Insulinoma in dogs: a review.

Insulinomas are rare malignant functional pancreatic tumors of the ß cells that retain the ability to produce and secrete insulin. Insulinomas are the most common pancreatic neuroendocrine tumor in dogs that can induce a variety of clinical signs that result from hypoglycemia and secondary neuroglycopenic and adrenergic effects. Diagnosis and treatment is considered challenging, and the prognosis can be extremely variable depending on the therapeutic choices. This review aims to summarize and update classic knowledge with current trends in the diagnosis, treatment, and prognosis of insulinomas.

Osteomyelitis associated with Bartonella henselae infection in a young cat.

Case summary: A 1-year-old male intact domestic shorthair cat was evaluated for acute onset non-weightbearing left forelimb lameness and generalized peripheral lymphadenopathy. CT identified a monostotic aggressive bone lesion with an incomplete fracture of the left radial metaphysis. Bone aspirates yielded osteoblasts with minimal nuclear atypia. Abdominal ultrasound revealed a nodular spleen and lymphadenopathy; cytologically, both contained lymphoid hyperplasia. A urine histoplasma antigen test was negative. Bartonella henselae and Mycoplasma haemominutum DNA was amplified by PCR from peripheral blood. Indirect immunofluorescence documented strong B henselae immunoreactivity, with lower Bartonella vinsonii subspecies berkhoffii and Bartonella koehlerae antibody titers. After the administration of doxycycline and pradofloxacin for suspected Bartonella-induced osteomyelitis, lameness resolved rapidly. Six-week post-treatment radiographs identified healing of the affected bone, and Bartonella species enrichment blood culture was negative. B henselae antibody titers decreased four-fold over a year, supporting seroreversion. Relevance and novel information: B henselae is a flea-transmitted, host-adapted species, not previously implicated as a cause of osteomyelitis in cats. B henselae subclinical bacteremia is highly prevalent among cats; however, bacteremia has been associated with lymphadenopathy and febrile illness in cats. This report describes a unique clinical presentation in association with B henselae infection in a cat.

Thyroid storm in a dog secondary to thyroid carcinoma.

OBJECTIVE: To describe the clinical presentation, clinical course, and management of a dog with thyroid storm (TS) secondary to a functional thyroid carcinoma. CASE SUMMARY: A 12-year-old neutered female Golden Retriever was evaluated for severe weight loss, hyperthermia, and tachycardia. The dog had a ventral neck mass and markedly increased thyroxine concentration. Cervical ultrasound showed a suspected left thyroid mass with invasion into the jugular vein. Despite aggressive therapy, the patient progressed to a clinical TS. Postmortem examination was supportive of the clinical diagnosis. NEW OR UNIQUE INFORMATION PROVIDED: To the authors' knowledge, this is the first report of TS in a dog.

Investigation of the effects of storage with preservatives at room temperature or refrigeration without preservatives on urinalysis results for samples from healthy dogs.

OBJECTIVE: To compare urinalysis results for canine urine samples stored in preservative-containing tubes at room temperature (20°C to 25°C [68°F to 77°F]) or refrigerated at 4°C (39.2°F) in plain glass tubes with results for the same samples immediately after collection. SAMPLES: Urine samples from 20 healthy dogs. PROCEDURES: Urine samples (1/dog) were divided into 6 aliquots (3 in preservative-containing tubes and 3 in plain glass tubes). Preservative-containing tubes were stored at room temperature and plain glass tubes were refrigerated. Urinalysis was performed 0, 24, and 72 hours after collection. Results for both storage conditions were compared with results for a reference sample (the 0-hour [immediate post-collection] aliquot in a plain glass tube) by Spearman correlation analysis with pairwise tests for selected variables. RESULTS: Physical variables (urine color and turbidity with and without centrifugation) for both storage conditions had high (rs = 0.7 to 0.9) or very high (rs = 0.9 to 1.0) degrees of positive correlation with reference sample results at all time points, except for color at 24 hours. Similar results were found for all biochemical variables with storage up to 72 hours. For microscopic characteristics, correlation with reference sample results ranged from low or nonsignificant to very high under both storage conditions. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that if a delay in urinalysis is expected, use of the preservative-containing tubes evaluated in this study may be a viable option for sample storage. Further research is warranted to assess direct comparability of results to those of freshly collected samples and use of these tubes to store samples from dogs with conditions affecting the urinary tract.

Cytologic diagnosis of generalized cutaneous sporotrichosis in a hunting hound.

A 1-year-old male Foxhound/Walker Hound mix was presented to the small animal internal medicine service at Louisiana State University School of Veterinary Medicine with a 6-week history of progressive, multifocal, ulcerative and draining, well-circumscribed lesions in a generalized distribution. Prior to referral, a presumptive diagnosis was made of sterile pyogranulomatous disease; immunosuppressive therapy was instituted but resulted in clinical deterioration. At presentation, the dog had marked neutropenia (1100 neutrophils/microL), and a mild toxic left shift (400 bands/microL). Cytologic findings in the exudates from a draining skin lesion included high numbers of markedly degenerate neutrophils (about 95% of nucleated cells) as well as low numbers of macrophages, small mature lymphocytes, and eosinophils. Low numbers of intracellular (within neutrophils and macrophages) and extracellular, pleomorphic, cigar-to-ovoid shaped organisms ( approximately 3x9 microm) consistent with Sporothrix were observed. Histopathologic examination of a skin biopsy showed marked, chronic, active, ulcerative, pyogranulomatous dermatitis and panniculitis, with intralesional yeast consistent with Sporothrix sp. The etiologic agent was confirmed as Sporothrix schenckii by macerated tissue fungal culture. The patient was treated with itraconazole, enrofloxacin, and clindamycin, with clinical resolution occurring over a 3-month period. This case is a rare example of the cytologic diagnosis of Sporothrix schenckii in a canine patient. Diagnosis of canine sporotrichosis is often challenging and usually requires tissue culture, as infected dogs typically harbor very few organisms. The patient's prior immunosuppressive therapy likely contributed to higher numbers of organisms in exudates from the cutaneous lesions, facilitating cytologic diagnosis.

Treatment of ibuprofen intoxication in a dog via therapeutic plasma exchange.

OBJECTIVE: To describe the treatment of ibuprofen intoxication with therapeutic plasma exchange in a dog (TPE). SUMMARY: A 13-year-old male neutered mixed breed dog presented after ingesting approximately 200 mg/kg of ibuprofen. Treatment consisted of supportive medical therapy with IV fluids, gastrointestinal protectants, antiemetics and prostaglandin analogs, and TPE. A cycle of TPE was performed over 180 minutes, achieving 1.5 plasma volume exchanges. During therapy, heparinized blood and effluent samples were collected. Ibuprofen concentrations were determined in the samples by high-pressure liquid chromatography. Post TPE, the dog was continued on supportive medical therapy and was discharged 96 hours after the overdose. NEW OR UNIQUE INFORMATION: This report describes the use of TPE as an adjunct for ibuprofen intoxication. An 85% reduction in plasma ibuprofen concentration occurred and recovery from a potentially lethal ingestion of ibuprofen was achieved with TPE and supportive care. TPE should be considered when presented with acute ibuprofen intoxication due to the rapid and efficacious nature of therapy.

Treatment of meloxicam overdose in a dog via therapeutic plasma exchange.

OBJECTIVE: To describe the treatment of a meloxicam overdose in a dog with therapeutic plasma exchange (TPE). CASE SUMMARY: A 6-month-old female Bulldog, presented for routine laparoscopic ovariectomy. Postoperatively the dog received an accidental overdose of meloxicam (1 mg/kg IV [intravenously]). The patient was treated with supportive medical therapy and TPE over 210 minutes achieving 1.2 plasma volume exchanges. During therapy, heparinized blood and effluent samples were collected. Meloxicam concentrations were determined in the samples by high pressure liquid chromatography. Post TPE, the dog continued to receive supportive medical therapy and was discharged 48 hours after the overdose. The dog remained asymptomatic for meloxicam intoxication. Follow-up rechecks at 1 and 6 weeks were unremarkable with no further treatment required. NEW OR UNIQUE INFORMATION: This report describes the successful use of TPE adjunctively following an acute meloxicam overdose. An 82% reduction of plasma meloxicam concentration was achieved over 210 minutes. Twenty-four hours after therapy, a 47% sustained reduction of plasma meloxicam was measured after redistribution of drug between body compartments.

Pneumothorax in a dog caused by necrotizing pneumonia secondary to heatstroke.

OBJECTIVE: To describe the clinical course, diagnostic findings, medical and surgical treatments, and outcome in a dog with spontaneous pneumothorax secondary to necrotizing pneumonia thought to be a delayed complication of heatstroke. CASE SUMMARY: A 1.5-year-old Labrador Retriever developed spontaneous pneumothorax 12 days after an episode of exertional heat stroke. Computed tomography was performed and showed bilateral pneumothorax and multifocal pulmonary consolidation, especially at the lung periphery. A median sternotomy was performed, and multifocal, well-demarcated areas of consolidated pulmonary tissue with purple discoloration were identified and resected from the right middle, right caudal, and accessory lung lobes. Histologic examination of the resected pulmonary tissue indicated necrotizing pneumonia, and bacteriologic culture of the tissue resulted in growth of Pseudomonas aeruginosa. Examination of tissue from a pectoral muscle biopsy performed at this time showed necrotizing myopathy. The dog was discharged 7 days after surgery and made a full recovery. NEW OR UNIQUE INFORMATION PROVIDED: This case report describes pneumothorax and multifocal necrotizing pneumonia as a delayed complication of heatstroke, and provides the first description of the computed tomography appearance of histologically confirmed necrotizing pneumonia in a dog. Multifocal necrotizing pneumonia with or without pneumothorax should be considered in dogs that develop respiratory distress following severe systemic illness.

Neurologic complications after melarsomine dihydrochloride treatment for Dirofilaria immitis in three dogs.

Melarsomine dihydrochloride is highly effective against both sexes of adult and L5 Dirofilaria immitis. Common adverse reactions include injection site irritation and reluctance to move. Neurologic complications associated with i.m. injection of melarsomine dihydrochloride for treatment of heartworm disease in 3 dogs are described. Different degrees of neurologic complications have been identified; the pathophysiologic features are unknown. It is speculated that the compound migrates out of the injection site via fascial planes and causes an ascending inflammation along nerve roots. The resulting extradural cord compression secondary to extensive inflammation and necrosis of epidural fat could induce a variety of neurologic deficits. Alternatively, inappropriate injection technique may result in direct contact of melarsomine with neural tissue. A heightened awareness of proper injection technique might prevent the development of most neurologic complications.

Firm rib mass aspirate from a dog.

A 9-year-old intact male Miniature Schnauzer presented laterally recumbent, cachexic, and dehydrated with multiple firm bone masses and a bilaterally enlarged prostate. Fine-needle aspiration of a rib mass revealed numerous basophilic polygonal to fusiform cells predominantly found in small to large clusters. The cells exhibited cytologic criteria of malignancy and infrequently displayed large cytoplasmic vacuoles containing finely- to coarsely-stippled azurophilic material. The cytologic diagnosis was metastatic adenocarcinoma and was suspected to be prostatic or transitional cell in origin because of the azurophilic vacuoles within malignant cells. Gross and histologic findings confirmed the clinical and cytologic diagnosis of prostatic adenocarcinoma with widespread metastasis. Cytochemical and immunohistochemical investigation confirmed glycogen was a component of the vacuolar material. The vacuoles observed in the tumor in this case are not a consistent finding in tumors of the prostate or urinary bladder; however, when associated with an epithelial tumor, they may aid in limiting the differentials of the primary tumor and in the selection of further diagnostics.

Outcome of a heartworm treatment protocol in dogs presenting to Louisiana State University from 2008 to 2011: 50 cases.

Since 2008, the American Heartworm Society has recommended using a three-dose melarsomine protocol (a single intramuscular injection of melarsomine dihydrochloride at 2.5mg/kg, followed approximately 1 month later with two doses administered 24h apart) for all heartworm-positive dogs, with doxycycline given at 10mg/kg twice daily for 4 weeks prior to administration of melarsomine. To report the efficacy and side effects of this standard heartworm treatment protocol in 50 dogs presenting to our hospital from 2008 to 2011, information on the history, clinical, laboratory, and diagnostic imaging findings and treatment was obtained from medical records. When possible, additional follow-up information was obtained through telephone interviews with referring veterinarians and owners. Twenty-six dogs (52%) experienced minor complications, such as injection site reactions, gastrointestinal signs (vomiting, diarrhea, inappetance), and behavioral changes (lethargy, depression) during or after heartworm treatment. Twenty-seven dogs (54%) experienced respiratory signs (coughing, dyspnea) and heart failure attributed to progressive heartworm disease and worm death. Seven dogs (14%) died within the treatment period. Owners frequently reported behavioral changes, such as depression and lethargy, suspected to be secondary to pain. Fifty percent of owners surveyed indicated that, prior to the diagnosis, they either were not currently administering heartworm preventative, or they had recently adopted the dog from a shelter that did not administer preventatives. After treatment, 100% were administering heartworm preventatives to their pet. Eighteen dogs (36%) received a heartworm antigen test 6 months after adulticide therapy, 12 of which tested negative and six tested positive. Four of the dogs with a positive test at 6 months had negative tests 1 month later with no additional treatment. Adverse effects were common with the recommended protocol, but the majority of these were mild. Dogs in Class 1 (i.e., heartworm positive but otherwise largely lacking clinical evidence of disease) did not experience any major adverse effects or death.

Histoplasmosis.

Histoplasmosis is the most commonly diagnosed major systemic mycosis in dogs and the second most commonly reported fungal infection in cats. The causative organism, Histoplasma capsulatum, is endemic in 31 of the 48 contiguous US states and has a worldwide distribution. Histoplasma organisms enter the body via inhalation or, possibly, ingestion. They are phagocytized by macrophages and can be disseminated via the bloodstream or lymphatic system to the reticuloendothelial and gastrointestinal (GI) systems and, sometimes, the bones, skin, eyes, or brain. Clinical signs are often nonspecific, including lethargy, weight loss, and inappetence, although respiratory or GI signs may help localize the infection. Definitive diagnosis requires identification of H. capsulatum on cytology or histopathology. However, antigen testing may be useful in animals in the future. Itraconazole is the treatment of choice. The prognosis is fair for animals with pulmonary histoplasmosis and guarded to poor for those with GI or disseminated disease.

Diagnosis of presumed acute ischemic stroke and associated seizure management in a Congo African grey parrot.

CASE DESCRIPTION: A 14-year-old Congo African grey parrot (Psittacus erithacus erithacus) was evaluated for an acute onset of falling off of its perch and tonic-clonic movements. CLINICAL FINDINGS: Clinical signs were consistent with partial seizures. Findings on whole-body radiography, CBC, and plasma biochemical analysis were unremarkable. Plasma magnesium, ionized calcium, and bile acids concentrations were within reference limits. A magnetic resonance imaging (MRI) examination of the head revealed the presence of a focal hyperintensity at the central to left side of the optic chiasm and a hyperintense focus in the right side of the midbrain area in T2-weighted and FLAIR pulse sequence images. These findings were most consistent with an acute ischemic stroke with 2 brain infarcts. TREATMENT AND OUTCOME: Seizures were initially managed with potassium bromide and phenobarbital administration. On the basis of poor results and difficulties to reach therapeutic blood concentrations, the treatment plan was changed to levetiracetam and zonisamide administration. Blood concentrations were monitored for both drugs, and the frequency of seizures substantially decreased thereafter. A follow-up MRI examination 2 months later revealed resolution of the hyperintense signals. During the 20-month follow-up period, subsequent clusters of seizures were managed by adjusting levetiracetam and zonisamide dosages and adding clonazepam and gabapentin administration to the treatment plan. Regression of intraparenchymal hyperintense lesions and improvement of clinical signs made a diagnosis of acute ischemic stroke most likely. CLINICAL RELEVANCE: Findings for this Congo African grey parrot indicated that an antemortem diagnosis of an acute ischemic stroke followed by long-term seizure management may be possible in affected psittacines.