from racing Thoroughbreds with a catastrophic displaced condylar fracture. In the palmar/plantar region, microcracking was associated with the formation of an array of macroscopic cracks in the condylar groove. A different pattern of microcracking was seen in specimens of bone from distal metaphyseal and diaphyseal MC3/MT3 failure surfaces from Thoroughbred racehorses with catastrophic fracture and non-racing horses with an accidental diaphyseal long bone fracture. Few microcracks were seen and typically did not form branching arrays. CONCLUSION: These data suggest that propagation of condylar fracture in Thoroughbred racehorses is initiated by the formation of nanoscale microcracks in adapted subchondral bone that form during exercise-induced bone adaptation. CLINICAL RELEVANCE: Accumulation and coalescence of branching microcracks into arrays or clusters appears to eventually lead to the development of macroscopic subchondral cracks in the condylar groove and initiation of a condylar fracture.

Effect of focused and radial extracorporeal shock wave therapy on equine bone microdamage.

OBJECTIVES: To determine whether bone microcracks are altered after application of focused and radial extracorporeal shock wave therapy (ESWT) to the equine distal limb. STUDY DESIGN: An ex vivo experimental model. SAMPLE POPULATION: A contralateral limb specimen was obtained from 11 Thoroughbred racehorses with a unilateral catastrophic injury. Distal limb specimens were also obtained from 5 non-racing horses. METHODS: Three separate skin-covered bone segments were obtained from the mid-diaphysis of the metacarpus (MC3) or metatarsus (MT3). Focused (9,000 shockwaves, 0.15 mJ/mm2, 4 Hz) and radial (9,000 shockwaves, 0.175 mJ/mm2, 4 Hz) ESWT treatments were randomized to the proximal and distal segments and the middle segment was used as a treatment control for pre-existing microcracks. After treatment, bone specimens were bulk-stained with basic fuchsin and microcracks were quantified in transverse calcified bone sections. RESULTS: ESWT had small but significant effects on microcracks. Microcrack density (Cr.Dn) and microcrack surface density (Cr.S.Dn) were increased after focused ESWT, whereas Cr.Le was increased after radial ESWT. In racing Thoroughbreds, Cr.Le increased with increased number of races undertaken. Cr.Dn and Cr.S.Dn were not significantly influenced by the number of races undertaken. CONCLUSION: ESWT has small but significant effects on bone microcracking ex vivo. CLINICAL RELEVANCE: These preliminary data suggest that ESWT has the potential to increase bone microcracking in equine distal limb bone in vivo. Such effects may be more pronounced in Thoroughbreds that are actively being raced, because in vivo microcracking increases with increased number of races undertaken.

Macroscopic changes in the distal ends of the third metacarpal and metatarsal bones of Thoroughbred racehorses with condylar fractures.

OBJECTIVE: To determine changes in the distal ends of the third metacarpal and metatarsal bones (MCIII and MTIII) of Thoroughbred racehorses that had sustained a catastrophic condylar fracture during high-speed exercise. SAMPLE POPULATION: Fractured and contralateral MCIIIs and MTIIIs from 11 Thoroughbred racehorses that sustained a displaced condylar fracture during racing, both MCIIIs from 5 Thoroughbred racehorses euthanatized because of a catastrophic injury other than a condylar fracture, and both MCIIIs from 5 horses of other breeds that had not been professionally trained or raced. PROCEDURE: Macroscopic observations were made of the distal ends of the bones before and after digestion of the articular cartilage with NaOH. RESULTS: In all 11 racehorses with a displaced condylar fracture, the fracture was associated with a branching array of cracks in the condylar groove. In this region, fracture margins were smooth, and there was loss of subchondral bone. Comminution of the dorsal cortex was also seen. Parasagittal linear wear lines in the articular cartilage, erosions in the articular cartilage of the condyles, loss of the underlying subchondral bone, and cracking of condylar grooves were all more severe in the Thoroughbred racehorses than in the horses that had not been professionally trained or raced. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that condylar fractures in horses are pathologic fatigue or stress fractures that arise from a preexisting, branching array of cracks in the condylar groove of the distal end of MCIII or MTIII.