Outcome and prognosis for canine appendicular osteosarcoma treated with stereotactic body radiation therapy in 123 dogs.

Canine appendicular osteosarcoma is commonly treated with limb amputation; however, limb-sparing options are frequently desired or necessary for a subset of patients. We evaluated 123 patients and 130 sites treated with stereotactic body radiation therapy (SBRT). Eighty-two out of 98 dogs (84%) had maximum lameness improvement at a median of 3 weeks for a median of 6 months duration. Histopathologic evaluation of available samples from amputation or necropsy revealed >80% tumor necrosis in 50% of limbs consistent with local disease control. Of evaluable patients, 41% fractured and 21% pursued an amputation after treatment. Fine needle aspirate (n = 52) and needle core biopsy (n = 28) did not result in increased fracture risk compared to those without tumor sampling (n = 50). Median survival time (MST) was 233 days and time to first event was 143 days. Gross tumor volume and planned target volume were significantly inversely associated with survival and tumor location was significantly associated with survival. Dogs with salvage amputation had a significantly longer MST compared to those without (346 vs 202 days; P = .04). The presence of metastatic disease at the time of treatment in 15 dogs did not significantly impact survival time (200 vs 237 days without metastasis; P = .58). Skin side effects correlated significantly with dose with 33% of patients with acute grade 3 effects developing consequential late grade 3 effects. While SBRT improves lameness in most patients, further investigation is needed to identify candidates with minimal early fracture risk prior to initiating therapy.

Association of tibial plateau leveling osteotomy with proximal tibial osteosarcoma in dogs.

OBJECTIVE To assess for any association between a history of tibial plateau leveling osteotomy (TPLO) and subsequent development of proximal tibial osteosarcoma in dogs. DESIGN Matched case-control study. ANIMALS 34 client-owned dogs in which proximal tibial osteosarcoma was diagnosed between January 2005 and December 2012 (cases) and 79 dogs without osteosarcoma, matched 3:1 to cases (when possible) by age, breed, and initial examination date (controls). PROCEDURES Information on each case and control was collected from the medical records and other sources regarding date of birth, sex and neuter status, body weight, breed, and whether TPLO had been performed ≥ 1 year ago. A multivariable conditional logistic regression model was constructed to evaluate associations of body weight and history of TPLO with the outcome of proximal tibial osteosarcoma in dogs. RESULTS After adjusting for body weight in the multivariable model, dogs with a history of TPLO were 40 times as likely to develop proximal tibial osteosarcoma as were dogs with no history of TPLO. In addition, each 1-kg (2.2-lb) increase in body weight was associated with an 11% increase in the odds of proximal tibial osteosarcoma. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that dogs with a history of TPLO were at increased risk of developing osteosarcoma of the proximal region of the tibia relative to dogs with no such history. Therefore, it is important for proximal tibial osteosarcoma to be included among the differential diagnoses for new or worsening hind limb lameness in dogs that underwent TPLO ≥ 1 year previously.

Dedifferentiated Chondrosarcoma in the Dog and Cat: A Case Series and Review of the Literature.

This retrospective case series describes seven dogs and one cat diagnosed with dedifferentiated chondrosarcoma, an uncommon, aggressive variant of chondrosarcoma. The purpose of the study is to describe clinical, imaging, and histopathological findings of this tumor. Medical records and the diagnostic laboratory database at Colorado State University from 2000 to 2015 were reviewed and complete medical records were available for the eight animals in this report. Similar to what has been reported in people, poor long-term survival and high metastatic rate, particularly to the lungs, was observed in our case series. A bimorphic pattern on imaging (radiographs, computed tomography, and MRI) consisting of mineralized and nonmineralized areas was seen mirroring the high-grade sarcomatous component adjacent to a low-grade chondroid component seen histopathologically. A review of the human literature including suspected etiology, imaging findings, histopathology, and survival times with various treatment options is presented. This article describes the first reported cases of dedifferentiated chondrosarcoma in the veterinary literature. Early accurate recognition could lead to treatment plans tailored to this variant.

Prognosis for dogs with stage III osteosarcoma following treatment with amputation and chemotherapy with and without metastasectomy.

OBJECTIVE To determine survival times of selected dogs with metastatic (stage III) osteosarcoma, whether disease-free interval (DFI) was associated with survival time after diagnosis of stage III disease (ie, stage III survival time), and whether a survival benefit of metastasectomy existed. DESIGN Retrospective case series with nested cohort study. ANIMALS 194 client-owned dogs treated for histologically confirmed appendicular osteosarcoma from 1997 through 2009. PROCEDURES Dogs were included if they had stage I or II osteosarcoma at the time of initial evaluation, had amputation of the affected appendage and ≥ 1 dose of chemotherapy afterward, and developed metastasis within the follow-up period or prior to death. Data collected from the medical records included signalment, primary tumor location, clinical and laboratory findings, whether metastasectomy was performed, and outcome. Various factors were examined for associations with outcome. RESULTS Dogs that received no treatment for the metastasis had a median survival time between 49 and 57 days after diagnosis of stage III osteosarcoma. Duration of the preceding DFI had no association with this period. Metastasectomy alone was associated with a longer median stage III survival time (232 days) than no metastasectomy (49 days). Among all dogs identified as qualifying for pulmonary metastasectomy on the basis of < 3 pulmonary nodules visible on thoracic radiographs and a DFI > 275 days (n = 21), a survival advantage was also identified for those that actually received pulmonary metastasectomy (6). CONCLUSIONS AND CLINICAL RELEVANCE Preceding DFI had no influence on survival time of dogs with stage III osteosarcoma. Metastasectomy was associated with an increase in survival time for selected dogs.

Use of PET/CT and Stereotactic Radiation Therapy for the Diagnosis and Treatment of Osteosarcoma Metastases.

This case report describes the use of two new concepts in the diagnosis and treatment of metastatic osteosarcoma (OSA) in one dog. The dog was initially presented for positron emission tomography and computed tomography (PET/CT) as full-body staging following amputation and adjuvant chemotherapy for treatment of OSA of the proximal tibia. The initial PET/CT did not show evidence of metastatic disease. Six mo after OSA, diagnosis pulmonary metastatic nodules were identified and oral toceranib phosphate was initiated. Twelve mo postdiagnosis the dog developed neck pain and non-ambulatory tetraparesis and was diagnosed with a C7 vertebral metastatic lesion based on magnetic resonance imaging. A second PET/CT was performed to screen for further metastatic lesions, and a nodule within the right ischium was identified. The C7 and ischial lesions were treated with stereotactic radiation therapy (SRT). Sixteen mo postdiagnosis, a third PET/CT was performed due to increasing size of the pulmonary nodules and a right-sided liver metastasis was detected. The liver mass was treated with SRT. The PET/CT scans facilitated identification of gross metastatic lesions that were subsequently treated with SRT, which resulted in clinical improvement of the dog's neurological signs.

Splenic liposarcoma in dogs: 13 cases (2002-2012).

OBJECTIVE: To describe the clinical signs, diagnostic findings, surgical management, and outcome in dogs with splenic liposarcoma. DESIGN: Retrospective case series. ANIMALS: 13 client-owned dogs with splenic liposarcoma. PROCEDURES: Medical and pathology records of dogs with a histopathologic diagnosis of splenic liposarcoma from 2002 to 2012 were reviewed for the following data: clinical signs, CBC, biochemical profile, thoracic and abdominal imaging, surgical management, histologic grade, and outcome (local recurrence, distant metastasis, and survival time). Telephone interviews were conducted with referring veterinarians. RESULTS: The median survival time (MST) was 623 days (range, 1 to 1,283 days). In 5 dogs that died of splenic liposarcoma, survival times ranged from 42 to 369 days. Metastasis at the time of surgery was a negative prognostic indicator: the MST was 45 days for dogs with metastasis and 767 days for dogs without metastasis. Dogs with grade 1 splenic liposarcoma had a significantly greater MST (1,009 days), compared with dogs with grade 2 or 3 splenic liposarcoma (MST, 206 and 74 days, respectively). CONCLUSIONS AND CLINICAL RELEVANCE: Results confirmed that splenic liposarcoma is a rare differential diagnosis in dogs with a splenic mass. Survival time was influenced by preoperative clinical stage and histologic grade.

Perioperative Mortality and Long-Term Survival in 80 Dogs and 32 Cats Undergoing Excision of Thymic Epithelial Tumors.

OBJECTIVE: To examine perioperative mortality, long-term survival, causes of death, and prognostic factors for dogs and cats undergoing surgical excision of thymic epithelial tumors (TETs). STUDY DESIGN: Multi-institutional case series. ANIMALS: Eighty dogs and 32 cats. METHODS: Follow-up information was obtained for dogs and cats that underwent surgical excision of a TET between 2001 and 2012. RESULTS: Perioperative mortality was 20% in dogs and 22% in cats. No independent risk factors for perioperative mortality were identified. The estimated median survival time for all dogs was 1.69 years (95% CI 0.56-4.32) and the 1- and 4-year survival rates were 55% (95% CI 44-67) and 44% (95% CI 32-56). The estimated median survival time for all cats was 3.71 years (95% CI 0.56-unestimatable) and the 1- and 4-year survival rates were 70% (95% CI 53-87) and 47% (95% CI 0-100). Of animals that survived to discharge, 42% of dogs and 20% of cats eventually died of TET-related causes. The presence of paraneoplastic syndromes (hazard ratio [HR] 5.78, 95% CI 1.64-20.45, P = .007) or incomplete histologic margins (HR 6.09, 95% CI 1.50-24.72, P = .01) were independently associated with decreased survival in dogs. No significant predictors of survival were identified in cats. Conclusions regarding the effect of chemotherapy or radiation therapy could not be made. CONCLUSIONS: While there is substantial risk of perioperative death in dogs and cats undergoing surgery for TETs, many animals that survive to discharge have prolonged survival. Survival is significantly decreased in dogs with paraneoplastic syndromes or incomplete histologic margins.

Outcome following curative-intent surgery for oral melanoma in dogs: 70 cases (1998-2011).

OBJECTIVE: To evaluate the outcome in terms of progression-free interval (PFI) and overall survival time (ST) after curative-intent resection of oral melanoma in dogs. DESIGN: Retrospective case series. ANIMALS: 70 client-owned dogs. PROCEDURES: An electronic medical record search and review was performed for dogs that underwent curative-intent resection of oral melanoma (May 1, 1998, to December 31, 2011). Information gathered included signalment, oral location of tumor, staging results, type of surgery, type of adjuvant therapy, findings on histologic evaluation, and outcome. RESULTS: 36 (51.4%), 16 (22.9%), 13 (18.6%), and 1 (1.4%) of 70 dogs had tumors classified as stage I, II, III, and IV, respectively; tumor stage could not be determined for 4 (5.7%) dogs because of the lack of tumor size information. Fifty-one (72.9%) dogs had tumors completely excised. Twenty-nine (41.4%) dogs received adjuvant therapy. Median PFI and ST were 508 and 723 days, respectively. Thirty-two (45.7%) dogs had disease progression. Significant associations with PFI or ST were found for administration of adjuvant therapy, presence of metastatic disease at the time of diagnosis, higher tumor stage (III or IV), increased tumor size (> 3 cm), and sexually intact female dogs. Administration of adjuvant treatment was associated with a 130% increased hazard (hazard ratio, 2.3; 95% confidence interval [CI], 1.0 to 5.0) of disease progression; the presence of metastases at the time of diagnosis was associated with a 281% increased hazard (hazard ratio, 3.8; 95% CI, 1.5 to 9.6) of death. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that dogs with oral melanoma can have a long PFI and ST after resection with wide margins.

Evaluation of outcome and prognostic factors for dogs living greater than one year after diagnosis of osteosarcoma: 90 cases (1997-2008).

OBJECTIVE: To evaluate clinical characteristics, outcome, and prognostic variables in a cohort of dogs surviving > 1 year after an initial diagnosis of osteosarcoma. DESIGN: Retrospective case series. ANIMALS: 90 client-owned dogs. PROCEDURES: Medical records for an 11-year period from 1997 through 2008 were reviewed, and patients with appendicular osteosarcoma that lived > 1 year after initial histopathologic diagnosis were studied. Variables including signalment, weight, serum alkaline phosphatase activity, tumor location, surgery, and adjuvant therapies were recorded. Median survival times were calculated by means of a Kaplan-Meier survival function. Univariate analysis was conducted to compare the survival function for categorical variables, and the Cox proportional hazard model was used to evaluate the likelihood of death > 1 year after diagnosis on the basis of the selected risk factors. RESULTS: 90 dogs met the inclusion criteria; clinical laboratory information was not available in all cases. Median age was 8.2 years (range, 2.7 to 13.3 years), and median weight was 38 kg (83.6 lb; range, 21 to 80 kg [46.2 to 176 lb]). Serum alkaline phosphatase activity was high in 29 of 60 (48%) dogs. The most common tumor location was the distal portion of the radius (54/90 [60%]). Eighty-nine of 90 (99%) dogs underwent surgery, and 78 (87%) received chemotherapy. Overall, 49 of 90 (54%) dogs developed metastatic disease. The median survival time beyond 1 year was 243 days (range, 1 to 1,899 days). Dogs that developed a surgical-site infection after limb-sparing surgery had a significantly improved prognosis > 1 year after osteosarcoma diagnosis, compared with dogs that did not develop infections. CONCLUSIONS AND CLINICAL RELEVANCE: Results of the present study indicated that dogs with an initial diagnosis of osteosarcoma that lived > 1 year had a median survival time beyond the initial year of approximately 8 months. As reported previously, the development of a surgical-site infection in dogs undergoing a limb-sparing surgery significantly affected prognosis and warrants further study.

Outcome and prognostic factors for osteosarcoma of the maxilla, mandible, or calvarium in dogs: 183 cases (1986-2012).

OBJECTIVE: To describe the biological behavior, clinical outcome, and prognostic factors of osteosarcoma of the maxilla, mandible, or calvarium in dogs. DESIGN: Retrospective case series. ANIMALS: 183 client-owned dogs with osteosarcoma of the maxilla, mandible, or calvarium. PROCEDURES: Medical records for dogs treated for osteosarcoma of the maxilla, mandible, or calvarium from 1986 through 2012 were reviewed. Dogs with a histopathologic diagnosis of osteosarcoma and treated for a primary tumor arising from these bones of the head were included. RESULTS: Mean age was 9.3 years, and body weight was 31.8 kg (70.0 lb). Most dogs (124/183 [67.8%]) were purebred, and the most common primary tumor site was the maxilla (80 [43.7%]). Treatments included palliative medical treatment only (11/183 [6.0%]), coarsely fractionated radiation therapy (RT; 12 [6.6%]), fractionated or stereotactic RT (18 [9.8%]), surgery (135 [73.8%]), and both surgery and fractionated RT (7 [3.8%]). Eighty-three (45.4%) dogs received adjuvant chemotherapy. Local recurrence or progression occurred in 80 of 156 (51.3%) dogs, and 60 of 156 (38.5%) dogs developed distant metastases. Median survival time for all dogs was 239 days. Dogs that underwent surgery had a median survival time of 329 days. Histologically tumor-free surgical margins were associated with significantly decreased hazards of progression or recurrence (hazard ratio [HR], 0.4) and death (HR, 0.5). Dogs with osteosarcoma of the calvarium had a significantly greater hazard of local recurrence or progression (HR, 2.0). CONCLUSIONS AND CLINICAL RELEVANCE: In this study, tumor excision in dogs with histologically tumor-free margins resulted in better local control and longer survival time than did other treatment types.

Toward a drug development path that targets metastatic progression in osteosarcoma.

Despite successful primary tumor treatment, the development of pulmonary metastasis continues to be the most common cause of mortality in patients with osteosarcoma. A conventional drug development path requiring drugs to induce regression of established lesions has not led to improvements for patients with osteosarcoma in more than 30 years. On the basis of our growing understanding of metastasis biology, it is now reasonable and essential that we focus on developing therapeutics that target metastatic progression. To advance this agenda, a meeting of key opinion leaders and experts in the metastasis and osteosarcoma communities was convened in Bethesda, Maryland. The goal of this meeting was to provide a "Perspective" that would establish a preclinical translational path that could support the early evaluation of potential therapeutic agents that uniquely target the metastatic phenotype. Although focused on osteosarcoma, the need for this perspective is shared among many cancer types. The consensus achieved from the meeting included the following: the biology of metastatic progression is associated with metastasis-specific targets/processes that may not influence grossly detectable lesions; targeting of metastasis-specific processes is feasible; rigorous preclinical data are needed to support translation of metastasis-specific agents into human trials where regression of measurable disease is not an expected outcome; preclinical data should include an understanding of mechanism of action, validation of pharmacodynamic markers of effective exposure and response, the use of several murine models of effectiveness, and where feasible the inclusion of the dog with naturally occurring osteosarcoma to define the activity of new drugs in the micrometastatic disease setting.

Osteosarcoma following tibial plateau leveling osteotomy in dogs: 29 cases (1997-2011).

OBJECTIVE: To determine the signalment, tibial plateau leveling osteotomy (TPLO) plate type, clinical staging information, treatment, and oncological outcome in dogs that developed osteosarcoma at the proximal aspect of the tibia following TPLO and to calculate the interval between TPLO and osteosarcoma diagnosis. DESIGN: Multi-institutional retrospective case series. ANIMALS: 29 dogs. PROCEDURES: Medical records from 8 participating institutions were searched for dogs that developed osteosarcoma (confirmed through cytologic or histologic evaluation) at previous TPLO sites. Signalment, TPLO details, staging tests, treatment data, and outcome information were recorded. Descriptive statistics were calculated, and disease-free intervals and survival times were evaluated by means of Kaplan-Meier analysis. RESULTS: 29 dogs met the inclusion criteria. The mean age was 9.2 years and mean weight was 45.1 kg (99.2 lb) at the time of osteosarcoma diagnosis. Most dogs had swelling over the proximal aspect of the tibia (17/21) and lameness of the affected limb (28/29). The mean interval between TPLO and osteosarcoma diagnosis was 5.3 years. One type of cast stainless steel TPLO plate was used in most (18) dogs; the remaining dogs had received plates of wrought stainless steel (n = 4) or unrecorded type (7). Twenty-three of 29 dogs underwent treatment for osteosarcoma. Median survival time for 10 dogs that underwent amputation of the affected limb and received ≥ 1 chemotherapeutic treatment was 313 days. CONCLUSIONS AND CLINICAL RELEVANCE: Results supported that osteosarcoma should be a differential diagnosis for dogs with a history of TPLO that later develop lameness and swelling at the previous surgical site. Oncological outcome following amputation and chemotherapy appeared to be similar to outcomes previously reported for dogs with appendicular osteosarcoma.

Evaluation of risk factors for outcome associated with adrenal gland tumors with or without invasion of the caudal vena cava and treated via adrenalectomy in dogs: 86 cases (1993-2009).

OBJECTIVE: To evaluate risk factors for outcome for dogs with adrenal gland tumors with or without invasion of the caudal vena cava treated via adrenalectomy. DESIGN: Retrospective study. ANIMALS: 86 dogs that underwent adrenalectomy for treatment of adrenal gland tumors. PROCEDURES: Medical records of dogs that underwent adrenalectomy for treatment of an adrenal gland tumor from 1993 to 2009 were reviewed; data collected including signalment, clinical signs, diagnostic test findings, treatments prior to surgery, findings at surgery including additional procedures performed and extent of caudal vena caval invasion (local invasion [caudal to the hepatic portion of the vena cava] or extensive invasion [cranial to the hepatic portion of the vena cava]), procedures performed during surgery, histopathologic diagnosis, perioperative complications, follow-up data, and necropsy findings. RESULTS: Of the 86 dogs, 14 had adenomas, 45 had adrenocortical carcinomas, and 27 had pheochromocytomas. Fourteen dogs had invasion of the caudal vena cava; of these tumors, 7 were locally invasive and 7 were extensively invasive. Risk factors for poor short-term survival (death within 14 days following surgery) were vena caval invasion, extent of invasion, pheochromocytoma, intraoperative transfusion, and postoperative factors including disseminated intravascular coagulation, pancreatitis, hypotension, hypoxemia, and renal failure. Multivariate analysis of risk factors for poor short-term survival revealed that extensive invasion was the most important factor. Regardless of extent of invasion or tumor type, long-term survival was possible. CONCLUSIONS AND CLINICAL RELEVANCE: Invasion of the caudal vena cava, particularly tumor thrombus extension beyond the hepatic hilus, was associated with a higher postoperative mortality rate, but did not affect long-term prognosis in dogs undergoing adrenalectomy because of an adrenal gland tumor.

Results of surgical excision and evaluation of factors associated with survival time in dogs with lingual neoplasia: 97 cases (1995-2008).

OBJECTIVE: To describe the clinical characteristics, treatments, outcomes, and factors associated with survival time in a cohort of dogs with lingual neoplasia that underwent surgical excision. DESIGN: Retrospective case series. Animals-97 client-owned dogs. PROCEDURES: Medical records of dogs with a lingual tumor examined between 1995 and 2008 were reviewed. Records were included if a lingual tumor was confirmed by histologic examination and surgical excision of the mass was attempted. Data were recorded and analyzed to identify prognostic factors. RESULTS: Clinical signs were mostly related to the oral cavity. For 93 dogs, marginal excision, subtotal glossectomy, and near-total glossectomy were performed in 35 (38%), 55 (59%), and 3 (3%), respectively. Surgery-related complications were rare, but 27 (28%) dogs had tumor recurrence. The most common histopathologic diagnoses for the 97 dogs were squamous cell carcinoma (31 [32%]) and malignant melanoma (29 [30%]). Eighteen (19%) dogs developed metastatic disease, and the overall median survival time was 483 days. Median survival time was 216 days for dogs with squamous cell carcinoma and 241 days for dogs with malignant melanoma. Dogs with lingual tumors ≥ 2 cm in diameter at diagnosis had a significantly shorter survival time than did dogs with tumors < 2 cm. CONCLUSIONS AND CLINICAL RELEVANCE: Similar to previous studies, results indicated that lingual tumors are most commonly malignant, and squamous cell carcinoma and malignant melanoma predominate. A thorough physical examination to identify lingual tumors at an early stage and surgical treatment after tumor identification are recommended because tumor size significantly affected survival time.

Diagnostic utility of abdominal ultrasonography for routine staging at diagnosis of skeletal OSA in dogs.

The rate of soft tissue metastases and the importance of abdominal ultrasonography in initial staging of canine skeletal osteosarcoma (OSA) are not known. The purpose of this study was to determine whether abdominal ultrasonography should be performed routinely at initial diagnosis of skeletal OSA or if certain abnormal physical examination or diagnostic findings would provide greater indication to perform ultrasonography. Eighty dogs with OSA that had an abdominal ultrasonogram performed at diagnosis were included. Abnormal findings were present in 36 of 80 dogs. Twenty-three abnormalities were evaluated with either fine-needle aspirate or biopsy and 19 were benign. None of the ultrasonograms revealed abdominal OSA metastases; however, 4 of the 80 ultrasonograms (5%) revealed another primary neoplasia. Further, 2 of the 9 cases that received an ultrasonogram due to a palpable abdominal mass were diagnosed with another primary neoplasia compared with only 1 of the 49 cases that received an ultrasonogram for routine staging. Abdominal ultrasonography as a part of staging is unlikely to reveal metastases from OSA and may not be a useful routine staging tool; however, in certain populations of dogs, such as those with palpable abdominal masses, abdominal ultrasonography may reveal abnormalities that may influence treatment decisions.

Bilateral appendicular bone tumors in four dogs.

Bilateral synchronous appendicular bone tumors, occurring in the same bone and same anatomic site within the bone are very rare. This report describes the clinical presentation and oncologic outcome for four dogs with this rare presentation. All cases presented to the authors following a history of unilateral lameness for several weeks. On presentation, case 1 had pain elicited in the contralateral proximal humerus but all the other cases had no abnormalities detectable on physical examination of the contralateral limb. All dogs had technetium 99m ((99m)Tc) nuclear scintigraphy performed that identified bilateral lesions of the distal radii in two dogs, proximal humeri and distal tibiae in one dog each. Thoracic radiographs performed on all dogs showed no evidence of pulmonary metastases. Three dogs were treated with palliative radiation therapy (two dogs received concurrent bisphosphonates) resulting in survival times from initial presentation of 50 days, 193 days, and 523 days, respectively. One dog had stereotactic radiation therapy (SRT) and a surgical limb-salvage performed followed by carboplatin chemotherapy, resulting in a survival time of 926 days from initial presentation. Palliative and curative-intent treatments for the bilateral synchronous appendicular bone tumors resulted in survival times similar to those reported for treatment of a single primary appendicular bone tumor.

Outcome following simultaneous bilateral thyroid lobectomy for treatment of thyroid gland carcinoma in dogs: 15 cases (1994-2010).

OBJECTIVE: To evaluate the outcome of resection of simultaneous discrete bilateral mobile thyroid gland carcinomas (TGCs) in dogs. DESIGN: Retrospective case series. ANIMALS: 15 dogs with resected simultaneous discrete bilateral mobile TGCs. PROCEDURES: Medical records (from 1994 to 2010) were searched for dogs with the appropriate diagnosis and treatment. Information collected included signalment, clinical signs, diagnostic test results, tumor mobility (mobile tumor identified by movement ≥ 1 cm in all planes during palpation), complications, adjuvant treatments, and outcome. RESULTS: Mobile, discrete, bilateral TGCs were removed in all dogs. Among the 15 dogs, complete parathyroidectomies were necessary in 9; parathyroid tissue was reimplanted in 4 and preserved in 2. Complications included hemorrhage and laryngeal nerve trauma, but without serious consequences. Thirteen dogs received calcitriol with or without supplemental calcium after surgery. In the immediate postoperative period, hypocalcemia developed and was corrected in 11 dogs. At the end of the study, 7 dogs continued to receive calcitriol with or without supplemental calcium, and 8 dogs required long-term thyroid hormone treatment. Six dogs received adjuvant chemotherapy. Local tumor recurrence or de novo distant metastasis was not detected at each dog's last follow-up examination. Median survival time was 38.3 months. Three dogs were lost to follow-up, 8 survived (4.3 to 77 months after surgery), and 4 died of unrelated causes. CONCLUSIONS AND CLINICAL RELEVANCE: In dogs with TGCs undergoing bilateral thyroid lobectomies, a successful outcome can be expected, even when parathyroid gland tissue cannot be preserved. The role of adjuvant chemotherapy in treatment outcome was not clearly defined.

Anatomic distribution and clinical findings of intermuscular lipomas in 17 dogs (2005-2010).

Intermuscular lipomas (IML) in dogs can be associated with ominous clinical signs, especially in the thoracic limb. However, the prognosis is excellent following surgical excision. There is a paucity of information in the veterinary literature regarding IML. Our objective was to describe the anatomical location, imaging techniques, and clinical findings in a series of dogs that were diagnosed and treated for IML. The prevalence of thoracic versus pelvic limb IML was not different. Most IML of the thoracic limb were located in the axilla. Operative time for IML of the thoracic and pelvic limb averaged 60 minutes. Complications were rare after marginal surgical excision and recurrence was not seen in any of the cases in this report. Intermuscular lipomas of the axilla are as common as IML of the caudal thigh. Surgical treatment of both axillary and caudal-thigh IML is associated with an excellent prognosis in dogs.

Pericardial free patch grafting as a rescue technique in surgical management of right atrial HSA.

A 7 yr old, neutered female vizsla underwent an exploratory thoracotomy after diagnosis of recurrent hemorrhagic pericardial effusion and a right auricular mass. Staging tests were negative for metastasis. The patient underwent a right, fourth intercostal thoracotomy, subtotal pericardectomy, right auricular mass excision, and pericardial free patch graft. The patient experienced blood loss during surgery, which required a packed red blood cell transfusion. The patient experienced transient arrhythmias postoperatively, but was discharged from the hospital 48 hr later. Histopathologic diagnosis of the mass was hemangiosarcoma. The patient was treated with carboplatin single-agent chemotherapy and palliative radiation therapy. The patient died at home, presumably from metastatic disease 260 days postoperatively. Surgical mass removal or debulking along with pericardial free patch grafting may be considered as palliative treatment options for dogs diagnosed with right auricular masses. In this case report, other techniques failed to repair the defect in the heart and a free patch graft offered a good rescue procedure with a favorable outcome without the need for inflow and outflow occlusion when used in conjunction with adjunctive therapies.

Multicystic bone disease (Gorham-Stout syndrome) in a spider monkey (Ateles geoffroyi ).

BACKGROUND: In April 2000, a 2.5-year-old pet female Geoffroyi's spider monkey presented for reduced activity, a subdued demeanor, and boney enlargement involving both radii. METHODS: On further examination, polyostotic bone cysts were identified involving many of the tubular bones and were identified radiographically. Microscopic examination of a bone biopsy revealed hemorrhage and other characteristics typical of an aneurysmal bone cyst. In addition, excessive osteoclasia was noted, in association with fibrotic areas rather than with Howship's lacunae as expected from a growing animal. RESULTS: These findings were consistent with Gorham-Stout syndrome, a rare condition reported previously in ∼175 human cases and in a dog at necropsy. The diet history and further testing suggested a negative calcium balance. Treatment included the administration of bis-phosphonates, which appeared to bring about marked improvement. Almost 8 years later (November 2008), radiographs were again taken and suggested some resolution of bone cysts, primarily those in the legs. CONCLUSIONS: This represents the first reported case and a potential therapy for this rare condition in a non-human primate.