Radiographic diagnosis of a rectourethral fistula in a dog.

An English bulldog was referred to the Veterinary Medical Teaching Hospital-University of Wisconsin (VMTH-UW) for re-evaluation of an 8-year history of chronic, recurrent prostatitis and cystitis. The patient was first referred to the VMTH-UW at 11 months of age with a history of antibiotic-responsive hematuria and stranguria. Four urinary tract contrast studies were performed during the 8-year time span; however, a rectourethral fistula was not diagnosed until the fourth study. The article presents a literature review of rectourethral fistula, describes the case management of the dog in this study, and provides an explanation as to the potential reasons the fistula was not diagnosed on the three previous imaging studies.     

Malignant transformation of an aneurysmal bone cyst in a dog

OBJECTIVE: To report malignant transformation of an aneurysmal bone cyst in a dog. STUDY DESIGN: Case report. SAMPLE POPULATION: Client-owned dog. RESULTS: A 5-year-old male Labrador retriever was diagnosed with an aneurysmal bone cyst of the distal aspect of the right ulna. Surgical curettage resulted in remission of clinical signs for 33 months. Because of recurrence of clinical signs, a distal ulnar ostectomy was performed. Histopathologic examination of the excised specimen revealed a moderately differentiated chondrosarcoma at the level of the bone cyst. Limb function was normal for 17 months until a subcutaneous mass, determined to be a chondrosarcoma, occurred at the level of the shoulder. A right forequarter amputation was performed. CONCLUSIONS: Aneurysmal bone cysts are benign but may be transformed into a malignancy after surgical manipulation. Complete surgical excision should be attempted where possible. In this case, distal ulnar ostectomy was an effective means of preserving limb function and preventing local recurrence of chondrosarcoma.     

Combined xeno/auto-grafting of a benign osteolytic lesion in a dog, using a novel bovine cancellous bone biomaterial

CASE HISTORY: A 4-year-old female Labrador Retriever was diagnosed with an osteolytic lesion of the right distal radius. CLINICAL FINDINGS: Radiographs indicated a well-circumscribed radiolucent area 18 x 15 x 8 mm, centred on the distal radial physeal scar. DIAGNOSIS: Histopathology, performed via Jamshidi needle biopsy and following surgical curettage, was inconclusive but suggested either an aneurysmal bone cyst or fibrous dysplasia. CLINICAL RELEVANCE: A novel processed cancellous bovine bone xenograft was used in conjunction with autogenous cancellous bone (at a ratio of approximately 4:1) to fill the curetted defect. There were no observed complications associated with the use of this new biomaterial. Osteointegration of the bone graft was followed using conventional radiographs and peripheral quantitative computed tomography (pQCT) for 10 months post-operatively. Radiographically, the osteolytic lesion modelled to resemble metaphyseal trabeculation. The cross-sectional area and the average bone density of the grafted lesion determined using pQCT data increased over time, suggesting healthy osteoconduction and native bone production.     

Cutaneous lesion caused by Mycobacterium tuberculosis in a dog

A 5-month-old female mixed-breed dog was examined because of nonhealing wounds in the right submandibular region. Treatment with antibiotics and surgical excision was ineffective. Specimens of the right mandibular lymph node and surrounding tissues were submitted for bacteriologic culturing, and Mycobacterium tuberculosis was isolated. The dog was euthanatized. The risk of infection of human beings who associate with dogs that have cutaneous wounds caused by mycobacteria is unknown.     

Osteochondral lesion and cranial cruciate ligament rupture in an immature dog stifle

An osteochondral flap was present on the medial femoral condyle of a stifle of a six-month-old female rottweiler in which there was also a ruptured cranial cruciate ligament. The lesion was probably osteochondritis dissecans, but the possibilities of it being secondary to joint in-stability or a subchondral fracture, as has been described in people with knee ligamentous injuries, are discussed.     

Polyostotic cystic bone lesions in a dog

The clinical, radiological, and pathological features of a polyostotic cystic bone lesion in a 9-month-old Doberman Pinscher are described. The patient was diagnosed as having nutritional secondary hyperparathyroidism at 6 weeks of age and after dietary correction it remained clinically normal until 9 months when there was sudden left hind-limb lameness due to a pathological fracture through a cystic lesion in the distal femur. Radiography revealed additional cystic structures in the metaphyses of the left radius, and left and right tibia. Pseudofractures were associated with two of the cystic lesions.
In some areas the cysts were crossed by trabeculae and in others there were bony ridges on the inner cystic wall. The cavities were lined with flesh-coloured fibrillar material which formed a lacy network extending into cavities. Histologically, multiple small cysts were present adjacent to the larger cavities noted radiographically. The secondary spongiosa and the metaphyseal periosteum were the major abnormal tissue sites. The small cysts appeared to arise in an oedematous and congested metaphyseal spongiosa. The cysts were accompanied by small foci of intense osteoclasis but unattended by compensatory bone production, and the consequent possibility of pseudofractures is an important clinical consideration. Earlier reports demonstrated that resolution of the lesions will follow surgical drainage and curettage of the cystic cavity. Of six cases of polyostotic cystic bone lesions observed in the dog, five were in the Doberman Pinscher breed.     

Multilobular tumour of bone at an unusual location in the axilla of a dog

Multilobular tumour of bone is a rare neoplasm of cartilage, bone and connective tissue that is seen almost exclusively in association with the skull of veterinary patients. A four-year-old, spayed Jack Russell terrier was presented to the University of Georgia Veterinary Teaching Hospital because of a progressive swelling in the right axilla. Radiographs of the region showed the mass to be caudal to the scapula, unattached to bone and to have numerous punctate calcific opacities throughout its substance. Excisional biopsy of the mass was carried out under general anaesthesia and histopathological examination showed it to be multilobular tumour of bone. This case report documents the occurrence of multilobular tumour of bone at a site other than the head. This tumour should be considered in the differential diagnosis of soft tissue masses with calcific opacities.     

Peliosis hepatis-like lesion in a pekingese dog. A case report

Peliosis hepatis (PH) is a rare condition characterized by dilatation of hepatic sinusoids and the presence of blood-filled spaces within the liver. The disease occurs mainly in subjects exposed to toxic substances or estrogens, and is often asymptomatic. A 9 year-old pekingese female dog was sent to Division of Pathology for autopsy because of sudden death of unclear cause. Autopsy revealed severe hydroperitoneum (1500 ml of transsudate), dilatation of heart ventricles, passive hyperemia of lungs, spleen and kidneys. The liver was enlarged, with slightly wrinkled surface, with many red spots, of different size and shape. Microscopic examination of the liver revealed the presence of areas with severe dilatation of hepatic sinusoids, and multiple cystic spaces filled with blood. Some of these spaces were lined with endothelium and other were not. Spaces were different in shape and size and were localized in the areas between dilated sinusoids. Based on the macroscopic and microscopic examination, the liver lesions were identified as severe hepatic sinusoidal dilatation with formation of peliosis hepatis-like structures.     

Multifocal idiopathic pyogranulomatous bone disease in a dog

Disseminated, multifocal idiopathic pyogranulomatous bone disease in a five-year-old neutered female crossbred cattle dog is described. The dog was presented for neck pain and reluctance to exercise. Radiography demonstrated polyostotic bone disease, the predominant change consisting of a mottled pattern of osteosclerosis interspersed with punctate foci of osteolysis. Numerous bones of the axial and appendicular skeleton were affected including cervical vertebrae, ribs, scapulae and humeri. Biopsy revealed sterile pyogranulomatous osteomyelitis. This was confirmed at necropsy which showed that lesions were restricted to bone. Idiopathic granulomatous or pyogranulomatous conditions have been described in the dog in relation to skin but not bone. In people, idiopathic granulomatous bone disease is one of a group of conditions collectively called histiocytosis X, which are thought to be immunoregulatory disorders related to Tlymphocyte suppressor cell deficiency and Langerhans' cell proliferation.     

Aneurysmal bone cyst in a six-month-old dog.

A 6-month-old female Yorkshire Terrier was examined because of acute left forelimb lameness secondary to a Salter-Harris type IV fracture of the lateral condyle of the humerus. Radiography revealed an eccentric, osteolytic lesion in the distal humeral metaphysis associated with a pathologic fracture. The limb was amputated, and the dog recovered. Microscopic examination revealed an extensive zone of hemorrhage and dilated coalescent spaces, which were filled with blood. Hemosiderin-laden macrophages and multinucleated giant cells were observed throughout the stroma. On the basis of clinical, radiographic, and histologic examinations, a diagnosis of aneurysmal bone cyst was made. Aneurysmal bone cysts generally have been detected in 11- to 13-year-old, medium- to large-sized dogs. They can develop secondary to malignant processes.     

Curative effect of autologous platelet-rich plasma on a large cutaneous lesion in a dog

A dorsal tail mass (1 × 1.2 cm) was observed on a 10-year-old castrated male, Shih-tzu dog. A biopsy of the mass was performed and diagnosed histopathologically as a follicular cyst. A necrotic lesion (2.5 × 3 cm) developed at the biopsy site 1 week after sampling and failed to respond to 2 weeks of normal saline cleansing and systemic antibiotic administration. Autologous platelet-rich plasma was applied to the lesion which gradually improved over a 4-week period possibly by a contribution to the secretion of growth hormone, which can accelerate tissue regeneration. This case report suggests that autologous PRP may be beneficial in the management of large skin defects or in delayed wound healing.     

Ultrasonographic and magnetic resonance imaging diagnosis of an oropharyngeal wood penetrating injury in a dog

A 5 yr old female intact English setter with a 17 day history of a penetrating oropharyngeal wound was referred for cervical swelling and pain. Physical examination revealed swelling at the left lateral aspect of the cranial cervical region. Pain was elicited upon flexion, extension, and leftward movement of the neck. Neurologic deficits were not identified. Cervical ultrasonography showed a 0.4 cm × 2.3 cm linear, hyperechoic structure in the soft tissues ventrolateral to the first (C1) and second (C2) cervical vertebrae. MRI demonstrated a linear structure 2 cm in length adjacent to the cranial aspect of C2. The foreign material was isointense to hyperintense on precontrast T1-weighted images, isointense on postcontrast T1-weighted images, and hypointense on T2-weighted images relative to adjacent muscle. Abnormalities within the spinal canal were not identified. Upon surgical exploration, a reed foreign body was identified deep to the serratus ventralis muscle. The patient was normal on follow-up evaluations 4 wk postsurgically.