Clinical application of a polymerase chain reaction assay for diagnosis of leptospirosis in dogs

OBJECTIVE: To evaluate the use of a polymerase chain reaction (PCR) assay on urine samples for diagnosis of leptospirosis in dogs. DESIGN: Prospective case study. ANIMALS: 132 dogs with clinical signs suggestive of leptospirosis and 13 healthy dogs. PROCEDURE: PCR testing was performed on urine samples to detect leptospiral DNA; results were compared with results of conventional criteria for the diagnosis of leptospirosis. RESULTS: Leptospirosis was diagnosed in 8 dogs via established criteria; all these dogs had positive results of PCR assay, including 1 dog with positive results before seroconversion developed. A positive PCR assay result was also obtained in 16 dogs that did not have a confirmed diagnosis of leptospirosis. In the 8 dogs that had a confirmed diagnosis of leptospirosis, serovars pomona (n = 3 dogs), grippotyphosa (2), canicola (2), and bratislava (1) were identified serologically. The remaining 121 dogs all had a diagnosis other than leptospirosis or were healthy. For PCR testing on urine, sensitivity was 100%, specificity was 88.3%, positive predictive value was 33%, and negative predictive value was 100%. CONCLUSIONS AND CLINICAL RELEVANCE: Positive PCR test results prior to seroconversion may have value in establishing an early diagnosis. Positive results in dogs that had signs consistent with leptospirosis despite failing to meet established criteria for leptospirosis raise questions regarding the sensitivity of serologic testing in diagnosis of leptospirosis. Serovars pomona, grippotyphosa, and canicola were most common.     

Computed tomography diagnosis of eight dogs with brain infarction

Objective Medical records of eight dogs presenting with acute onset of neurological signs and a diagnosis of brain infarction as determined by computed tomography (CT) imaging were reviewed. Design Retrospective single-centre case review Results Ischaemic infarction in the territory of the rostral cerebellar artery was identified in three spaniel-breed dogs. All cerebellar infarcts were non-haemorrhagic. Telencephalic infarcts were identified in five dogs, in the territories of the middle cerebral artery (2/5) and rostral cerebral artery (3/5). One of these dogs had an ischaemic infarction, but all other infarctions appeared haemorrhagic. All dogs were geriatric (≥8 years old), with concurrent medical conditions identified in six dogs. One dog was euthanased after diagnosis because of the severity of its neurological signs and one dog was euthanased as a result of associated renal disease 2 months after diagnosis. Six dogs were alive at least 1 year after diagnosis. Conclusions CT is useful in the diagnosis of cerebrovascular accident in dogs, which can present as a spectrum of images with early changes in attenuation and subtle mass effects detected after infarction. CT is particularly sensitive for detecting haemorrhagic infarction, but under-represent ischaemic and lacunar infarctions when compared with MRI.     

Cytological Analysis of Bronchoalveolar Lavage Fluid in the Diagnosis of Spontaneous Respiratory Tract Disease in Dogs: A Retrospective Study

Results of cytological analysis of bronchoalveolar lavage (BAD fluid were compared with clinical diagnoses in dogs that presented with signs of respiratory disease to referral hospitals. Of 68 dogs in which a clinical diagnosis was possible, BAL cytological findings were considered definitive for the diagnosis in 17 cases (25%), supportive of the diagnosis in 34 cases (50%), and not helpful in 17 cases (25%). Findings were most often considered supportive of or definitive for the clinical diagnosis in dogs with alveolar or bronchial radiographic patterns, or the presence of pulmonary masses. BAL results among lung lobes differed in 23 of 63 dogs (37%) with diffuse radiographic patterns. Tracheal wash cytology differed from BAL fluid cytology in 45 of 66 dogs (68%). Bronchoalveolar lavage was a clinically useful procedure for the diagnostic evaluation of dogs with signs of respiratory disease.     

A comparison of five different bone resorption markers in osteosarcoma-bearing dogs, normal dogs, and dogs with orthopedic diseases

BACKGROUND: Various bone resorption markers in humans are useful for supporting the diagnosis of malignant skeletal pathology, with certain bone resorption markers appearing to be more discriminatory for detecting cancer-induced osteolysis than others. Canine osteosarcoma (OSA) is characterized by focal bone destruction, but a systematic investigation for determining which bone resorption marker best supports the diagnosis of OSA in dogs has not been reported. HYPOTHESIS: Dogs with OSA will have increased concentrations of bone resorption markers compared with healthy dogs and dogs with orthopedic disorders. Differences will exist among various bone resorption markers for their ability to support the diagnosis of malignant osteolysis in dogs with OSA. ANIMALS: Single time point, cross-sectional, cohort study including dogs with OSA (n = 20) or orthopedic disorders (n = 20) and healthy dogs (n = 22). METHODS: Basal concentrations of urine and serum N-telopeptide (NTx), urine and serum C-telopeptide (CTx), and urine deoxypyridinoline (DPD) were compared among all 3 groups. RESULTS: Compared with healthy dogs and dogs with orthopedic disorders, urine NTx, serum NTx, and serum CTx concentrations were significantly increased in dogs with OSA. For urine NTx and serum NTx, the calculated lower and upper 95% confidence limits in dogs with OSA did not overlap with dogs diagnosed with orthopedic disorders or healthy dogs. CONCLUSIONS AND CLINICAL IMPORTANCE: Of the markers evaluated in this study, urine NTx and serum NTx appear to be the most discriminatory resorption markers supporting the diagnosis of focal malignant osteolysis in dogs with OSA.     

Implantable loop recorders: a viable diagnostic tool in veterinary medicine

Objective : The purpose of this study was to investigate whether implantable loop recorders could be used in the diagnosis of unexplained collapse in dogs. Methods : The medical records of six dogs presented to the University of Liverpool Small Animal Teaching Hospital between May 2003 and October 2006 for further evaluation of intermittent syncopal episodes, collapse or episodic weakness, were reviewed. All these dogs underwent standard investigations and had implantable loop recorders placed. Results : A provisional diagnosis of supraventricular tachycardia was made in one dog, and diagnoses of exclusion of arrhythmogenic right ventricular cardiomyopathy and idiopathic epilepsy was made in two dogs. One dog suffered no further syncopal episodes, a diagnosis was not reached in another dog and the final dog was lost to follow‐up. Clinical Significance : The implantable loop recorder can be used successfully for the diagnosis of unexplained collapse in dogs.     

Exocrine pancreatic insufficiency as an end stage of pancreatitis in four dogs

Chronic pancreatitis is a common cause of exocrine pancreatic insufficiency (EPI) in humans and cats but is rarely recognised in dogs in which pancreatic acinar atrophy (PAA) is reportedly more common. This paper describes four dogs which developed EPI secondary to pancreatitis. Two of the dogs also had diabetes mellitus which developed before EPI. One diabetic dog had concurrent hyperadrenocorticism and was euthanased five months after presentation; the other diabetic dog died 48 months after diagnosis. The remaining dogs were alive 78 and 57 months after diagnosis. The number of affected dogs was comparable to the number of cases of presumed PAA seen over the same time period in the same institution. Chronic pancreatitis may be a more common cause of EPI in dogs than previously assumed and may be under-recognised because of difficulties in diagnosis. The relative importance of chronic pancreatitis as a cause of canine diabetes mellitus remains to be ascertained.     

USE OF MAGNETIC RESONANCE ANGIOGRAPHY FOR DIAGNOSIS OF PORTOSYSTEMIC SHUNTS IN DOGS

A prospective study was conducted to determine the sensitivity and specificity of diagnosis of portosystemic shunts (PSS) and the accuracy of anatomically locating single congenital PSS in dogs using magnetic resonance angiography (MRA). MRA was performed on 10 normal dogs and 23 dogs with PSS. Sensitivity and specificity of MRA to diagnose any shunt among all dogs were 80% and 100%, respectively. Among dogs identified with PSS, sensitivity and specificity of MRA for diagnosis of multiple extrahepatic shunts were 63% and 97%, respectively, and for diagnosis of single congenital shunts were 79% and 100%, respectively. Using MRA, radiologists correctly identified shunts as extrahepatic or intrahepatic in 83% of patients and correctly identified the origin and insertion of the shunts in 57% and 97% of patients, respectively. Use of MRA is specific for diagnosis of PSS and is a sensitive indicator of anatomic location of single congenital portosystemic shunts.     

Evaluation of 1,2-O-dilauryl-rac-glycero glutaric acid-(6′-methylresorufin) ester (DGGR) and 1,2-diglyceride lipase assays in dogs with naturally occurring hypercortisolism

1,2-O-dilauryl-rac-glycero glutaric acid-(6′-methylresorufin) ester (DGGR) lipase activity has been proposed as a faster and less expensive test used in the diagnosis of acute pancreatitis (AP) compared to canine pancreatic lipase immunoreactivity (cPLI), which is considered the most sensitive and specific serum test available for dogs. Elevations in lipase activity have been observed in dogs with naturally occurring hypercortisolism (HC) and in those treated with exogenous steroids, which complicates the diagnosis of AP in dogs with HC. We compared lipase activity measured by DGGR and 1,2-diglyceride (1,2-DiG) assays in 22 dogs with HC, 22 with AP, and 22 healthy dogs. The dogs with HC had no clinical signs or ultrasonographic findings consistent with AP. DGGR lipase activity was elevated in 64% and 73% of the dogs with HC and AP, respectively, and in 18% of healthy dogs. 1,2-DiG lipase activity was high in 23% and 36% of the dogs with HC and AP, respectively, and in 5% of the healthy dogs. Both DGGR and 1,2-DiG lipase activities were significantly different between the healthy dogs and the other 2 groups, whereas no differences were detected between the dogs with HC and those with AP. Our results support a lack of specificity for both DGGR and 1,2-DiG lipase activity assays in aiding the diagnosis of AP in dogs with HC.     

CT-GUIDED BRAIN BIOPSY USING A MODIFIED PELORUS MARK III STEREOTACTIC SYSTEM: EXPERIENCE WITH 50 DOGS

This report describes the results of CT-guided stereotactic brain biopsies performed on 50 consecutive dogs using a modified Pelorus Mark III Stereotactic System. Based on available histopathologic samples (stereotactic biopsy [n = 50], surgery [n = 17], necropsy [n = 9]) the patient population consisted of 34 dogs with primary brain tumors, 2 with invasive nasal adenocarcinomas, and 13 with non-neoplastic brain lesions. Brain tissue was not obtained from one dog. In 22 dogs a final diagnosis was made from tissue subsequently obtained from surgical resection or at necropsy. The final diagnosis was in agreement with the stereotactic biopsy diagnosis in 20 of these 22 dogs. In 17 other dogs without follow-up, stereotactic biopsy provided a diagnosis of a specific primary brain tumor subtype. Postoperative complications associated with the biopsy procedure were assessed in 41 dogs. The other 9 dogs either went directly to surgery (n = 7) or were killed (n = 2) immediately after the biopsy procedure. Thirty-six dogs recovered without apparent clinical complications. Postoperative clinical complications in the remaining 5 dogs included transient epistaxis (1 dog), transient exacerbation of cerebellar signs (1 dog), obtundation progressing to coma (1 dog), and medically uncontrollable seizures (2 dogs). The latter 3 dogs with severe neurologic complications all had large primary brain tumors and had been receiving high doses of phenobarbital and glucocorticoids to control seizures at the time of biopsy. These results suggest that this CT-guided biopsy procedure can provide an accurate pathologic diagnosis of brain lesions detected by CT and MR neuroimaging. Further refinement of both technique and case selection is expected to reduce the rate of clinical complications and to improve the accuracy of the procedure.     

Outcome of surgical versus medical treatment of dogs with beta cell neoplasia: 39 cases (1990-1997).

OBJECTIVE: To compare outcome of surgical versus medical treatment of dogs with beta cell neoplasia. DESIGN: Retrospective study. ANIMALS: 39 dogs with clinical signs of hypoglycemia and serum glucose and insulin concentrations consistent with a diagnosis of beta cell neoplasia. PROCEDURE: Information on signalment; clinical history; physical examination findings; results of CBC, serum biochemical analyses, and urinalysis; serum glucose and insulin concentrations; results of thoracic radiography and abdominal ultrasonography; treatment and treatment complications; survival time; and cause of death were obtained from medical records. RESULTS: 26 dogs underwent exploratory celiotomy and partial pancreatectomy; 13 dogs were treated medically (i.e., dietary change and prednisone). Median survival time was significantly longer for dogs treated surgically than for dogs treated medically. Significant differences were not found in mean age, body weight, duration of clinical signs prior to diagnosis, serum glucose and insulin concentration, or results of other serum biochemical tests between dogs treated surgically and dogs treated medically; also, there was no significant correlation between any of these parameters and survival time for either group of dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that exploratory celiotomy and partial pancreatectomy are indicated once a tentative diagnosis of beta cell neoplasia is established in dogs.     

Formal pathogenesis, average age and breed distribution in the comparison of 61 Lysodren-treated and 36 untreated cases of canine hyperadrenocorticism which were dissected in the years 1975 to 1991 at the Institute for Veterinary Pathology of the Free University of Berlin]

61 Lysodren -treated dogs with hyperadrenocorticism are compared with 36 untreated dogs with the same disease. 75.14% of the treated dogs had pituitary-dependent-hyperadrenocorticism (PDH) whereas this diagnosis was found in 63.89% of the untreated dogs. A functioning adrenocortical tumor (FAT) was found in 13.11% of the treated dogs but was evident in 22.22% of the untreated dogs. Simultaneous pituitary and adrenal Cushing's syndrome (PDH/FAT) were found in 11.48% of the treated and 8.33% of the untreated cases. Sex distribution was equal in both groups. Overall slightly more females than males were affected by the disease. Poodles (38.14%) and dachshunds (23.71%) were the mainly affected races. Race-distribution of diseased animals is compared to the overall race-distribution in a ten years statistic (1981-1990) of all necropsied animals (Walter und Schwegler, 1992). The mean age of Lysodren -treated dogs with a PDH diagnosis (10.0 years) is lower as the mean age of untreated dogs with the same diagnosis (10.3 years). Reasons for this unexpected finding are discussed.     

Clinical features and heritability of hypoadrenocorticism in Nova Scotia Duck Tolling Retrievers: 25 cases (1994-2006)

OBJECTIVE: To evaluate the clinical features and heritability of naturally occurring hypoadrenocorticism in Nova Scotia Duck Tolling Retrievers (NSDTRs). DESIGN: Retrospective case series. ANIMALS: 25 NSDTRs with hypoadrenocorticism. PROCEDURES: Questionnaires completed by owners of NSDTRs with hypoadrenocorticism and medical records from veterinarians were reviewed for information regarding diagnosis, age at diagnosis, concurrent diseases, age at death, and cause of death. Pedigrees were analyzed for heritability and mode of inheritance of hypoadrenocorticism (including complex segregation analysis of pedigrees of 1,515 dogs). RESULTS: On the basis of results of ACTH stimulation testing, hypoadrenocorticism was diagnosed in 16 female and 9 male NSDTRs (including 6 full siblings). Median age at diagnosis was 2.6 years; the diagnosis was made prior to 2 years of age in 11 dogs. Seventeen dogs had hyponatremia, hyperkalemia, or both, and serum electrolyte concentrations were within reference ranges for 8 dogs at the time of diagnosis. Median survival time after diagnosis for 4 dogs that died or were euthanized as a result of medical causes was 1.6 years. Heritability was calculated at 0.98 with no sex effect, and complex segregation analysis fit a major gene model with an autosomal recessive mode of inheritance. CONCLUSIONS AND CLINICAL RELEVANCE: In NSDTRs, hypoadrenocorticism was diagnosed at an earlier age, compared with published reports of age at diagnosis among the general dog population. Among the study dogs, 32% had no serum electrolyte abnormalities at the time of diagnosis, and the disease appeared to have an autosomal recessive mode of inheritance in the breed.     

Measurement of serum antinuclear antibody titer in dogs with and without systemic lupus erythematosus: 120 cases (1997-2005)

OBJECTIVE: To determine serum antinuclear antibody (ANA) titers in dogs with systemic lupus erythematosus (SLE) and in dogs with related clinical and clinicopathologic findings. DESIGN: Retrospective case series. ANIMALS: 120 dogs. PROCEDURES: Information that was evaluated included signalment, clinical signs, results of routine laboratory testing, ANA titer, and diagnosis. RESULTS: The most common clinical signs were arthralgia, myalgia, and stiffness (n = 41 [34.2%]); the most common clinicopathologic abnormality was thrombocytopenia (30 [25%]). Serum ANA titer was < 160 (seronegative) in 89 dogs (74.2%), 160 in 14 dogs (11.7%), 320 in 5 dogs (4.2%), and > or = 640 in 12 dogs (10%). Immune-mediated disease was confirmed in 40 dogs, 18 of which fulfilled the criteria for a definitive or probable diagnosis of SLE. Only 1 of 47 dogs with no major signs compatible with SLE had immune-mediated disease, compared with 26 of 57 dogs with 1 major sign and 13 of 16 dogs with > or = 2 major signs. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that measurement of ANA titer was not a useful diagnostic test in dogs without any major clinical or clinicopathologic abnormalities suggestive of SLE. In contrast, there was a good chance that results of the ANA assay would be positive and that the dog would be found to have immune-mediated disease if at least 2 major signs were evident. Findings suggest that it would be reasonable to limit the use of the ANA assay to those dogs that have at least 1 major sign compatible with a diagnosis of SLE.     

Chronic lymphocytic leukemia in dogs and cats: the veterinary perspective.

Chronic lymphocytic leukemia (CLL) in dogs and cats shares many similarities with its human counterpart but also has significant differences. In marked contrast to people, CLL in dogs and cats is primarily a T-lymphocyte proliferation. Cytotoxic T-cell proliferations with granular lymphocyte morphology predominate in dogs, and T helper cell proliferations seem to be most common in cats with CLL. Immunophenotyping and assessment of clonality by molecular genetic analysis are newer adjunctive tools in veterinary medicine that are useful in the characterization and diagnosis of CLL in dogs and cats. The clinical presentation, typical hematologic findings, diagnosis, course of disease, prognosis, and therapy of CLL in dogs and cats are discussed.     

Indirect hemagglutination for the diagnosis of Heterobilharzia americana infections in dogs

An indirect hemagglutination test was developed for the diagnosis of canine schistosomiasis. Specific-pathogen-free dogs and dogs infected with a variety of other helminths were experimentally infected with Heterobilharzia americana. Sera collected at various times after the dogs were exposed to cercariae were evaluated. Glutaraldehyde-fixed sheep erythrocytes sensitized with whole adult worm antigens provided a stable antigen substrate when tested over a period of months. The test produced sensitive and specific diagnosis at an appropriate serum dilution. Serum dilutions less than 1:80 from dogs with other helminth infections resulted in nonspecific agglutination. By postexposure day 60, coinciding with the end of the prepatent period, serum titers of dogs infected only with H americana equaled, and then surpassed, those of the other dogs.     

Stereotactic CT-guided brain biopsy in the dog

This study evaluated the accuracy of a new stereotactic CT-guided brain biopsy (SCTGBB) device on 23 client-owned dogs which presented with a brain lesion. Biopsy of the lesion was achieved in 95 per cent of cases. The target tissue was not sampled in one dog. Complications were observed in six dogs. Two dogs with highly vascularised brainstem tumours died after SCTGBB. Minor complications (slight variation in the neurological status) were observed in a further four cases. A diagnosis was reached in 16 dogs after cytological examination and in 21 dogs after histological evaluation. SCTGBB is an accurate diagnostic method for the diagnosis of brain lesions.     

Postanesthetic esophageal dysfunction in 13 dogs

Thirteen dogs with postanesthetic esophageal dysfunction were identified; 10 of these animals had esophageal stricture. Regurgitation was noted in six dogs during the inciting anesthetic event. Clinical problems common to all dogs included vomiting/regurgitation and weight loss. Coughing was noted in six dogs, and aspiration pneumonia was present in four of these dogs. The associated mortality rate was 23%. The duration of symptoms ranged from 17 to 150 days, and the diagnosis was often delayed (up to 76 days from onset of clinical signs to diagnosis). Postanesthetic esophageal dysfunction was a debilitating and costly problem that developed in one dog despite current preventative treatment.     

Endoscopic examination of the choanae in dogs and cats: 118 cases (1988-1998).

OBJECTIVE: To determine whether endoscopic examination of the choanae resulted in diagnosis of various diseases in dogs and cats with signs of respiratory tract disease. DESIGN: Retrospective study. ANIMALS: 91 dogs and 27 cats that had endoscopic examination of the choanae. PROCEDURE: Medical records were reviewed for endoscopy findings and results of examination of biopsy or cytologic specimens. RESULTS: 34 animals had neoplasia in the choanal region; in 26 animals, diagnosis was confirmed by evaluation of specimens obtained by endoscopy. Five dogs with neoplasia had an erroneous diagnosis of rhinitis made on the basis of evaluation of specimens obtained by endoscopy. Six dogs and 2 cats had foreign objects in the choanae; 7 foreign objects were removed endoscopically, whereas 1 required nasal flushing. Results of endoscopy and biopsy of the choanae provided diagnosis of cryptococcosis and aspergillosis, but did not aid in the diagnosis of pythiosis or nasal mites. CONCLUSIONS AND CLINICAL RELEVANCE: Endoscopic examination of the choanae may assist in rapid diagnosis of nasal neoplasms, foreign objects, and certain infectious organisms.