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The filamentous basidiomycetous fungus, Oxyporus corticola, has not previously been reported in the human or veterinary medical literature. Identification of this organism as the etiologic agent of fungal osteomyelitis and multiorgan dissemination in a German shepherd dog was confirmed by comparison of ITS and D1/D2 sequences with known isolates.

A 7-year-old-spayed female standard poodle dog presented to the Iowa State University Veterinary Teaching Hospital with an 8-day history of lethargy, left hind limb lameness, ptyalism and peripheral lymphadenomegaly. On physical examination, the dog was lethargic, febrile (40.5 degrees C) and had multifocal to coalescing erythematous papular to pustular eruptions on the skin of all four limbs, periocularly and on the ventral and lateral thorax and abdomen. Histopathological findings from skin biopsies of the papules revealed a severe diffuse neutrophilic dermatitis with sub- and intra-epithelial pustules. Four days after being admitted the dog died from cardiac and respiratory failure. At necropsy, in addition to the multifocal to coalescing erythematous papules, the skin contained scattered pustules. Additionally, the subcutaneous tissue surrounding the right stifle was diffusely oedematous, and the peripheral and visceral lymph nodes were enlarged. The predominant histologic lesion was neutrophilic inflammation, in the absence of detectable bacteria in the skin, heart, lungs, oesophagus and left tarsus. In the absence of neoplasia or bacteraemia, a syndrome similar to Sweet's Syndrome should be considered as a differential diagnosis in dogs with cutaneous and extracutaneous neutrophilic infiltrates.

Case Description: A 7-year-old Siberian Husky-type dog with heterochromia irides was evaluated because of signs of pain associated with the right eye., Clinical Findings: Unilateral panuveitis, iris bombé, and secondary glaucoma were detected in the right eye. Tear production was low bilaterally. Facial and truncal poliosis and vitiligo were also evident; skin biopsy specimens were obtained from the nasal planum. Uveodermatologic syndrome was diagnosed on the basis of histopathologic findings of a lichenoid interface dermatitis and pigmentary incontinence within the dermis. Immunohistochemical analysis was performed on skin samples retrospectively, and findings were inconclusive., Treatment and Outcome: Treatment involved topical (ocular) and oral administration of corticosteroids, oral administration of azathioprine, and topical (ocular) administration of a carbonic anhydrase inhibitor and a lacrimostimulant. The secondary glaucoma was refractory to treatment, and the right eye was enucleated. Uveodermatologic syndrome was confirmed via histologic examination of ocular tissues. The left eye remained free of inflammation 16 months after the initial diagnosis. The periocular skin and skin of the nose partially regained pigment, but the hair did not., Clinical Relevance: Some breeds in which uveodermatologic syndrome has been reported (eg, Siberian Huskies, Old English Sheepdogs, Australian Shepherds, and Shetland Sheepdogs) often have heterochromia irides. This case highlights the fact that dogs with asymmetric uveal pigmentation may have unilateral ocular changes; therefore, uveodermatologic syndrome should not be excluded as a differential diagnosis on the basis of unilateral clinical signs.

A 10-year-old terrier crossbreed presented with a change in bark intonation of 3-4 month's duration and pronounced panting. Four variably sized masses were observed within the oral cavity. The largest mass was located within the parenchyma at the caudal region of the tongue. Others were located on the left arytenoid, within the soft palate, and in the oropharynx above the soft palate. Histopathologic specimens consisted of large round to polygonal cells occasionally containing multiple nuclei and rare faint cytoplasmic cross striations. Staining was weakly positive with periodic acid-Schiff. Immunocytochemistry was strongly diffusely positive for muscle-specific actin, myoglobin, and desmin and scattered positive for S-100 and vimentin. Phosphotungstic acid-hematoxylin staining enhanced cytoplasmic cross striations. The cytoplasm of all neoplastic cells was filled with mitochondria on electron microscopy. The final diagnosis was multifocal/metastatic rhabdomyosarcoma.

The purpose of the study was to determine if neovascularization, a measure of angiogenesis, is correlated with metastasis of mammary tumors in dogs. Forty-six paraffin-embedded tissue blocks of benign and malignant canine mammary tumors obtained from 42 clinical cases at the Iowa State University Veterinary Teaching Hospital were retrieved from the archives of the Department of Veterinary Pathology. Of the dogs with malignant tumors, cases with and without lymph node metastasis were chosen. Neovascularization was quantified by light microscopy on formalin-fixed, paraffin-embedded sections of canine mammary tumors using an avidin biotin immunoperoxidase assay for factor VIII-related antigen. Mean microvessel counts for each group were statistically evaluated using analysis of variance. The mean number of microvessels was highest in the malignant tumors of dogs with lymph node metastasis (44). This number was significantly different from the mean number of microvessels in the benign tumors (28; P = .03) and a trend occurred toward higher microvessel counts in malignant tumors with lymph node metastasis versus malignant tumors of dogs without metastasis (32; P = .1). No significant difference was found between the number of microvessels found in malignant tumors without metastasis versus benign tumors. The trend toward higher microvessel counts in mammary tumors that have metastasized supports the premise that angiogenesis may be an independent and significant prognostic indicator in dogs with malignant mammary tumors, as it is in women with breast cancer.

A 14-year-old spayed female shepherd/collie crossbred dog had a 6 x 4-cm mass excised from below the right ear. The partially encapsulated, neoplastic mass had a necrotic core and was embedded in the mandibular salivary gland. Histologically, the mass was composed of numerous multinucleate giant cells and large, oval, pleomorphic cells that produced osteoid. Neoplastic cells were immunoreactive for vimentin and actin but not for keratin, desmin, or S-100 protein. At postmortem examination 1 month later, an 11-cm spherical mass had recurred at the surgical site, and there were metastatic nodules in the lungs, ipsilateral mandibular lymph nodes, and kidney. The tumor was diagnosed as an osteosarcoma of the mandibular salivary gland with pulmonary, lymphatic, and renal metastasis. In addition, a 17-year survey of canine salivary-gland neoplasms revealed that most were adenocarcinomas or carcinomas.

A 6-week-old Siberian Husky pup had an unusual group of congenital heart anomalies that included a right-to-left patent ductus arteriosus, a small left ventricular chamber and ascending aorta, and a dysplastic mitral valve that may have been stenotic. Anomalies were diagnosed, using cardiac catheterization, angiocardiography, and blood gas determinations. Findings were confirmed by postmortem examination.

A 3 1/2-year-old dog with extensive tumor metastases to the lungs was found to have neutrophilic leukocytosis termed a leukemoid reaction. The term leukemoid reaction describes an absolute increase in the blood leukocyte concentration without regard to a predominant cell type or to the degree of cell immaturity. These types of reactions are extremely difficult to differentiate from leukemia. Leukemoid reactions can be acute or chronic and they may have an infectious, inflammatory, toxic, or neoplastic origin. Those reactions attributable to neoplasia have been documented in medical literature, but the mechanism causing the granulocytosis has not always been clearly understood. A granulopoietin capable of stimulating a leukemoid reaction may be elaborated by certain types of tumors, tumors with extensive metastasis, or tumors involving the lungs, liver, or stomach.

Three Portuguese water dog siblings, all females aged 5 to 7 months, were killed following a brief period of neurologic disease. Tissues were processed for light and electron microscopy and for biochemical analyses. All pups had membranous cytoplasmic inclusions in neurons throughout the brain and spinal cord. Cytoplasmic vacuoles were present in cells of many organs outside the nervous system. GM1 ganglioside in brain was markedly elevated in all three dogs, and beta-galactosidase activity was less than 10% of control values. These findings are similar to those in GM1 gangliosidosis of man and animals although the number of organs and tissues containing vacuolated cells is greater.

Two female Shetland Sheepdog littermates simultaneously developed pemphigus foliaceus at 6 months of age. Three other littermates were not affected. One bitch (tricolored) was not treated, and the disease has remained active for 2 years. The other bitch (blue merle) has been successfully managed with glucocorticoids and gold salts.