The development of ventricular fibrillation as a complication of pericardiectomy in 16 dogs.

OBJECTIVE: To describe the clinical characteristics, perioperative protocols, and outcomes in dogs diagnosed with ventricular fibrillation (VF) while undergoing pericardiectomy. STUDY DESIGN: Retrospective, multi-institutional study. ANIMALS: Sixteen client-owned dogs. METHODS: Cases were accrued through a listserve request posted to 3 subspecialty veterinary societies. Dogs were included if they developed VF during a pericardiectomy performed through an open or thoracoscopic approach. Data collected included signalment, history and physical examination, surgical approach, histopathology, treatment, and outcome. RESULTS: Indications for pericardiectomy included idiopathic chylothorax (n = 7), neoplasia (4), idiopathic pericardial effusion (4), and foreign body granuloma (1). Surgical approaches included thoracoscopy (12), intercostal thoracotomy (3) and median sternotomy (1). Electrosurgical devices were used to complete at least part of the pericardiectomy in 15 of 16 dogs. Ventricular fibrillation appeared to be initiated during electrosurgical use in 8/15 dogs. However, in 5/15 dogs it was not obviously associated with electrosurgical use. In 3/16 dogs the timing of initiation of VF was unclear. In 7/16 dogs, cardiac arrhythmias were noted prior to the development of VF. Fourteen of 16 dogs died from intraoperative VF. CONCLUSION: In most dogs ventricular fibrillation was a fatal complication of pericardiectomy. Ventricular fibrillation might be associated with the use of electrosurgical devices and cardiac manipulation during pericardiectomy although a causal link could not be established from the data in this study. CLINICAL SIGNIFICANCE: Surgeons must be aware of the risk of VF during pericardial surgery. Electrosurgery might need to be used judiciously during pericardiectomy, particularly in dogs exhibiting cardiac arrythmias.

Transorbital craniectomy for treatment of frontal lobe and olfactory bulb neoplasms in two dogs.

CASE DESCRIPTION: An 8-year-old spayed female Shih Tzu crossbreed dog (dog 1) and a 13-year-old neutered male Miniature Fox Terrier (dog 2) were evaluated for removal of neoplasms involving both the frontal lobe and olfactory bulb. CLINICAL FINDINGS: Physical examination revealed decreased menace response and behavioral changes in both dogs. For dog 1, neuroanatomic localization of the lesion was the left forebrain region; for dog 2, neuroanatomic localization of the lesion was the right forebrain region. Both dogs underwent CT, and dog 1 also underwent MRI. Results of diagnostic imaging were consistent with frontal lobe and olfactory bulb neoplasia in both cases. Dog 1 had lysis of the frontal bone adjacent to the neoplasm. TREATMENT AND OUTCOME: Both dogs underwent a transorbital craniectomy to permit surgical tumor removal. Dog 1 was discharged from the hospital 48 hours after surgery, at which time its mentation and cranial nerve examination findings were considered normal. Dog 2 developed neurologic deterioration after surgery but was ultimately discharged from the hospital after 72 hours, at which time its mentation appeared normal. CLINICAL RELEVANCE: The transorbital approach to the cranium provided excellent access to facilitate removal of frontal lobe and olfactory bulb neoplasms in these 2 dogs.

Tumor size as a predictor of lymphatic invasion in oral melanomas of dogs.

OBJECTIVE: To investigate putative associations between oral melanoma size and variables of histologic grade such as mitotic index, nuclear atypia, junctional activity, ulceration, lymphatic invasion, and degree of pigmentation. SAMPLE: 59 samples of oral melanomas from dogs sourced from 6 diagnostic laboratories within Australia. PROCEDURES: The size of each melanoma was microscopically measured, and each sample was evaluated for variables of histologic grade including mitotic index, nuclear atypia, junctional activity, ulceration, lymphatic invasion, and degree of pigmentation by a veterinary pathologist. The association between tumor size and histologic outcomes was then statistically evaluated. RESULTS: A significant relationship was identified between the size of oral melanomas and a single variable of histologic grade, lymphatic invasion, with larger tumors more likely to show lymphatic invasion. Further analysis revealed 2 applicable size thresholds for different clinical scenarios. Results indicated lymphatic invasion can confidently be ruled out for tumors < 6.5 mm in diameter (100% sensitivity) and ruled in for tumors ≥ 24.5 mm in diameter (100% specificity). CONCLUSIONS AND CLINICAL RELEVANCE: An association was found for oral melanomas of dogs between tumor size and lymphatic invasion.

Parathyroid hormone receptor 1 (PTHR1) is a prognostic indicator in canine osteosarcoma.

Osteosarcoma (OS) is the most common malignant primary bone tumour in humans and dogs. Several studies have established the vital role of parathyroid hormone-related protein (PTHrP) and its receptor (PTHR1) in bone formation and remodeling. In addition, these molecules play a role in the progression and metastasis of many human tumour types. This study investigated the expression of PTHR1 and PTHrP in canine OS tissues and assessed their prognostic value. Formalin-fixed, paraffin-embedded tissue samples from 50 dogs diagnosed with primary OS were immunolabeled with antibodies specific for PTHR1 and PTHrP. The immunostaining intensity of tumours from patients with OS was correlated with survival time. Both PTHR1 and PTHrP were detected in all OS samples (n = 50). Dogs with OS tumours showing high immunostaining intensity for PTHR1 (n = 36) had significantly shorter survival times (p = 0.028, Log Rank; p = 0.04, Cox regression) when compared with OS that had low immunostaining intensity for PTHR1 (n = 14).PTHrP immunostaining intensity did not correlate with survival time (p > 0.05). The results of this study indicate that increased expression of PTHR1 antigen in canine OS is associated with poor prognosis. This suggests that PTHR1 may be useful as a prognostic indicator in canine OS.

Adverse events and outcomes in dogs with appendicular osteosarcoma treated with limb amputation and a single subcutaneous infusion of carboplatin.

OBJECTIVE: To evaluate adverse events and outcomes in dogs with appendicular osteosarcoma treated with limb amputation followed by a single SC infusion of carboplatin. ANIMALS: 45 client-owned dogs with appendicular osteosarcoma treated with limb amputation and SC infusion of carboplatin between January 1, 2006, and January 15, 2017. PROCEDURES: Medical records were reviewed, and data collected included signalment, tumor location, treatment, results of clinicopathologic analyses and diagnostic imaging, adverse effects of chemotherapy, metastasis-free interval, survival time, and communications with owners and referring veterinarians. Findings were evaluated with the Kaplan-Meier survival analysis and Mantel-Haenszel log-rank test. RESULTS: 45 dogs were identified that met the inclusion criteria (12 of the 45 dogs had been reported in a previous case series). No dogs had pulmonary metastases detectable by CT or radiography before treatment. All dogs completed the protocol as planned. Median survival time (MST) was 196 days; metastasis-free interval was 197 days. Three of the 45 (7%) dogs required hospitalization for gastrointestinal signs related to chemotherapy. There were no chemotherapy-related deaths. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that although treatment with SC infusion of carboplatin was well tolerated, the MST for dogs in the present study was similar to reported MSTs in dogs with appendicular osteosarcoma treated with limb amputation alone and was in the lower range of historically reported survival times for dogs receiving IV adjunctive chemotherapy. Therefore, we could not recommend this protocol of SC infusion of carboplatin but recommended that protocols with IV administration of carboplatin be used instead.

Apocrine gland anal sac adenocarcinoma in cats: 30 cases (1994-2015).

OBJECTIVE To describe the signalment, clinical signs, biological behavior, and outcome for cats with apocrine gland anal sac adenocarcinoma (AGASACA) that underwent surgical excision. DESIGN Retrospective case series. ANIMALS 30 client-owned cats. PROCEDURES Databases of 13 Veterinary Society of Surgical Oncology member-affiliated institutions were searched for records of cats with a histologic diagnosis of AGASACA that underwent tumor excision. For each cat, information regarding signalment, clinical signs, diagnostic test results, treatment, and outcome was extracted from the medical record. The Kaplan-Meier method was used to determine median time to local recurrence (TLR), disease-free interval (DFI), and survival time. Cox regression was used to identify factors associated with TLR, DFI, and survival time. RESULTS Perineal ulceration or discharge was the most common clinical sign in affected cats. Eleven cats developed local recurrence at a median of 96 days after AGASACA excision. Incomplete tumor margins and a high nuclear pleomorphic score were risk factors for local recurrence. Nuclear pleomorphic score was negatively associated with DFI. Local recurrence and a high nuclear pleomorphic score were risk factors for death. Median DFI and survival time were 234 and 260 days, respectively. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that, in cats, perineal ulceration or discharge should raise suspicion of AGASACA and prompt rectal and anal sac examinations. Local recurrence was the most common life-limiting event in cats that underwent surgery for treatment of AGASACA, suggesting that wide margins should be obtained whenever possible during AGASACA excision. Efficacy of chemotherapy and radiation therapy for treatment of cats with AGASACA requires further investigation. (J Am Vet Med Assoc 2019;254:716-722).

Second intention healing after wide local excision of soft tissue sarcomas in the distal aspects of the limbs in dogs: 31 cases (2005-2012).

OBJECTIVE: To determine outcomes for dogs with soft tissue sarcomas in the distal aspects of the limbs that underwent second intention healing after wide excision (2-cm lateral surgical margins and a margin 1 fascial plane deep) of the tumors. DESIGN: Retrospective case series. ANIMALS: 31 dogs with soft tissue sarcomas in the distal aspects of the limbs that underwent second intention healing following wide local excision of their tumors. PROCEDURES: Tumors were excised with 2-cm lateral margins and a margin 1 fascial plane deep to tumors. Wounds healed by means of second intention. Time to healing, complications during healing, and information regarding tumor recurrence were recorded. RESULTS: All tumors were excised with histologically tumor-free margins. Twenty-nine (93.5%) wounds healed completely by second intention (median time, 53 days). Two (6.5%) dogs required free skin graft procedures to facilitate healing. Complications during open wound management developed for 7 (22.6%) dogs. Long-term complications were detected for 8 (25.8%) dogs, including intermittent epidermal disruption (5/31 [16.1%]) and wound contracture (3/31 [9.7%]). All complications were managed conservatively. Local tumor recurrence was detected for 1 (3.2%) dog. Median follow-up time was 980 days (range, 380 to 2,356 days). No patients died because of tumor-related causes. CONCLUSIONS AND CLINICAL RELEVANCE: Results of this study indicated second intention healing of large wounds in the distal aspects of the limbs was complete and typically without complications for dogs that underwent wide excision of soft tissue sarcomas. Wide local excision of soft tissue sarcomas in the distal aspects of the limbs with 2-cm lateral margins and margins 1 fascial plane deep to the tumors provided excellent long-term local tumor control.

Successful treatment of malakoplakia of the bladder in a kitten.

A 4-month-old female kitten presented with chronic lower urinary tract signs and Escherichia coli cystitis, and was diagnosed with urinary bladder malakoplakia based upon histopathology. The kitten was treated with a prolonged antibiotic course and the malakoplakia resolved. Malakoplakia is a chronic granulomatous reaction characterized by the formation of Michaelis-Gutman bodies within von Hansemann macrophages. It is well described in humans, but has never been documented in a living veterinary patient. This case report describes the first successful treatment of malakoplakia in veterinary medicine.

Evaluation of a single subcutaneous infusion of carboplatin as adjuvant chemotherapy for dogs with osteosarcoma: 17 cases (2006-2010).

OBJECTIVE: To evaluate adverse effects and survival times in dogs with osteosarcoma that received a single SC infusion of carboplatin as adjunctive chemotherapeutic treatment following limb amputation or limb-sparing surgery. DESIGN: Retrospective case series. ANIMALS: 17 client-owned dogs with spontaneously occurring osteosarcoma. PROCEDURES: Medical records of dogs that underwent limb amputation or limb-sparing surgery followed by a single continuous SC infusion of carboplatin (total dose, 300 mg/m(2) infused over 3, 5, or 7 days) were evaluated. Signalment, tumor location, type of surgery (amputation or limb-sparing), duration of carboplatin infusion, results of hematologic and serum biochemical analyses, and adverse effects were recorded. Kaplan-Meier survival analysis was performed. RESULTS: Median survival time for all dogs was 365 days. Nine dogs had adverse bone marrow-related (hematologic) effects, 1 had adverse gastrointestinal effects, and 7 had infections at the surgical site. No significant differences were detected in survival times of dogs grouped according to tumor location, type of surgery, duration of carboplatin infusion, or development of postoperative infection. CONCLUSIONS AND CLINICAL RELEVANCE: Median survival time and adverse effects in dogs with osteosarcoma that received a single SC infusion of carboplatin over a 3-, 5-, or 7-day period as adjunctive treatment following limb amputation or limb-sparing surgery were comparable to those of previously reported chemotherapy protocols requiring IV drug administration over several weeks. Further investigation is needed to evaluate the efficacy of this protocol as adjunctive treatment for osteosarcoma and other tumors in dogs.

Radical excision with five-centimeter margins for treatment of feline injection-site sarcomas: 91 cases (1998-2002).

OBJECTIVE: To evaluate outcomes of radical excision of feline injection-site sarcomas (ISS) via assessment of local recurrence and metastasis rates, survival times, and complications associated with surgery. DESIGN: Retrospective case series. ANIMALS: 91 cats with ISS. PROCEDURES: Medical records of cats that had radical excision of ISS without adjunctive treatment were reviewed. Information extracted included sex, type of surgical procedure, histologic tumor grade, tumor diameter, time from tumor detection to definitive surgery, complications associated with surgery, whether tumors recurred locally or metastasized, and survival times. Diagnosis of ISS was histologically confirmed, and additional follow-up was performed. RESULTS: Overall median survival time was 901 days. Thirteen of 91 (14%) cats had local tumor recurrence; 18 (20%) cats had evidence of metastasis after surgery. Median survival time of cats with and without recurrence was 499 and 1,461 days, respectively. Median survival time of cats with and without metastasis was 388 and 1,528 days, respectively. Tumor recurrence and metastasis were significantly associated with survival time, whereas other examined variables were not. Major complications occurred in 10 cats, including 7 with incisional dehiscence. CONCLUSIONS AND CLINICAL RELEVANCE: Radical excision of ISS resulted in a metastasis rate similar to rates reported previously; the local recurrence rate appeared to be substantially less than rates reported after less aggressive surgeries, with or without adjuvant treatment. Major complication rates were similar to rates reported previously after aggressive surgical resection of ISS. Radical excision may be a valuable means of attaining an improved outcome in the treatment of feline ISS.

Externalized ileocolic anastomosis: case report.

A 6-year-old, spayed female Labrador retriever was presented 48 hours after an intestinal resection and anastomosis for management of a small intestinal foreign body. Abdominal ultrasound confirmed the presence of peritoneal effusion. Cytology of fluid collected by abdominocentesis revealed a large number of degenerate neutrophils with intracellular cocci. A diagnosis of septic peritonitis was made, presumably because of dehiscence of the anastomosis. Upon repeat exploratory celiotomy, the intestinal anastomosis (located 4 cm orad to the cecum) was found to be leaking intestinal contents into the abdomen. The distal ileum, cecum, and proximal colon were resected. An end-to-end, ileocolic anastomosis was performed and subsequently exteriorized into the subcutaneous space via a paramedian incision through the abdominal wall. The anastomosis was inspected daily for 4 days before it was returned to the abdomen and the subcutaneous defect was closed. Serial cytology of the peritoneal fluid, which was performed during this 4-day postoperative period, confirmed progressive resolution of peritonitis. The dog was discharged from the hospital 2 days following return of the anastomosis into the abdomen. Externalized intestinal anastomosis is used with good success in human medicine for repair of colonic injuries. In this case, externalization of the anastomosis permitted healing of the intestinal anastomosis in an environment isolated from the detrimental effects created by septic peritonitis. In addition, direct visualization of the anastomosis allowed assessment of healing. To our knowledge, this procedure has not been previously reported in companion animals.

Improved survival associated with postoperative wound infection in dogs treated with limb-salvage surgery for osteosarcoma.

BACKGROUND: Limb-salvage surgery and adjuvant chemotherapy are performed as a treatment of appendicular osteosarcoma in dogs. Approximately 50% of dogs that undergo limb-salvage surgery develop postoperative surgical wound infections. Postoperative surgical infections may affect survival in cancer patients. The purposes of this study were to examine the effect of surgical wound infection on survival, local recurrence, and metastasis in relation to other prognostic factors for dogs with spontaneous osteosarcoma treated with limb-salvage surgery. METHODS: Forty-seven client-owned dogs with osteosarcoma of the distal radius were treated with limb-salvage surgery and adjuvant chemotherapy--either carboplatin or carboplatin and doxorubicin. Hazard ratios were estimated by using the Cox proportional hazard model, and survival functions were estimated by using the Kaplan-Meier product-limit life-table method. RESULTS: Of the 47 dogs in this study, 32 (68%) developed a postoperative wound infection. Infection, dog weight, and extent of the primary tumor (percentage of length) significantly affected survival, and infection and percentage of length significantly affected time to metastasis. None of the variables considered in this study affected local recurrence. Dogs that were diagnosed with an infection were less likely to die (hazard ratio, .446), and dogs with greater body weight and greater percentage length involvement were more likely to die (hazard ratios of 3.37 and 3.66, respectively). CONCLUSIONS: In dogs with osteosarcoma treated with limb-salvage surgery, infection has a positive influence on survival, as does a smaller initial length of radius involved and lower body weight.

Evaluation of cisplatin in combination with a biologic response modifier in a murine mammary carcinoma model.

The purpose of this study was to determine the efficacy of intracavitary cisplatin against local regrowth and metastasis after resection of a murine mammary carcinoma and the ability of a biologic response modifier (Virulizin) to enhance chemotherapy. C3H-HeJ mice were injected with Gollin-B tumor cells. Once growth reached 8 mm, tumors underwent marginal resection and the mice were assigned randomly to intraperitoneal (i.p.) cisplatin, Virulizin, a controlled release cisplatin-impregnated sponge (OPLA-Pt), a combination of treatments or no treatment and were evaluated for local regrowth, metastasis, and toxicity at 14 or 60 days after surgery. A possible beneficial interaction was seen between OPLA-Pt and Virulizin at 14 days. All cisplatin groups had significant advantages over controls in all variables measured with OPLA-Pt displaying significant advantages over i.p. cisplatin in local recurrence rate, tumor score, survival time, and delay in regrowth at 60 days. No toxicity related to either cisplatin or Virulizin was observed.