Evaluation of two test procedures for diagnosis of giardiasis in dogs.

Two commercially available tests, an antigen-capture ELISA for use on fecal samples, and a peroral nylon string test for use in dogs, were compared with a zinc sulfate fecal concentration technique (ZSCT) for detection of giardiasis in dogs. Of 77 dogs and 164 fecal samples (from these dogs), 33 and 52, respectively were found to be Giardia-positive on the basis of results of the ZSCT. The ELISA gave false-negative results for 10 and 14% of ZSCT-positive dogs and fecal samples, respectively, and false-positive results (relative to the ZSCT test results) in 13 and 10% of ZSCT-positive dogs and fecal samples, respectively. Of the 18 string-tested dogs, 14 were positive by results of the ZSCT. Of the 4 dogs that were Giardia-negative by ZSCT, 2 were Giardia-positive by ELISA. Dogs were sedated and given water and metoclopramide to aid passage into the duodenum of the capsule containing a nylon string. Of the 21 string tests performed on the 18 dogs, only 5 strings reached the duodenum, and 0 of the 5 yielded positive results for Giardia sp. Because the string broke in 1 dog (leaving most in the gastrointestinal tract and, therefore, producing a risk of string foreign body) further string tests were not done.     

Plasma D-dimer for the diagnosis of thromboembolic disorders in dogs.

D-dimer is formed during thrombus formation when factor XIIIa crosslinks the terminal D-domains of fibrin. The D-dimer epitope is exposed when the thrombus is lysed by plasmin. Thus, D-dimer represents both thrombin and plasmin activation and is specific for fibrinolysis. D-dimer concentrations are increased in dogs with DIC or other thromboembolic disorders, but because D-dimer is an indicator of physiologic or pathologic fibrinolysis, values are elevated in other conditions associated with fibrinolysis, including orthopedic surgery, neoplasia, and internal hemorrhage. It can be used as an ancillary test for the diagnosis of DIC but is not recommended as a sole test for this purpose. D-dimer has the potential to be a useful laboratory test for the detection of pulmonary thromboembolism in dogs. Further studies are needed to determine the appropriate applications for this test in veterinary patients to aid in clinical decision making, treatment, and patient care.     

Evaluation of a bladder tumor antigen test for the diagnosis of lower urinary tract malignancies in dogs

OBJECTIVE: To evaluate the use of a human bladder tumor antigen test for diagnosis of lower urinary tract malignancies in dogs. SAMPLE POPULATION: Urine samples from dogs without urinary tract abnormalities (n = 18) and from dogs with lower urinary tract neoplasia (20) or nonmalignant urinary tract disease (16). PROCEDURE: Test results were compared among groups and among 3 observers. The effects of urine pH and specific gravity, degree of hematuria, and storage temperature and time of urine samples on test results were also assessed. RESULTS: Test sensitivity and specificity were 90 and 94.4%, respectively, for differentiating dogs with lower urinary tract neoplasia from dogs without abnormalities. However, specificity decreased to 35% for differentiating dogs with neoplasia from dogs with nonmalignant urinary tract disease. In dogs with neoplasia, results were significantly affected by degree of hematuria. However, addition of blood to urine from dogs without hematuria had no significant effect on test results. Although intraobserver variation was significant, urine pH, specific gravity, or storage time or temperature had no significant effect on results. CONCLUSIONS AND CLINICAL RELEVANCE: Although this bladder tumor antigen test was sensitive for differentiating dogs with malignancies of the lower urinary tract from dogs without urinary tract disease, it was not specific for differentiating dogs with neoplasia from dogs with other lower urinary tract abnormalities. It cannot, therefore, be recommended as a definitive diagnostic aid for the detection of lower urinary tract malignancies in dogs.     

Evaluation of a modified hemimandibulectomy for treatment of oral neoplasms in dogs

A modified hemimandibulectomy was performed for treatment of oral neoplasms in 21 dogs. Intra- and postoperative evaluations included assessment of procedure difficulty, complications, mastication, cosmesis, and the time interval between surgery and recurrence of the neoplasm or clinical evidence of metastasis. Malignant melanoma was the most common neoplasm treated using this technique. The modified hemimandibulectomy was uncomplicated with minimal intraoperative hemorrhage. Three dogs had difficult mastication at 24-hours following surgery, while 5 dogs had partial wound dehiscence. Wound infection was diagnosed in 1 dog. All owners considered the postoperative outcome to provide acceptable cosmesis. Local neoplasm recurrence was documented in 5 dogs and distant (pulmonary) metastasis was diagnosed in 5 different dogs following surgery. The technical modification described in this study seemed to provide for improved mastication during the acute postoperative period compared with other hemimandibulectomy techniques performed by the authors.     

A modified coproantigen test used for surveillance of Echinococcus spp. in Tibetan dogs

Recently an immunological test for Echinococcus spp. antigens in dog faeces has been developed. The antigens appear to be carbohydrates, which survive proteolytic digestion and environmental degradation. For ELISA a capture antibody is used to capture the antigens, followed by a detection antibody. This paper describes a modification of the test whereby capture and detection antibodies are generated exclusively to the carbohydrate portion of the parasite tegument. Faecal extracts were heated to 70 degrees C overnight and the addition of foetal calf serum to the extracts was not necessary. The use of this modification as a surveillance tool in an extensive field trial of hydatid control in Western Sichuan is described. From 2003 onwards all dogs received a treatment with praziquantel pills in the spring and the autumn of each year. On each of six occasions 580 faecal samples were collected from 29 villages and analysed. Prevalence of Echinococcus spp. coproantigen-positive samples was 50% in year 2000, and decreased from 35% to 17% through 2003-2005. This coproantigen technique is now being used as part of the Chinese National Hydatid Disease Control Program, initially in 10 counties in Sichuan Province.     

Evaluation of an allergy screening test for use in atopic dogs.

An in-office allergy screening kit was evaluated for its repeatability, sensitivity, and specificity in 21 atopic dogs. Results of this testing were compared with results of a full regionalized allergy test offered by the same manufacturer. Results of the screening kit were repeatable and had high specificity but poor sensitivity. The kit as presently marketed is of questionable value as a diagnostic aid for use in dogs with atopy.     

Evaluation of the bromosulfophthalein 30-minute retention test for the diagnosis of hepatic disease in dogs

The purpose of this study was to evaluate efficacy of bromosulfophthalein (BSP) retention testing in dogs with and without histopathologically confirmed hepatobiliary disease. Medical records of 150 dogs with hepatobiliary disease having both a BSP test and hepatic biopsy were retrieved. Histopathologic slides of liver tissue were reviewed, and dogs were classified according to 1 of 11 histopathologic categories. Twenty-five clinically normal random-source dogs were used as controls for hepatic biopsy and BSP testing. No dogs suffered adverse effects due to BSP administration. BSP retention was significantly (P < .05) higher in hospitalized (13.9%) than control (3.2%) dogs, but the test could not distinguish between hospitalized dogs with different types of hepatobiliary disease. Sensitivity, specificity, and predictive values of BSP retention as a test for hepatic disease were calculated. Using 5.0% as a cutoff for normal BSP retention resulted in a specificity of 88% and a sensitivity of 76%. Using 6.0% as a cutoff for normal BSP retention resulted in a specificity of 100% and a sensitivity of 70%. Dogs of this study having BSP retention of >6% had at least an 86% chance of having an abnormal liver. We concluded that continued use of BSP retention testing is warranted as a noninvasive diagnostic test for liver disease in dogs.     

Use of a low-dose ACTH stimulation test for diagnosis of hypoadrenocorticism in dogs

BACKGROUND: Although definitive diagnosis of hypoadrenocorticism usually is made by an adrenocorticotrophic hormone (ACTH) stimulation test using 250 microg/dog of synthetic ACTH (cosyntropin/tetracosactrin), increased costs have prompted a search for less-expensive diagnostic methods. HYPOTHESIS: A low-dose ACTH stimulation test (5 microg/kg) will distinguish between dogs with nonadrenal illness and hypoadrenocorticism. Additionally, administration of cosyntropin will not affect the results of another ACTH stimulation test performed 24 hours later. ANIMALS: Eight healthy adult dogs and 29 hospitalized dogs with suspected hypoadrenocorticism. METHODS: In this prospective study, each healthy dog received 4 ACTH stimulation tests. Dogs received either 5 microg/kg or 250 microg/dog of cosyntropin on day 1 and the alternate dose on day 2. The opposite dosing sequence was used after a 2-week washout period (days 15 and 16). Dogs with suspected Addison's disease received 2 ACTH stimulation tests, 24 hours apart, using either a dose of 5 microg/kg cosyntropin or 250 microg/dog on the 1st day and the alternate dose on the 2nd day. RESULTS: In healthy dogs, poststimulation cortisol concentrations on days 2 and 16 and days 1 and 15 were equivalent (90% confidence interval [CI]: 86.7-101.2%). In dogs with suspected Addison's disease, mean (+/-SD) cortisol responses to ACTH in the 5 microg/kg dose (16.2+/-7.7 microg/dL) and 250 microg/dog dose (15.9+/-6.3 microg/dL) were statistically equivalent (90% CI: 91.2-105.4%). CONCLUSIONS AND CLINICAL IMPORTANCE: Low-dose ACTH stimulation testing distinguishes between dogs with nonadrenal illness and hypoadrenocorticism. Additionally, the administration of 2 ACTH stimulation tests on consecutive days does not affect results of the second test.     

Use of a direct enzyme-linked antiglobulin test for laboratory diagnosis of immune-mediated hemolytic anemia in dogs.

Detection of autoantibody, complement, or both bound to RBC is an essential requirement for unequivocal diagnosis of immune-mediated hemolytic anemia in dogs. An enzyme-linked antiglobulin test was adapted for laboratory diagnosis of this disease. The refinement and routine use of this assay have allowed further observation of the pathogenesis of the disease process. In particular, degree of hemolysis can be related to the degree of RBC sensitization associated with primary immune-mediated hemolytic anemia, and this correlation is highest for IgG autoantibody. Results indicate that autoantibody isotype might have an important role in the hemolytic process.     

Evaluation of a serological test system for the diagnosis of natural Echinococcus granulosus infection in dogs using E. granulosus protoscolex and oncosphere antigens

Serum antibody responses in feral or domesticated dogs naturally infected with Echinococcus granulosus or/and other common helminths were examined in an enzyme-linked immunosorbent assay (ELISA) using antigens prepared from E. granulosus protoscoleces or oncospheres. The ELISA using the protoscolex antigen was optimised with serums from experimental dogs monospecifically infected with E. granulosus or other helminth parasites, and helminth-free dogs. Anti-protoscolex antibody was detected in 16 of 22 (72.7%) serums from feral dogs with E. granulosus burdens ranging from 300 to 302,600 worms per dog. Seven serums from feral dogs which did not harbour E. granulosus at autopsy but which originated from an endemic hydatid region were tested using protoscolex antigen, and 1 serum gave a positive reaction. One hundred and two serums from dogs known never to have been infected with E. granulosus all gave negative reactions to protoscolex antigen. The sensitivity of the ELISA test proved to be superior to that which has been achieved by arecoline purging as a method of diagnosis for E. granulosus infection in dogs. For use of the assay in hydatid control or eradication campaigns, its sensitivity can be increased by choosing a lower absorbance discrimination value above which serums are regarded as having positive reactions. However, this does introduce positive reactions of some serums from dogs infected with helminths other than E. granulosus. In further development of the assay, use of defined recombinant antigens may improve both sensitivity and specificity.(ABSTRACT TRUNCATED AT 250 WORDS)     

Evaluation of immunohistochemistry for the diagnosis of sporotrichosis in dogs

The aim of this study was to apply immunohistochemistry (IHC) for the diagnosis of canine sporotrichosis and to compare this method with the Grocott’s silver stain (GSS) and periodic acid Schiff (PAS) techniques. Eighty-seven dogs with sporotrichosis (group 1) and 35 with American tegumentary leishmaniosis (ATL) (group 2) were studied. The fungus was detected in group 1 by GSS, PAS and IHC. IHC was also applied to group 2 to evaluate the occurrence of cross-reactions. PAS, GSS and IHC detected yeast cells in 19.5%, 43.7% and 65.5% of the group 1 cases, respectively. The detection of intracellular antigens of Sporothrix schenckii by IHC increased the sensitivity of the histological diagnosis to 80.5%. No positive reaction was observed in ATL lesions. The results suggest that IHC may be indicated for the diagnosis of sporotrichosis because of its higher diagnostic sensitivity.     

Evaluation of the six-minute walk test in dogs

OBJECTIVE: To determine the feasibility for use of a 6-minute walk test (6-MWT) in dogs with congestive heart failure (CHF) and document that the distance walked in 6 minutes decreases when a dog has CHF. ANIMALS: 16 young mature male hound-crossbred dogs weighing between 25 and 37 kg. PROCEDURE: An unobstructed path (22.73 m) was measured in a hallway. Each dog was walked on a leash for 6 minutes; each dog was allowed to set its own pace. At the end of 6 minutes (as measured by use of a stopwatch), the total distance walked was measured. Heart rate (HR) obtained by auscultation and mean systemic arterial pressure (MAP) obtained by oscillometry were recorded before and after the 6-MWT. Heart failure was induced by use of rapid ventricular pacing. Mean of the distance walked, HR, and MAP before and after the 6-MWT were compared between the control period and after dogs developed induced CHF. RESULTS: Dogs with CHF had a significant increase in resting HR, significant decrease in MAP, and a significant decrease in the distance walked in 6 minutes. The MAP increased slightly after exercise during the control period but decreased slightly after exercise during the CHF period. Fractional shortening decreased significantly when dogs had CHF. CONCLUSIONS AND CLINICAL RELEVANCE: Analysis of these results indicated that the distance walked in 6 minutes decreased significantly when a dog had CHF. The 6-MWT requires little time, space, or equipment and may replace the treadmill exercise test.     

Evaluation of a cattle rapid test for early pregnancy diagnosis in sheep

Tropical Animal Health and Production - The early pregnancy diagnosis allows optimizing production and timely management correction, with a greater reproductive output of livestock. The Idexx Rapid...     

Evaluation of tongue as a complementary sample for the diagnosis of parvoviral infection in dogs and cats.

Diagnosis of canine parvovirus type 2 and feline panleukopenia virus infection in dogs and cats may be hampered by the severity of enteric lesions, secondary bacterial overgrowth, and rapid onset of autolysis. In contrast to small intestine, tongue epithelium is less sensitive to postmortem changes. Sections of tongue and small intestine from 11 dogs and 11 cats with a clinical history and gross and microscopic lesions compatible with canine and feline parvoviral infection were examined for parvoviral infection using real-time polymerase chain reaction (PCR), immunohistochemistry (IHC), and direct fluorescent antibody testing (FA). Parvoviral DNA was detected by PCR in both small intestine and tongue of all but 1 dog. Nineteen of 22 animals (86%) with suspect or positive FA staining in the small intestine also had positive FA and IHC staining in the tongue. Three of 3 dogs (100%) whose carcasses had been frozen and thawed prior to necropsy had more consistently positive staining in tongue than in small intestine by FA and IHC. These data confirm tongue as an excellent complementary sample for parvoviral testing in dogs and cats, especially in cases in which postmortem autolysis has occurred.     

Evaluation of a low-dose synthetic adrenocorticotropic hormone stimulation test in clinically normal dogs and dogs with naturally developing hyperadrenocorticism.

OBJECTIVE: To determine whether low doses of synthetic ACTH could induce a maximal cortisol response in clinically normal dogs and to compare a low-dose ACTH stimulation protocol to a standard high-dose ACTH stimulation protocol in dogs with hyperadrenocorticism. DESIGN: Cohort study. ANIMALS: 6 clinically normal dogs and 7 dogs with hyperadrenocorticism. PROCEDURE: Each clinically normal dog was given 1 of 3 doses of cosyntropin (1, 5, or 10 micrograms/kg [0.45, 2.3, or 4.5 micrograms/lb] of body weight, i.v.) in random order at 2-week intervals. Samples for determination of plasma cortisol and ACTH concentrations were obtained before and 30, 60, 90, and 120 minutes after ACTH administration. Each dog with hyperadrenocorticism was given 2 doses of cosyntropin (5 micrograms/kg or 250 micrograms/dog) in random order at 2-week intervals. In these dogs, samples for determination of plasma cortisol concentrations were obtained before and 60 minutes after ACTH administration. RESULTS: In the clinically normal dogs, peak cortisol concentration and area under the plasma cortisol response curve did not differ significantly among the 3 doses. However, mean plasma cortisol concentration in dogs given 1 microgram/kg peaked at 60 minutes, whereas dogs given doses of 5 or 10 micrograms/kg had peak cortisol values at 90 minutes. In dogs with hyperadrenocorticism, significant differences were not detected between cortisol concentrations after administration of the low or high dose of cosyntropin. CLINICAL IMPLICATIONS: Administration of cosyntropin at a rate of 5 micrograms/kg resulted in maximal stimulation of the adrenal cortex in clinically normal dogs and dogs with hyperadrenocorticism.     

Evaluation of a modified Rose Bengal test and an indirect enzyme-linked immunosorbent assay for the diagnosis of Brucella melitensis infection in sheep

A modified Rose Bengal test (mRB) and an indirect ELISA (iELISA) with Protein G as the conjugate, were evaluated for the diagnosis of Brucella melitensis infection in unvaccinated sheep with a known bacteriological status, and their diagnostic efficacy was compared with that of the standard Rose Bengal (RB) and Complement Fixation (CF) tests used in the current eradication campaign in EU countries. All tests showed 100% specificity when testing the sera from 212 Brucella-free sheep. When testing the sera from 219 Brucella melitensis culture-positive sheep, both the mRB and iELISA tests were more sensitive (98.6% and 96.8%, respectively) than the RB and CF tests (95.0% and 92.7%, respectively). These results were similar when testing the sera from 181 animals belonging to infected flocks but found bacteriologically negative, suggesting that the mRB or iELISA tests could advantageously replace the current RB procedure used as the screening test.     

Validation of a Leishmania infantum ELISA rapid test for serological diagnosis of Leishmania chagasi in dogs

Canine visceral leishmaniasis (CVL) is caused by Leishmania donovani complex parasites including L. donovani, Leishmania infantum and Leishmania chagasi. As some studies suggest that L. chagasi and L. infantum may be very similar or even the same species, the aim of the present study was to evaluate a commercial rapid ELISA test, originally designed for L. infantum, in the diagnosis of CVL in dogs naturally infected by L. chagasi. A total of 400 serum canine samples, including 283 positive dogs for CVL from an endemic area, 86 clinically healthy dogs from a non-endemic area and 31 dogs seropositive for confounding infectious agents (Trypanosoma cruzi, Toxoplasma gondii, Neospora caninum, Babesia canis and Ehrlichia canis) were used for test validation. An overall sensitivity of 94.7% (95% CI=91.41-97.01%) and specificity of 90.6% (95% CI=83.80-95.21%) was found, with a high degree of agreement (k=0.8445) to the indirect ELISA. When confounding infectious diseases were excluded, specificity increased to 100% (95% CI=95.8-100%), with a higher degree of agreement (k=0.8928). In conclusion, the commercial kit designed for L. infantum was a highly sensitive and specific device for detection of L. chagasi infection in dogs, which indicates high immunoreactivity similarities between L. infantum and L. chagasi.