Eumycotic mycetoma caused by Pseudallescheria boydii in the abdominal cavity of a dog

An abdominal eumycotic mycetoma with multiorgan dissemination was diagnosed in a 2-year-old dog. Clinical signs included fever, vomiting, diarrhea, weight loss, and a palpable abdominal mass. The dog developed disseminated intravascular coagulation and died. Pseudallescheria boydii was isolated from the abdominal mass, liver, and peritoneal fluid. Relevant history included an ovariohysterectomy when the dog was 6 months old, which was complicated by dehiscence of the incision site and evisceration. It appears that P boydii has a propensity for establishing itself in the abdominal cavity of the dog, subsequent to surgical dehiscence.     

IMAGING DIAGNOSIS—ECTOPIC SPLEEN MIMICKING HEPATIC TUMOR WITH INTRA‐ABDOMINAL METASTASES INVESTIGATED VIA TRIPLE‐PHASE HELICAL COMPUTED TOMOGRAPHY IN A DOG

A 10‐year‐old castrated male miniature dachshund was presented with an abdominal mass. The dog had a history of splenectomy. Triple‐phase helical computed tomography was utilized, revealing a hepatic mass and multiple intra‐abdominal solid masses. In triple‐phase helical computed tomography the images, hepatic mass and two of four intra‐abdominal masses were heterogenous in all phases. Therefore, we diagnosed a malignant hepatic tumor and presumed intra‐abdominal metastases. The masses were surgically removed and were histologically composed of normal spleen tissues, findings which were consistent with ectopic spleen.     

Eumycotic mycetoma: review and report of a cutaneous lesion caused by Pseudallescheria boydii in a horse

A cutaneous mass (1.5 cm in diameter) was removed from the head of a horse and was diagnosed histologically as eumycotic mycetoma. Immunofluorescence, performed on formalin-fixed, paraffin-embedded tissue, identified Pseudallescheria boydii as the etiologic agent. Findings from earlier reports of eumycotic mycetoma were compared with those of this horse.     

Eumycotic mycetoma caused by Pseudallescheria boydii in a dog

Abdominal eumycotic mycetoma caused by Pseudallescheria boydii was diagnosed in a 3-year-old male Siberian Husky. The dog was examined because of weight loss and signs of depression. Initially, pyrexia was the only clinical finding. Antibiotic and corticosteroid treatment was ineffective. Two weeks later, the dog's appetite had decreased, it had vomited a few times, and the caudal portion of the abdomen was sensitive to palpation. Hematologic and serum biochemical abnormalities consisted of anemia, leukocytosis, hypoglycemia, hypoalbuminemia, hyperglobulinemia, and high alkaline phosphatase activity. One week later, the dog's condition continued to worsen, and testicular swelling was observed. The dog was castrated. Microscopic examination of specimens obtained at surgery revealed pyogranulomatous periorchitis with mycetoma granules. Ketoconazole treatment was initiated and continued until the dog died one month later. Necropsy revealed multifocal duodenal ulcers, with transmural pyogranulomatous enteritis, pancreatitis, and peritonitis. This case is unique because the etiologic agent apparently entered via the intestinal tract rather than by contamination of an external wound.     

Pulmonary lipoma in a dog

An eight‐year‐old, neutered, male German short‐haired pointer was presented for a chronic cough and an intrathoracic mass. Computed tomography revealed a mass with low attenuation in the right caudal lung lobe that invaded the principal bronchi. The mass was removed by right caudal and accessory lung lobectomy. The histopathological diagnosis was pulmonary lipoma. The clinical signs resolved following surgery. There was no evidence of recurrence or de novo lesions on computed tomography performed 12 months post‐surgery. To the authors’ knowledge, this is the first report of a pulmonary lipoma in a dog.     

Diagnosis and management of Candida utilis infectious arthritis in a Standardbred filly

A 3‐year‐old Standardbred filly was admitted to the hospital for evaluation and management of previously diagnosed infectious arthritis of the right metacarpophalangeal joint (MCPJ). Candida utilis was isolated from multiple synovial samples submitted for bacterial culture and susceptibility. Following treatment with systemic and intra‐articular fluconazole and regional limb perfusion with amphotericin B and a second arthroscopic debridement the lameness improved and subsequent cultures were negative for bacterial or fungal growth. Infectious fungal arthritis should be a differential diagnosis for atypical or unresponsive joint infections especially in horses previously treated with a combination of intra‐articular corticosteroids and antibiotics.     

Successful treatment of bilateral paecilomyces pyelonephritis in a German shepherd dog

A six‐year‐old female entire German shepherd dog was investigated for polyuria, polydipsia and lethargy. Investigations revealed a mild azotaemia and abdominal ultrasound revealed marked bilateral dilation of the renal pelves with echogenic material and proximal left hydroureter. Urine cytological examination and aspirates from the right renal pelvis revealed mats of fungal hyphae consistent with fungal bezoar formation. Fungal cultures revealed a profuse growth of Paecilomyces variotii. Initial treatment with oral itraconazole was unsuccessful, leading to bilateral nephrotomies to remove the fungal material. Postoperatively the Paecilomyces infection persisted despite continued itraconazole therapy. Treatment was commenced with amphotericin B, leading to resolution of the dog's clinical signs. To the authors’ knowledge this is the first report of canine Paecilomyces pyelonephritis, without disseminated systemic disease, which documents its successful treatment.     

Vaginal Neurofibroma in a Hysterectomized Poodle Dog

A 15‐year‐old, spayed, female poodle dog was presented for evaluation of a mass of tissue prolapsed from the vulva. The dog had been hysterectomized when it was 5 years old. A vaginal mass had been removed approximately 10 months before presentation. Haematological and serum biochemistry analyses demonstrated mild leucocytosis and glycaemia. A vaginal smear was predominantly made up of parabasal cells and intermediate cells with no neoplastic cells. Thoracal and abdominal radiographic findings were unremarkable. The ovaries could not be identified using abdominal ultrasonography. A midline exploratory laparotomy identified both ovaries that were surgically excised. The vaginal mass was also removed following an episiotomy procedure. Histopathological examination of the mass demonstrated that it was a neurofibroma. Both ovaries had cystic changes. Four months after the surgery, the owner reported that the dog was clinically normal. To the authors’ knowledge, this is the first reported case of a vaginal neurofibroma after an incomplete ovariohysterectomy in the dog.     

Postsurgical intra-incisional 5-fluorouracil in dogs with incompletely resected, extremity malignant spindle cell tumours: a pilot study

The safety and efficacy of intra‐incisional 5‐fluorouracil (5‐FU) in the management of incompletely resected malignant spindle cell tumours of extremities was evaluated in six dogs. After marginal surgery, the dogs underwent weekly intra‐incisional 5‐FU for a minimum of six cycles. Treatment was well tolerated by all dogs, with no systemic adverse effects and only one episode of local cutaneous hyperpigmentation, which completely and spontaneously resolved. Median follow‐up for all the dogs was 546 days (mean 619; range 297–1207). At the date of analysis, four dogs were still alive with no evidence of local recurrence, and two dogs had died as a result of their disease. The cause of death was development of distant metastases in one dog and tumour regrowth in the other. Despite the small sample size, this study documents that intra‐incisional 5‐FU chemotherapy is a safe and efficacious adjuvant treatment in the case of incompletely resected malignant spindle cell tumours in dogs and that long disease control can be achieved.     

IMAGING DIAGNOSIS—MALIGNANT PERIPHERAL NERVE SHEATH TUMOR PRESENTING AS AN INTRA‐AXIAL BRAIN MASS IN A YOUNG DOG

A 3‐year‐old Labrador retriever was presented with acute onset seizures. Magnetic resonance imaging demonstrated an intra‐axial mass affecting the right temporal lobe of the brain. Surgical resection and histopathological findings were most consistent with a malignant peripheral nerve sheath tumor. After initial recovery, deterioration 3 months post surgery prompted euthanasia. Post‐mortem revealed a mass protruding from the ventral surface of the temporal lobe, encroaching upon the optic chiasm and invading the brain. Histopathology findings were again consistent with malignant peripheral nerve sheath tumor. Although rare, this tumor should be included as a possible differential diagnosis for intra‐axial brain masses in dogs.     

Paraganglioma,pituitary adenoma,and osteosarcoma in a dog

An 11‐year‐old neutered male Alaskan Malamute mixed‐breed dog was presented with a complaint of polyuria/polydipsia (PU/PD), weight loss, tachypnea, regurgitation, and a previous history of nontreated osteosarcoma of the right distal radius, diagnosed 21 months prior. On physical examination, an abdominal mass was palpated. The abdominal mass was aspirated and cytologically diagnosed as a neuroendocrine tumor, suspected to be a pheochromocytoma. Laboratory examination revealed a mild anemia and thrombocytopenia, markedly elevated ATP and ALP activities, and moderate hypercalcemia. A low‐dose dexamethasone suppression test and endogenous adrenocorticotropic hormone (ACTH) concentration were compatible with pituitary hyperadrenocorticism. On urinalysis, proteinuria was noted as well as a high urine metanephrine/creatinine ratio, consistent with a diagnosis of pheochromocytoma. The dog was treated with supportive care and euthanized 6 months later due to decreasing quality of life. On necropsy, an extra‐adrenal pheochromocytoma (paraganglioma) was diagnosed in the caudal abdomen, and a pituitary adenoma and an osteosarcoma of the right distal radius were confirmed.     

Cardiopulmonary effects associated with head-down position in halothane-anesthetized ponies with or without capnoperitoneum

Objective To compare the cardiopulmonary effects of the head‐down position, with or without capnoperitoneum, in halothane‐anesthetized horses. Study design Prospective randomized study. Animals Five ponies (four mares, one stallion; bodyweight 302 ± 38.4 kg [mean ± SD]) were used. Methods The ponies were anesthetized with xylazine, guiafenesin, ketamine, and maintained with halothane/oxygen and lungs were ventilated to 40 ± 2 mm Hg (5.3 ± 0.3 kPa) end‐tidal CO₂ tension. After baseline cardiopulmonary measurements, ponies were kept in horizontal position for 30 minutes, then tilted head‐down 30° to the horizontal position for 60 minutes, and then returned to a horizontal position for final measurements. Capnoperitoneum (intra‐abdominal pressure: 12 mm Hg [1.6 kPa]) was introduced after baseline cardiopulmonary measurements, until 5 minutes before the final measurements (treatment INS). Ponies in the control treatment (CON) did not receive capnoperitoneum. Cardiopulmonary data were collected every 10 minutes following the baseline measurements until recovery. Results In the head‐down position, in both treatments, significant decreases were observed in PaO₂, and significant increases were observed in PaCO₂, right atrial blood pressure, arterial to end‐tidal CO₂ gradient, calculated V_d/V_t and ratios. During the head‐down position, in CON there was decreased cardiac index, and in INS, there were decreases in arterial plasma pH and increases in mean systemic arterial and airway pressures. Treatment INS developed ventilation–perfusion mismatch earlier in the study, and had longer recovery times compared to CON. Conclusion Cardiac index and systemic blood pressure appeared to be preserved in INS during the head‐down position, but ventilation–perfusion mismatch appeared earlier with head‐down position and capnoperitoneum. Clinical relevance Healthy ponies tolerate capnoperitoneum at 12 mm Hg (1.6 kPa) intra‐abdominal pressure when tilted head down 30° to the horizontal position.     

Use of contrast‐enhanced ultrasonography in the diagnosis of a liver lobe torsion in a rabbit (Oryctolagus cuniculus)

A 1‐year‐old male French Lop rabbit (Oryctolagus cuniculus) was presented with a sudden onset of hyporexia. Physical examination revealed cranial abdominal discomfort. Liver enzymes were elevated on serum biochemistry profile. Abdominal radiographs showed diffusely gas‐dilated small intestinal loops. On abdominal ultrasound, a lobe in the right aspect of the liver was hypoechoic with rounded margins and was surrounded by hyperechoic fat and anechoic fluid. Contrast‐enhanced ultrasonography showed complete lack of perfusion in the abnormal right liver lobe. Exploratory laparotomy revealed torsion of the quadrate liver lobe. Diffuse coagulation necrosis was noted on histopathologic examination. The rabbit fully recovered after surgery.     

Malignant pheochromocytoma presenting as a bradyarrhythmia in a dog

Objective: To describe a case of atrioventricular block and syncope secondary to systemic hypertension in a dog with malignant pheochromocytoma. Case Summary: A 13‐year‐old spayed female mixed‐breed dog presented following an acute onset of collapse. The dog was hypertensive and had paradoxical high‐grade second‐degree atrioventricular block with concurrent syncope. Initial emergent therapy included a nitroprusside infusion for the systemic hypertension and vagolytic therapy for the bradyarrhythmia. A left adrenal mass was seen on abdominal ultrasound and was further characterized by MRI. Following medical stabilization with phenoxybenzamine and propantheline, a left adrenalectomy was performed. Histological diagnosis was consistent with a malignant pheochromocytoma. Following tumor removal there has been no further hypertension, atrioventricular block or syncope. Unique information provided: This is the first documented case of a malignant pheochromocytoma presenting as syncope secondary to hypertension induced atrioventricular block.     

Management of an infected cementless cup with prosthetic retention and antibiotic therapy in a dog

A two‐year‐old Rottweiler presented for acute onset of a right hindlimb lameness 20 weeks after a cementless total hip replacement (THR) and 16 weeks after open reduction to address luxation of the THR. Radiographs revealed periosteal proliferation of the medial acetabulum and a stable implant. Synovial fluid cytology was consistent with inflammatory joint fluid. Treatment consisted of surgical debridement and intravenous and oral antibiotics. THR implants were not removed. Culture of tissue removed from the THR site yielded growth of Pseudomonas and Staphylococcus species. Lameness resolved 2 months after surgery. Twenty months after surgery, the dog was exercising normally with no clinical lameness and pelvic radiographs revealed no evidence of implant loosening and markedly decreased periosteal reaction. To the authors’ knowledge, this is the first report of an infected THR site successfully treated without prosthesis explantation in the dog.     

Late Abscess Formation Caused by Silk Suture Following Hysterectomy in a Female Dog

A 5‐year‐old female cross‐breed dog was presented for a one‐month history of lethargy, poor appetite and weight loss. A hysterectomy had been performed 2 years ago. Abdominal palpation revealed a mid‐abdominal mass and haematological analysis showed leucocytosis with left shift. On abdominal radiographs, a 9 cm in diameter soft tissue opacity mass ventral to the colon and caudal to the left kidney was observed. The abdominal ultrasonography revealed a mass well circumscribed, with a hyperechoic capsule and hypoechoic center with echoic debris. The presumptive diagnosis was an abscess due to foreign body granuloma. Laparotomy was performed and a mass close to the left ovary was found. Adhesions and residues of the suture material were observed close to the right ovary and the uterine body stump. The mass, both ovaries and adhesions were removed. On cut section of the mass two cavities were observed. The small one contained three embedded silk suture residues. Histopathological examination confirmed the diagnosis of a chronic abscess caused by silk suture.     

Comparison of direct and indirect methods of intra‐abdominal pressure measurement in normal horses

Objectives – To develop a direct method for measuring intra‐abdominal pressures in the standing horse, identify a reference interval for direct intra‐abdominal pressures, compare these pressures to indirect intra‐abdominal pressures measured from the bladder, and determine the optimal bladder infusion volume for indirect pressure measurement. Design – Prospective, experimental study. Setting – A university‐based equine research facility. Animals – Ten healthy adult horses, 5 males and 5 females. Interventions – Direct intra‐abdominal pressures were measured through an intraperitoneal cannula and zeroed at the height midway between the height of the tuber ishii and point of the shoulder. Indirect measurements of intra‐abdominal pressure were performed by measuring intravesicular pressures through a transurethral catheter zeroed at the tuber ishii. Measurements and Main Results – Direct pressure measurements obtained in the standing horse were subatmospheric (mean, ?1.80 cm H₂O; SD, 1.61 cm H₂O; 95% CI, ?2.80 to ?0.80) and were shown to decrease as the horse's weight increased (Pearson's r=?0.67, P=0.04), with no effect of head position (P=0.15). Mean baseline indirect pressure measurements (mean, ?8.63 cm H₂O; SD, 4.37 cm H₂O; 95% CI, ?13.05 to ?4.21) were significantly different from the pressures measured directly from the abdomen (P<0.001). Indirect pressure measurements were noted to increase with increasing volumes infused into the bladder, and were statistically different at a volume of 100 mL (P=0.004). There was low to moderate correlation between direct and indirect pressure measurements of intra‐abdominal pressure over a range of fluid volumes infused into the bladder (Pearson's correlation range ?0.38 to 0.58). Conclusion – Pressures measured directly in the standing horse were subatmospheric, and increased as the horse's weight increased. Indirect pressures measured were altered by increasing volumes infused in the bladder. There was no significant correlation between the 2 methods of intra‐abdominal pressure measurement.     

INITIAL INFLUENCE OF RIGHT VERSUS LEFT LATERAL RECUMBENCY ON THE RADIOGRAPHIC FINDING OF DUODENAL GAS ON SUBSEQUENT SURVEY VENTRODORSAL PROJECTIONS OF THE CANINE ABDOMEN

Identification of the duodenum and potential abnormalities on survey abdominal radiographs is often difficult unless it contains gas. This study investigated the effect of patient positioning on the presence of duodenal gas in survey abdominal radiographs. One hundred dogs receiving a three‐view survey abdominal radiographic study were enrolled in a prospective, randomized study where all dogs were divided into two groups. Group A (n = 51) dogs had a left lateral projection first, followed by a ventrodorsal projection, ending with a right lateral projection. Group B (n = 49) dogs had a right lateral projection first, followed by a ventrodorsal projection, ending with a left lateral projection. The presence of gas within the duodenum and level of distribution of gas throughout the duodenum were recorded for all three projections. In addition, the presence or absence of duodenal pseudoulcers was evaluated on all three projections for each dog. The results for the two groups were compared using Chi‐square analysis with a P‐value of less than 0.05 being considered significant. Results showed that dogs first placed in left lateral recumbency were significantly more likely to have duodenal gas on the subsequent ventrodorsal and right lateral radiographic projections compared to dogs first placed in right lateral recumbency (P‐value < 0.0001). Pseudoulcers were seen in 11 dogs that had duodenal gas making the visualization of pseudoulcers on survey abdominal radiographs somewhat commonplace. This study emphasizes the benefit of using initial left lateral abdominal projections prior to other views for subsequent evaluation of the duodenum.     

Resolution of severe thrombocytopenia in two standard Poodles with surgical correction of splenic torsion

Objective: To describe the diagnosis and treatment of 2 cases of severe thrombocytopenia associated with splenic torsion and to discuss the pathophysiologic mechanisms underlying the thrombocytopenia. Summary: We report 2 cases of severe thrombocytopenia associated with splenic torsion. Each dog presented with non‐specific clinical signs, radiographic evidence of an intra‐abdominal mass, and platelet counts of less than 25,000 platelets/μL. The diagnosis of splenic torsion was made with abdominal ultrasonography and was confirmed during exploratory laparotomy. Both dogs recovered rapidly following splenectomy. The cause of thrombocytopenia associated with splenic torsion is not fully elucidated, but may be because of either platelet sequestration within the torsed spleen, platelet consumption in disseminated intravascular coagulation, or a combination of both. New information provided: This report provides previously unreported evidence that the degree of thrombocytopenia associated with splenic torsion may be of a severity at which primary hemostasis is compromised, and resolution of thrombocytopenia occurs after splenectomy.     

Successful Treatment of Disseminated Nocardiosis Caused by Nocardia veterana in a Dog

A 5‐year‐old male castrated Lhasa Apso cross was evaluated for a 1‐month history of inappetence, lethargy, gagging, and progressive right thoracic limb lameness. Synovial fluid analysis revealed nonseptic suppurative inflammation, and a diagnosis of immune‐mediated polyarthritis (IMPA) was made. After 3 months of treatment with prednisone and later cyclosporine, the dog developed multiple firm cutaneous and subcutaneous masses and a focal mass within the jejunum. Cultures of blood, urine, skin lesions, and the jejunal mass identified Nocardia veterana by matrix‐absorption laser desorption ionization‐time‐of‐flight mass spectrometry (MALDI‐TOF MS) and allowed for earlier identification of the organism compared to more traditional secA1 gene sequencing. Immunosuppressive drug treatment was discontinued, and the dog was treated for 3 months by administration of trimethoprim‐sulfamethoxazole (TMS). No recurrence of clinical signs was reported 1 year later. This case report highlights the clinical utility of MALDI‐TOF MS, particularly for the rapid identification of slow‐growing, fastidious organisms.