Evaluation of healing in feline femoral defects filled with cancellous autograft, cancellous allograft or Bioglass.

Cancellous bone grafting is a widely accepted technique in human and veterinary orthopaedic surgery. However, the use of autogenous bone graft is limited by the additional surgical time required to harvest the graft, the morbidity associated with the donor site, and the limited availability of cancellous bone, especially in feline patients. Various allografts and bone graft substitutes are available commercially but have not been fully evaluated for efficacy in the cat. The purpose of this study was to compare the incorporation of autogenous and allogenous cancellous bone graft and Bioglass, a synthetic bone graft substitute, in femoral defects in cats. Four (4.0 mm diameter) defects were created in the lateral diaphyseal cortex of the left femur with an orthopaedic drill. In each femur, one of the cortical defects was filled with autogenous cancellous graft (harvested from the tibia), one was filled with allogenic cancellous graft, and one was filled with Bioglass. The fourth defect remained unfilled. Graft incorporation within the femoral defects was evaluated by radiographic evaluation every two weeks. Six weeks after the grafting procedure, the cats were euthanatized and high detailed radiography, dual energy X-ray absorptiometry (DEXA), histopathology and histomorphometry of the defects were performed. Satisfactory bone healing was observed within all of the defects.

Cerebrospinal fluid changes after iopamidol and metrizamide myelography in clinically normal dogs.

Cerebrospinal fluid samples from 2 groups of clinically normal dogs were compared after iopamidol (n = 9) and metrizamide (n = 8) myelography. Iopamidol (200 mg of I/ml) and metrizamide (170 mg of I/ml) were administered by cerebellomedullary injection at dosage of 0.45 ml/kg of body weight. In dogs of both groups, postmyelographic CSF changes included high specific gravity, Pandy score, protein concentration, and WBC count. The high specific gravity and Pandy score were false-positive effects attributed to nonionic contrast media. Although postmyelographic protein concentration and total WBC count were greater in CSF samples from dogs given metrizamide than in those given iopamidol, differences were not statistically significant. The differential WBC counts were consistent with mild, acute leptomeningitis; these findings were supported by results of histologic examination. Iopamidol and metrizamide should be considered low-grade leptomeningeal irritants in dogs.

Full-length diaphyseal sequestrum as a consequence of segmental transverse fractures of the large metatarsal bone in a calf.

A 1-week-old calf was treated for fractured right metatarsus; however, at 3.5 months of age, the fracture site again became unstable. Radiography disclosed segmental transverse metatarsal fractures with an isolated, full-circumference diaphyseal sequestrum. Arteriography and nuclear scintigraphy confirmed the isolation and necrosis of the diaphyseal segment. Diaphyseal sequestra usually develop as cortical or partial circumferential necrotic fragments. The finding of a full-length diaphyseal sequestrum was unusual.

Single-phase methylene diphosphate bone scintigraphy in the diagnostic evaluation of dogs with osteosarcoma.

In this study, 25 dogs each with a histopathologically diagnosed appendicular or axial osteosarcoma were prospectively and consecutively examined by methylene diphosphate nuclear scintigraphy. Scannings that revealed scintigraphically enhanced focal increased activity via bone uptake of the 99mTc methylene diphosphate radionuclide at sites other than the primary tumor site were compared with scintigrams obtained from dogs without osteosarcoma. Secondary scintigraphic sites were evaluated by survey radiography and, if possible, by histologic examination (biopsy or necropsy specimens). On the basis of our findings, scintigraphy seems to be more efficient than physical examination and radiographic bone survey for the diagnosis of multicentric, metachronous, or metastatic canine osteosarcoma.

Intraperitoneal circulation and drainage in the dog.

The patterns of dispersion and drainage of a low viscosity, oil-based contrast medium within the peritoneal cavity were examined in 12 normal dogs. Intraperitoneal injection of contrast medium was cranial or caudal and drainage was by the sump-Penrose or open peritoneal method. Radiographs were made over a 96 hour period, before and after peritoneal drainage was established. Each dog was euthanatized and necropsied. The contrast medium was dispersed throughout the peritoneal cavity 15 to 30 minutes after cranial injection and 1 to 2 hours after caudal injection. Most of the contrast medium drained within 6 hours after open peritoneal drainage and within 24 to 48 hours after sump-Penrose drainage. At necropsy, there was complete encasement of all sump-Penrose drains and partial occlusion of all open peritoneal incisions by omentum adhered to the abdominal wound edges. Peritonitis was not grossly evident, but all dogs showed histologic evidence of an acute inflammatory reaction associated with the drain or wound edge.

Conservative management of fractures of the mandibular condyloid process in three cats and one dog.

Three cats and 1 dog with fracture of the mandibular condyloid process and concomitant fracture(s) of the rostral portion of the mandible were treated successfully by wire fixation of the rostral mandibular fracture(s) and by conservative management of the mandibular condylar fracture. All animals regained satisfactory dental occlusion and normal, pain-free motion of the jaw. Fracture of the mandibular condyloid process is an infrequently diagnosed injury that usually occurs with other mandibular fractures. If satisfactory dental occlusion can be achieved by surgical stabilization of the noncondylar fractures, surgical repair of the mandibular condyloid fracture may not be necessary.

The effects of beveling the margins of articular cartilage defects in immature dogs.

Eight 4 month old crossbred puppies underwent surgery simulating treatment of osteochondritis dissecans. Both humeral heads were exposed by a caudal approach to the shoulder joint. In one, an 8 mm circular, full-thickness cartilage defect was created so that the remnant cartilage margin was perpendicular to the joint surface. In the other, a similar 8 mm defect was created with the chondral margins beveled at approximately 45 degrees. There was no clinical lameness in any of the dogs. At necropsy after 16 weeks, the cartilage defects with beveled edges were significantly larger (11.0 +/- 0.6 mm SD) than those with perpendicular edges (8.0 +/- 0.1 mm SD), because of the beveling (p = 0.0039). Fibrocartilage was present but did not always completely fill the defects. Articular surfaces of the glenoid cavities suffered erosion and fibrillation more frequently opposite beveled defects than opposite defects with vertical walls (p = 0.0312). This was presumably due to the larger apposing defect. It was concluded that the cartilage margins surrounding a chondral defect should not be beveled.

Intermittent open-mouth lower jaw locking in five dogs.

Intermittent open-mouth lower jaw locking was documented in 5 dogs. In contrast to what has been reported in other cases, pronounced radiographic abnormalities in the temporomandibular joints were not observed. In 4 of the dogs, locking episodes started at a later age (35 to 83.5 months) than had been reported by others (6 to 22 months). Duration and frequency of locking were variable. Lateral shifting of the jaw and lack of neurologic deficits indicated a temporomandibular joint abnormality. Excision of the rostroventral portion of the involved zygomatic arch prevented locking in all cases. This syndrome involves variable severity of temporomandibular joint dysplasia, which could account for the variable age of onset and random frequency of locking episodes.

Ivermectin for treatment of nasal capillariasis in a dog.

One oral dose of ivermectin successfully rid a dog of Capillaria aerophila that were infecting the nasal passages. Diagnosis was made by finding the eggs in the feces and in the nasal discharge, and or finding the worms in a biopsy specimen taken from the nasal passage. Ivermectin was chosen because of ease of administration, expected efficacy, and minimal expense. Although this dog did not show any of the adverse CNS effects associated with the use of ivermectin, these potential side-effects should be kept in mind any time this anthelmintic is used in dogs.