Meticillin-resistant Staphylococcus aureus in a veterinary orthopaedic referral hospital: staff nasal colonisation and incidence of clinical cases

OBJECTIVES: To evaluate staff nasal colonisation with meticillin-resistant Staphylococcus aureus in a veterinary orthopaedic referral hospital, and its effect on the occurrence of meticillin-resistant Staphylococcus aureus-associated postoperative wound complications in orthopaedic and spinal surgical patients. METHODS: Nasal bacterial swabs were collected from veterinary staff and environmental surfaces swabbed at six monthly intervals for meticillin-resistant Staphylococcus aureus monitoring over an 18 month period. The incidence of meticillin-resistant Staphylococcus aureus-associated postoperative wound complications of two veterinary orthopaedic surgeons was reviewed for a period when one was positive for nasal meticillin-resistant Staphylococcus aureus. RESULTS: Meticillin-resistant Staphylococcus aureus was isolated from a maximum of two out of 10 staff on each occasion. The persistently infected clinician was primary surgeon in 180 cases, of which four developed meticillin-resistant Staphylococcus aureus-associated wound complications. None of 141 operations led by the other surgeon developed meticillin-resistant Staphylococcus aureus-associated complications. This difference is not statistically significant (P=0.0974). The 95 per cent confidence interval for this odds ratio was 0.83 to 44.0. Meticillin-resistant Staphylococcus aureus resistance patterns of the human nasal isolates and three of four wound-associated isolates were similar. CLINICAL SIGNIFICANCE: Veterinary workers are at increased risk for meticillin-resistant Staphylococcus aureus colonisation, so it is likely that many veterinary patients are treated by meticillin-resistant Staphylococcus aureus-positive staff. Nasal colonisation of veterinary surgeons with meticillin-resistant Staphylococcus aureus appears to present only a small risk to their patients when appropriate infection control procedures are followed.     

Acquired urinary incontinence in bitches: its incidence and relationship to neutering practices

A five-year cohort study was conducted on bitches chosen by a sample of 233 randomly selected practising veterinary surgeons in the UK, to estimate the incidence of acquired urinary incontinence (AUI) in neutered and entire animals, and to investigate possible risk factors associated with neutering practices. Information was collected using questionnaires, and data on 809 bitches, of which 22 developed AUI, were obtained. The estimated incidence rates in neutered and entire animals were 0·0174 and 0·0022 per animal-year, respectively (95 per cent confidence intervals: 0·0110, 0·0275 and 0·0009, 0·0058, respectively). The relative risk, neutered vs entire, was 7·8 (95 per cent confidence interval: 2·6, 31·5). The attributable proportion_exposed and population attributable proportion were 87·1 per cent and 63·1 per cent (95 per cent confidence intervals: 61·9 per cent, 95·6 per cent, and 28·3 per cent, 88·5 per cent, respectively). An increased risk, significant at the conventional 5 per cent level, was not demonstrated in animals neutered before, vs after, first heat (relative risk: 3·9, 95 per cent confidence interval: 0·8, 10·4), although the result was significant at the 10 per cent level. Removal of the cervix was not shown to be a risk factor in neutered dogs.     

The perceived and actual diagnostic utility of veterinary cytological samples

O bjectives : To establish the proportion of cytology samples sent to a commercial veterinary laboratory that yields diagnostically useful information in the context of current use and perceptions of cytology.
M ethods : Nine hundred and forty-five cytology submissions were retrospectively collected and categorised according to diagnostic utility. A survey into the use and perceptions of cytology was distributed at the British Small Animal Veterinary Association Congress 2008.
R esults : A specific diagnosis was reached in 23·1 per cent of samples and a cytological diagnosis in 35·3 per cent. 22·4 per cent of samples yielded some useful information, but 19·2 per cent were unacceptable. Seventy-four participants in the survey took an average of 3·9 cytological samples per week, of which they examined 27·0 per cent in-house only, 21·6 per cent in-house before sending to an external laboratory and 51·4 per cent were sent externally without prior examination. "To obtain a definitive diagnosis" was the principal reason cited for performing cytology.
C linical S ignificance : Results suggest that cytology is underused and may be applied in an inappropriate context in the UK. It is hoped that illustrating the diagnostic outcome of samples received by a commercial laboratory will encourage increased, appropriate use of cytology.     

The effects of nitrous oxide on recovery from isoflurane anaesthesia in dogs

O bjectives : To assess rate and quality of recovery from anaesthesia where isoflurane was delivered in oxygen or oxygen/nitrous oxide.
M ethods : Dogs anaesthetised with propofol were randomly allocated to receive isoflurane maintenance in either 100 per cent oxygen (group 1) or 66 per cent nitrous oxide (N₂O)/34 per cent oxygen (group 2). Time from end of anaesthesia to achieving sternal recumbency was recorded. Incidence of adverse behaviours (vocalisation, uncontrolled head movement and restlessness) were assessed. Recovery quality was recorded on a visual analogue scale (VAS) (anchored at 0 with "best possible" recovery and "did not recover" at 100 mm). Age, weight, gender, anaesthetic duration, mean vaporiser setting, VAS scores, recovery times, postoperative temperature and behavioural scores were compared (chi-squared test, Mann-Whitney U test or t -test as appropriate, significance P≤0·05).
R esults : Objective data from 54 dogs were analysed, only VAS data where the observer was unaware of treatment group were used (n=33). Recovery was faster in group 2 dogs (median 10 min [range 4 to 31] compared with 14 minutes [3 to 43] in group 1, P=0·049) with less restlessness (0 [0 to 4] compared with 2 [0 to 4] in group 1, P=0·013) and uncontrolled head movement (0 [0 to 4] compared with 1 [0 to 3] in group 1, P<0·001). However, VAS scores were not statistically different between groups (group 1: mean 39·4 mm [s.d. 24·0)]; group 2: 30·1 mm [25·9]; P=0·303).
C linical S ignificance : Addition of N₂O to isoflurane anaesthesia results in a lower incidence of adverse behaviour (for example restlessness) and marginally faster recovery.     

The efficacy of chlorhexidine gluconate in canine skin preparation – practice survey and clinical trials

O bjectives : To determine the use in practice and efficacy of different concentrations of chlorhexidine gluconate for canine pre-operative skin preparation.
M ethods : Questionnaires were used to establish which antiseptics and techniques were used for patients undergoing elective neutering. In a clinical study, five different concentrations of chlorhexidine gluconate – 0 per cent (tap water, as a control) 1, 2, 3 and 4 per cent – were tested on 50 dogs undergoing elective ovariohysterectomies and orchidectomies.
R esults : A variety of preparation practices occurred but only 21 per cent of the veterinary nurses surveyed were aware of the concentration and contact time they used whilst preparing animals. The clinical study revealed there was a significant difference (P<0·001) between the different concentrations used. All concentrations of chlorhexidine were significantly more effective than the control tap water. There was a tendency towards increasing efficacy as concentration increased from 1 to 4 per cent but this was not statistically significant.
C linical S ignificance : The lack of significant differences in efficacy between the different concentrations of chlorhexidine gluconate means that current practices may be adequate, although if the chlorhexidine gluconate concentrations and contact times used are unknown, they may be lower than those tested here and, possibly, ineffective, especially if contact times are short.     

Outcome following removal of canine spindle cell tumours in first opinion practice: 104 cases

O bjectives : To define the outcome of a cohort of canine patients with a histological diagnosis of spindle cell tumour of soft tissue managed solely by surgery in first opinion practice.
M ethods : Clinical details of 104 spindle cell sarcomas submitted to Finn Pathologists during the year 2000 were reviewed. Questionnaires were sent to the submitting veterinarians, requesting details about the tumour, surgery performed and ultimate outcome of the patient.
R esults : The method of surgical resection was described as marginal in 45 dogs (44·2 per cent). Excision margins of 3 cm or more were described in less than 10 per cent of cases. Tumours recurred locally in 29 dogs (27·9 per cent). Eighteen dogs (21·7 per cent) died of tumour-related causes. Most deaths were unrelated to sarcoma (50 dogs, 60·2 per cent) or unknown (15 dogs, 18 per cent). The median survival time was 1013 days. Tumour size, location or degree of surgical resection were not significantly related to survival or tumour recurrence. A palpable assessment of tumour invasion into underlying tissues was significantly associated with decreased disease-free interval (P<0·0001) and survival time (P = 0·0070).
C linical S ignificance : The results of this retrospective study indicate that many spindle cell tumours managed in first opinion practice exhibit a low-grade biological behaviour and may respond well to more conservative surgery than current recommendations advise.     

Prevalence, antibiotic resistance and molecular characterisation of Staphylococcus aureus in pigs at agricultural fairs in the USA

Fairs and petting zoos have been associated with outbreaks of zoonotic disease. Previously, the presence of meticillin-resistant Staphylococcus aureus (MRSA) was documented in commercial pigs; therefore, it was hypothesised that antibiotic-resistant S aureus may also occur in pigs exhibited at agricultural fairs. To test this hypothesis, 157 pigs were swabbed at two state fairs in 2008 to 2009. Both nares were sampled and cultures were grown in enrichment broth, then plated onto selective MRSA plates and blood plates. S aureus was confirmed using phenotypic and molecular methods, and was analysed using spa typing, gene-specific polymerase chain reaction and antibiotic susceptibility testing. The presence of S aureus was confirmed in samples collected from pigs exhibited at USA pig shows. Twenty-five of 157 (15.9 per cent) samples were positive for S aureus. Two isolates (8 per cent) were resistant to meticillin; 23/25 (92 per cent), 14/25 (56 per cent) and 15/25 (60 per cent) were resistant to tetracycline, erythromycin and clindamycin, respectively. spa typing revealed multiple isolates of spa type t034 (9/25, 36 per cent) and t337 (7/25, 28 per cent) and singletons of t002, t209, t526, t1236, t1334, t1683, t3075, t5784 and t5883. These results verify the presence of antibiotic-resistant S aureus in pigs exhibited at USA fairs, suggesting that pigs are a potential reservoir for S aureus within this environment.     

Prevalence of diagnostic characteristics indicating canine autoimmune lymphocytic thyroiditis in giant schnauzer and hovawart dogs

O bjectives : To investigate prevalence of autoantibodies to thyroglobulin (TgAA) and/or elevated levels of thyroid stimulating hormone (TSH), indicating canine autoimmune lymphocytic thyroiditis (CLT) and/or hypothyroidism, in two high-risk dog breeds.
M ethods : A cohort study was conducted in two birth cohorts of giant schnauzer and hovawart dogs. The cohorts were three to four and six to seven years of age at the time of blood sampling and screening for TgAA and TSH levels. Blood sampling was accompanied by one initial and one follow-up questionnaire to the dog owners. A total number of 236 giant schnauzers and 95 hovawarts were included in the study.
R esults : Seventeen (7.2 per cent) giant schnauzers and three (3·2 per cent) hovawarts had been diagnosed as hypothyroid at the time of sampling. Out of the remaining dogs, 22 giant schnauzers (10·0 per cent) and nine hovawarts (10·1 per cent) had elevated TgAA and/or TSH levels. Prevalence of elevated TgAA and TSH levels varied with age.
C linical S ignificance : The high prevalence of diagnostic characteristics indicating CLT/hypothyroidism in these two breeds suggests a strong genetic predisposition. It would be advisable to screen potential breeding stock for TSH and TgAA as a basis for genetic health programmes to reduce prevalence of CLT in these breeds.     

Ketone measurements using dipstick methodology in cats with diabetes mellitus

O bjectives : To compare the results of urine and plasma ketone dip test in a group of diabetic cats with possible ketosis or ketoacidosis, using laboratory plasma β-hydroxybutyrate measurements as the gold standard.
M ethods : According to clinical examinations, plasma β-hydroxybutyrate measurements and venous blood gas analysis, 54 cats with diabetes mellitus were classified as non-ketotic (n=3), ketotic (n=40) or ketoacidotic (n=11). Plasma and urine acetoacetate concentrations were determined using urine reagent strips.
R esults : Although there was a significant positive correlation between blood and urine ketone measurements (r=0·695, P<0·001), the results differed significantly (Z=−3·494, P<0·001). Using the differential positive rates, the best cut-off value to detect cats with ketoacidosis was 1·5 mmol/l for urine and 4 mmol/l for plasma. The sensitivity/specificity was 82/95 per cent for urine and 100/88 per cent for plasma, respectively.
C linical S ignificance : The urine and plasma ketone dip tests have a different diagnostic accuracy, and results have to be interpreted differently. Because of its high sensitivity, the plasma ketone dip test performs better than the urine ketone dip test to identify cats with impending or established ketoacidosis.     

Efficacy of directed misting application of a peroxygen disinfectant for environmental decontamination of a veterinary hospital

OBJECTIVE: To evaluate effectiveness of 4% peroxymonosulfate disinfectant applied as a mist to surfaces in a large animal hospital as measured by recovery of Staphylococcus aureus and Salmonella enterica serovar Typhimurium. DESIGN: Field trial. SAMPLE POPULATION: Polyester transparencies inoculated with bacteria. PROCEDURE: Polyester transparencies were inoculated with S aureus or S Typhimurium and placed in various locations in the hospital. After mist application of the peroxygen disinfectant, viable bacterial numbers were quantified and compared with growth from control transparencies to assess reduction in bacterial count. RESULTS: When applied as a mist directed at environmental surfaces contaminated with a geometric mean of 4.03 x 10(7) CFUs of S aureus (95% confidence interval [CI], 3.95 x 10(7) to 4.11 x 10(7)) or 6.17 x 10(6) CFUs of S Typhimurium (95% Cl, 5.55 x 10(6) to 6.86 x 10(6)), 4% peroxymonosulfate reduced the geometric mean number of viable S aureus by 3.04 x 10(7) CFUs (95% Cl, 8.6 x 10(5) to 1.7 x 10(6)) and S Typhimurium by 3.97 x 10(6) CFUs (95% Cl, 8.6 x 10(5) to 3.5 x 10(6)). CONCLUSIONS AND CLINICAL RELEVANCE: Environmental disinfection with directed mist application of a 4% peroxymonosulfate solution was successful in reducing counts of bacterial CFUs by > 99.9999%. Directed mist application with this peroxygen disinfectant as evaluated in this study appeared to be an effective and efficient means of environmental disinfection in a large animal veterinary hospital and would be less disruptive than more traditional approaches to intensive environmental cleaning and disinfection.     

A comparative randomized field trial on intramammary and intramuscular dry cow antibiotic treatment of subclinical Staphylococcus aureus mastitis in dairy cows

The efficacy of two dry cow treatment (DCT) regimens for subclinical Staphylococcus aureus mastitis was evaluated in naturally infected dairy cows. At dry-off, cows were assigned to two treatment groups by randomized blocks on the basis of parity and somatic cell count (SCC). Two antibiotic DCT regimens were used, namely: (1) a single intramammary infusion containing sodium nafcillin, procaine benzylpenicillin and dihydrostreptomycin; and (2) systemic cefquinome administered intramuscularly, twice at a 24-h interval. In the intramammary (IMM) treatment group, the S. aureus intramammary infection (IMI) rate was reduced from 40% (56/140 quarters) before dry-off to 20% (28/140) after calving. Seventy per cent (39/56) of the S. aureus-positive quarters were negative after calving, and 13% (11/84) of the negative quarters were positive after calving. In the systemic treatment group, the S. aureus IMI rate increased from 39% (29/74 quarters) before dry-off to 55% (41/74) after calving. Twenty-eight per cent (8/29) of the S. aureus-positive quarters were negative after calving and 45% (20/45) of the negative quarters were positive after calving. The odds ratio of an S. aureus-positive quarter being negative after calving in the IMM group relative to the systemic therapy group was 44.6 (95% confidence interval = 2.1-909.1, P < 0.01). Parity, quarter, milk SCC and N-acetyl-beta-D-glucosaminidase were tested in the model, and were found to have no significant effect on S. aureus cure rates or new IMI rates. The IMM treatment resulted in a higher cure rate compared with that observed in previous studies. The very low cure rate after systemic cefquinome treatment was comparable to the spontaneous cure rate observed in untreated controls in previous studies. The unfavourable results of the cefquinome systemic DCT might reflect inadequate pharmacokinetic properties of the drug regarding poor udder penetration in subclinical mastitis and short antimicrobial effect compared with the IMM treatment.     

The effect of omeprazole on oesophageal pH in dogs during anaesthesia

O bjectives : Intra-operative, gastro-oesophageal reflux may be associated with post-anaesthestic complications such as oesophagitis and oesophageal stricture in dogs. The aim of this study was to investigate the effect of preoperative administration of omeprazole, a proton pump inhibitor, on oesophageal pH in anaesthetised dogs.
M ethods : Forty-seven dogs undergoing elective pelvic limb orthopaedic surgery were enrolled into the study. These were randomly allocated to treatment group (n=22) or control group (n=25). The treatment group received one dose of omeprazole (1 mg/kg po) at least 4 h before anaesthesia. All dogs were anaesthetised by the same standardised protocol. A pH probe was inserted into the distal oesophagus after induction of anaesthesia and oesophageal pH was continuously monitored.
R esults : In the treatment group, four animals (18 per cent) showed a sudden decrease in oesophageal pH (<4). In the control group the same phenomenon was detected in 13 animals (52 per cent). Gastro-oesophageal reflux occurred more frequently in the control group compared with the omeprazole group (odds ratio 4·7, 95 per cent C.I. 1.1 to 24.7, P=0.032).
C linical S ignificance : This study suggests that the preoperative administration of omeprazole is effective in reducing the incidence of gastro-oesophageal reflux during anaesthesia in dogs.     

Radiographic appearance of cardiogenic pulmonary oedema in 23 cats

O bjective : To describe the radiographic appearance of pulmonary oedema in cats with cardiac failure.
M ethods : Thoracic radiographs of 23 cats presented to a first opinion practice with signs of cardiac failure were reviewed. All cats had tachypnoea and/or dyspnoea and enlarged left atrium on echocardiography.
R esults : Pulmonary oedema was characterised radiographically by an increased opacity associated with a range of patterns and variable distribution. All cats had evidence of a reticular or granular interstitial pattern. This occurred in combination with alveolar pattern in 19 (83 per cent) cats, including six with air bronchograms, with increased diameter of pulmonary vessels in 16 (71 per cent) cats and with bronchial pattern in 14 (61 per cent) cats. The distribution of pulmonary oedema was considered to be diffuse/non-uniform in 14 (61 per cent) cats, diffuse/uniform in four (17 per cent) cats, multi-focal in four (17 per cent) cats and focal in the remaining one (4 per cent). Nine (39 per cent) cats were considered to have a regional distribution of oedema, including five (22 per cent) with a ventral distribution, three (13 per cent) with a caudal distribution and one (4 per cent) cat with a hilar distribution. The distribution of pulmonary opacities was bilaterally symmetrical in five (22 per cent) cats.
C linical S ignificance : The variable appearance of feline pulmonary oedema is likely to complicate its radiographic diagnosis.     

Chiari-like malformation in the Griffon Bruxellois

O bjectives : This study describes Chiari-like malformation and syringomyelia in the Griffon Bruxellois and establishes if skull radiographs are useful for disease prediction.
M ethods : Magnetic resonance imaging from 56 Griffon Bruxellois dogs was assessed for Chiari-like malformation and cerebrospinal fluid pathway abnormalities. Skull radiographs were obtained in 33 dogs. Two rostrocaudal and two ventrodorsal measurements were made, and ratios of one length to another were compared.
R esults : In this selected sample, 60·7 per cent had Chiari-like malformation. Syringomyelia occurred with and without Chiari-like malformation (37·5 and 8·9 per cent study population, respectively). The radiographic study demonstrated that one measurement ratio could be used to predict Chiari-like malformation (sensitivity of 87 per cent and specificity of 78 per cent) and that there were significant interaction factors between sex and syringomyelia for two measurement ratios.
C linical S ignificance : The study suggests that Chiari-like malformation is characterised by a shortening of the basicranium and supra-occipital bone with a compensatory lengthening of the cranial vault, especially the parietal bone. We described a simple radiographic technique, which may be useful as a screening test until a more definite genetic test for Chiari-like malformation is available.     

Patellar luxation in 70 large breed dogs

O bjectives : To report the signalment, history, clinical features, and outcome in dogs weighing greater than 15 kg, treated surgically and non-surgically for patellar luxation. Risk factors for the development of patellar luxation, postoperative complications, and outcome were evaluated.
M ethods : Details regarding signalment, bodyweight, breed, aetiology, unilateral or bilateral luxation, duration of lameness, grade of luxation, direction of luxation, grade of lameness at presentation, concomitant cranial cruciate ligament rupture, method of treatment, surgical technique, surgeon, and complications were obtained from the medical records. Outcome was graded as excellent, good, fair, or poor, according to the degree of lameness.
R esults : Seventy dogs (45 males and 25 females) were included. Thirty-five had bilateral luxations (105 limbs). Mean age was two years, and mean weight was 30 kg. The relative risk for Labrador retrievers was 3·3 (P<0·001). All luxations were developmental. Luxations were medial in 102 stifles and lateral in three. Fourteen stifles had concomitant cranial cruciate ligament rupture. As the grade of patellar luxation increased, so did the grade of lameness (P<0·001). Surgery was performed in 70 stifles, and outcome was excellent/good in 94 per cent and fair/poor in 6 per cent of stifles. Complications occurred in 29 per cent of stifles, and increasing bodyweight was found to be a risk factor (P=0·03). Thirty-five stifles were managed non-surgically, and outcome was excellent/good in 86 per cent and fair/poor in 14 per cent of stifles.
C linical S ignificance : In view of the potential risk of postoperative complications, all surgically treated cases of patellar luxation in large breed dogs should be managed with a femoral trochleoplasty, a tibial tuberosity transposition (stabilised with K-wires and a tension band wire), and soft tissue releasing and tightening procedures.     

Feline extranodal lymphoma: response to chemotherapy and survival in 110 cats

O bjective : To determine response to treatment, survival and prognostic factors for feline extranodal lymphoma in the UK.
M ethods : Records of cats diagnosed with lymphoma of extranodal sites at seven referral centres were reviewed and information on signalment, tumour location, prior treatment and chemotherapy protocol recorded. Factors influencing response to treatment and survival were assessed.
R esults : One hundred and forty-nine cases met inclusion criteria. Sixty-nine cats had nasal lymphoma, 35 renal, 15 central nervous system, 11 laryngeal and 19 miscellaneous locations. Sixty-six cats received cyclophosphamide, vincristine, prednisolone, 25 Wisconsin-Madison doxorubicin-containing multi-agent protocol, 10 prednisolone alone and nine other combinations. The response rate for the 110 treated cats was 85·5 per cent. Of cyclophosphamide, vincristine, prednisolone treated cats 72·7 per cent achieved complete remission, median survival 239 days. Sixty-four per cent of Wisconsin-Madison treated cats achieved complete remission, median survival 563 days. Cats with nasal lymphoma achieving complete remission had the longest survival (749 days) and cats with central nervous system lymphoma the shortest (70 days). If complete remission was achieved, prior treatment with corticosteroids significantly reduced survival time.
C linical S ignificance : Cats with extranodal lymphoma respond to chemotherapy and achieve survival times comparable to other locations. Corticosteroid pretreatment reduced survival time in cats achieving complete remission.     

Long-term results of transarticular pinning for surgical stabilisation of coxofemoral luxation in 20 cats

O bjectives : The objective of this study was to describe initial and long-term results of open reduction and transarticular pinning for treatment of coxofemoral luxations in cats.
M ethods : Cats were treated by open reduction and transarticular pinning for coxofemoral luxation over a five year period at two institutions. Follow-up assessment included orthopaedic examination, radiography and owner questionnaires.
R esults : Twenty cats were included in the study (14 males and six females). One cat was affected bilaterally. Mean time to follow-up was 21 months. Seventeen joints were stabilised with a 1·6 mm pin, three with 2·0 mm pins and a 1·2 mm pin was used in the remaining joint. An Ehmer sling was not utilised in any case. All transarticular pins except one were removed (mean 3·5 weeks), with all hips still in reduction The overall success rate was 77 per cent, with two reluxations and one resorbed femoral head noted on radiographs of 13 joints followed long term. All 20 owners reported good to excellent long-term functional outcome for their cats.
C linical S ignificance : Results from this study indicate that transarticular pinning for stabilisation of coxofemoral luxation in cats can provide a good long-term outcome without sacrificing the integrity of the coxofemoral joint.     

Detection of Leishmania infantum by real-time PCR in a canine blood bank

O bjectives : Risk for transmission of Leishmania infantum from blood products has been largely demonstrated in human and veterinary literature. Appropriate screening of canine blood donors is important especially in an endemic area such as Barcelona (Spain). The purpose of this study was to evaluate the presence of L infantum DNA parasites by real-time quantitative PCR in our canine blood bank.
M ethods : Samples from blood products obtained from 92 canine blood donors were assayed for L infantum by means of real-time PCR amplification and quantification.
R esults : The prevalence of quantitative PCR-positive blood samples among healthy seronegative blood donors was 19·6 per cent.
C linical S ignificance : The results of this study show that L infantum infection is common in canine blood donors and their blood products in an endemic area, despite a negative commercial serological screening for infectious diseases. Therefore, screening by PCR should be included in an integrated approach to evaluate L infantum infection among potential blood donors.     

Comparison of magnetic resonance imaging sequences in dogs with multi-focal intracranial disease

OBJECTIVES: To compare the value of different magnetic resonance sequences in the detection of brain lesions in dogs with multi-focal intracranial neurolocalised lesions and abnormal cisternal cerebrospinal fluid analysis. METHODS: T2-weighted, T1-weighted, T1-weighted-Gd, FLAIR (fluid attenuated inversion recovery) images of 73 dogs with multi-focal intracranial localised lesions were reviewed retrospectively. Control dogs (19) were selected on the basis of normal neurological examination, magnetic resonance images and cerebrospinal fluid analysis. Two board-certified radiologists blindly reviewed the magnetic resonance images. Magnetic resonance sequence sensitivities were compared using the chi-squared test and logistic regression, accounting for clustering at the patient level. Statistical significance was set at the 5 per cent level. RESULTS: The FLAIR sequence was found to have the highest sensitivity (84 per cent, 61 of 73), followed by T2-weighted (63 per cent, 46 of 73), T1-weighted postcontrast (62 per cent, 45 of 73) and T1-weighted (23 per cent, 17 of 73) (P<0.001). FLAIR images were 106.1 times (95 per cent confidence interval 25.2 to 447.5) more likely to correctly identify cerebrospinal fluid-positive patients than T1-weighted, 6.4 times (95 per cent confidence interval 2.2 to 18.2) than T1-weighted postcontrast and 5.8 times (95 per cent confidence interval 2.0 to 16.4) than T2-weighted. FLAIR identified 14 per cent of cases that were classified as normal based on the three others sequences. CLINICAL SIGNIFICANCE: Routine use of FLAIR sequence should be encouraged in dogs undergoing a brain magnetic resonance imaging and probably more specifically in cases of suspected inflammatory brain disease.     

Demographic characteristics of the equine population of northern Britain.

The size, composition and distribution of the equine population of Scotland and the five northernmost counties in England were estimated through a series of mailed questionnaire surveys of sentinel veterinary practices and horse owners. An estimated 96,622 equine animals were kept by an estimated 26,114 owners. The mean (sd) age of the population was 11.0 (7.5) years (range one month to 37 years). Thoroughbred or thoroughbred-cross animals were the most numerous, constituting 30 per cent (95 per cent confidence interval 27 to 33 per cent) of the total population. The ratio of males:females was 1:1.