Spinal dural ossification causing neurological signs in a cat

A six-year-old Ragdoll cat underwent examination due to a six-month history of slowly progressive gait abnormalities. The cat presented with an ambulatory tetraparesis with a neurological examination indicating a C1-T2 myelopathy. Radiographs of the spine showed a radiopaque irregular line ventrally in the vertebral canal dorsal to vertebral bodies C3-C5. In this area, magnetic resonance imaging revealed an intradural extramedullary/extradural lesion compressing the spinal cord. The spinal cord was surgically decompressed. The cause of the spinal cord compression was dural ossification, a diagnosis confirmed by histopathological examination of the surgically dissected sample of dura mater. The cat gradually improved after the procedure and was ambulating better than prior to the surgery. The cat’s locomotion later worsened again due to ossified plaques in the dura causing spinal cord compression on the same cervical area as before. Oral prednisolone treatment provided temporary remission. Ten months after surgery, the cat was euthanized due to severe worsening of gait abnormalities, non-ambulatory tetraparesis. Necropsy confirmed spinal cord compression and secondary degenerative changes in the spinal cord on cervical and lumbar areas caused by dural ossification. To our knowledge, this is the first report of spinal dural ossification in a cat. The reported cat showed neurological signs associated with these dural changes. Dural ossification should be considered in the differential diagnosis of compressive spinal cord disorders in cats.     

Identification of a periorbital wooden foreign body as the cause of chronic ocular discharge in a horse

The clinical, diagnostic and therapeutic features of a horse with a wooden foreign body embedded in the deep portion of the right masseter muscle adjacent to the right orbit are presented. The purpose of this report is to describe the clinical presentation, magnetic resonance imaging findings and treatment of a penetrating wooden foreign body in a horse that had no history of trauma or evidence of a puncture wound. This report documents the usefulness of magnetic resonance imaging to detect a wooden foreign body embedded in the soft tissues of a horse with a chronic copious ocular discharge. Two surgical procedures were necessary, which is a frequent complication encountered with wooden foreign bodies.     

Distal luxation of the patella in a horse

A 19-year-old Thoroughbred gelding presented with sudden onset, non-weight bearing lameness in the right hindlimb. Radiography confirmed distal luxation of the patella, which was replaced into its normal anatomical location under general anaesthesia. There were no pathological sequelae noted on follow-up examination 9 months after the initial injury. To our knowledge, this is a rare manifestation of patellar luxation, only reported once previously in the equine literature.     

Comparison of two approaches to performing an inferior alveolar nerve block in the horse

Objectives To compare two approaches to performing the inferior alveolar nerve block in the horse and to evaluate the consistency of described topographical landmarks. Design Experimental cadaver model. Methods Eleven cadaver heads were positioned to mimic a standing sedated horse and the position of the mandibular foramen approximated. The vertical approach to the approximate location of the mandibular foramen was undertaken and red dye was deposited. The angled approach was then undertaken and blue ink was used to identify it. The heads were then dissected to determine the location of the dye. Placement was categorised as a hit or a miss for each technique for each side of the head. The distance of the dye from the nerve was recorded. Straight lateral radiographs of the sectioned heads were taken to evaluate the topographical landmarks for performing this nerve block. Results Each method was performed 22 times. A hit was achieved 16 times (73%) for the angled approach and 13 times (59%) for the vertical approach. There was no significant difference between the two approaches (P = 0.34). Radiographs revealed that the topographical landmarks used to approximate the mandibular foramen were relatively accurate. Conclusion Both methods were found to be equivalently accurate. The previously reported topographic landmarks for locating the approximate position of the mandibular foramen on the medial aspect of the mandible were found to be accurate, but currently recommended doses of local anaesthetic may be excessive.     

Primary alimentary lymphoma with metastasis to the liver causing encephalopathy in a horse

A 23‐year‐old, 467‐kg Palomino mare was examined for evaluation of sudden onset severe ataxia and depression. The mare had been found down in a pasture and was unable to rise. She was observed, by her owner, to be normal 24 hours earlier. This mare had resided with this owner for approximately 1.5 years, had always lived out on pasture, and had experienced numerous episodes of colic since the time she was purchased. Recent reported feed changes included introduction of new hay. Upon arrival at the hospital, the mare was severely ataxic in all 4 limbs and extremely disoriented. She head‐pressed several times during the course of the evaluation and yawned repeatedly. The mare was tachycardic, with a heart rate of 98 beats per minute, and tachypneic, with a respiratory rate of 60 breaths per minute, and the mucous membranes were hyperemic and purple, with a capillary refill time of greater than 3 seconds. The mare was blind bilaterally, as indicated by absence of both menace and pupillary light responses. She had bilateral facial nerve paralysis and decreased hypoglossal nerve function. She was able to prehend, but was dysphagic with decreased tongue tone and movement. Analysis of the venous blood revealed metabolic acidosis and respiratory alkalosis with a normal pH of 7.38 (reference range 7.32–7.44), HCO₃ of 13 mEq/L (reference range 25–30 mEq/L), PCO₂ of 21.2 mmHg (reference range 36–46 mmHg), and BE of ‐12 mEq/L (reference range ‐1‐1 mEq/L).^a It also revealed a low blood urea nitrogen concentration of 8 mg/dL (reference range 11–27 mg/dL) and a high blood glucose concentration of 263 mg/dL (reference range 63–134 mg/dL).^a Both packed cell volume and total solids were high at 52% (reference range 32–53%), and 8 g/dL (reference range 5.8–7.7 g/dL), respectively. The blood ammonia concentration was 120 μmol/L (reference range 18–78 μmol/L)^b.     

Detailed insight into genetic diversity of the Old Kladruber horse substructure in comparison to the Lipizzan breed

The aim of the present study was to analyse the genetic subdivision of the Old Kladruber horse population compared to the historically close Lipizzan breed and to estimate genetic relatedness between them. A set of 13 microsatellites was used for genotyping a total of 270 Old Kladruber horses representing grey and black colour varieties and 418 Lipizzan horses from Slovak and Slovenian studs. The proportion of obtained heterozygosity indicates no major loss of genetic diversity within them. At the individual level across analysed populations, the formation of clusters in respect to breed’s origin and particular studs was observed. The Wright’s F_ST and genetic distances indicated genetic segregation of both colour varieties at the intraspecific level of the Kladruber breed. Moreover, the membership probability outputs showed that the frequencies of alleles varied across the three main regions represented by both Old Kladruber varieties and Lipizzan, depending on breeding history and strategy of studs.     

Mastocytoma in the common carpal sheath of the digital flexor tendons of a horse

A 13-year-old Morgan gelding was examined for right forelimb lameness and tenosynovitis of the right common carpal sheath of the digital flexor tendons. The horse had moderate right forelimb lameness at the trot and marked effusion of the right common carpal sheath of the digital flexor tendons. Ultrasonographic examination revealed a soft tissue mass within the proximal pouch of the affected tendon sheath, located adjacent to the distal physis of the radius. Cytology and culture of the fluid revealed a sterile, eosinophilic tenosynovitis. Tenoscopic exploration confirmed the presence of a capsulated soft tissue mass. Thecotomy was required to fully debride the mass, which histology revealed to be a mast cell tumour. At 22 months postoperatively, the horse developed mild right forelimb lameness and eosinophilic tenosynovitis because of recurrence of the mastocytoma. Mastocytosis is a possible differential diagnosis in any horse exhibiting lameness associated with tenosynovitis. Surgical excision combined with rest and postoperative intrasynovial and systemic corticosteroids may be palliative.     

An undifferentiated sarcoma in the cervical region in a horse

An Italian Saddle Horse mare was admitted for a hard, nonpainful mass localised in the cervical region. Clinical and diagnostic investigations were performed, which were suggestive of a multilobulated ossifying mass of neoplastic origin. Due to poor prognosis the horse was subjected to euthanasia. Post mortem computed tomography, anatomopathological examination and immunohistochemistry were used to make a definitive diagnosis of undifferentiated sarcoma in the cervical region.     

The use of porcine urinary bladder matrix (UBM) to repair a perforated corneal ulcer with iris prolapse in a horse

This report describes the use of porcine urinary bladder matrix (UBM) to repair a full thickness defect in the cornea of a Thoroughbred racehorse. The horse presented with acute keratomalacia of the right eye of 12 h duration that had rapidly progressed to perforation of the cornea with partial iris prolapse. The cornea was surgically debrided with the horse under general anaesthesia and the defect repaired with ACell multilayer wound matrix. A temporary tarsorrhaphy was performed. The defect in the cornea was successfully repaired and the horse regained vision in the eye. Four months after surgery the defect was still undergoing remodelling and the area of opacity in the cornea was progressively reducing.     

Medial collateral ligament desmitis of the distal interphalangeal joint in the hindlimb of a horse: treatment with cast immobilisation

A 12‐year‐old show‐jumping mare was presented for investigation of a chronic hindlimb lameness of 16 weeks duration. Perineural anaesthesia and ultrasonography localised the lesion to the medial collateral ligament of the distal interphalangeal joint of the left hindlimb. Treatment consisted of a heavily padded distal limb cast for 6 weeks, strict box rest and a strictly regulated hand walking program. Serial ultrasonographic examinations were performed throughout the rehabilitation period. Collateral ligament desmitis of the distal interphalangeal joint is a commonly diagnosed condition of the forelimb; however, hindlimb collateral ligament desmitis has been rarely reported. Ultrasonographic examination in this case was an invaluable diagnostic and follow‐up tool. Immobilisation of the foot by means of a heavily padded distal limb cast allowed excellent healing of the ligament and is presented as a novel treatment for collateral ligament desmitis. At the time of writing the mare had returned to her previous level of exercise and was showing no signs of lameness.     

An unusual cyst‐like lesion in the metaphysis of the tibia in a horse

A 6‐year‐old Haflinger gelding was presented with a chronic right hindlimb lameness. Scintigraphy, radiography and computed tomography confirmed an active large cyst‐like lesion in the distal metaphysis of the right tibia. A transcortical surgical approach was used to curette the lesion and fill it with an autologous bone graft and a calcium phosphate bone substitute material. Histopathology revealed mild histiocytic inflammatory changes, mild fibrosis and bone necrosis. This case report describes an unusual cyst‐like lesion in the tibial metaphysis of a horse.     

Treatment of a subchondral cystic-like lesion in the distal scapula with a translesional bone screw in a horse

A 2-year-old French Warmblood stallion was presented for lameness investigation. The diagnostic procedures identified the reason for lameness as being a subchondral cystic-like lesion (SCL) in the glenoid cavity of the scapula. The horse was surgically treated with a translesional 4.5 mm cortical bone screw inserted through the SCL under radiographic guidance. Sixty days after surgery, the horse was sound and the SCL showed significant radiographic signs of healing. Radiographs obtained 180 days after surgery showed further radiographic healing, with the SCL presenting a radiodensity similar to the surrounding bone. At 4 years post-operative follow-up, the horse is sound and competing successfully as a 6-year-old in Concours de Saut International (CSI) competitions.     

Predictive value of hypoglycin A and methylencyclopropylacetic acid conjugates in a horse with atypical myopathy in comparison to its cograzing partners

Hypoglycin A (HGA) was detected in blood and urine of a horse suffering from atypical myopathy (AM; Day 2, serum, 8290 μg/l; urine: Day 1, 574, Day 2, 742 μg/l) and in its cograzing partners with a high variability (46–1570 μg/l serum). Over the period of disease, the level of the toxic metabolites (methylencyclopropylacetic acid [MCPA]‐conjugates) increased in body fluids of the AM horse (MCPA‐carnitine: Day 2, 0.246, Day 3, 0.581 μmol/l serum; MCPA‐carnitine: Day 2, 0.621, Day 3, 0.884 μmol/mmol creatinine in urine) and HGA decreased rapidly (Day 3, 2430 μg/l serum). In cograzing horses MCPA‐conjugates were not detected. HGA in seeds ranged from 268 to 367 μg/g. Although HGA was present in body fluids of healthy cograzing horses, MCPA‐conjugates were not detectable, in contrast to the AM horse. Therefore, increasing concentrations of MCPA‐conjugates are supposed to be linked with the onset of AM and both parameters seem to indicate the clinical stage of disease. However, detection of HGA in body fluids of cograzing horses might be a promising step in preventing the disease.     

Treatment of a metallic foreign body in the cranial cervical region of a horse

Ingestion of foreign bodies is uncommon in horses when compared with indiscriminate grazers such as cattle. This case report describes the diagnosis and treatment of a cervical abscess in a Thoroughbred racehorse thought to be associated with ingestion of wire. Radiographic and ultrasonographic examination provided a diagnosis, and conservative treatment of the lesion with antimicrobials initially allowed the lesion to localise closer to the skin for safer surgical exploration. Intra-operative ultrasonographic imaging facilitated surgical access, removal of the foreign body, and drainage. While surgical treatment is usually necessary to resolve an abscess, initially conservative therapy may help to improve the prognosis by simplifying surgical access and reducing the risk of surgical complications.     

Radiographic assessment of carpal conformation in the horse,part 2: Finding acceptable limits to postural and rotational variations during radiography

Finding an appropriate location for perpendicular positioning of the X-ray machine to produce zero lateromedial (ZLM) and zero dorsopalmar (ZDP) carpal images (views) and finding an acceptable range of rotational variations for measurement of carpal conformational parameters were two major challenges identified during field radiography of equine forelimbs. 16 cadaver forelimbs transacted at antebrachial midshaft from 10 horses (aged 9.13 ± 4.59 years) were axially mounted into a custom-built frame, and the radiographic machine and plate were perpendicularly aligned with the limb. Each limb was then radiographed at 2.5° interval of vertical rotation of the machine until ZLM and ZDP images were acquired, and at 24 other postural and rotational positions from ZLM and ZDP at 5° interval for comparison of measurements with the standardized ZLM and ZDP images. ZLM radiographs were produced at a mean vertical projection angle (VPA) of 9.84 ± 3.47° palmarolateral–dorsomedial oblique (PaL-DMO), while ZDP was acquired at VPA of 6.41 ± 2.73° dorsolateral–palmaromedial oblique (DL-PaMO). Changes in limbs’ postural tilts, vertical plate rotations (VPR) and horizontal beam rotations (HBR) had no effect on the quality of the radiographs and on carpal measurements, while vertical beam rotation (VBR) of X-ray beam produced significant changes on the quality of radiographs and on measurements of carpal parameters. It is recommended that field radiographs of equine forelimbs intended for carpal measurement be obtained within a proposed range of VPA of 2.5° to 12.5° PaL-DMO for ZLM and 2.5° to 10° DL-PaMO for ZDP in order to minimize potential errors attributable to vertical rotational movements.     

Evaluation of an electronic device used as a quick screening method to detect changes in the red cell content of the blood in horses participating in endurance trail rides

Dehydration, to varying degrees, will inevitably occur in horses participating in endurance trail rides. This water loss is directly related to the amount of body water lost through evaporative cooling, that in turn being related to the amount and rate of work performed, and to the environmental temperature and humidity.An electronic apparatus that can substitute for the conventional and time-consuming venous haematocrit was developed to measure the animals' hydration status. The mechanism of this electrometer is based upon the relationship between the red cell content and the electrical conductivity of the blood. The electrometer reading gave a significant correlation (p<0.001) with the venous haematocrit, thus indicating that the electrometer is a reliable apparatus for determining the animals' hydration status within seconds of venepuncture.     

Unilateral degenerative joint disease of a cervical articular process joint between the fourth and fifth cervical vertebrae causing asymmetrical ataxia in a young horse

A 5-year-old horse was examined for investigation of asymmetrical, quadrilateral ataxia and paresis. Clinical examination was unremarkable, and a thorough neurological examination localised the lesion to the cervical spine. Following this, magnetic motor evoked potentials were acquired to allow for latency times to be determined. Abnormal conduction times were found to the right thoracic and right pelvic limbs, confirming that the horse had an asymmetrical cervical spinal myelopathy. Radiographs were acquired to ensure that the horse had no significant pathology which would contraindicate general anaesthesia. There were no abnormalities noted on these, so the horse underwent contrast-enhanced computed tomography of its cervical spine which revealed enlargement of the right articular process joint between C4 and C5 with dorsolateral impingement of the spinal canal and cord. Due to the poor prognosis for future performance, the horse was subsequently euthanised. A post-mortem examination confirmed the findings of degenerative joint disease, with some unexpected changes seen on histology of the spinal cord. The unilateral right-sided compression had caused degenerative changes to ascending and descending tract bilaterally indicating a dynamic component to this lesion, which would be more commonly understood to be static.