Comparative histomorphometric analysis of cellular phenotype in canine stifle ligaments and tendon.

OBJECTIVE: To measure the density of cellular phenotypes in canine caudal cruciate ligament (CaCL), cranial cruciate ligament (CrCL), medial collateral ligament (MCL), and long digital extensor tendon (LDET). STUDY DESIGN: Ex-vivo study. METHODS: Ten CaCL, CrCL, MCL, and LDET obtained from 1 stifle of 10 dogs with no gross pathology were analyzed histologically. The density of cells with 3 nuclear phenotypes (fusiform, ovoid, and spheroid) was determined within the core region of each specimen. RESULTS: Cells with fusiform nuclei were most dense in the MCL (median [range], 319 [118-538] cells/mm2 ) and LDET (331 [61-463]), whereas cells with ovoid nuclei were most dense in the CaCL (276 [123-368]) and CrCL (212 [165-420]). The spheroid nuclear phenotype had the lowest density in all structures (31 [5-61] in CaCL, 54 [5-90] in CrCL, 2 [0-14] in MCL, and 5 [0-80] in LDET); however, the CrCL contained a denser population of spheroid cells compared with MCL and LDET (P < .05). Total cell densities did not differ among the 4 structures (P > .05). CONCLUSION: Phenotype density varied within the ligaments and tendon tested here. The cell population of CaCL and CrCL differed from that of dense collagenous tissues such as MCL and LDET. CLINICAL SIGNIFICANCE: The relatively higher density of spheroid phenotype in CrCL may reflect a distinctive native cellular population or a cellular transformation secondary to unique mechanical environment or hypoxia. This intrinsic cellular population may explain altered tissue properties prone to pathological rupture or poor healing potential of the canine CrCL.

Detection of bacterial DNA by PCR in dogs with stifle pathology.

OBJECTIVE: To determine presence of bacterial DNA in canine stifles with cranial cruciate ligament rupture (CCLR) and medial patellar luxation (MPL) compared to normal canine stifles (control). STUDY DESIGN: Prospective clinical study. ANIMALS: Dogs (n = 44). METHODS: Dogs of varying age, breed, sex, and weight residing in California were assessed for stifle pathology (CCLR, MPL, or normal control). Synovial fluid of all stifles was assessed for the presence of bacterial DNA using broad-ranging 16S rRNA primers and PCR. RESULTS: Bacterial DNA was detected in normal control stifles and those with CCLR and MPL. There were no statistical differences in the copy numbers of bacterial DNA in the stifle synovial fluid among groups (P > .05); however, synovial fluid specimens from dogs with stifle pathology (CCLR and MPL combined) tended to have higher copy numbers of bacterial DNA than those from controls (P = .06). There was no significant difference in the number of bacterial DNA between the CCLR and MPL groups (P = .57). The copy numbers of bacterial DNA had a weak positive significant correlation with the duration of lameness in CCLR group (P < .05). CONCLUSIONS: Increased detection of bacterial DNA in the stifle synovial fluid may indicate joint pathology but not be directly linked to a specific joint disease.

Histomorphometric analysis and regional variations of full thickness skin grafts in dogs.

OBJECTIVE: To (1) compare thickness of the epidermis and dermis of anatomically different donor sites in dogs, and (2) evaluate hair follicle damage during full thickness skin grafts (FTSG) preparation from anatomically different donor sites. Another objective was to compare the extent of agreement between gross and histologic quality of graft preparation. STUDY DESIGN: Ex vivo study. ANIMALS: Healthy Beagle dogs (n = 12). METHODS: Skin samples were harvested from fresh cadavers free of gross dermatopathology and FTSG prepared. Regional, epidermal and dermal thickness, and hair follicle density in intact skin and FTSG specimens from different regions were determined by histomorphometric analysis. Hair follicle density in intact skin and FTSG specimens, and skin thickness measurements were compared among regions. RESULTS: Mean epidermis and dermis thickness of the dorsal lumbar and lateral neck regions were significantly greater when compared with other sites. Total hair follicle (superficial and deep dermis) densities were significantly less in prepared FTSG versus intact skin specimens. The dorsal lumbar region had the highest hair follicle density. CONCLUSIONS: Thickness of the epidermis and dermis is dependent on body region. Hair follicle density in the FTSG specimens was decreased compared with intact skin specimens, which may affect hair regrowth in FTSG.

Pathologic fracture in dogs with suspected or confirmed osteosarcoma.

OBJECTIVE: To evaluate clinical presentation of pathologic fractures associated with suspected or confirmed osteosarcoma in dogs and to assess treatment and survival times. STUDY DESIGN: Case series. ANIMALS: Dogs (n=25) appendicular pathologic fracture. METHODS: Medical records (January 1997-May 2008) of dogs with pathologic fracture associated with a suspected or confirmed osteosarcoma were reviewed. Dogs were included if they had radiographic evidence of a pathologic fracture and a presumptive or definitive diagnosis of osteosarcoma. Radiographic details, histopathology, and/or cytology findings were recorded. Overall median survival time (MST) and MST of treated dogs were calculated. Age, sex, breed, and other concurrent treatment were evaluated. RESULTS: Rottweilers, Irish Wolfhounds, and Greyhounds were the most common breeds represented. Most dogs had minor trauma and 60% had lameness preceding the fracture. Most commonly, fractures were nondisplaced with minimal comminution. None of the dogs had radiographic evidence of pulmonary metastases at admission. Immediate (13 dogs; 52%) and delayed (4; 16%) euthanasia were performed. One dog was not treated and died 90 days after diagnosis. Three dogs (12%) were treated by amputation alone, 1 (4%) with amputation and chemotherapy, and 3 (12%) with internal fixation using an interlocking nail. Overall MST was 1 day (range, 0-623 days) and MST of treated dogs was 406.5 days. Histologic confirmation of osteosarcoma was available in all treated dogs and 6 euthanatized dogs. CONCLUSIONS: Treatment of pathologic fracture associated with presumptive osteosarcoma should be considered as an option to amputation or euthanasia if owners desire other options.

Outcome after repair of a sarcoma-related pathologic fracture in dogs: a Veterinary Society of Surgical Oncology Retrospective Study.

OBJECTIVE: To report outcome in dogs after internal fixation of a sarcoma-related pathologic fracture of the appendicular skeleton. STUDY DESIGN: Multi-institutional case series. ANIMALS: Dogs (n=16). METHODS: Medical records of participating VSSO members were reviewed for dogs with pathologic fracture associated with a confirmed bone sarcoma of the appendicular skeleton repaired by external or internal fixation. Dogs were included if they had a histological diagnosis of osteosarcoma or sarcoma and excluded if they had radiation before fracture. Data collected were analyzed for signalment, fracture location, staging performed, method of fracture fixation, histopathology, adjunctive treatment and outcome. RESULTS: Signalment and fracture location of 16 dogs that met the inclusion criteria was similar to dogs with appendicular OSA without fracture. One of 14 dogs had pulmonary metastasis and 3 of 5 dogs had bone metastasis. Bone plate or interlocking nail were used for repair in 12 dogs. Limb use immediately after surgery in 13 dogs was good (4), weight-bearing but lame (7) and non-weight bearing (2). Adjunctive therapy was administered in 5 dogs (chemotherapy, 3; radiation, 4; pamidronate, 3). Survival time ranged from 18 to 897 days; median survival was 166 days. CONCLUSIONS: Repair of pathologic fracture can result in palliation and prolonged survival.

Immunohistochemical and histomorphometric evaluation of vascular distribution in intact canine cranial cruciate ligament.

OBJECTIVES: To (1) describe vascular distribution in the grossly intact canine cranial cruciate ligament (CCL) using immunohistochemical techniques specific to 2 components of blood vessels (factor VIII for endothelial cells, laminin for basement membrane); and (2) compare the vascularity in different areas of interest (craniomedial versus caudolateral bands; core versus epiligamentous regions; and proximal versus middle versus distal portions) in the intact normal canine CCL. STUDY DESIGN: In vitro study. ANIMALS: Large, mature dogs (n=7) of breeds prone to CCL disease that were euthanatized for nonorthopedic conditions. METHODS: Intact CCL were collected from fresh canine cadavers free from stifle pathology. CCL tissue was processed for immunohistochemistry and stained for factor VIII and laminin. Vascular density was determined by histomorphometric analysis. RESULTS: Specific vascular staining was sparsely identified throughout the CCL; however, the proximal portion of the CCL appears to have a greater number of vessels than the middle or distal portion of the ligament. CONCLUSIONS: The CCL is a hypovascular tissue and its vascular distribution is not homogeneous.

Vascular distribution in ruptured canine cranial cruciate ligament.

OBJECTIVE: To (1) determine the microanatomic vascular distribution in ruptured canine cranial cruciate ligaments (CCL) using specific vascular immunohistochemical techniques, and (2) compare vessel density between ruptured and intact canine CCL and between different areas of interest in ruptured CCL using histomorphometric analysis. STUDY DESIGN: In vitro study. ANIMALS: Dogs (n=41) admitted for surgical treatment of ruptured CCL and 19 dogs euthanatized for nonorthopedic conditions. METHODS: Diseased (variable CCL rupture) and intact (normal control) CCL were processed for immunohistochemical staining specific to vessels (factor VIII, laminin). Mean vascular density was assessed and compared in areas of interest (torn end versus remaining core regions of CCL, proximal femoral versus distal tibial core CCL regions). RESULTS: Ruptured CCL was more vascular than intact CCL; however there was no difference in vascular density between the torn end and the remaining core area of the ruptured CCL. Ruptured CCL was vascularized to a greater degree at the proximal portion than the distal portion of the CCL. Partially ruptured CCLs had a higher vessel density than completely ruptured CCLs. CONCLUSIONS: Vascular density is increased in diseased CCL compared with intact CCL. It remains to be determined whether this finding is associated with the cause of CCL rupture or is a result of CCL degeneration and rupture.

Use of color flow Doppler ultrasonography to diagnose a bleeding neuroendocrine tumor in the gallbladder of a dog.

CASE DESCRIPTION: A 13-year-old neutered female Keeshond-cross was evaluated because of a history of melena, anemia, hematemesis, vomiting, and high serum liver enzyme activities over a 1.5-year period. CLINICAL FINDINGS: Abdominal ultrasonography revealed a hyperechoic mass in the gallbladder. In the gallbladder mass itself, a distinct linear blood flow pattern was detected by use of color flow Doppler ultrasonography. TREATMENT AND OUTCOME: A cholecystectomy was performed, and clinical signs resolved. Samples of the mass were examined histologically and immunohistochemically, and findings supported a diagnosis of neuroendocrine tumor of the gallbladder. CLINICAL RELEVANCE: Tumors of the biliary tree are a potential source of blood loss into the gastrointestinal tract. Color flow Doppler ultrasonography in conjunction with conventional grayscale ultrasonography may be useful in evaluation of the gallbladder in dogs. When echogenic material is detected in the gallbladder, it is important to evaluate the region for blood flow.

Tracheal rupture in a cat: diagnosis by computed tomography.

A cat was presented with a history of worsening generalized subcutaneous emphysema following dental prophylaxis. Tentative diagnosis of tracheal rupture was made. The location and extent of the tear was confirmed with the help of computed tomography. This is the 1st computed tomographic description of tracheal rupture in the veterinary literature.

Cecal inversion followed by ileocolic intussusception in a cat.

A cat was presented with a history of constipation, tenesmus, and malaise. Ultrasonography revealed an ileocolic intussusception and cecal inversion. Surgical findings included an easily reducible intussusception and an inverted cecum that was moderately difficult to reduce. A typhlectomy and bowel plication was performed. The cat had an uneventful recovery.

Spontaneous left medial liver lobe torsion and left lateral lobe infarction in a rottweiler.

The abdominal ultrasonogram of a dog admitted for acute onset of collapse revealed an abnormally displaced left medial liver lobe with no blood flow. Surgical and histological findings confirmed the ultrasonographic diagnosis of left liver lobe torsion. Ultrasonographic findings were useful and probably sufficient for a correct diagnosis.