Treatment of a Cyst-Like Synovial Hernia Associated with the Digital Flexor Tendon Sheath of a 17-Year-Old Pony

The aim of this study is to describe the successful treatment of a synovial hernia associated with the digital flexor tendon sheath (DFTS) in a 17-year-old pony. The pony presented with left forelimb lameness and multiple unusual swellings of the palmar and plantar aspect of the fetlock. The lameness was isolated to a swelling in close proximity to the DFTS of the left forelimb using diagnostic analgesia, and on diagnostic imaging, the swelling was found to be associated with the DFTS. The hernia resolved after percutaneous drainage and intralesional corticosteroids and atropine and pressure bandaging. Reports of synovial hernias in the horse associated with the DFTS are rare. This difference should be considered when presented with cases exhibiting similar clinical signs.     

Parotid salivary gland adenocarcinoma with bilateral ocular and osseous metastases in a dog

A case of primary parotid salivary gland adenocarcinoma is described in a three-year-old entire female great dane. The presenting complaint was sudden onset blindness concomitant with the development of bilateral hyphaema and anterior uveitis. A soft-tissue swelling of the left subaural region and right forelimb lameness were also present. A definitive diagnosis of primary parotid salivary gland adenocarcinoma with bilateral ocular metastases was made on post mortem examination. Metastases were also present in the right proximal humerus, left and right prescapular lymph nodes, left axillary lymph node, left retropharyngeal lymph node, bronchial lymph nodes and all lung lobes.     

Lameness in a mare with signs of arteriovenous fistula

A 5-year-old mare was evaluated for lameness and swelling of the right forelimb. Clinical findings, including peripheral edema, venous pulsation, palpable thrill in the cephalic vein, disparate arteriovenous oxygen tension differences between the left and right forelimbs, and Branham sign, were suggestive of arteriovenous fistula. Failure to identify the fistula by angiography was attributed to closure of the shunt during anesthesia. Surgical exploration of the affected limb to identify the shunt also was unsuccessful.     

Primary hemangiosarcoma of the humerus in a Maltese dog

A 14-year-old intact male Maltese dog was presented with a history of pain and swelling of the left upper forelimb and lameness for 3 weeks. Hematological and radiographical examinations showed regenerative anemia and osteolysis of the humerus. Fine needle aspiration biopsy detected epithelioid- and fibroblast-like anaplastic cells with blood components. A hemorrhagic and osteolytic malignant tumor was suspected, and the affected forelimb was amputated. Histopathologically, the dog was diagnosed with primary hemangiosarcoma of the humerus. Thereafter, metastatic lesions appeared in the skin, and the dog was euthanized 1 month after the operation.     

Computed Tomography and Magnetic Resonance Imaging of an Epidermoid Cyst in a Foot of a Horse

An 18-year-old Quarter Horse mare was evaluated because of moderate left forelimb lameness of 4 weeks’ duration. The clinical evaluation and diagnostic perineural analgesia localized the lameness to the distal portion of the left forelimb. There was swelling on the dorsal and lateral aspect of the coronary band. Radiography, ultrasound, magnetic resonance imaging, and computed tomography of the foot revealed circumscribed well-capsulated soft tissue mass causing a focal deformation of the dorsolateral border of the middle phalanx. The treatment aimed to remove the mass surgically and stabilized the interphalangeal joint, but the owner elected human euthanasia before treatment attempt. Histopathology diagnosis was an epidermoid cyst, which was characterized by multilayers of keratin surrounded by stratified squamous epithelium. Although rare, an epidermoid cyst should be considered as a differential diagnosis for space-occupying mass in horses’ foot that develops chronic lameness after trauma. This report describes the multimodality appearance of the epidermoid cyst.     

Osteolysis of the radius and ulna induced by a circumferential foreign body in a cat

CASE DESCRIPTION: A 1-year-old neutered male cat was examined because of a 6-month history of recurrent swelling and draining wounds affecting the craniomedial aspect of the distal portion of the left forelimb. CLINICAL FINDINGS: No lameness or neurologic deficits were evident. Examination of craniocaudal and lateromedial radiographic views revealed nonprogressive circumferential osteolysis and a mildly radiopaque, ring-shaped foreign body surrounding the radius and ulna. TREATMENT AND OUTCOME: During surgery, a tight elastic band surrounded by a thick fibrous tissue capsule was found encircling the limb. Microbial culture yielded a Staphylococcus sp that was susceptible to clindamycin. Follow-up monitoring via telephone communication with the owners 1.5 years after removal of the foreign body indicated that the cat had healed with no recurrence of drainage. CLINICAL RELEVANCE: Pressure osteolysis of the bones of the forelimb can be caused by a circumferential foreign body without associated neurologic abnormalities or lameness.     

Development of small-cell osteogenic sarcoma after ulnar ostectomy in a dog

A 5-year-old male Saint Bernard was evaluated for vague forelimb lameness. Four and a half years earlier, the dog had undergone left ulnar ostectomy to correct a valgus deformity. Focal bone lysis was evident radiographically at the ostectomy site. Four months later, marked bony swelling was apparent and the dog was bearing partial weight. The dog was euthanatized, and at necropsy, a bone tumor with lung metastasis was found. Microscopically, features of the tumor were compatible with those of small-cell osteogenic sarcoma.     

Hypervitaminosis A in the cat: a case report and review of the literature

A case of hypervitaminosis A with secondary entrapment and compression of the left brachial plexus nerve roots is described. A 9-year-old male castrated domestic shorthair, fed a home-made diet based on raw pork liver, was submitted for examination for a left forelimb lameness that evolved to paralysis over a 2-month period. Clinical examination revealed a flaccid paralysis and atrophy of all left forelimb muscles. An ipsilateral Horner's syndrome was also noted. Radiological examination of the cervical and thoracic spine showed massive new bone formation at the ventral aspect of the second cervical to sixth thoracic vertebra. The diagnosis of hypervitaminosis A was made, based on the clinical and radiographic findings, as well as the determination of serum vitamin A concentration, which was 630 microg/dl, three times above the upper normal limit for this species. Despite the unfavourable initial prognosis, the cat progressively regained function of the affected limb approximately 6 months after the diet was changed to a commercial canned food.     

Streptococcus pneumoniae-associated cellulitis in a two-month-old Domestic Shorthair kitten.

An approximately 2-month-old, reproductively intact female Domestic Shorthair kitten was presented to the Mississippi Veterinary Research and Diagnostic Laboratory with a history of possible trauma to the left shoulder region while playing with children, and was found dead the following day. Marked swelling, with subcutaneous edema and hemorrhages, was observed in the left forelimb. Severe pleocellular, but largely suppurative cellulitis, fasciitis, and interstitial myositis with edema were observed microscopically in sections from the affected limb. Massive numbers of gram-positive diplococci also were observed. Other pathologic changes included moderate interstitial pneumonia, mild cholangitis, lymph node hemorrhage, gastrointestinal nematodiasis, mild enteritis, and mild interstitial nephritis. Bacteriologic culture identified Streptococcus pneumoniae as the causative agent, which was confirmed by polymerase chain reaction amplification of the pneumolysin gene from chromosomal DNA of the isolate.     

Detection of an epidermoid cyst in the foot of a horse by use of magnetic resonance imaging

CASE DESCRIPTION-A 4-year-old Quarter Horse stallion was evaluated because of a 10-month history of moderate (grade 3/5) left forelimb lameness (detectable during trotting over a smooth, hard surface). CLINICAL FINDINGS-No abnormalities were detected in either forelimb via palpation or application of hoof testers; however, lameness was eliminated after administration of a palmar digital nerve block in the left forelimb. Whereas radiography and ultrasonography did not identify any left forelimb foot abnormalities, magnetic resonance (MR) imaging revealed a circumscribed soft tissue mass in the distal aspect of the digital flexor tendon sheath (DFTS) dorsal to the lateral aspect of the deep digital flexor tendon. Subsequently, the left forelimb DFTS was injected with local anesthetic, which resulted in 90% improvement of the horse's lameness. TREATMENT AND OUTCOME-The distal aspect of the left forelimb DFTS was evaluated tenoscopically. The mass was removed under tenoscopic guidance, after which the distal digital annular ligament was transected. The horse received phenylbutazone orally for 10 days, and the left forelimb DFTS was injected with hyaluronic acid and methylprednisolone acetate 7 days after the surgery. Following a rehabilitation program, the horse was returned to full training at 6 months after surgery and competed successfully during a 2-year follow-up period. CLINICAL RELEVANCE-Use of MR imaging should be considered in all lame horses for which a definitive diagnosis cannot be made via radiography, ultrasonography, or other imaging techniques, especially when the lameness has been localized to a specific anatomic region by use of diagnostic anesthesia.     

Localization of the Motoneurons Innervating the Forlimb Muscles in the Spinal Cord of the Domestic Fowl

The origins of the motor nerve fibers supplying the individual forelimb muscles were elucidated in the fowl by the retrograde degeneration method. Chromatolytic cells were seen in the ipsilateral lamina 9 of the cervical enlargement. Motoneurons innervating the individual forelimb muscles occupy the restricted area in the lamina 9. The muscles acting on the shoulder joint are supplied by motoneurons of the more cranial segments and the others acting on the elbow and the more distal joints by those of the more caudal ones. The origin of the dorsal cord is situated laterally in the lamina 9 and that of the ventral cord is located medially in it.     

Comparison of nociceptive withdrawal reflexes and recruitment curves between the forelimbs and hind limbs in conscious horses

OBJECTIVE: To compare nociceptive withdrawal reflexes (NWRs) evoked from the distal aspect of the left forelimb and hind limb in conscious standing horses and to investigate NWR recruitment for graded electrical stimulation intensities. ANIMALS: 20 adult horses. PROCEDURE: Surface electromyographic (EMG) activity evoked by transcutaneous electrical stimulation of the digital palmar (or plantar) nerve was recorded from the common digital extensor and cranial tibial muscles. Stimuli consisted of 25-millisecond train-of-5 constant current pulses. Current intensity was gradually increased until NWR threshold intensity was reached. The EMG signal was analyzed for quantification of the NWR. Behavioral responses accompanying the reflex were scored (scale, 0 to 5). The NWR recruitment curves were determined at 0.9, 1.1, 1.2, and 1.3 times the NWR threshold intensity. RESULTS: The NWR threshold was significantly higher for the hind limb (median value, 6.6 mA; range, 3 to 10 mA) than the forelimb (median, 3 mA; range, 1.7 to 5.5 mA). The NWR of the hind limb had a significantly longer latency (median, 122.8 milliseconds; range, 106 to 172 milliseconds), compared with the forelimb (median, 98 milliseconds; range, 86 to 137 milliseconds), and it was associated with significantly stronger behavioral reactions. Gradual increase of NWR amplitude was evident at increasing stimulation intensities and supported by the behavioral observations. CONCLUSIONS AND CLINICAL RELEVANCE: We documented NWRs evoked from the forelimb and hind limb and their recruitment with stimuli of increasing intensity in horses. These results provide a basis for use of NWRs in studies on nociceptive modulation in horses.     

Histochemical and Morphometric Analyses of the Musculature of the Forelimb of the Subterranean Rodent Ctenomys talarum (Octodontoidea)

Histochemical and morphometric analyses were performed to characterize the fibre‐type composition of two forelimb muscles of the South American subterranean rodent Ctenomys talarum. The studied muscles were the triceps lateralis, an extensor of the elbow, and the teres major, a flexor of the shoulder. It was found that these muscles had an elevated proportion of fast oxidative‐glycolytic (FOG) fibres, and lower proportions of slow oxidative (SO) and fast glycolytic (FG) fibres. This composition probably qualifies the teres major and triceps muscles to perform the sustained effort required in tunnelling excavation. The results were discussed considering published data on fibre‐type composition of mammals having different modes of life and digging behaviour. We here suggest that C. talarum has the potential of generating forces linked to rapid, powerful movements during sustained periods by means of an elevated proportion of FOG fibres, together with osteological changes that result in a great mechanical advantage of the forelimb muscles.     

Necrotising fasciitis in a domestic shorthair cat – negative pressure wound therapy assisted debridement and reconstruction

A 10‐year‐old, domestic shorthair cat was presented for acute lameness of the left forelimb accompanied by severe pain, swelling, skin necrosis, malodorous discharge and pyrexia. Following a presumptive diagnosis of necrotising fasciitis aggressive surgical debridement of the affected soft tissues of the antebrachium and negative pressure wound treatment of the open defect were performed. Surgical findings supported the tentative diagnosis of necrotising fasciitis and Streptococcus canis was isolated from the wound. A free skin graft was performed 29 days after admission, and augmented by 3 days of negative pressure wound therapy to facilitate graft incorporation. Healing was achieved without complications and no functional or aesthetic abnormalities remained.     

Delayed diagnosis of fungal osteomyelitis with early scintigraphic lesions in a dog

A 4-year-old neutered male golden retriever was diagnosed with osseous blastomycosis of the distal left forelimb by means of radiographs and histopathology. Presumptive bacterial pneumonia and left forelimb lameness had been diagnosed 2 y previously, at which time bone scintigraphy revealed increased uptake in the distal left forelimb, but radiographs showed no detectable lesion. Though not specific, bone scintigraphy appears more sensitive than radiography in identifying early lesions of fungal osteomyelitis in dogs.     

Spontaneous bilateral ankylosis of the carpometacarpal joint in a Paint Horse

An 8‐year‐old Paint Horse gelding was evaluated for a persistent left forelimb lameness (grade 4/5), with a hard swelling at the dorsomedial aspect of the carpometacarpal joint, due to osteoarthritis. Previous systemic and local anti‐inflammatory therapy had only a temporary effect. Partial carpal arthrodesis was suggested, but the owner elected for conservative treatment. The horse was confined to a small paddock and received phytotherapeutic supplementation with Harpagophytum procumbens. The lameness gradually resolved but a similar hard swelling developed on the right carpus. Radiographic follow‐up 1.5 years later revealed a spontaneous bilateral ankylosis of the carpometacarpal joint.     

Carpal hyperextension in a Percheron mare caused by a palmar carpal ligament tear

A Percheron mare was presented for acute, severe lameness and marked swelling of the right forelimb after being cast. The mare was initially diagnosed with cellulitis of the forelimb but as her condition improved and the affected limb was able to bear more weight it became apparent that the limb was hyperextended at the level of the carpus. Widening of the palmar aspect of the middle carpal joint was observed radiographically. During ultrasonographic examination, excessive fluid in the carpal sheath and perithecal swelling were noted and tearing of the palmar carpal ligament was suspected. A dynamic brace was fabricated to prevent hyperextension of the carpus. After discontinuation of systemic antibiotics, the mare became febrile and forelimb lameness worsened. Cytology of fluid from the middle carpal joint confirmed joint sepsis and the mare was anaesthetised for arthroscopic examination. A tear in the palmar carpal ligament, characterised by focal fibre disruption and fibrillation, was identified during arthroscopic and tenoscopic examination. Communication between the carpal flexor tendon sheath and middle carpal joint was identified during these procedures. Both the middle carpal joint and carpal flexor tendon sheath were lavaged with physiological saline solution. Post operatively, swelling and lameness slowly resolved. Four months after discharge, the mare was sufficiently sound to be maintained at pasture. Viewed from its lateral aspect, the limb no longer appeared to be hyperextended from the carpus.     

Itraconazole for treatment of sporotrichosis in a dog residing on a Christmas tree farm

Sporotrichosis was diagnosed in a 2-year-old male Golden Retriever that was allowed to roam free on the owner's Christmas tree farm in Minnesota. Clinical signs had been evident for 1 month and included swelling of the claw bed of the third digit on the left forelimb and a fluctuant nodular lesion in the area of the left carpus. Few organisms were seen in affected tissues, and diagnosis was confirmed on the basis of results of fungal culture. The condition responded to treatment with itraconazole. Previous reports of sporotrichosis in dogs have described lesions that were distributed predominantly on the head, ears, and trunk. A history of exposure to environments that favor survival of the organism may be an important consideration when evaluating animals suspected to have sporotrichosis. To the authors' knowledge, use of itraconazole to treat a dog with sporotrichosis has not been reported previously.     

MAGNETIC RESONANCE IMAGING IN THE DIAGNOSIS OF LYMPHOMA INVOLVING THE BRACHIAL PLEXUS IN A CAT

An 11-year-old, neutered, female Domestic Long Hair cat had a 3-week history of left forelimb lameness. Conscious proprioception and postural reflexes were absent on the left thoracic limb. The cat had slightly reduced placing and hopping responses on the left pelvic limb, absent cutaneous trunci muscle reflex on the left side, and left triceps muscle atrophy. Magnetic resonance imaging revealed a 2 x 2 x 2 cm mass in the region of the left brachial plexus. The cat was treated by left forelimb amputation and hemilaminectomy. Histopathology of the brachial plexus revealed lymphoma.     

Forelimb amputation for the treatment of distal radius osteosarcoma in an African pygmy hedgehog (Atelerix albiventris)

Neoplasia is a common finding in African pygmy hedgehogs. Both skeletal and extraskeletal osteosarcomas have been previously reported in this species, but the only reported case of appendicular osteosarcoma was diagnosed postmortem. A 3-year-old intact female African pygmy hedgehog presented with a 10-day history of left foreleg swelling and lameness. Radiographs performed by the referring veterinarian confirmed the presence of a lytic lesion affecting the distal radius. A whole-body computed tomography scan was performed and confirmed a marked osteolytic lesion affecting the distal radius, which was consistent with bone neoplasia, however osteomyelitis could not be excluded. There was no evidence of thoracic or abdominal metastasis. Ultrasound-guided fine needle aspiration of the lesion yielded a nondiagnostic sample. The affected forelimb was amputated and along with the axillary lymph node, was submitted for histological analysis which confirmed a well differentiated osteosarcoma within the distal radius. The patient made a full recovery with no complications and remained disease free at the time of writing, 12 months after presentation. Osteosarcoma is rarely diagnosed antemortem in African pygmy hedgehogs. This case describes the management, diagnostic techniques, and successful treatment of an osteosarcoma affecting the distal radius by forelimb amputation.