A. McBrearty

Comparison of rectal, tympanic membrane and axillary temperature measurement methods in dogs

The aim of this study was to compare axillary and tympanic membrane (TM) temperature measurements to rectal temperature in a large group of clinical canine patients. We also sought to ascertain whether certain factors affected the differences between the measurements and to compare the ease of measurement. Axillary temperatures were easy to obtain but tended to be lower than rectal readings (median difference 0.6°C). In 54.7 per cent of dogs there was a difference of >0.5°C between the two readings. Weight, coat length, body condition score and breed size were significantly associated with the difference between the rectal and axillary temperature. TM temperatures were more similar to rectal temperatures (median difference 0°C) but in 25 per cent of dogs, there was a difference of >0.5°C between rectal and TM readings. TM measurements were less well tolerated than axillary measurements. None of the factors assessed were associated with the difference between the rectal and TM temperature. As a difference of >0.5°C has previously been described as unacceptable for different methods of temperature measurement, neither axillary nor TM temperatures are interchangeable with rectal temperatures for the measurement of body temperature.

Clinical factors associated with death before discharge and overall survival time in dogs with generalized megaesophagus

OBJECTIVE To investigate the association of 6 clinical features with outcome of dogs with generalized megaesophagus. DESIGN Retrospective cohort study. ANIMALS 71 client-owned dogs with radiographic evidence of generalized esophageal dilation. PROCEDURES Medical records were reviewed for data on signalment, age at onset of clinical signs, body weight, evidence of undernutrition, and the administration of drugs to treat or prevent esophagitis. Radiographs were reviewed for evidence of aspiration pneumonia (AP) and to calculate the relative esophageal diameter. Details of outcome were collected from the medical records and by contacting owners and referring veterinarians. The association of 6 factors with death before discharge and overall survival time was assessed. RESULTS Overall median survival time was 90 days. Nineteen (26.7%) patients died before discharge from the hospital. Radiographic evidence of AP was both positively associated with death before discharge and negatively associated with overall survival time. An age at onset of clinical signs of >13 months was negatively associated with overall survival time. No evidence of an association of the degree of esophageal dilation or the use of drugs to prevent or treat esophagitis with death before discharge or overall survival time was found. CONCLUSIONS AND CLINICAL RELEVANCE Radiographic evidence of AP and the age at onset of clinical signs were the only variables found to be significantly associated with survival time in this study, and this should be considered when advising on prognosis in dogs with megaesophagus.

Agarose gel serum protein electrophoresis in cats with and without lymphoma and preliminary results of tandem mass fingerprinting analysis

BACKGROUND Serum electrophoretic profiles in cats are poorly characterized with respect to the proteins that comprise the globulin fractions, and interpretation of the electrophoretograms is routinely done in the absence of information about identity of the proteins found within each fraction. OBJECTIVES The aims of this study were to compare protein fractions separated by serum protein electrophoresis (SPE) in healthy cats and in cats with lymphoma and to confirm some component proteins in the major fractions following SPE using tandem mass fingerprinting analysis (TMFA). METHODS Total protein concentration was measured and agarose gel SPE performed on serum from 14 healthy cats and 14 cats with lymphoma. The absolute protein concentration within each fraction was compared between the 2 groups. Bands corresponding to the SPE fractions were excised from the gels of 2 control cats and 1 cat with lymphoma and analyzed by liquid chromatography coupled to mass spectrometry. Results were compared with sequences in the National Center for Biotechnology Information protein database. RESULTS Median albumin concentrations were significantly decreased and median β-globulin concentrations were significantly increased in cats with lymphoma. Narrow electrophoretic spikes were present in the β/γ-globulin fraction in 3 cats with lymphoma. Following TMFA, multiple proteins were identified in each fraction, and their mobility agreed with results from previous studies generated using alternative techniques. Inter-α (globulin) inhibitor 4 was identified in feline serum for the first time. CONCLUSIONS Cats with lymphoma had lower albumin and higher β-globulin concentrations than did healthy cats. Despite limitations of one-dimensional agarose gel SPE, TMFA provided preliminary data to confirm the protein components of the various fractions.

Evaluation of auditory function in a population of clinically healthy cats using evoked otoacoustic emissions

Cats may demonstrate deafness due to a variety of aetiologies and the current preferred method for assessing auditory function is the brainstem auditory evoked response (BAER). The BAER has largely been replaced by otoacoustic emission (OAE) testing in human neonatal deafness screening as the equipment is more readily available, is cheaper and the test is less invasive and simpler. This is the first study to demonstrate that transient evoked OAEs (TEOAE) and distortion product OAEs (DPOAE) can be recorded in cats using commercially available equipment. Protocols for recording the emissions and analysing the results are given. DPOAE testing is suggested to be quicker in this population of healthy cats and shows promise in rapidly providing detailed information about auditory function at a variety of different frequencies.

Comparison of axillary, tympanic membrane and rectal temperature measurement in cats

Objectives Rectal temperature (RT) is routinely used to assess body temperature in cats but has limitations and can be poorly tolerated. Axillary temperature (AT) and tympanic membrane temperature (TMT) are reported alternatives. This study aimed to determine the differences between RT and AT, and between RT and TMT in cats. Additional aims were to examine the effect of environmental and patient factors on these differences and to assess patient tolerance to each technique. Methods AT, TMT and RT were measured in immediate succession. Measurement order was randomised, as was the choice of left or right axilla and tympanic membrane. A digital thermometer and a veterinary infrared ear thermometer were used. The subjective tolerance of each procedure was recorded. Results One hundred and fifty cats were included. Significantly more conscious cats were tolerant of AT (90.6%) than TMT (81.2%) and RT (53.0%). The rectal–axillary temperature difference ranged from −1.2°C to 1.4°C (median 0.1°C) and was within ±0.5°C in 78.0% of cats. On multivariable analysis the difference was larger in overweight cats, neutered cats, cats in which the right axilla was used and as the RT increased. The rectal–tympanic membrane temperature difference ranged from −1.6°C to 3°C (median −0.3°C) and was within ±0.5°C in 51.3% of cats, significantly fewer than for AT (P <0.001). The rectal–tympanic membrane temperature difference increased as the RT increased. Conclusions and relevance TMT and AT should not be used interchangeably with RT in cats. When RT measurement is not possible, AT is recommended over TMT as it is better tolerated and significantly fewer cats had clinically unacceptable differences (>0.5°C). AT may more closely reflect RT in normal or underweight cats than it does in overweight cats.

Clinical evaluation of cochlear hearing status in dogs using evoked otoacoustic emissions.

OBJECTIVES Evoked otoacoustic emission testing is the preferred test in human patients for sensorineural deafness screening in neonates and cochlear outer hair cell function monitoring in adults. This study evaluated evoked otoacoustic emission testing for cochlear function assessment in dogs within a clinical setting. METHODS Two populations of anaesthetised dogs were included. In group 1 the evoked otoacoustic emission response was compared to the brainstem auditory evoked response in 10 dogs having hearing assessment. Group 2 comprised 43 presumed normal dogs, in which the suitability of two types of evoked otoacoustic emissions, transient-evoked and distortion product otoacoustic emissions, were evaluated (brainstem auditory evoked response was not performed in this group). RESULTS Valid transient-evoked otoacoustic emission and distortion-product otoacoustic emission responses were successfully recorded within the clinical setting and correctly identified deaf and hearing ears. Within presumed healthy dogs, normal otoacoustic emission response was demonstrated in more than 80% of dogs using a single, short distortion-product otoacoustic emission run and in 78% of dogs with valid transient-evoked otoacoustic emission responses using a series of three repeated transient-evoked otoacoustic emission short runs. CLINICAL SIGNIFICANCE Transient-evoked otoacoustic emission and distortion-product otoacoustic emission testing provided a rapid, non-invasive frequency-specific assessment of cochlear function. Transient-evoked otoacoustic emission and distortion product otoacoustic emission testing is suitable as a screening procedure to detect loss of cochlear function in dogs, although further investigation is needed.

The effect of magnetic resonance imaging noise on cochlear function in dogs

Noise produced by magnetic resonance imaging (MRI) scanners (which can peak at a sound pressure level of 131 dB) has been shown to cause noise-induced cochlear dysfunction in people. The aim of this study was to investigate whether noise produced during MRI had a deleterious effect on cochlear function in dogs, using distortion product otoacoustic emission (DPOAE) testing, which allows frequency specific, non-invasive assessment of cochlear function. DPOAE testing was performed before and after MRI in one or both ears under general anaesthesia at 14 frequency pairs (f2 frequency ranging from 0.84 kHz to 8.0 kHz). A control group comprised dogs undergoing anaesthesia of a similar duration for quiet procedures. Thirty-six dogs (66 ears) and 17 dogs (28 ears) were included in the MRI and control groups respectively. There was a reduction in DPOAE at all frequencies tested in the MRI group; a similar effect was not evident in the control group. This reduction in the MRI group was statistically significant in five of the 14 frequencies assessed (P < 0.05). These results demonstrate that exposure to MRI noise results in a significant reduction in frequency-specific cochlear function in dogs, although it is not known whether this is reversible or permanent. This suggests that all dogs undergoing MRI studies should be provided with ear protection as a routine precautionary measure.

Hair nicotine concentration measurement in cats and its relationship to owner-reported environmental tobacco smoke exposure

OBJECTIVES To investigate the association between hair nicotine concentration in cats and owner-reported exposure to environmental tobacco smoke. MATERIALS AND METHODS Owner questionnaires documented exposure. Nicotine was extracted from hair by sonification in methanol followed by hydrophilic interaction chromatography with mass spectrometry. Relationships between hair nicotine concentration and owner-reported exposure were examined using hypothesis-testing statistics and receiver operating characteristic curve analysis. RESULTS The hair nicotine concentration of reportedly exposed cats was significantly higher than unexposed cats and groups of cats with different levels of exposure had significantly different median hair nicotine concentrations corresponding to exposure. A hair nicotine concentration of 0·1 ng/mg had a specificity of 98% (95% confidence interval: 83 to 100) and a sensitivity of 69% (95% confidence interval: 54 to 84) for detecting environmental tobacco smoke exposure. Outdoors access, coat colour, urban or rural environment and length of time living with the owner were not obviously associated with hair nicotine concentration. CLINICAL SIGNIFICANCE Feline hair nicotine concentration appears strongly associated with owner-reported environmental tobacco smoke exposure. Feline hair nicotine concentration could therefore be used as a biomarker for tobacco smoke exposure, allowing future studies to assess whether exposed cats have an increased risk of specific diseases.

Use of accelerometry to investigate physical activity in dogs receiving chemotherapy

OBJECTIVES To perform a preliminary study to assess whether single-agent palliative or adjuvant chemotherapy has an impact on objectively measured physical activity in dogs. METHODS Fifteen dogs with neoplasia (treatment group) wore ActiGraph™ accelerometers for 5-day periods before, during and after receiving single-agent adjuvant or palliative chemotherapy. Mean 5-day total physical activity and time spent in three different intensities of activity (sedentary, light-moderate and vigorous) before, during and after receiving chemotherapy were compared to a group of 15 healthy dogs (control group). Results were also compared within the treatment group across time. RESULTS Prior to chemotherapy, treated dogs tended to be less active than control dogs. Treatment group dogs were slightly more active at restaging than they were prior to treatment but had similar activity levels to control dogs. Marked effects of chemotherapy on physical activity were not detected. Physical activity was slightly lower in treated dogs during chemotherapy when compared to control dogs but there was a slight increase in physical activity of treated dogs during chemotherapy when compared with pretreatment recordings. There was little change in the mean 5-day total physical activity between treated dogs during chemotherapy and at restaging but a mild decrease in time spent sedentary and increase in time spent in light-moderate activity at this comparison of time points. CLINICAL SIGNIFICANCE Single-agent adjuvant or palliative chemotherapy had minimal impact on physical activity levels in dogs with neoplasia.

The challenge of teaching undergraduates evidence-based veterinary medicine

The Royal College of Veterinary Surgeons now lists ‘How to evaluate evidence’ as a day one competence for newly qualified vets. In this article, representatives from each of the veterinary schools in the UK discuss how the challenge of delivering and assessing the concepts of evidence-based veterinary medicine in a crowded undergraduate curriculum can be met.