Marta T Costa

Measurement of thyroxine and cortisol in canine and feline blood samples using two immunoassay analysers

OBJECTIVES The AIA-360 (Tosoh Corporation) is an automated immunoassay analyser. The aims of this study were to estimate the precision of thyroxine and cortisol AIA-360 immunoassays in canine and feline samples and to compare the results produced with those obtained by a chemiluminescence analyser (Immulite® 1000, Siemens). METHODS Blood samples from 240 clinical cases (60 dogs and 60 cats for both thyroxine and cortisol) were analysed using both instruments. RESULTS Deming regression calculations showed excellent correlation (thyroxine, canine rs  = 0 · 94, feline rs  = 0 · 97; cortisol, canine rs  = 0 · 97, feline rs  = 0 · 97). Agreement between the two instruments was examined by Bland-Altman difference plots, which identified wide confidence intervals and outliers for thyroxine (canine n = 6, feline n = 4) and cortisol (canine n = 3, feline n = 4) results. Inter/intra-run precision of the AIA-360 was excellent for both cortisol and thyroxine (coefficients of variation <7%). CLINICAL SIGNIFICANCE The instrument showed excellent correlation for cortisol and thyroxine in canine and feline samples demonstrating that the AIA-360 can be used in clinical practice. The agreement studies suggest that the results from the AIA-360 cannot be used interchangeably with those generated by the Immulite 1000 and should be interpreted using reference intervals that have been established specific to the AIA-360.

European multicenter study on antimicrobial resistance in bacteria isolated from companion animal urinary tract infections

BackgroundThere is a growing concern regarding the increase of antimicrobial resistant bacteria in companion animals. Yet, there are no studies comparing the resistance levels of these organisms in European countries. The aim of this study was to investigate geographical and temporal trends of antimicrobial resistant bacteria causing urinary tract infection (UTI) in companion animals in Europe. The antimicrobial susceptibility of 22 256 bacteria isolated from dogs and cats with UTI was determined. Samples were collected between 2008 and 2013 from 16 laboratories of 14 European countries. The prevalence of antimicrobial resistance of the most common bacteria was determined for each country individually in the years 2012–2013 and temporal trends of bacteria resistance were established by logistic regression.ResultsThe aetiology of uropathogenic bacteria differed between dogs and cats. For all bacterial species, Southern countries generally presented higher levels of antimicrobial resistance compared to Northern countries. Multidrug-resistant Escherichia coli were found to be more prevalent in Southern countries. During the study period, the level of fluoroquinolone-resistant E. coli isolated in Belgium, Denmark, France and the Netherlands decreased significantly. A temporal increase in resistance to amoxicillin-clavulanate and gentamicin was observed among E. coli isolates from the Netherlands and Switzerland, respectively. Other country-specific temporal increases were observed for fluoroquinolone-resistant Proteus spp. isolated from companion animals from Belgium.ConclusionsThis work brings new insights into the current status of antimicrobial resistance in bacteria isolated from companion animals with UTI in Europe and reinforces the need for strategies aiming to reduce resistance.

Frequency of blood type A, B, and AB in 515 domestic shorthair cats from the Lisbon area

BACKGROUND The A, B, and AB feline blood types are recognized worldwide and their frequencies vary geographically and among breeds. Frequencies of feline blood types have been reported previously from northern Portugal; however, they are unknown in other parts of the country. OBJECTIVES This 13-year retrospective study was undertaken to determine the frequency of feline blood types in domestic shorthair (DSH) cats from the Lisbon area of central Portugal. METHODS Blood samples were obtained at the Veterinary Teaching Hospital of the Technical University of Lisbon and its Veterinary Blood Bank and at several veterinary clinics in the Lisbon area. Blood-typing was performed by the classical agglutination assay or using a cartridge assay. RESULTS The study population comprised 515 DSH cats of both sexes and various ages. Frequencies of blood types A, B, and AB were 97.5%, 2.1%, and 0.4%, respectively. CONCLUSION As in other parts of the world, this study showed a clear predominance of type-A cats in the Lisbon area of Portugal.

Diagnostic accuracy of two point-of-care kits for the diagnosis of Giardia species infection in dogs

OBJECTIVES The objective of this study was to compare results obtained by ZnSO4 Flotation and SNAP ®Giardia to those generated by the new point‐of‐care tests Single and Triple Rapid. METHODS Prospective study evaluating 51 canine faecal samples submitted at a reference laboratory for the presence of Giardia spp. Kappa statistics, specificity, sensitivity, positive predictive value (PPV) and negative predictive value (NPV) were calculated by comparing the new tests to the combined results of ZnSO4 and SNAP tests. RESULTS There was fair (Single Rapid, j=0·434) to good (Triple Rapid, j =0·797) agreement with the reference tests. At this studys prevalence (59 to 61%), specificities and PPV were high (1·00) with both Rapid tests, but sensitivities and NPV were lower for the Single than for the Triple (0·48 vs 0·83 and 0·55 vs 0·80) tests. At lower prevalence rates, both tests exhibited a high PPV (1·00), but the NPV were higher with the Triple (0·96 to 0·99) than the Single (0·88 to 0·96) Rapid test. CLINICAL SIGNIFICANCE Both tests exhibited excellent PPV values at all prevalence rates but an excellent NPV only at low prevalence. As the prevalence is likely to be low (<15%) in clinical settings, we propose that these tests may be helpful in the in‐house diagnosis of Giardia spp infection. However, they exhibit lower sensitivity than the combined sensitivity of ZnSO4 and SNAP tests, particularly in high prevalence settings.

Measurement of prothrombin time and activated partial thromboplastin time in citrated whole blood samples from clinically ill dogs following storage

OBJECTIVES To assess the reliability of prothrombin time and activated partial thromboplastin time results generated from citrated whole blood samples following short-term storage at room temperature. METHODS Clotting times were measured in blood samples from 40 dogs that showed a variety of clinical signs. Before measurement of prothrombin time and activated partial thromboplastin time in citrated plasma, whole blood samples were split in three aliquots; one was processed within 30 minutes of collection (fresh) while the remaining two were stored unseparated at room temperature for 24 (24RT) or 48 (48RT) hours. RESULTS The median prothrombin time for the 24RT (7 seconds) and 48RT (7·2 seconds) samples were not significantly different to those obtained from the fresh (7·1 seconds) samples but the median activated partial thromboplastin time for the 24RT (12·6 seconds) and 48RT (12 seconds) samples were significantly shorter than those obtained from the fresh samples (14·2 seconds). CLINICAL SIGNIFICANCE Storage of citrated whole blood at room temperature for 24 or 48 hours did not significantly alter the measurement of prothrombin time but resulted in significantly shorter activated partial thromboplastin time results. Extrapolating from these findings, it is proposed that unseparated clinical samples that are submitted to an external diagnostic laboratory for the performance of clotting times, may generate reliable prothrombin time but unreliable activated partial thromboplastin time results.

Surgical resolution of an oesophageal duplication cyst causing regurgitation in a domestic shorthair cat

Case summary An 18-month-old female domestic shorthair cat was referred for investigation of a 6 month period of regurgitation. Contrast radiography indicated an intramural oesophageal structure. Ultrasound-guided fine-needle aspiration of the area retrieved viscous fluid containing high numbers of squamous epithelial cells. Computed tomography disclosed a thin-walled contrast-enhancing structure containing non-enhancing homogenous contents. Exploratory thoracotomy confirmed an intramural cystic oesophageal structure, which was resected. Histopathological analysis of the resected tissue demonstrated an intramural oesophageal duplication cyst. A 12 month follow-up period has seen complete resolution of the cat’s clinical signs. Relevance and novel information This is the first report of successful oesophageal duplication cyst removal in a cat. Oesophageal duplication cysts should be included on the differential list for dysphagia and regurgitation in cats. Complete surgical removal in this cat carried a good long-term outcome.