Mycobacterium fortuitum lipoid pneumonia in a dog.

A 1-year old female spayed German Shepherd dog was evaluated for acute onset of dyspnea. Pyogranulomatous inflammation and green globoid structures were present on aspirates of the affected lung. Impression smears and histopathology confirmed pyogranulomatous pneumonia, with large amounts of lipid corresponding to the green structures noted cytologically, and identified poorly staining bacterial rods within lipid vacuoles. Special stains confirmed the presence of acid-fast bacterial rods, and polymerase chain reaction and DNA sequencing identified the organism as Mycobacterium fortuitum. M. fortuitum pneumonia is well described in humans and has previously been reported in 4 dogs and 1 cat. Lipid was a prominent cytologic and histologic feature, as is often described in humans and in the single feline case report. Additionally, this case highlights the variable cytologic appearance of lipid, as well as Mycobacterium spp, which are classically nonstaining with Wright-Giemsa.

Development and evaluation of an ELISA for the quantitation of anti-Lagenidium giganteum forma caninum antibodies in dogs.

BACKGROUND: Lagenidium giganteum forma caninum infection causes severe cutaneous and disseminated disease in dogs. Currently, diagnosis requires culture and rRNA gene sequencing. OBJECTIVE: To develop and evaluate an ELISA for quantitation of anti-L. giganteum f. caninum IgG in canine serum. ANIMALS: Sera were evaluated from 22 dogs infected with L. giganteum f. caninum, 12 dogs infected with Paralagenidium karlingii, 18 dogs infected with Pythium insidiosum, 26 dogs with nonoomycotic fungal infections or other cutaneous or systemic diseases, and 10 healthy dogs. METHODS: Antigen was prepared from a soluble mycelial extract of L. giganteum f. caninum. Optimal antigen and antibody concentrations were determined by checkerboard titration. Results were expressed as percent positivity (PP) relative to a strongly positive control serum. RESULTS: Medians and ranges for PP for each group were: L. giganteum f. caninum (73.9%, 27.9-108.9%), P. karlingii (55.0%, 21.0-90.6%), P. insidiosum (31.3%, 15.8-87.5%), nonoomycotic fungal infection or other cutaneous or systemic diseases (19.2%, 3.2-61.0%), and healthy dogs (9.9%, 7.6-24.6%). Using a PP cutoff value of 40%, sensitivity and specificity (with 95% CI) of the ELISA for detecting L. giganteum f. caninum infection in clinically affected dogs were 90.9% (72.2-97.5%) and 73.2% (60.4-83.0%), respectively. Specificity in dogs infected with P. karlingii was 41.7% (19.3-68.1%) and with P. insidiosum was 66.7% (43.8-83.7%). CONCLUSIONS AND CLINICAL IMPORTANCE: Quantitation of anti-L. giganteum f. caninum antibodies for detection of this infection in dogs has moderately high sensitivity but poor specificity, the latter because of substantial cross-reactivity with anti-P. karlingii and anti-P. insidiosum antibodies.

Gastrointestinal pythiosis in 10 dogs from California.

BACKGROUND: Pythium insidiosum is an aquatic oomycete that causes severe segmental thickening of the canine gastrointestinal (GI) tract, resulting in weight loss, vomiting, diarrhea, and death. Infection in dogs previously has been observed primarily in the southeastern United States. OBJECTIVE: To describe the clinicopathologic and epidemiologic findings associated with GI pythiosis in 10 dogs from California. METHODS: Dogs were initially identified on the basis of supportive clinical findings and routine histology. Pythiosis was confirmed in each dog with at least one of the following: immunoblot serology, enzyme-linked immunosorbent assay serology, immunohistochemistry, and culture followed by species-specific polymerase chain reaction, rRNA gene sequencing, or both. RESULTS: Between September 2003 and December 2006, GI pythiosis was confirmed in 1 dog from central California and 9 dogs that lived within a 30-mile radius of Davis, CA. Seven of 8 dogs for which environmental data were available had frequent access to flooded rice fields or other water sources. Esophageal lesions were present in 2 of 10 dogs. Common laboratory findings included eosinophilia (7/9), hypoalbuminemia (9/9), and hyperglobulinemia (8/9). Median survival time was 26.5 days (range, 0-122 days), and the disease was ultimately fatal in all 10 dogs. CONCLUSIONS AND CLINICAL IMPORTANCE: The geographic distribution of pythiosis has widened in recent years to include the western United States. Factors that may have contributed to this change include altered rice-farming practices and landscape irrigation. Veterinarians in California should be familiar with the clinicopathologic features associated with GI pythiosis to aid in early diagnosis and effective treatment.

Exophiala oligosperma causing olecranon bursitis.

A 62-year-old male with a history of Wegener's granulomatosis and immunosuppressive therapy presented with chronic olecranon bursitis. A black velvety mould with brown septate hyphae and tapered annellides was isolated from a left elbow bursa aspirate and was identified as an Exophiala species. Internal transcribed sequence rRNA sequencing showed the isolate to be identical to Exophiala oligosperma. The patient was successfully treated with aspiration and intrabursal amphotericin B.

Identification of Exophiala mesophila isolated from treated dental unit waterlines.

Members of the genus Exophiala are often difficult to identify to the species level because of their variable morphological appearances. This paper describes the methods used to identify Exophiala mesophila and provides salient differential features for distinguishing other mesophilic members of the genus.

Phenol poisoning in three dogs.

Three adult dogs were evaluated following oral administration of phenol by the owner. All three dogs experienced severe oral and gastric ulceration. Hematological abnormalities included neutropenia with the presence of toxic neutrophils, thrombocytopenia, and increased muscle enzymes. Endoscopic examination was performed, and biopsies yielded a diagnosis of gastric mucosal necrosis in two of the dogs. Following supportive care, the dogs recovered completely. Phenol is a caustic, highly poisonous derivative of coal tar. The dogs of this report were poisoned inadvertently by their owner who received misinformation concerning the use of this chemical via the Internet.

Extensive venous thrombosis and hind-limb edema associated with adrenocortical carcinoma in a dog.

A 10-year-old, spayed female, mixed-breed dog was referred for evaluation of bilateral hindlimb edema and weakness. Abdominal ultrasonography showed increased echogenicity of the lumen of the caudal vena cava from the level of the urinary bladder to the level of the cranial pole of the right kidney. Bilateral saphenous venograms displayed numerous filling defects in the caudal vena cava, right external iliac vein, right femoral vein, and the right common iliac vein. Extensive venous thrombosis was diagnosed, and the animal was euthanized. Necropsy confirmed the presence of venous thrombosis and revealed a right adrenocortical carcinoma that had invaded the caudal vena cava.

Tetraparesis due to vertebral physeal fracture in an adult dog with congenital hypothyroidism.

A four-year-old male affenpinscher was referred for evaluation of hindlimb weakness that had progressed to tetraparesis over a period of four weeks. Neurological examination was suggestive of a cervical spinal cord lesion. Radiographic examination revealed diffuse skeletal immaturity with open physes and epiphyseal dysplasia in long bones and vertebrae, consistent with a diagnosis of congenital hypothyroidism. Total and free serum T4 concentrations were very low, indicative of hypothyroidism. Survey radiographs of the cervical spine revealed a dorsally displaced Salter-Harris type I fracture of the cranial portion of the fourth cervical vertebra with the endplate present in the vertebral canal. Although signs of transverse myelopathy are uncommon in dogs with congenital hypothyroidism, they may be associated with either intervertebral disc protrusion or endplate displacement into the vertebral canal secondary to the epiphyseal abnormalities associated with congenital hypothyroidism.

Atraumatic rupture of the gastrocnemius muscle after corticosteroid administration in a dog.

A 6-year-old spayed female Shetland Sheepdog was referred for evaluation of lameness, muscle atrophy, and a partial plantigrade stance of the right hind limb of 5 weeks' duration. Without history of trauma, atraumatic rupture of the right gastrocnemius muscle was diagnosed. Surgical repair was unsuccessful. The dog then developed signs of hyperadrenocorticism. Results of ACTH stimulation and low-dose dexamethasone suppression tests were consistent with iatrogenic adrenal suppression. One deleterious effect of excessive use of corticosteroids on muscle and connective tissue is degenerative myopathy. Steroid-induced myopathy with subsequent rupture of the gastrocnemius muscle was suspected in this dog. Clinical signs of myopathy most often develop with use of triamcinolone acetonide; therefore, care should be taken when administering this and other corticosteroids.

Dysautonomia in dogs: a retrospective study.

Dysautonomia was diagnosed in 11 young (median age, 14-months), predominantly medium- to large-breed dogs from 1988 to 1995. Clinical signs caused by autonomic dysfunction of the urinary, alimentary, and ocular systems were most common. Dysuria, mydriasis, absence of pupillary light reflexes, decreased tear production, dry mucous membranes, weight loss, and decreased anal tone were present in over 75% of affected dogs. Ocular pharmacological testing with a dilute (0.1%) solution of pilocarpine was used to demonstrate iris sphincter receptor function in all dogs. A low-dose (0.0375 mg/kg s.c.) bethanechol test and pharmacological testing with phenylephrine and epinephrine also demonstrated cholinergic and adrenergic receptor function in 4 dogs. All dogs died or were euthanized as a results of autonomic dysfunction. Neuronal depletion, with associated gliosis and minimal inflammation were noted histologically in the autonomic ganglia of each dog. The pelvic, ciliary, celiac, cranial cervical, and cranial and caudal mesenteric ganglia were affected in all dogs. The cause of autonomic failure in these dogs was not determined.

Ultrasonographic characteristics of the adrenal glands in dogs with pituitary-dependent hyperadrenocorticism: comparison with normal dogs.

Ultrasonographic evaluation of the adrenal glands was performed in 10 dogs with pituitary-dependent hyperadrenocorticism (PDH) and in 10 age- and weight-matched healthy control dogs. Thickness, shape, and echogenicity were determined for each adrenal gland. Adrenal thickness in dogs with PDH (median, 10 mm-left; 8.5 mm-right) was significantly greater than thickness in control dogs (median, 6 mm-left; 6 mm-right). Other ultrasonographic characteristics associated with PDH included bilaterally symmetrical adrenomegaly and maintenance of normal adrenal shape. Adrenal echogenicity was homogeneous and less than that of the adjacent renal cortex in 8 of 10 dogs with PDH and in 10 of 10 control dogs. Heterogenous echogenicity was present in 2 of 10 dogs with PDH, and was associated with nodular cortical hyperplasia in one of those dogs. Results of this study confirm the difference in sonographic appearance between PDH-induced bilateral cortical hyperplasia and functional adrenocortical neoplasia, and show a difference in sonographically determined adrenal size between healthy dogs and dogs with PDH.

Systemic Mycobacterium smegmatis infection in a dog.

A 3-year-old female Basset Hound was examined because of fever and lameness of 2 months' duration. Physical examination revealed a small cranial abdominal mass, which had an ultrasonographic appearance of a large abdominal lymph node. Cytologic examination of an ultrasound-guided fine-needle aspirate of the mass revealed a few macrophages that contained numerous linear unstained structures consistent with mycobacteria. Intracellular acid-fast bacilli were identified in an aspirate that was stained with modified Ziehl-Neelsen. Exploratory laparotomy revealed wide-spread abdominal lymphadenopathy. Histologic examination of hepatic and lymph node biopsy specimens revealed chronic granulomatous hepatitis and lymphadenitis. Acid-fast organisms isolated after bacteriologic culturing of a mesenteric lymph node specimen were identified as Mycobacterium smegmatis. Because the prognosis was poor, the dog was euthanatized.

Hepatic abscesses associated with diabetes mellitus in two dogs.

Two diabetic dogs were presented for anorexia, persistent fever, and poor control of hyperglycemia. Both had neutrophilia with left shift, hypoalbuminemia, and increased serum alkaline phosphatase (SAP) activity. Radiography indicated intrahepatic gas densities in 1 dog and a hepatic mass in the other. Abdominal sonography demonstrated multiple well-demarcated hypoechoic hepatic lesions consistent with abscesses. Both dogs were successfully treated by surgical resection of the abscessed liver lobes in conjunction with antibiotics and supportive therapy. Good control of hyperglycemia was achieved in both dogs after recovery. Intracellular and extracellular Gram-negative rod-shaped bacteria were abundant in the abscesses from both dogs. These cases suggest an association between diabetes mellitus and hepatic abscessation.