Hypospadias in a polar bear (Ursus maritimus).

Corrective surgery on a 1.5-yr-old male polar bear (Ursus maritimus) with hypospadias included amputation of the vestigial penis, bilateral orchiectomy with scrotal ablation, and distal perineal urethrostomy. Hypospadias in other species is a congenital deformity that may be caused by extra- and intrauterine factors resulting in a disruption of the testosterone balance during urethral development, but the causative mechanism in this bear is unknown. The urethrostomy site was functional without complications 8 mo after surgery.

Tracheal rupture in cats: 16 cases (1983-1998).

OBJECTIVE: To determine causes of tracheal rupture in cats and the mechanism of injury. DESIGN: A retrospective study was conducted to identify cats with tracheal rupture. A second study was conducted to establish mechanism of injury, and a third study was conducted to determine volume of air needed to obtain an airtight seal when inflating the cuff of an endotracheal tube in a cat. ANIMALS: 16 cats with clinical signs of tracheal rupture, 10 cat cadavers, and 20 clinically normal cats that were undergoing anesthesia. PROCEDURES: Details were extracted from medical records of 16 cats with tracheal rupture (9 treated surgically and 7 treated conservatively). For the cadaver study, the trachea of each cat cadaver was intubated and observed during overinflation of the endotracheal tube cuff. For clinically normal cats, volume of air needed to obtain an airtight seal for the endotracheal tube was recorded. RESULTS: Most ruptures were associated with cats anesthetized for dental procedures. Clinical signs associated with tracheal rupture included subcutaneous emphysema, coughing, gagging, dyspnea, anorexia, and fever. Tracheoscopy was the method of choice for documenting tracheal rupture. Surgical and conservative management were successfully used, unless the injury extended to the carina. In the cadaver study, overinflation of the endotracheal tube cuff with > 6 ml of air resulted in tracheal rupture in 7 of 10 cadavers. For clinically normal cats, the volume of air (mean +/- SD) needed to obtain an airtight seal was 1.6 +/- 0.7 ml. CLINICAL IMPLICATIONS: Overinflation of an endotracheal tube cuff may result in tracheal rupture in cats.

Surgical removal of an undifferentiated abdominal sarcoma from a koi carp (Cyprinus carpio).

An undifferentiated abdominal sarcoma was removed surgically from a koi carp. The diagnostic procedures, including radiography and computed tomography, and the procedures for general anaesthesia and the surgical approach for a celiotomy in a fish are described. The gross and microscopic appearance of the tumour is described and illustrated.

Prognosis for dogs with nonlymphomatous, small intestinal tumors treated by surgical excision.

Long-term follow-up information was obtained for 39 dogs that had undergone surgical excision of nonlymphomatous, small intestinal tumors. For all dogs evaluated in this study, the median survival time was 10 months, and the one- and two-year survival rates were 40.5% and 33.1%, respectively. There was no difference in survival times between dogs with adenocarcinomas (n=23) and dogs with leiomyosarcomas (n=16). Survival times were significantly (p less than 0.0001) shorter for dogs with histological evidence of metastases at the time of surgery (median, 3.0 months) than for dogs with no histiological evidence of metastases (median, 15.0 months).

Diagnosis and surgical management of obstructive ureteral calculi in cats: 11 cases (1993-1996).

OBJECTIVE: To evaluate diagnostic methods, surgical treatment, perioperative management, and renal function of cats with obstructive calcium oxalate ureteroliths. DESIGN: Retrospective case series. ANIMALS: 11 cats that underwent surgery for removal of calcium oxalate ureteroliths. PROCEDURE: Medical records were reviewed, and the following information was recorded: signalment; results of physical examination, clinicopathologic analyses, and abdominal imaging; surgical procedure; postoperative management; and results of ureterolith quantitative analysis. RESULTS: Ureteroliths in the proximal portion of the ureter were removed from 5 cats (pyelotomy, 1 cat; unilateral ureterotomy, 2 cats; bilateral ureterotomies, 2 cats). Calculi in the middle and distal part of the ureter were removed by partial ureterectomy and ureteroneocystostomy (6 cats). Ten cats recovered from surgery and were discharged from the hospital. One cat died from unknown causes 4 months after surgery, and 1 cat had a nephrectomy elsewhere 5 weeks after ureterolith removal. Eight cats were evaluated 12 to 20 months after surgery. Of these, 2 cats that were markedly azotemic before surgery improved after surgery, and 2 cats developed nephroliths after surgery. Also, of 5 cats that had nephroliths that were not removed at the time of surgery, 4 still had visible nephroliths. One cat had recurrent ureteral obstruction from a ureterolith and persistent urinary tract infection. Ureteroliths or ultrasonographic evidence of ureteral obstruction were not detected in other cats. CLINICAL IMPLICATIONS: A combination of microsurgical techniques and intensive postoperative care is necessary to minimize morbidity of cats after removal of a ureterolith. Renal function may improve or stabilize after removal of the ureteral obstruction.

Radiation therapy and surgery for fibrosarcoma in 33 cats.

Thirty-three cats with histologically confirmed fibrosarcomas were treated with radiation therapy followed by surgery. The median (95% confidence interval) disease free interval and overall survival were 398 (261,924) and 600 (lower limit 515) days, respectively. There were 19 treatment failures; 11 cats had only local recurrence, 4 cats developed metastatic disease, 3 cats had local recurrence followed by metastasis, and 1 cat developed simultaneous local and distant disease. Twelve cats are alive and disease free. Two cats died without evidence of treatment failure. The presence of tumor cells at the margin of resected tissue after radiation was the only variable which influenced treatment success. The median (95% confidence interval) disease free interval in 5 cats with tumor cells at the margin of the resected specimen was 112 (94,150) days versus 700 (lower limit 328) days for 26 cats with negative tumor margins, p < 0.0001. We did not identify a relationship between tumor volume, number of prior tumor excisions, concomitant use of chemotherapy or various descriptors of the radiation therapy technique and disease free interval.

Surgical management of extrathoracic tracheal collapse in two large-breed dogs.

Collapse of the cervical portion of the trachea was diagnosed for 2 young large-breed dogs. Clinical signs included worsening respiratory stridor and coughing exacerbated by exercise. The diagnosis was confirmed by use of conventional radiography and fluoroscopy of the trachea. A polypropylene, spiral ring, extraluminal, tracheal prosthesis was used to successfully treat tracheal collapse in each dog. Although tracheal collapse typically affects middle-aged and old small-breed dogs, tracheal collapse should be considered as a differential diagnosis for large-breed dogs with a honking cough and respiratory stridor.

The intraosseous blood supply of the canine radius: implications for healing of distal fractures in small dogs.

The intraosseous vascular anatomy of the radius was studied in 12 pairs of canine cadaver limbs. Six pairs of specimens were obtained from small-breed dogs (less than 6 kg) and six pairs were obtained from large-breed dogs (18 to 30 kg). All specimens were studied after arterial injection with India ink. Samples were fixed, frozen, then sectioned and processed using a modified Spalteholz technique. In all specimens, the intraosseous blood supply arose from the nutrient artery with its associated branches and the metaphyseal arteries. In small-breed dogs, there was decreased vascular density at the distal diaphyseal-metaphyseal junction compared with large-breed dogs. The reduced vascularity corresponded to the region associated with a poor prognosis for fracture healing in small-breed dogs. This regional association suggests that a decreased vascular supply in the distal radius may contribute to a higher frequency of delayed union and nonunion in smaller dogs.

Use of a caudal auricular axial pattern flap in cats.

A caudal auricular axial pattern flap was used in 3 cats to successfully reconstruct large cutaneous defects of the head that were a result of trauma or surgical excision of neoplasms. The technique was a convenient, practical, one-stage procedure for closure of the defects, and flaps up to 7.0 x 12.0 cm were developed. All flaps healed without complications. Anatomic landmarks and surgical guidelines for developing the flap were determined through anatomic dissections and angiographic studies of the cutaneous vasculature of the head and neck in feline cadavers. This report confirms findings of a previous study describing a platysma myocutaneous flap.

Diagnostic and therapeutic considerations in a hypercalcemic dog with multiple endocrine neoplasia.

Hypercalcemia was found in a dog examined for episodic weakness and disorientation. A right adrenal mass identified on abdominal ultrasonographic examination was diagnosed as a pheochromocytoma based on increased 1231-metaiodobenzylguanidine uptake and characteristic histopathological features. Serum intact parathyroid hormone (iPTH), total serum calcium, and ionized serum calcium were increased prior to surgery. Although both total and ionized serum calcium concentrations decreased to within normal reference ranges following surgery through postoperative day 17, subsequent high concentrations with increased serum iPTH concentrations confirmed concurrent primary hyperparathyroidism. A right parathyroid tumor was suspected based on a technetium-99m-sestamibi (99mTc-sestamibi) scan.

Controlled tissue expansion in the distal extremities of dogs.

Controlled tissue expansion using a 100 cc rectangular silicone elastomer expander was performed in the mid-antebrachium and mid-crus of eight adult mixed-breed dogs. Two expander inflation schedules were followed. Group 1 dogs (n = 4) underwent expander inflation using 10 cc sterile saline every other day, and group 2 dogs (n = 4) underwent expander inflation using 15 cc sterile saline every other day until the nominal volume (100 cc) was attained. Significant mean postexpansion increases in skin surface area of 94.1 cm2 (35.9%) and 108.9 cm2 (37.3%) were measured in the antebrachium and crus, respectively (p < .05). In a second procedure, the expanders were removed and skin flaps were developed from the redundant tissue generated during the expansion process. Single pedicle advancement flaps and transposition flaps were used to cover surgically created defects measuring 5 x 10 cm in the antebrachium and crus. Single pedicle advancement flaps consistently measured 10 x 10 cm and could be advanced to cover defects involving one third of the mid-antebrachial or mid-crural circumference. Transposition flaps were rotated up to 170 degrees and the donor site defects were easily closed under minimal or no tension. Complications included an abscess in one dog and seroma formation in four dogs. Differences in success or complication rates between group 1 dogs and group 2 dogs were not observed; an accelerated inflation schedule using 15 cc sterile saline every other day was recommended.

Oral complications of cancer therapy and their management.

As the standards and client expectations for care of small animal patients with cancer increase, so does our awareness and understanding of the oral manifestations of complications associated with the treatment of these malignancies. This article has given an overview of some of the more common problems that can be anticipated when treating cancers, particularly those involving the head, neck, and oral cavity, and provided guidelines for the management of these problems when they do develop. In the future, as our management of these diseases becomes even more common, I would expect the veterinary dentist to play a vital role in the pretreatment evaluation, planning, and management of these animal patients.

Replantation of a maxillary canine tooth after traumatic avulsion in a dog.

An infrequent traumatic injury in dogs is avulsion of a tooth from its alveolus. The management of the avulsed tooth is complex. This report describes the treatment of a traumatically avulsed maxillary canine tooth in a dog. Replantation and splinting of the tooth was performed. Despite a protracted extraoral time, follow up clinical and radiographic assessment of the tooth indicated successful replantation.

Belt loop gastropexy in the management of gastroesophageal intussusception in a pup.

Gastroesophageal intussusception and megaesophagus were diagnosed in a 5-week-old German Shepherd Dog. Exploratory surgery was performed, and belt loop gastropexy was used to maintain proper gastric position after manual reduction of the intussusception. The pup survived surgery and was clinically normal when it was 6 months old. Follow-up contrast radiography revealed resolution of the megaesophagus and apparent permanent gastropexy. Previous reports have indicated extremely high mortality for gastroesophageal intussusception, and resolution of megaesophagus in the dog is unusual.

Prognosis for dogs with appendicular osteosarcoma treated by amputation alone: 162 cases (1978-1988).

Long-term follow-up information pertaining to 162 dogs with appendicular osteosarcoma treated by amputation alone was collected from 17 veterinary institutions. The majority (72.5%) of dogs died or were euthanatized because of problems documented to be related to metastases. The first clinically apparent sites of metastasis were the lungs (60.8% of total), the skeleton (5.2%), or both (4.6%). A Kaplan-Meier survivorship distribution was plotted on the basis of available survival time data in all 162 dogs. The mean and median survival times were estimated to be 19.8 and 19.2 weeks, respectively, and the 1- and 2-year survival rates were estimated to be 11.5 and 2.0% respectively. Statistically significant relationships were not found between survival time and reporting institution, gender, site of primary tumor, whether the primary tumor was proximally or distally located, whether the primary tumor was located in the forelimb or hind limb, whether presurgical biopsy was performed, and whether death was tumor related. A significant (P less than 0.01) quadratic relationship was found between age and survival time. Survival time was longest in dogs 7 to 10 years old and was shorter in older and younger dogs.

Spinal lymphoma in cats: 21 cases (1976-1989).

Medical records of 21 cats with spinal lymphoma were reviewed. All cats were evaluated for neurologic deficits, although 85% of cats necropsied had multicentric disease. Eighty-one percent of cats had hind limb paresis. Results of FeLV tests were positive in 84.2% (16/19) of the cats, and 68.7% (11/16) of the cats had leukemic bone marrow. Spinal lymphoma was confirmed by necropsy in 13 cats, by examination of a biopsy specimen in 1 cat, and by examination of cells aspirated from an epidural lesion in 2 cats. In the remaining 5 cats, a presumptive diagnosis was made on the basis of neurologic examination findings, positive FeLV test results, and leukemic bone marrow. Nine cats were treated with chemotherapy alone. The complete remission rate was 50% in 6 cats given cyclophosphamide, vincristine, and prednisone. The median duration of complete remission was 14 weeks. Complete remissions were not observed in 3 cats given only corticosteroids. A single cat treated by laminectomy and postoperative chemotherapy had a prolonged remission (62 weeks). At necropsy, lymphoma of the CNS was limited to the vertebral canal in 10 of 13 cats; 2 cats had malignant tissue in the brain and vertebral canal, and in the remaining cat, the tumor extended into the brachial plexus. Most tumors extended over multiple vertebral bodies, and 4 cats had more than 1 level of spinal cord involvement. The lymphoma was high-grade lymphoblastic or immunoblastic type in all cats.