Rectal ganglioneuroma in a dog

An 18-month-old, spayed female Australian terrier cross was presented with a 10-month history of chronic large bowel diarrhea. Ulceration and two proliferative masses in the rectum were seen on colonoscopy. Surgical resection was performed to remove the masses, and the dog recovered without complications related to surgery. Histopathology was consistent with the diagnosis of ganglioneuroma. The dog had no clinical signs of disease within three months of surgery and was completely normal 2.5 years after diagnosis. This is the first report providing follow-up and successful outcome of a ganglioneuroma in the gastrointestinal tract of a dog.     

NODULAR FAT NECROSIS IN THE FELINE AND CANINE ABDOMEN

The radiographic appearance of nodular fat necrosis is described in ten cats and one dog. The most common radiographic sign was the presence of a focal mineralized circular to oval soft tissue mass in the abdominal fat as present in 9 cats. These masses had a distinct eggshell-like rim encapsulating the lesion. In one cat and one dog multiple masses were present, without radiographic signs of mineralization. Abdominal ultrasound was performed in three cats and one dog, findings included the presence of hyperechoic masses with associated acoustic shadowing, some with a hypoechoic centre. Almost all animals were old and obese. In three cats and one dog, changes were confirmed with biopsy or post mortem examination. Lesions having the appearance of those in this paper are most likely incidental findings and should not be confused with abdominal masses of neoplastic origin. Ultrasound can be helpful in identifying such lesions.     

Spontaneous lymphoma in a prairie dog (Cynomys ludovicianus)

A 4-year-old, female, black-tailed prairie dog (Cynomys ludovicianus) was examined for acute dyspnea and two skin masses. Tentative diagnosis of lymphoma was made based on cytology of pleural effusion and the skin masses. Administration of prednisolone was initially effective in improving the condition; however, the clinical signs deteriorated after radiation therapy and administration of cyclophosphamide. Postmortem examination revealed that neoplastic lymphocytes had infiltrated most of the organs, and the histopathological diagnosis was multi-centric lymphoma.     

HYPERTROPHIC OSTEOPATHY ASSOCIATED WITH PULMONARY BLASTOMYCOSIS IN A DOG

Hypertrophic osteopathy (HO) associated with pulmonary blastomycosis was diagnosed in a 5–year-old male mixed-breed dog. One year prior to referral, increased pulmonary opacity had been identified on radiographs made during an examination for a chronic cough. Although serologic tests for blastomycosis were negative, the dog was treated with oral ketoconozole on the basis of suspicious lesions seen on radiographs and clinical signs. Ten months after completing the ketoconozole therapy, the dog was presented for a persistent cough and lameness. Intrapulmonary masses and periosteat proliferation were observed radiographically. A biopsy of the pulmonary masses was done, and Blastomyces dermatitidis was identified. Amphotericin B and ketoconozole administration resulted in clinical improvement and partial resolution of the HO lesions five months after initiation of therapy.     

Glucagon constant-rate infusion: a novel strategy for the management of hyperinsulinemic-hypoglycemic crisis in the dog

A six-year-old, spayed female, cocker spaniel was presented for hypoglycemic seizures. Hypoglycemia with concomitant hyperinsulinemia suggested an insulin-secreting tumor. Pancreatic masses were resected, and insulinoma was diagnosed. Six weeks later, the dog presented in hyperinsulinemic-hypoglycemic crisis (HHC). The dog was initially stabilized with intravenous dextrose boluses and infusions, but seizure activity recurred and persisted. A glucagon constant-rate infusion (GCRI) was initiated, and neurological signs quickly resolved. Dextrose was withdrawn over 24 hours, and euglycemia was maintained by GCRI alone. Despite aggressive medical management including the use of prednisone, diazoxide, bovine somatotropin, and streptozocin, the dog presented on two subsequent occasions in HHC and both times was rapidly stabilized with GCRI alone. In this dog, GCRI was a fast, safe, and effective method of achieving and maintaining euglycemia despite intractable hyperinsulinism. The clinical use of GCRI merits further investigation for management of HHC in veterinary species.     

ULTRASONOGRAPHIC EVALUATION OF BRACHIAL PLEXUS TUMORS IN FIVE DOGS

Five dogs with unilateral thoracic limb lameness, neurologic deficits, muscle atrophy, and pain, or a combination of these signs, were examined using ultrasonograghy. Large, hypoechoic tubular masses that displaced vessels and destroyed the normal architecture were found in each dog. The affected axilla of each patient was then imaged with computed tomography or magnetic resonance to fully assess the extent of the masses. We describe the use of ultrasound in screening patients for brachial plexus tumors.     

RADIOGRAPHIC FINDINGS IN TEN DOGS WITH THORACIC ACTINOMYCOSIS

The radiographic findings in ten dogs with thoracic actinomycosis are presented. Radiographic findins varied, but pleural effusion, pulmonary infiltrates and mediastinal masses were most commonly found. Rib involvement, commonly accompanying actinomycosis in man, was present in only one dog. The differential diagnosis of actinomycosis includes many disease entities, but based on the radiographic signs it may be possible to narrow down the number of possiblities considerably. A combination of mediastinal or pulmonary masses, pleural effusion and encapsulated fluid is strongly indicative for actinomycosis. For confirmation a bacteriological examination is indicated.     

Diffuse annular fusiform adenocarcinoma in a dog

Canine colonic intestinal adenocarcinoma typically presents as rectal polypoid or annular stenotic masses causing clinical signs consistent with large bowel disease. This report discusses an unusual case of intestinal adenocarcinoma in an 11-year-old, neutered male German shepherd dog presented for evaluation of anorexia, profuse watery diarrhea, and weight loss. In this dog, colonic adenocarcinoma diffusely infiltrated the entire large bowel and caused an annular fusiform lesion, as confirmed by endoscopic biopsies and postmortem examination. Other unique features included a paucity of desmoplasia associated with the neoplastic lesion and widespread metastasis to regional lymph nodes, lung, and prostate.     

Nasal and oral masses in a dog

A 5-year-old, intact male, stray dog was presented in poor body condition, with pallor, muzzle deformity, multiple oozing fistulas with grass awns, bilateral sanguinopurulent nasal discharge and a fleshy friable mass occupying part of the hard palate. A friable mass occupying both nasal cavities was found on rhinoscopy. The dog had moderate nonregenerative normochromic-microcytic anemia, thrombocytopenia, hyperglobulinemia, and hypoalbuminemia. Cytologic preparations of the nasal and oral masses contained a neoplastic population of round cells with intracytoplasmic and extracellular vacuoles. Leishmania amastigotes also were observed, in the cytoplasm of macrophages and, occasionally, within neoplastic cells. A diagnosis of transmissible venereal tumor and concurrent leishmaniosis was made. Treatment with vincristine and allopurinol resulted in complete resolution of clinical signs and disappearance of the masses. The presence of amastigotes in neoplastic TVT cells may suggest an alternative mode of transmission of canine leishmaniosis where these diseases co-exist.     

Erupted bilateral compound odontomas in a dog

A six-month-old, male Black Russian terrier dog was presented for oral masses on the distolingual aspect of the mandibular left and right first molar teeth. Intraoral dental radiographs showed periodontal support of the small teeth (denticles). Oral and radiographic examinations of the remaining teeth indicated no other dental abnormalities. The denticles had histomorphologic features of small teeth including normal appearing crown and root structures. Clinical and histopathologic examinations resulted in a diagnosis of bilateral compound odontomas with completely erupted denticles. Treatment consisted of extraction of all denticles and extensive curettage. The dog had uncomplicated wound healing with no signs of recurrence based on oral examination performed 15-months postoperatively.     

Vaginal cysts causing tenesmus in a bitch

An eight-year-old female border collie was referred with a two-month history of faecal tenesmus. Ultrasonography and radiology identified fluid-filled masses in the cranial vagina. The fluid was drained from the vaginal cysts via an episiotomy and the clinical signs resolved. Histological examination confirmed that the cysts were of urogenital origin. This is believed to be the first report of vaginal cysts causing faecal tenesmus in the dog.     

Uveodermatologic lymphoma in two young related Portuguese water dogs

Purpose Canine lymphoma (CL) is one of the most common forms of spontaneous canine neoplasia. Improved understanding of the genetic and environmental factors associated with CL may provide benefits for the study of non‐Hodgkin’s and Hodgkin’s lymphoma in humans. Uveodermatologic lymphoma is reported in a single household of Portuguese water dog, and the etiology is discussed. Methods A 1‐year‐old female intact Portuguese water dog was referred to the Ophthalmology Service of the Veterinary Teaching Hospital of the Autonomous University of Barcelona because of acute blepharospasm of the right eye in association with a multinodular dermatosis. Physical and ophthalmological examination and a complete diagnostic work‐up, including skin and ocular histopathology and immunohistochemistry, were performed. Three months prior, in Galicia (Spain), 1200 km away from Barcelona, a male dog of the same litter showed very similar oculodermatological clinical signs and skin histopathology, and immunohistochemistry were obtained. Results The clinical diagnoses were anterior exudative uveitis, iridal masses, and secondary glaucoma. Histopathology and immunohistochemistry revealed a nonepitheliotropic lymphoma rich in B cell in dog 1 and rich in T cell in dog 2. Conclusion It is proposed that an underlying genetic predisposition could have played a role in the development of lymphoma in these two young related dogs.     

GASTRIC LYMPHOSARCOMA IN A DOG: A CASE REPORT

A 9-year-old female spayed mixed-breed dog was presented with a ten-week history of vomiting. A survey abdominal radiograph showed a soft tissue mass on the lesser curvature of the stomach and an adjacent thickened greater curvature. A barium contrast study confirmed the presence of this mass. The radiographic diagnosis was gastric tumor. Radiographic signs of gastric neoplasia include soft tissue masses or thickening of the stomach wall, delayed gastric emptying, immobility of portions of the stomach wall, and residual stomach-wall staining by barium. Necropsy revealed a gastric lymphosarcoma that had infiltrated the entire circumference of the pyloric antrum. The most common gastric malignancy in the dog is adenocarcinoma. Gastric lymphosarcoma is considered rare.     

Multicentric nerve sheath fibrosarcomas of multiple cranial nerve roots in two dogs

Nerve sheath fibrosarcomas of the left 5th through 8th cranial nerve roots were diagnosed in 1 dog and of the left 4th through 8th cranial nerve roots in another dog. Clinical signs in both dogs included head tilt to the left, circling to the left, left hemiparesis and proprioception deficits, rotary nystagmus, left-sided atrophy of masticatory muscles, and cutaneous hypalgesia of the left side of the face. Cranial nerve roots from both dogs were incorporated in discrete, firm, encapsulated, lobulated, tan masses of various sizes that compressed adjacent brain stem and cranial nerves. There were no regional or distant metastases; however, there was enlargement of nerve roots adjacent to the masses. The masses were composed of bundles and sheets of anaplastic, polymorphic to spindle-shaped cells that infiltrated cranial nerves and ganglia and extended into the brain along nerve roots. Masses contained various amounts of collagen and reticulin fibers, but no mucopolysaccharide ground substance. There was no myelin or S-100 protein associated with neoplastic cells. The tumors appeared to have a multicentric origin from cranial nerve sheaths.     

Multiple metastases of thyroid cancer in the cranium and pituitary gland in two dogs

Two dogs, a 14-year-old, female American Eskimo dog and a 14-year-old, male Maltese dog, were presented with thalamic syndromes, including lowered levels of consciousness, poor postural responses and presence of masses in the neck region. In both dogs, magnetic resonance imaging revealed multiple masses inside the cranium, including the pituitary gland. One dog died from status epilepticus two days after magnetic resonance imaging and the other died two months after magnetic resonance imaging from respiratory failure. These dogs were histopathologically diagnosed with multiple metastases of thyroid cancer occurring inside the cranium, including the pituitary gland. To the authors' knowledge, this is the first time this tumour pattern has been reported in dogs, but it is possible that it is not uncommon.     

Mast cell tumor in the mandibular salivary gland in a dog

A mast cell tumor in the mandibular salivary gland was diagnosed in a 9-year-old English Setter. Dense infiltrating sheets of mast cells were present within the mandibular salivary gland, the medial retropharyngeal lymph node and in two subcutaneous masses on the flank. The salivary gland, lymph node, and masses were excised. The dog was treated postoperatively with the histamine receptor antagonist, cimetidine and the alkylating agent, chlorambucil. The tumor recurred at the angle of the mandible 4 months later and the dog was killed.     

Papillary ovarian cystadenocarcinoma in a dog

An 11-year-old female German Shepherd dog was presented for investigation of progressive enlargement of the abdomen, periodic bloody discharge from the vulva and rapid exhaustion. Transabdominal ultrasonography and lateral abdominal radiography demonstrated an echogenic formation with anechogenic cavities located cranial to the urinary bladder and a homogeneous shadow with an elliptical shape was located caudal to the rib arc. Both showed indistinct borders. Exploratory laparotomy identified bilateral ovarian masses and ovariohysterectomy was performed. Histopathology confirmed ovarian cystadenocarcinoma. The dog remained clinically normal without evidence of metastatic disease 4 months after surgery. Papillary cystadenocarcinoma in the bitch could affect both ovaries and manifests with a rapid growth rate and clinical signs such as rapid exhaustion, abdominal enlargement and vulval discharge. Ovariohysterectomy is the treatment option.     

Toxic Myopathy in a Dog Associated with the Presence of Monensin in Dry Food

This report describes a case of toxic myopathy in a two year old sheltie dog with clinical signs of profound weakness, myoglobinuria, and muscle enzyme elevations. The clinical signs were likely related to the accidental inclusion of monensin sodium in the dog's food. This food was prepared by a small feed milling company that also prepares cattle and chicken rations. A change of dog food resulted in remission of the clinical signs.     

B‐cell lymphoma with Mott cell differentiation in two young adult dogs

Abstract: Two young adult dogs with gastrointestinal signs were each found to have an intra‐abdominal mass based on physical examination and diagnostic imaging. On exploratory laparotomy, small intestinal masses and mesenteric lymphadenopathy were found in both dogs; a liver mass was also found in dog 1. Cytologic and histologic examination of intestinal and liver masses and mesenteric lymph nodes revealed 2 distinct lymphoid cell populations: lymphoblasts and atypical Mott cells. With Romanowsky stains, the atypical Mott cells contained many discrete, clear to pale blue cytoplasmic inclusions consistent with Russell bodies that were positive by immunohistochemistry for IgM and CD79a in both dogs and for IgG in dog 2. The Mott cells and occasional lymphoblasts stained strongly positive with periodic acid‐Schiff. Using flow cytometric immunophenotyping in dog 1, 60% of peripheral blood mononuclear cells and 85% of cells in an affected lymph node were positive for CD21, CD79a, IgM, and MCH II, indicative of B‐cells. With electron microscopy, disorganized and dilated endoplasmic reticulum was seen in Mott cells in tumors from both dogs. Antigen receptor gene rearrangement analysis of lymph node and intestinal masses indicated a clonal B‐cell population. Based on cell morphology, tissue involvement, and evidence for clonal B‐cell proliferation, we diagnosed neoplasms involving Mott cells. To the authors' knowledge, this is the second report of Mott cell tumors or, more appropriately, B‐cell lymphoma with Mott cell differentiation, in dogs. More complete characterization of this neoplasm requires further investigation of additional cases. This lymphoproliferative disease should be considered as a differential diagnosis for canine gastrointestinal tumors.     

Colorectal adenocarcinoma in dogs: 78 cases (1973-1984)

Colorectal adenocarcinoma was diagnosed in 78 dogs. Clinical signs in all 78 dogs included tenesmus, hematochezia, and dyschezia; most of the dogs had clinical signs less than or equal to 12 weeks before examination. Ultimately, most dogs were euthanatized because of the severity of clinical signs. Proctoscopy and colonoscopy were essential for complete assessment of extent of disease. Tumors were classified by gross appearance and included single, pedunculated masses, 2 or more nodular masses, and annular or intraluminal masses. In dogs in which survival time was compared with location and gross appearance of the tumor, dogs with annular masses had the shortest mean survival time (1.6 months), and dogs with single, pedunculated, polypoid tumors had the longest mean survival time (32 months). The rectum was a more common site than the colon, with 48.2% of the tumors developing in the middle portion of the rectum. Six different modes of surgical treatment were used, depending on the location and type of mass. Dogs that did not have surgical treatment had a mean survival time of 15 months. Mean survival time in the surgically treated dogs varied slightly according to mode of treatment; they survived 7 to 9 months longer than the untreated dogs. Dogs that underwent cryosurgery and local excision had the longest survival times (24 and 22 months, respectively). Statistical analysis disclosed a significantly longer survival time for dogs treated by excision or cryosurgery, as opposed to dogs undergoing biopsy only (P = 0.001). Statistical difference in survival times was not found between dogs that had mass excision and those that had cryosurgery.