Surgical excision of a feline orbital lacrimal gland adenocarcinoma with adjunctive cryotherapy and carboplatin‐impregnated bead implantation

The purpose of this report was to discuss the diagnosis, treatment, and outcome of a cat with an orbital lacrimal gland adenocarcinoma. A 14.5‐year‐old spayed female domestic shorthair cat was evaluated for a firm swelling at the left dorsotemporal orbital rim. The orbital mass was excised with preservation of the globe, and adjunctive cryotherapy was performed. A definitive diagnosis of lacrimal gland adenocarcinoma was obtained after histopathologic evaluation and histochemical staining with periodic acid–Schiff and mucicarmine. Thirteen months postoperatively, tumor regrowth occurred with a much larger osteolytic lesion, and a second surgery was performed consisting of tumor excision with implantation of carboplatin‐impregnated calcium sulfate hemihydrate beads. The cat has remained free of recurrence 11 months after the second surgery (26 months after initial diagnosis and surgery). A feline orbital lacrimal gland adenocarcinoma was successfully managed utilizing globe‐preserving surgical excision with adjunctive cryotherapy and subsequent carboplatin‐impregnated bead implantation. Orbital lacrimal gland adenocarcinoma in cats may not be as aggressive as other forms of periocular, head, and neck adenocarcinomas.     

Canine and feline emphysematous gastritis may be differentiated from gastric emphysema based on clinical and imaging characteristics: Five cases

Gastric pneumatosis is an imaging finding defined as the presence of gas foci in the gastric wall. In humans, this imaging feature can result from one of two separate clinical entities: life‐threatening emphysematous gastritis or clinically benign gastric emphysema. This retrospective case series study describes the clinical and imaging features in five animals diagnosed with spontaneous gastric pneumatosis without gastric dilatation‐volvulus. Three canine and two feline cases of spontaneous gastric pneumatosis were identified on radiographic and ultrasonographic examinations. In addition to gastric pneumatosis, one dog and two cats presented concomitant systemic signs such as lethargy, hematemesis, anemia, or leukocytosis. Two dogs remained asymptomatic or presented mild gastrointestinal signs. Portal gas was described in two dogs and one cat, and pneumoperitoneum in one dog. These features were not considered clinically significant. The dog and two cats with systemic signs were euthanized due to clinical deterioration and diagnosed with emphysematous gastritis. The gastric pneumatosis of both dogs without systemic signs resolved while on medical management without antibiotic therapy. These latter cases were interpreted as consistent with gastric emphysema. Findings from the current study indicated that gastric pneumatosis can occur without gastric dilatation‐volvulus in cats and dogs and that a combination of clinical and imaging characteristics may help to differentiate between potentially life‐threatening emphysematous gastritis and relatively benign gastric emphysema. More studies are needed to determine the etiology and risk factors associated with these conditions.     

Retrobulbar lymphoma associated with a ballistic foreign body in a cat

A seven‐year‐old domestic shorthair cat, adopted 5 years previously with a corneal perforation of the left eye, was presented for investigation of a left orbital mass. Computed tomography revealed a metallic foreign body within a contrast‐enhancing, heterogeneous orbital mass. Large cell lymphoma was diagnosed from a fine needle aspirate. The cat staged negatively and was treated with l‐asparaginase, prednisolone and three fractions of radiation therapy. A rapid clinical remission was obtained and the cat remained in remission for 3 years after therapy. This is the first report of large cell lymphoma likely occurring secondary to a foreign body.     

Iohexol myelography in the dog and cat: a series of one hundred cases, and a comparison with metrizamide and iopamidol

Iohexol has been found to be a safe and radiographically satisfactory myelographic contrast medium in man and some experimental animals. This study has shown it is also suitable for the dog and cat. No adverse side effects were encountered and radiographic quality was good. A random comparison found it superior in radiographic quality to metrizamide. Iohexol is recommended as the contrast medium of choice for small animal myelography.     

BILATERAL ELBOW MALFORMATION IN A CAT CAUSED BY RADIO-ULNAR SYNOSTOSIS

A 9-month-old neutered male cat was referred because of left forelimb lameness. Physical examination, laboratory analysis, and radiographic examination of the entire skeleton were performed. The radiographic diagnosis was bilateral radio-ulnar synostosis with secondary elbow malformation. A comparison between clinical and radiographic findings of the cat and those described in children affected by radio-ulnar synostosis is reported. Correlations and differences are discussed.     

Lacrimal bone agenesis in a dog

A 20-month-old neutered male dachshund dog was referred because of a 10-week history of swelling close to the medial canthus of the left eye. Recurrence of the lesion and cytological appearance of the fluid content were suggestive of inflammation. Computed tomography revealed a triangular-shaped bone defect in the skull deep to the lesion. Computed tomography dacryocystography demonstrated contrast medium pooling within the maxillary recess and nasal cavity rather than filling the lacrimal duct. Lacrimal bone agenesis was diagnosed.Key clinical message:Congenital skull including lacrimal bone agenesis may be responsible for swelling of the medial canthus of the eye and computed tomography dacryocystography is helpful in making a diagnosis.     

Orbito-nasal cyst in a young European short-haired cat

Purpose To describe a case of an orbito‐nasal cyst in a cat. Procedure An 18‐month‐old male European short‐haired cat was presented to the Ophthalmology service of the Vetsuisse Faculty, University of Zurich for a subcutaneous swelling in the medial canthal region of the right eye (OD). Ophthalmologic, ultrasound and CT examinations, and fine needle aspiration were performed. After lesion excision, the removed tissue was submitted for histopathology. CT examination was repeated 5 months after removal of the cyst. Results Ophthalmologic examination revealed a large fluctuant swelling inferonasal to OD. Despite patent lacrimal puncta, only the first few mm of the lacrimal canaliculi could be cannulated. A normal globe with moderate enophthalmos was present. Ultrasound examination showed a well‐defined lobulated cyst‐like structure in the right orbit, inferonasal and anterior to the eye. CT examination revealed extension of this lesion through the medial orbital wall into the right nasal cavity. Fine needle aspiration confirmed the cystic nature of the lesion. An orbito‐nasal cyst was diagnosed. The orbital part of the cyst was dissected from the surrounding tissue and excised from the periosteum in the medial orbital wall defect. Part of the maxillary bone was removed to allow removal of the cyst from the nasal cavity. Histologically, the cyst wall consisted of a single to multilayered, mostly cuboidal epithelium and surrounding connective tissue. Follow‐up revealed a good functional result and no recurrence 7 months after cyst removal. Conclusions Similar orbito‐nasal cystic structures were reported in dogs but not in cats.     

FEASIBILITY OF ULTRASOUND‐GUIDED EPIDURAL ACCESS AT THE LUMBO‐SACRAL SPACE IN DOGS

Epidural injections are commonly performed blindly in veterinary medicine. The aims of this study were to describe the lumbosacral ultrasonographic anatomy and to assess the feasibility of an ultrasound‐guided epidural injection technique in dogs. A cross sectional anatomic atlas of the lumbosacral region and ex vivo ultrasound images were obtained in two cadavers to describe the ultrasound anatomy and to identify the landmarks. Sixteen normal weight canine cadavers were used to establish two variations of the technique for direct ultrasound‐guided injection, using spinal needles or epidural catheters. The technique was finally performed in two normal weight cadavers, in two overweight cadavers and in five live dogs with radiographic abnormalities resulting of the lumbosacral spine. Contrast medium was injected and CT was used to assess the success of the injection. The anatomic landmarks to carry out the procedure were the seventh lumbar vertebra, the iliac wings, and the first sacral vertebra. The target for directing the needle was the trapezoid‐shaped echogenic zone between the contiguous articular facets of the lumbosacral vertebral canal visualized in a parasagittal plane. The spinal needle or epidural catheter was inserted in a 45° craniodorsal–caudoventral direction through the subcutaneous tissue and the interarcuate ligament until reaching the epidural space. CT examination confirmed the presence of contrast medium in the epidural space in 25/25 dogs, although a variable contamination of the subarachnoid space was also noted. Findings indicated that this ultrasound‐guided epidural injection technique is feasible for normal weight and overweight dogs, with and without radiographic abnormalities of the spine.     

Comparison of mesenteric lymphadenography performed via surgical and laparoscopic approaches in dogs

OBJECTIVE: To determine whether injection of a mesenteric lymph node with iodinated aqueous contrast medium results in radiographic delineation of the thoracic duct and its branches, ascertain the ideal interval between injection and radiographic imaging, and evaluate mesenteric lymphadenography performed via laparoscopic and surgical approaches in dogs. ANIMALS: 10 adult dogs. PROCEDURE: In each dog, a right paracostal laparotomy or a right laparoscopic approach was performed to identify a mesenteric lymph node for injection of an iodinated aqueous contrast agent (0.22 mL/kg [81.4 mg of iodine/kg]). Lateral radiographic views were obtained at 60, 120, 180, 240, and 300 seconds after injection. RESULTS: A mesenteric lymph node was identified and injected with contrast medium in each dog. Via paracostal laparotomy, lymph node injection resulted in successful lymphangiographic evaluation in 4 of 5 dogs, whereas via the laparoscopic approach, lymph node injection resulted in successful lymphangio-graphic evaluation in 2 of 5 dogs. In successful radiographic evaluations, injected lymph nodes, mesenteric lymphatics, and the thoracic duct and its branches were delineated. Radiographs obtained at 60 and 120 seconds after injection of contrast medium provided the most detail. CONCLUSIONS AND CLINICAL RELEVANCE: Injection of a mesenteric lymph node directly with contrast medium appears to be a feasible technique for delineation of the thoracic duct and its branches in dogs and might be useful in small animals in which mesenteric lymphatic catheterization can be difficult and lymphangiography is more likely to fail. Refinement of the laparoscopic technique may provide a minimally invasive approach to lymphadenography.     

Diffusion of radiodense contrast medium after a mid‐pastern ring block

Diffusion of local anaesthetic solution after a mid‐pastern ring block has not previously been investigated. The aim of this study was to demonstrate potential distribution of local anaesthetic solution following injection of radiodense contrast medium as performed for a mid‐pastern ring block. Twelve mature horses were used and 1.5 ml radiodense contrast medium injected over the medial or lateral palmar digital nerve at the level of the proximal aspect of the ungular cartilages. A dorsal ring block was performed on the ipsilateral side, 1.5 cm proximal to the palpable palmar aspect of the proximal eminence of the middle phalanx, using 2 or 5 ml contrast medium. Both forelimbs were injected on 2 days (48 injections). Four standard radiographic views of the pastern were obtained immediately, 10 and 20 min after injections. Images were analysed subjectively and objectively. After dorsal injections, the contrast medium was distributed in a diffuse patch over the ipsilateral half of the proximal phalanx (P1), extending proximally over the half of the length of P1 in all limbs (greatest proximal extension: 89.0% of the length of P1 [from distal] after 2 ml, 94.2% after 5 ml). There was significant proximal diffusion in the first 10 min after injection and significant dorsal diffusion between all time points (P<0.01). There was significant positive association between injected volume and the proximal extension of the dorsal contrast patch (P = 0.01). The median dorsal diffusion was to the dorsal midline of P1; 5 ml contrast medium resulted in significantly greater dorsal diffusion than 2 ml (P<0.01). The dorsal and palmar contrast patches did not merge. In conclusion, diffusion to the proximal aspect of P1 following a mid‐pastern ring block may occur even if only 2 ml of local anaesthetic solution is used.     

Pneumatosis in Canine Gastric Dilatation-Volvulus Syndrome

Retrospectively, 243 dogs with radiographic evidence of gastric dilatation-volvulus (GDV) were studied for radiographic signs of pneumatosis (intramural gas), pneumoperitoneum, splenomegaly, and severity of gastric distention. The sensitivity, specificity, and predictive value of these imaging signs as predictors of gastric wall necrosis, as determined by visual inspection at surgery or necropsy, were determined. The sensitivity and specificity of gastric pneumatosis were 14.1% and 92.7%, respectively. The prevalence of gastric wall necrosis was 26.6%. The positive and negative predictive values of gastric pneumatosis for predicting gastric necrosis were 40.9% and 74.9%, respectively. Gastric pneumatosis and pneumoperitoneum were identified together in four dogs. Pneumoperitoneum, either alone or in conjunction with pneumatosis, yielded similar results as a test for gastric necrosis. Splenomegaly and severity of gastric distention were insensitive and nonspecific for gastric wall necrosis. Splenomegaly did not predict the need for splenectomy at surgery. Although pneumatosis and pneumoperitoneum are relatively specific signs of gastric wall necrosis, the utility of these signs as a test for gastric necrosis is limited in clinical practice. The significance of pneumatosis should be taken into consideration with previous treatments for gastric decompression, as percutaneous gastric trocharization or orogastric intubation may increase the number of false-positive results.     

Aberrant migration and surgical removal of a heartworm (Dirofilaria immitis) from the femoral artery of a cat

A cat was evaluated for an acute‐onset of right pelvic limb paresis. Thoracic radiographs revealed normal cardiac size and tortuous pulmonary arteries. Abdominal ultrasound identified a heartworm (HW) extending from the caudal abdominal aorta into the right external iliac artery and right femoral artery. The cat was HW‐antigen positive. Echocardiography revealed a HW within the right branch of the main pulmonary artery and evidence of pulmonary hypertension. An agitated‐saline contrast echocardiogram revealed a small right to left intracardiac shunt at the level of the atria. Surgical removal of the HW was performed with no substantial postoperative complications. There was return of blood flow and improved motor function to the limb. The cat remains mildly paretic on the affected limb with no other clinical signs.     

Surgical closure of an atrial septal defect using cardiopulmonary bypass in a cat

Objective: To describe surgical repair of a large atrial septal defect (ASD) in a cat. Study Design: Clinical report. Animal: A 3‐year‐old, 3.3 kg, intact male Japanese domestic short‐haired cat. Methods: A 10.2‐mm‐diameter ASD detected by echocardiography was surgically corrected because pulmonary vascular resistance‐to‐systemic vascular resistance ratio (Q_p/Q_s) was 3.2. Using cardiopulmonary bypass (CPB), open surgical repair was achieved with an expanded polytetrafluoroethylene (e‐PTFE) graft. The priming volume of the CPB circuit was minimized by cutting the CPB tubing, and partially replacing the priming fluid with whole cat blood. To prevent hemodilution associated with use of cardioprotective agents, surgery was performed on the beating heart. Results: At 1‐year echocardiographic evaluation, the repair was intact, and at 3 years, the cat was alive without need of medication. Conclusions: Large ASD in a cat can be repaired using e‐PTFE under CPB.     

IMAGING DIAGNOSIS: COMPUTED TOMOGRAPHIC FINDINGS IN A CASE OF ADENOSQUAMOUS CARCINOMA OF THE HEAD AND NECK IN A CAT

A 15‐year‐old female spayed domestic long‐haired cat was referred for trismus, hypersalivation, and bilateral ocular discharge. On examination, the cat showed pain on palpation of the left zygomatic arch, palpable crepitus of the frontal region, and limited retropulsion of both globes. A contrast‐enhanced sinonasal computed tomographic study was performed, showing facial distortion and extensive osteolysis of the skull, extending beyond the confines of the sinonasal and paranasal cavities. Additionally, soft tissue and fluid accumulation were observed in the nasal cavities and paranasal sinuses. Postmortem biopsy samples acquired from the calvarium yielded a histologic diagnosis of sinonasal adenosquamous carcinoma, a rare and particularly aggressive neoplasm previously only reported in the esophagus of one cat.     

Diffuse mesenteric lipodystrophy (massive fat necrosis) in a cat

Clinical, radiographic, and pathological findings of diffuse mesenteric lipodystrophy in a 3-year-old, female domestic short-haired cat are described. The animal had fallen from a height of approximately 20 metres 6 weeks previously, after which it developed respiratory distress and anorexia. The cat was thin, exhausted and had rapid, shallow, open-mouthed breathing. Serial upper gastrointestinal contrast radiographs showed a prolonged transit time of the contrast medium due to restricted gastric emptying, and filling defects of the duodenojejunal portions of the small intestines. The cranial abdominal cavity contained large, firm, white masses that adhered to most of the anterior abdominal organs. The intestinal walls were completely surrounded by large, hard, lobulated masses of lipomatous tissue. The masses were characterised histologically by extensive areas of coagulative necrosis of adipocytes containing foci of saponification. The lesions resembled those of massive fat necrosis or lipomatosis in cattle, pigs and deer.     

CONTRAST RADIOGRAPHY OF THE GASTROINTESTINAL TRACT IN SEA TURTLES

Intestinal obstruction by radiolucent foreign bodies is common in sea turtles. The absence of clinical signs and the extended fasting periods in these animals means that intestinal obstructions may not be diagnosed early. Digestive tract radiographic contrast procedures were performed to evaluate the gastrointestinal transit time and intestinal obstructions in loggerhead sea turtles. Barium sulfate and nonionic iodinate contrast medium were used for radiographic contrast procedures. Contrast medium was administered via a gastric tube or into the colon. These procedures are often necessary and are useful to document intestinal obstruction and foreign objects. The diagnostic procedures were not easily performed in some turtles, but often they were adequate for the diagnosis.     

POSITIVE-CONTRAST RHINOGRAPHY

Contrast rhinography is a simple noninvasive procedure that may be a useful diagnostic method for positive-contrast radiographic evaluation of the nasal cavity, nasopharynx, and paranasal sinuses in the dog. A standardized and reliable technique was developed using healthy adult Greyhounds. The radiographic appearance of the regional anatomy after intranasal administration of positive-contrast medium was established. Four contrast media: 60% propyl iodine, 37% organically bound iodine, a 60% barium sulfate suspension, and a 30% barium sulfate suspension were evaluated on the basis of their radiographic contrast and detail, distribution, and degree of evoked tissue reaction as defined by clinical assessment. A 30% barium sulfate suspension was selected using these criteria. Contrast medium enhanced the radiographic appearance of the regional anatomy when compared with noncontrast techniques. A procedure for positive-contrast radiographic evaluation of the nasal cavity, nasopharynx, and paranasal sinuses is described in detail. Recommendations are made regarding methods of contrast medium administration and positioning to ensure uniform distribution within the area of interest.     

Cervical thymoma originating in ectopic thymic tissue in a cat

Abstract: An 11‐year‐old female spayed domestic shorthair cat was referred to The Ohio State University Veterinary Teaching Hospital (OSU‐VTH) for evaluation of a 6 × 4 × 3.5 cm mass in the left midcervical region causing increased respiratory sounds and lateral deviation of the trachea. A fine needle aspirate of the mass was obtained before referral and the cytology results were compatible with a reactive lymph node. Immunocytochemistry showed increased numbers of CD3+ T lymphocytes and small numbers of CD20+ and CD79a+ medium to large lymphocytes. Differential diagnoses from the referral pathologist were T‐cell‐rich B‐cell lymphoma and feline Hodgkin's‐like lymphoma. A subsequent fine needle aspirate performed at the OSU‐VTH showed similar results. On flow cytometry the majority of cells were CD3+ T lymphocytes that were double positive for CD4 and CD8 (73%), compatible with either a double‐positive (CD4+CD8+) T‐cell lymphoma or lymphocytes from ectopic thymic tissue. The mass was surgically removed. Histopathology and immunohistochemistry of the mass revealed a predominant population of CD3+ small lymphocytes and small numbers of medium to large lymphocytes with moderate anisocytosis and anysokaryosis. A population of cytokeratin‐positive epithelial cells surrounded small microcystic structures filled with eosinophilic material and structures interpreted as Hassall's corpuscles. These findings were consistent with thymic tissue and a diagnosis of ectopic thymoma was made. PCR results for lymphocyte antigen receptor rearrangement (PARR) were negative. The cat had no evidence of disease 16 months after removal of the mass. To our knowledge this is the first report of an ectopic cervical thymoma in a cat. The clinical and diagnostic features of this unusual case will be useful in helping veterinarians and pathologists obtain a presurgical diagnosis and establish a prognosis for similar lesions.     

Acute renal failure associated with contrast medium administration in a dog.

Intravenous administration of an ionic radiographic contrast medium was believed to have caused acute oliguric renal failure in a young dog. Intravenous pyelography was done on a healthy 14-month-old female Lhasa Apso prior to reconstructive surgery for pseudohermaphroditism. Within 24 hours of the radiographic procedure, acute oliguric renal failure developed. Cause for the renal failure was not found other than the recent IV administration of radiographic contrast medium. Treatment with fluids, furosemide, and dopamine was successful in returning renal function to normal. Various adverse reactions to IV administration of contrast media in human beings and animals have been reported; however, to our knowledge, acute renal dysfunction induced by IV administration of contrast material has not been reported in dogs.