The aim of this study was to develop a method for spermatogonial stem cell transplantation into the bovine testis. Five-month-old Holstein-Friesian calves were used and half of the calves were hemicastrated to allow autologous transplantation and the other half were used for homologous transplantation. Approximately 20 g of each testis was used for cell isolation. On average 10 6 cells per gram of testis containing about 70% type A spermatogonia were isolated. The cells were frozen in liquid nitrogen until transplantation. Testes were irradiated locally with 10-14 Gy of Xrays to deplete endogenous spermatogenesis. At 2 months after irradiation, cells (approximately 10 × 10 6 ) were injected into the rete testis through a long injection needle (18 gauge), using ultrasonography and an ultrasound contrast solution. At 2.5 months after transplantation, calves were castrated and samples of testes were taken for histological examination. After 2.5 months in the irradiated non-transplanted control testes, only 45% of the tubules contained type A spermatogonia. However, after autologous spermatogonial transplantation, > 80% of the tubule cross-sections contained type A spermatogonia. In addition, only 20% of the tubules of the control testes contained spermatocytes and, except for a few tubules (5%) with round spermatids, no more advanced germ cells were found. After autologous spermatogonial transplantation, about 60% of the tubules contained spermatocytes; 30% contained spermatids and in about 15% of tubules spermatozoa were found. No improvement in spermatogonial repopulation was found after homologous transplantation. The results of this study demonstrate, for the first time, successful autologous transplantation of bovine spermatogonial stem cells resulting in a complete regeneration of spermatogenesis.

Summary Reasons for performing study: The occurrence of unexpectedly high numbers of horses with neurological signs during two outbreaks of strangles required prompt in‐depth researching of these cases, including the exploration of magnetic resonance imaging (MRI)as a possible diagnostic technique. Objectives: To describe the case series and assess the usefulness of MRI as an imaging modality for cases suspected of space‐occupying lesions in the cerebral cavity. Methods: Four cases suspected of suffering from cerebral damage due to Streptococcus equi subsp. equi infection were examined clinically, pathologically, bacteriologically, by clinical chemistry (3 cases) and MRI (2 cases). In one case, MRI findings were compared to images acquired using computer tomography (CT). Results: In all cases, cerebral abscesses positive for Streptococcus equi subsp. equi were found, which explained the clinical signs. Although the lesions could be visualised with CT, MRI images were superiorin representing the exact anatomic reality of the soft tissue lesions. Conclusions: The diagnosis of bastard strangles characterised by metastatic brain abscesses was confirmed. MRI appeared to be an excellent tool for the imaging of cerebral lesions in the horse. Potential clinical relevance: The high incidence of neurological complications could not be explained but possibly indicated a change in virulence of certain strains of Streptococcus equi subsp. equi. MRI images were very detailed, permitting visualisation of much smaller lesions than demonstrated in this study and this could allow prompt clinical intervention in less advanced cases with a better prognosis. Further, MRI could assist in the surgical treatment of brain abscesses, as has been described earlier for CT.

No abstract

The cranial nuchal bursa can be identified on ultrasonographic and magnetic resonance images. An endoscopic approach to the cranial nuchal bursa is clinically feasible and offered an easy, repeatable entry into the cranial nuchal bursa, which allowed adequate observation of the structures within the bursa. This may be of help for diagnosis and treatment of conditions affecting the cranial nuchal bursa in horses.

Nuchal bursitis can be successfully managed with either medical or surgical treatment. Prognosis for return to work tends to be worse in horses requiring surgical intervention following failed medical management.

The importance of the equine thoracolumbar vertebral column in orthopaedic disorders is well recognized and diagnostic imaging becomes more feasible, but little is known about variations in the anatomical configuration within breeds. In this descriptive post‐mortem study, anatomical variations in three widely differing breeds: Warmblood horses, Shetland ponies and semi‐feral Konik horses are described. The caudal cervical (C), thoracic (T), lumbar (L) and sacral (S) regions of the vertebral column of 30 Warmblood horses, 29 Shetland ponies and 18 Konik horses were examined using computed tomography and visualized by volume rendering. Homologous/morphologic variations in the caudal cervical area were frequently seen in Warmblood horses (43%), which was significantly more than in the other breeds (p < 0.001). The as standard described equine formula of 18 T, 6 L and 5 S vertebrae was seen in 78% of Konik horses, but only in 53% Warmblood horses and 38% Shetland ponies, which was significantly different (p < 0.05). Overall, Shetland ponies showed a higher tendency of thoracoization, lumbarization and more variations in the number of vertebrae and pairs of ribs. Ankylosed intertransverse joints (ITJs) between transverse processes of the lumbar vertebrae were most common between the second last and last lumbar vertebra and prevalence was significantly higher in Shetland ponies (61%), than in Warmblood horses (38%) and Konik horses (7%) (p < 0.0001). Cranial to the second last lumbar vertebra there were fewer ITJs ankylosed (14%) in Warmblood horses (p < 0.0095), and this decrease in number of ankylosed ITJs was different compared to the change in ankylosed ITJs in Shetland ponies (p < 0.005). ITJs occurred asymmetrically in 15% (12/77) of the cases. A limitation of the study was that clinical data of the horses were only incompletely available, precluding any conclusions about the potential clinical implications of anatomical variations. Knowledge of variation in osseous anatomy of the equine thoracolumbar vertebral column is important for the interpretation of diagnostic imaging. To assess the functional importance and clinical relevance of this variation, follow‐up studies are necessary.

Mandigers PJ, Nes jJ van, Knol BW, Ubbink GJ, and Gruys E. J Vet Intern Med 1992; 6: 175- SUMMARYA 22-year-old Dutch Warmblood mare was referred to Utrecht University with progressive left hind limb paresis and hyporeflexia. The preliminary clinical diagnosis was the neurological form of equine herpes virus (EHV-1) infection. Within 1 day of admission, the mare became recumbent and deteriorated rapidly. Postmortem examination revealed an adenocarcinoma of the caecum, with metastases in all regional lymph nodes and extending from the lumbar nodes into the vertebral canal, causing spinal cord compression and destruction of the left 4th and 5th lumbar nerves.

The relationship between lameness-related adaptations in equine appendicular motion and muscle activation is poorly understood and has not been studied objectively. The aim of this study was to compare muscle activity of selected fore- and hindlimb muscles, and movement of the joints they act on, between baseline and induced forelimb (iFL) and hindlimb (iHL) lameness. Three-dimensional kinematic data and surface electromyography (sEMG) data from the fore- (triceps brachii, latissimus dorsi) and hindlimbs (superficial gluteal, biceps femoris, semitendinosus) were bilaterally and synchronously collected from clinically non-lame horses (n = 8) trotting over-ground (baseline). Data collections were repeated during iFL and iHL conditions (2–3/5 AAEP), induced on separate days using a modified horseshoe. Motion asymmetry parameters and continuous joint and pro-retraction angles for each limb were calculated from kinematic data. Normalized average rectified value (ARV) and muscle activation onset, offset and activity duration were calculated from sEMG signals. Mixed model analysis and statistical parametric mapping, respectively, compared discrete and continuous variables between conditions (α= 0.05). Asymmetry parameters reflected the degree of iFL and iHL. Increased ARV occurred across muscles following iFL and iHL, except non-lame side forelimb muscles that significantly decreased following iFL. Significant, limb-specific changes in sEMG ARV, and activation timings reflected changes in joint angles and phasic shifts of the limb movement cycle following iFL and iHL. Muscular adaptations during iFL and iHL are detectable using sEMG and primarily involve increased bilateral activity and phasic activation shifts that reflect known compensatory movement patterns for reducing weightbearing on the lame limb. With further research and development, sEMG may provide a valuable diagnostic aid for quantifying the underlying neuromuscular adaptations to equine lameness, which are undetectable through human observation alone.