Pituitary tumor size, neurologic signs, and relation to endocrine test results in dogs with pituitary-dependent hyperadrenocorticism: 43 cases (1980-1990).

Pituitary neoplasm was identified in 43 dogs with pituitary-dependent hyperadrenocorticism via necropsy (n = 33), diagnostic imaging with computerized tomography or magnetic resonance imaging (n = 5), or diagnostic imaging and necropsy (n = 5). All dogs had clinical signs and clinicopathologic test results typical of hyperadrenocorticism. Thirty-seven dogs had grossly visible pituitary tumors, and 6 dogs had microscopic pituitary tumors. Fifteen dogs had developed neurologic signs typical of those resulting from an enlarging pituitary mass. Twenty-three dogs had pituitary tumors greater than or equal to 1 cm in diameter. Provocative testing of the pituitary-adrenocortical axis was performed on all dogs. Dogs with grossly visible pituitary tumors and dogs with neurologic signs had significantly (P less than 0.05) higher mean plasma endogenous ACTH concentrations, compared with values from dogs with microscopic tumors and dogs without neurologic signs, respectively. Dogs with grossly visible pituitary tumors and dogs with tumors greater than or equal to 1 cm in diameter had significantly (P less than 0.05) lower adrenocortical responsiveness to exogenous ACTH, compared with dogs with microscopic pituitary tumors and dogs with tumors less than 1 cm in diameter, respectively. Despite these differences, there was overlap between test results among dogs. On the basis of endocrine test results, it would appear difficult to distinguish dogs with pituitary-dependent hyperadrenocorticism and large pituitary tumors from those with pituitary-dependent hyperadrenocorticism and microscopic pituitary tumors prior to onset of neurologic signs.     

Pituitary macroadenomas and macroadenocarcinomas in dogs treated with mitotane for pituitary-dependent hyperadrenocorticism: 13 cases (1981-1986)

Pituitary macroadenoma/macroadenocarcinoma (PMA; tumor size greater than or equal to 1 cm in diameter) was diagnosed in 13 dogs after 0.5 to 24 months of mitotane treatment for pituitary-dependent hyperadrenocorticism (PDH). The diagnosis of PDH was established on the basis of results of common tests of the pituitary-adrenocortical axis in conjunction with results of x-ray computed tomography or necropsy. Initial clinical findings and clinicopathologic test results were typical of PDH. Signs referable to the CNS developed in 7 of the 13 dogs. The most common neurologic sign was stupor. Pituitary macroadenoma/macroadenocarcinoma was an unexpected finding in the other 6 dogs, because none had clinical signs of disease referable to the CNS at the time that pituitary tumor was documented. In the 13 dogs, strong correlation existed between tumor volume, compression/invasion of the surrounding nervous tissue, and development of neurologic signs, ie, neurologic signs were most frequently associated with larger tumors. The size of the tumor, however, was not always an indication of whether neurologic signs would be observed. All 7 dogs with neurologic signs were euthanatized because of the deleterious effects of the PMA. Of the 6 dogs without neurologic signs, 2 died of unrelated cause. Alternative treatment (ie, hypophysectomy, 60Co-teletherapy) was used successfully in 2 other dogs. Alternative treatment would seem indicated if PMA is documented in a dog with PDH. However, identification of PMA is dependent on evaluation of x-ray computed tomographic images. Signalment, history, physical examination, and alterations in routine clinicopathologic findings in these 13 dogs of our study were similar to previously reported findings in dogs with PDH but apparently without large pituitary tumors.(ABSTRACT TRUNCATED AT 250 WORDS)     

Radiographic findings in dogs with pulmonary blastomycosis: 125 cases (1989-2006)

OBJECTIVE: To identify radiographic patterns in dogs with pulmonary blastomycosis and radiographic factors associated with outcome. DESIGN: Retrospective case series. ANIMALS: 125 dogs with pulmonary blastomycosis. PROCEDURES: Medical records were reviewed, and for each lung lobe, the primary radiographic pattern and percentage of lobar involvement at the time of initial examination were recorded. RESULTS: 79 dogs survived, 38 died, and 8 were euthanized without treatment. The initial radiographic pattern was variable and not significantly associated with outcome. Mean half-time for radiographic resolution of pulmonary infiltrates was 41.4 days for all patterns except masses, for which mean half-time to resolution was 90.8 days. Transient radiographic worsening was seen in 20 of 87 (23%) dogs but was not associated with a poor prognosis. Pulmonary bullae were seen in 20 (16%) dogs, most often in association with an alveolar pattern. Accuracy of using percentage of right caudal lung lobe involvement ( 20%) to predict outcome was 74.4%; accuracy of using number of affected lobes (< 4 vs >or= 4) to predict outcome was 65.8%. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that a nonuniform distribution of pulmonary infiltrates was equally as likely as a diffuse nodular interstitial pattern in dogs with pulmonary blastomycosis. On the basis of half-time for resolution of pulmonary infiltrates, follow-up radiography should be performed no more often than every 4 to 6 weeks in clinically stable patients. Transient radiographic worsening that occurred during the initial weeks of treatment was not associated with a poorer prognosis.     

Magnetic resonance imaging findings in dogs with thoracolumbar intervertebral disk disease: 69 cases (1997-2005)

OBJECTIVE: To determine magnetic resonance imaging (MRI) abnormalities in dogs with intervertebral disk disease (IVDD) and develop a classification scheme for IVDD in dogs based on MRI findings. DESIGN: Retrospective case series. ANIMALS: 69 dogs. PROCEDURE: Medical records of dogs admitted because of thoracolumbar IVDD in which MRI of T9 through L7 had been performed were reviewed. RESULTS: A total of 759 intervertebral disk spaces were examined. Of these, 342 (45.1%) were classified as having a normal MRI appearance; the remaining 417 (54.9%) had various types of IVDD. Disk degeneration was identified in 276 disk spaces in 56 dogs, bulging of the intervertebral disk was identified in 37 disk spaces in 24 dogs, disk protrusion was identified in 54 disk spaces in 32 dogs, and disk extrusion was identified in 50 disk spaces in 48 dogs. Cartilage endplate changes were identified in 35 vertebrae in 17 dogs, and increased signal intensity of the spinal cord was identified in 21 dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Four types of IVDD (disk degeneration, bulging of the intervertebral disk, disk protrusion, and disk extrusion) were identified on the basis of MRI findings in dogs with thoracolumbar IVDD. We recommend that a standardized nomenclature be adopted for the various types of thoracolumbar IVDD in dogs.     

Clinical findings associated with prairie rattlesnake bites in dogs: 100 cases (1989-1998)

OBJECTIVE: To identify clinically relevant variables and treatments for dogs bitten by prairie rattlesnakes (Crotalus viridis viridis). DESIGN: Retrospective study. ANIMALS: 100 client-owned dogs. PROCEDURE: Records of dogs evaluated for rattlesnake envenomation from 1989 to 1998 were reviewed. Analysis was performed to test for significant associations among clinical variables or treatments and cell counts, costs, and duration of hospitalization. RESULTS: Most prairie rattlesnake bites occurred between May and September. Dogs were 3 months to 12 years old (median, 3.7 years); most were bitten on the head in the late afternoon. There was no sex predilection. Median time to evaluation was 1 hour (range, 15 minutes to 13 hours). Swelling in the area of the bite was the primary physical abnormality. Principal initial laboratory findings were echinocytosis, thrombocytopenia, leukocytosis, and prolonged activated clotting time. Ninety-four dogs were hospitalized; 48 were discharged the following day. Antimicrobials and crystalloid fluids, glucocorticoids, antihistamines, and antivenin administered i.v. were the most commonly used treatments. One dog died, and small dogs were hospitalized longer than large dogs. Antivenin administration was not significantly associated with duration of hospitalization but was associated with higher platelet counts after treatment and higher total hospital costs. CONCLUSIONS AND CLINICAL RELEVANCE: Prairie rattlesnake envenomation in dogs is associated with high morbidity rate but low mortality rate. The efficacy of administration of antivenin for dogs with bites from this snake species is questionable.     

Clinicopathologic findings and outcome in dogs with infective endocarditis: 71 cases (1992-2005)

OBJECTIVES: To evaluate clinical, laboratory, and necropsy findings in dogs with infective endocarditis (IE). DESIGN: Retrospective case series. ANIMALS: 71 dogs with possible or definite IE. PROCEDURES: Medical records were reviewed for signalment, clinical features, and results of clinicopathologic testing and diagnostic imaging. Yearly incidence and the effect of variables on survival were determined by use of survival curve analysis. RESULTS: The overall incidence of IE was 0.05%. Most affected dogs were of large breeds, and > 75% were older than 5 years. The aortic valve was affected in 36 of the 71 (51%) dogs, and the mitral valve was affected in 59%. Lameness caused by immune-mediated polyarthritis, septic arthritis, or peripheral arterial thromboembolism was observed in 53% of the dogs. Neurologic complications were diagnosed in 17 of 71 (24%) dogs. Thromboembolic disease was suspected in 31 of 71 (44%) of dogs. The mortality rate associated with IE was 56%, and median survival time was 54 days. Factors negatively associated with survival included thrombocytopenia, high serum creatinine concentration, renal complications, and thromboembolic complications. CONCLUSIONS AND CLINICAL RELEVANCE: A diagnosis of IE should be suspected in dogs with fever, systolic or diastolic murmur, and locomotor problems. Dogs with thrombocytopenia, high serum creatinine concentration, thromboembolism, or renal complications may have a shorter survival time.     

Liposarcomas in dogs: 56 cases (1989-2000)

OBJECTIVE: To determine the biological behavior of liposarcomas in dogs and identify clinical signs, the effect of treatment on survival time, and potential prognostic factors. DESIGN: Retrospective study. ANIMALS: 56 dogs with histologically confirmed liposarcoma. PROCEDURE: Information was obtained on signalment, tumor size, location of the tumor, stage of disease, remission duration, overall survival time, cause of death, type of surgery (incisional biopsy, marginal excision, or wide excision), and any additional treatments given. RESULTS: Surgery consisted of incisional biopsy in 6 dogs, marginal excision in 34, and wide excision in 16. Twenty-five dogs had histologic evidence of tumor cells at the surgical margins and 28 did not (status of the margins was unknown in 3 dogs). Twelve of 43 dogs had local recurrence. Median survival time was 694 days, and the only factor significantly associated with survival time was type of surgery performed. Median survival times were 1,188, 649, and 183 days, respectively, for dogs that underwent wide excision, marginal excision, and incisional biopsy. Factors that were not found to be significantly associated with survival time included tumor size, status of the margins, tumor location, and histologic subtype. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that in dogs, liposarcomas are locally invasive neoplasms that rarely metastasize and occur primarily in appendicular or axial locations and that wide excision is preferred to marginal excision when feasible.     

Association of clinical and magnetic resonance imaging findings with outcome in dogs suspected to have ischemic myelopathy: 50 cases (2000-2006)

OBJECTIVE: To determine whether clinical signs or magnetic resonance imaging findings were associated with outcome in dogs with presumptive ischemic myelopathy. DESIGN: Retrospective case series. ANIMALS: 50 dogs. PROCEDURES: Medical records and magnetic resonance images were reviewed. A neurologic score from 1 (normal) to 5 (most severe degree of dysfunction) was assigned on the basis of neurologic signs at the time of initial examination. Follow-up information was obtained from the medical records and by means of a telephone questionnaire completed by owners and referring veterinarians. RESULTS: Median neurologic score at the time of initial examination was 3 (range, 2 to 5). Median follow-up time was 584 days (range, 4 to 2,090 days). Neurologic score at the time of initial examination and extent of the lesion seen on magnetic resonance images (quantified as the lesion length-to-vertebral length ratio and as the percentage cross-sectional area of the lesion) were significantly associated with outcome. Sensitivity of using a lesion length-to-vertebral length ratio > 2.0 or a percentage cross-sectional area of the lesion > or = 67% to predict an unsuccessful outcome was 100%. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that severity of neurologic signs at the time of initial examination and extent of the lesions seen on magnetic resonance images were associated with outcome in dogs with ischemic myelopathy.     

Treatment of dogs infected with Hepatozoon americanum: 53 cases (1989-1998)

OBJECTIVE: To determine clinical and pathologic findings before and after short-term (group 1) and long-term (group 2) treatment in dogs with Hepatozoon americanum infection. DESIGN: Retrospective study. ANIMALS: 53 dogs with H. americanum infection. PROCEDURE: Medical records of dogs that were treated for hepatozoonosis diagnosed on the basis of meront or merozoite stages in skeletal muscle were reviewed. RESULTS: Circulating gametocytes of H. americanum were identified in 12 of 53 dogs. Dogs were treated with various drugs, including toltrazuril, trimethoprim-sulfadiazine, clindamycin, pyrimethamine, and decoquinate. Mean WBC counts prior to treatment were 85,700 and 75,200 cells/microl in groups 1 and 2, respectively, and 1 month after initiation of treatment were 12,600 and 14,600 cells/microl, respectively. Initial response to treatment was excellent in all dogs. Twenty-three of 26 dogs in group 1 relapsed at least once and died within 2 years; mean (+/- SD) survival time was 12.6+/-2.2 months. Twenty-two of 27 group-2 dogs survived; 11 dogs had no clinical signs and were still receiving decoquinate (mean duration of treatment, 21 months), 11 dogs had no clinical signs after treatment for 14 months (range, 3 to 33 months; mean survival time, 39 months [range, 26 to 53 months]), 2 dogs were lost to follow-up, and 3 dogs were euthanatized because of severe disease. CONCLUSIONS AND CLINICAL RELEVANCE: Although no treatment effectively eliminated the tissue stages of H. americanum, treatment with trimethoprim-sulfadiazine, clindamycin, and pyrimethamine followed by long-term administration of decoquinate resulted in extended survival times and excellent quality of life.     

Acute postretinal blindness: ophthalmologic,neurologic, and magnetic resonance imaging findings in dogs and cats (seven cases)

Objective To describe the ophthalmologic, neurologic, and magnetic resonance imaging (MRI) findings of seven animals with acute postretinal blindness as sole neurologic deficit. Methods Medical records were reviewed to identify dogs and cats with postretinal blindness of acute presentation, that had a cranial MRI performed as part of the diagnostic workup. Only animals lacking other neurologic signs at presentation were included. Complete physical, ophthalmic, and neurologic examinations, routine laboratory evaluations, thoracic radiographs, abdominal ultrasound, electroretinography, and brain MRI were performed in all animals. Cerebrospinal fluid analysis and postmortem histopathologic results were recorded when available. Results Four dogs and three cats met the inclusion criteria. Lesions affecting the visual pathways were observed on magnetic resonance (MR) images in six cases. Location, extension, and MRI features were described. Neuroanatomic localization included: olfactory region with involvement of the optic chiasm (n = 4), pituitary fossa with involvement of the optic chiasm and optic tracts (n = 1), and optic nerves (n = 1). Of all lesions detected, five were consistent with intracranial tumors (two meningiomas, one pituitary tumor, two nasal tumors with intracranial extension), and one with bilateral optic neuritis that was confirmed by cerebrospinal fluid analysis. Histologic diagnosis was obtained in four cases and included one meningioma, one pituitary carcinoma, one nasal osteosarcoma, and one nasal carcinoma. Conclusions Central nervous system (CNS) disease should be considered in dogs and cats with acute blindness, even when other neurologic deficits are absent. This study emphasizes the relevance of MRI as a diagnostic tool for detection and characterization of CNS lesions affecting the visual pathways.     

Causes of uveitis in dogs: 102 cases (1989-2000)

Uveitis is one of the most common ocular diseases and one of the most common causes of blindness in dogs. The purpose of this retrospective study was to correlate the signalment, history, clinical signs and ophthalmic findings of dogs with uveitis with the underlying etiology. We conducted a retrospective study of 102 dogs presented to the NCSU-VTH from 1989 to 2000 with clinical signs of uveitis. Medical records of dogs presented for uveitis were reviewed. Dogs were included in the study only if a complete diagnostic work-up database was collected, if sufficient follow-up was documented, and if the uveitis was not secondary to trauma or a hypermature cataract. The mean age +/- SD of all dogs in this study was 6.2 +/- 3.6 years. There were 33 intact and 16 castrated males, and 14 intact and 27 neutered females. Fourteen breeds were represented, with the Golden Retriever (n = 14) most common. Fifty-nine dogs (58%) were diagnosed with idiopathic/immune-mediated uveitis, neoplasia was diagnosed in 25 dogs (24.5%) and 18 dogs (17.6%) were diagnosed with infectious causes of uveitis. Aqueous flare was the most common clinical sign, occurring in 88 dogs (86%). The most common infectious organisms associated with uveitis in the dogs of this study were Ehrlichia canis (n = 7). Lymphosarcoma (n = 17) was the most common neoplasm. In approximately 60% of dogs presenting for uveitis an underlying cause was not found, and a diagnosis of immune-mediated or idiopathic uveitis was made. However, approximately 25% of dogs had ocular and/or systemic neoplasia (with 17% of cases having lymphosarcoma) and 18% with an underlying infectious cause for uveitis. Because of the high percentage of systemic disease associated with uveitis in dogs, extensive diagnostic testing is recommended before instituting symptomatic anti-inflammatory therapy.     

5-Hydroxytryptophan toxicosis in dogs: 21 cases (1989-1999)

OBJECTIVE: To determine epidemiologic characteristics, clinical findings, and treatment outcome of 5-hydroxytryptophan (5-HTP) toxicosis in dogs. DESIGN: Retrospective study. ANIMALS: 21 dogs with evidence of accidental 5-HTP ingestion. PROCEDURE: Information was retrieved from the National Animal Poison Control Center database. Records of dogs ingesting 5-HTP between January 1989 and February 1999 were reviewed for information on signalment, dose ingested, clinical signs (onset, severity, duration), treatments administered, and outcome. RESULTS: Clinical signs of toxicosis developed in 19 of 21 (90%) dogs. Neurologic signs included seizures (9 dogs), depression (6), tremors (5), hyperesthesia (5), and ataxia (4). Gastrointestinal tract signs included vomiting or diarrhea (12 dogs), signs of abdominal pain (3), and hypersalivation (2). Other clinical signs were hyperthermia (7 dogs) and transient blindness (3). Three dogs died. No important clinical laboratory or necropsy findings were reported. The doses of 5-HTP ingested ranged from 2.5 to 573 mg/kg (1.1 to 260 mg/lb) of body weight; the minimum toxic dose reported in our study was 23.6 mg/kg (10.7 mg/lb), and the minimum lethal dose was 128 mg/kg (58.1 mg/lb). Onset of signs ranged from 10 minutes to 4 hours after ingestion, and signs lasted up to 36 hours. Of 17 dogs with clinical signs of toxicosis that received treatment, 16 recovered; treatment consisted of decontamination, seizure control, thermoregulation, fluid therapy, and supportive care. CONCLUSIONS AND CLINICAL RELEVANCE: Ingestion of 5-HTP in dogs can result in a potentially life-threatening syndrome resembling serotonin syndrome in humans, which requires prompt and aggressive care.     

Clinical, radiographic, and pathologic abnormalities in dogs with multiple epiphyseal dysplasia: 19 cases (1991-2005)

OBJECTIVE: To determine clinical, radiographic, and pathologic abnormalities in dogs with multiple epiphyseal dysplasia (MED). DESIGN: Retrospective case series. ANIMALS: 19 dogs with MED from 10 litters. PROCEDURES: The diagnosis was made on the basis of radiographs of the shoulder region and vertebral column. Ten dogs underwent necropsy. RESULTS: There were 11 Hygenhund, 6 Dunker, 1 Golden Retriever, and 1 English Pointer. Most dogs were examined because of lameness that developed at 5 to 8 months of age. The most common radiographic abnormality was a deficiency in ossification of the epiphyses, apophyses, and cuboidal bones of the appendicular skeleton and the epiphyses of the vertebrae; ossification of the metaphyses and the diaphyses typically were normal. Disease severity was consistent among littermates, but varied among dogs from different litters. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that MED is a rare condition in dogs characterized by a deficiency in ossification of the epiphyses of the long bones, the epiphyses of the vertebrae, the cuboidal bones, and the apophyses. Radiographic abnormalities were evident in dogs examined as young as 8 weeks of age, and most dogs had developed severe lameness by 5 to 8 months of age. The condition most likely had an autosomal recessive mode of inheritance, although genetic studies of mode of inheritance could not be performed.     

Correlation between thoracic radiographs and postmortem findings in dogs with hemangiosarcoma: 77 cases (1984-1989).

Thoracic radiographic and postmortem findings were compared in dogs with histologically confirmed hemangiosarcoma (HSA). On the basis of results of radiography, a false-negative diagnosis was made for pulmonary HSA in 10 (21.7%) of 46 dogs, and in 26 (53.1%) of 49 dogs for cardiac HSA. The incidence of false-negative radiographic diagnosis for pulmonary HSA was lower in dogs when left and right lateral views were obtained. The radiographic sensitivity was 78%, and the negative-predictive value was 74% for pulmonary HSA. The radiographic sensitivity was 47%, and the negative-predictive value was 43% for cardiac HSA.     

Vacuolar hepatopathy in dogs: 336 cases (1993-2005)

OBJECTIVE: To determine disorders associated with vacuolar hepatopathy (VH), morphologic hepatic and clinicopathologic abnormalities, and affiliation with steroidogenic hormone excess in dogs. DESIGN: Retrospective case series. Animals-336 dogs with histologically confirmed moderate or severe VH. PROCEDURES: Information on signalment, results of diagnostic testing, definitive diagnoses, and exposure to glucocorticoids (ie, exogenous glucocorticoid administration or high endogenous concentrations of steroidogenic hormones) was obtained from medical records. Dogs were grouped by underlying disorder, glucocorticoid exposure, acinar zonal distribution of lesions, and histologic severity. RESULTS: 12 disease groups (neoplastic, acquired hepatobiliary, neurologic, immune-mediated, gastrointestinal tract, renal, infectious, cardiac disease, diabetes mellitus, portosystemic vascular anomaly, adrenal gland dysfunction, and miscellaneous disorders) were identified. There were 186 (55%) dogs with and 150 (45%) dogs without evidence of glucocorticoid exposure. Acinar zonal distribution of hepatic vacuolation and clinicopathologic values did not differ between dogs with and without evidence of glucocorticoid exposure. However, a 3-fold increased likelihood of severe VH was associated with steroidogenic hormone exposure. Of 226 dogs with high serum alkaline phosphatase activity, 102 (45%) had no evidence of glucocorticoid exposure. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that neoplasia and congenital or acquired hepatobiliary disease are common in dogs with VH and provide support for the suggestion that VH, high alkaline phosphatase activity, and illness-invoked physiologic stress may be associated. Histologic confirmation of VH should initiate a diagnostic search for a primary disease if glucocorticoid treatment and hyperadrenocorticism are ruled out.     

Hemophagocytic syndrome in dogs: 24 cases (1996-2005)

OBJECTIVE: To determine the frequency, potential causes, and clinical and clinicopathologic features of hemophagocytic syndrome in dogs. DESIGN: Retrospective study. ANIMALS: 24 client-owned dogs. PROCEDURES: Records for dogs in which diagnostic bone marrow specimens (including an aspiration smear and core biopsy material) were obtained from 1996 to 2005 were reviewed. Inclusion criteria were presence of bicytopenia or pancytopenia in the blood and > 2% hemophagocytic macrophages in the bone marrow aspirate. RESULTS: Of 617 bone marrow specimens evaluated, evidence of hemophagocytic syndrome was detected in 24 (3.9%). The Tibetan Terrier breed was overrepresented among dogs with hemophagocytic syndrome. Clinical signs associated with hemophagocytic syndrome included fever, icterus, splenomegaly, hepatomegaly, and diarrhea. Hemophagocytic syndrome was associated with immune-mediated, infectious, and neoplastic-myelodysplastic conditions and also occurred as an idiopathic condition. Overall, dogs with infection-associated hemophagocytic syndrome had better 1-month survival rates than dogs with immune-associated and idiopathic hemophagocytic syndrome. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that hemophagocytic syndrome may occur more frequently in dogs than has previously been suspected on the basis of the paucity of reported cases. Although most dogs had definable underlying disease conditions, idiopathic hemophagocytic syndrome was also identified. Hemophagocytic syndrome of any cause is potentially life-threatening; however, the prognosis should be adjusted on the basis of the associated disease process and potential for successful treatment.     

Ultrasonographic findings in dogs with hyperammonemia: 90 cases (2000-2002)

OBJECTIVE: To determine ultrasonographic abnormalities in dogs with hyperammonemia. DESIGN: Retrospective study. ANIMALS: 90 client-owned dogs with hyperammonemia. PROCEDURE: Ultrasonography of the abdominal vessels and organs was performed in a systematic way. Dogs in which the ultrasonographic diagnosis was a congenital portosystemic shunt were included only if they underwent laparotomy or necropsy. Dogs in which the abdominal vasculature appeared normal and dogs in which the ultrasonographic diagnosis was acquired portosystemic shunts and portal hypertension were included only if liver biopsy specimens were submitted for histologic examination. RESULTS: Ultrasonography excluded portosystemic shunting in 11 dogs. Acquired portosystemic shunts were found in 17 dogs, of which 3 had arterioportal fistulae and 14 had other hepatic abnormalities. Congenital portosystemic shunts were found in 61 dogs, of which 19 had intrahepatic shunts and 42 had extrahepatic shunts. Intrahepatic shunts originated from the left portal branch in 14 dogs and the right portal branch in 5. Extrahepatic shunts originated from the splenic vein, the right gastric vein, or both and entered the caudal vena cava or the thorax. Ultrasonography revealed splenic-caval shunts in 24 dogs, right gastric-caval shunts in 9 dogs, splenic-azygos shunts in 8 dogs, and a right gastric-azygos shunt in 1 dog. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that ultrasonography is a reliable diagnostic method to noninvasively characterize the underlying disease in dogs with hyperammonemia. A dilated left testicular or ovarian vein was a reliable indicator of acquired portosystemic shunts.     

Bacteria associated with pyothorax of dogs and cats: 98 cases (1989-1998)

OBJECTIVE: To determine the organisms most commonly isolated from pleural fluid from dogs and cats with pyothorax. DESIGN: Retrospective study. ANIMALS: 51 dogs and 47 cats. PROCEDURE: Results of bacteriologic culture of pleural fluid samples obtained by means of thoracentesis were obtained from medical records. To obtain information on in vitro antimicrobial susceptibility of organisms commonly isolated from dogs and cats, records of all dogs and cats examined during 1998 were reviewed, and information was obtained on identity and in vitro antimicrobial susceptibility of aerobic organisms isolated from samples other than urine or urinary tract samples. RESULTS: Median ages of dogs and cats were 4 years. Bacteria were isolated from pleural fluid samples from 47 of 51 (92%) dogs and 45 of 47 (96%) cats. Obligate anaerobic bacteria were isolated from 28 dogs and 40 cats. A mixture of obligate anaerobic and facultative bacteria was isolated from 17 dogs and 20 cats. Samples from cats most often yielded a member of the nonenteric group (most commonly members of the genus Pasteurella), whereas those from dogs more often yielded a member of the family Enterobacteriaceae (most commonly E coli). CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that antimicrobial agents chosen for the initial treatment of dogs and cats with pyothorax should be active against a mixture of obligate anaerobic and facultative bacteria.