Characteristics of residency training associated with first-time pass rate on the American College of Veterinary Ophthalmologists certifying examination.

OBJECTIVE: The aim of this study was to examine the association of various aspects of veterinary ophthalmology residency training with the first-time pass rate (FTPR) of the American College of Veterinary Ophthalmologists (ACVO) examination, as well as the individual written, image recognition, animal examination, and surgical sections of the examination. PROCEDURES: Program type, resident evaluations, cumulative surgery and case logs, and scores from ACVO examinations from 2007 to 2010 were evaluated. RESULTS: Data were available for 71 candidates. The overall FTPR was 35% (n = 25). For the different sections of the examination, FTPRs were as follows: written (68%), image recognition (76%), intraocular surgery (80%), extraocular surgery (65%), and animal examination (75%). The overall FTPR among candidates from academic residency (AR) programs was 43% (20 of 47), while the FTPR of residents in private practice (PPR) programs was 21% (5 of 24; P = 0.07). The AR candidates were more likely to pass the written portion than PPR residents (P = 0.02), and AR candidates had significantly more time off clinics (median 25%) vs PPR residents (median 18%; P = 0.007). The AR residents also had a higher reported percentage of direct supervision than PPR residents (95% vs 76%, respectively). Although PPR residents did significantly more surgeries and examined significantly more dogs and cats, those from ARs examined significantly more equine, bovine, avian, camelid, and reptile species. CONCLUSIONS: Overall, AR residents had a higher FTPR and were more likely to pass the written portion of the examination. Total case and surgery numbers were not associated with FTPR.

Effects of butorphanol versus dexmedetomidine sedation on intradermal allergen and histamine responses in dogs with atopic dermatitis.

BACKGROUND: Sedation is commonly used during intradermal testing (IDT). Morphine and its derivatives have long been avoided because of their histamine-releasing effects. HYPOTHESIS/OBJECTIVES: Butorphanol, an opioid agonist/antagonist, will not adversely affect IDT in dogs. ANIMALS: Ten client-owned dogs diagnosed with atopic dermatitis. METHODS: Dogs were randomized to be sedated with butorphanol (0.4 mg/kg) or dexmedetomidine (5 µg/kg). Routine IDT along with intradermal injections of various dilutions of histamine were performed on the lateral thorax, followed 7 days later by the alternative sedative and IDT on the opposite side. The injection sites were subjectively scored and objectively measured by one investigator, blinded to the sedatives, and compared between groups. RESULTS: When the mean wheal diameters from the objective measurements of all antigens, including saline and histamine dilutions, were compared, butorphanol was associated with significantly smaller reactions than dexmedetomidine (P = 0.0001). There was a high level of agreement between sedatives when positive reactions subjectively scored as ≥3+ were compared (κ = 0.91). When mean wheal diameters of histamine at concentrations of 1:100,000, 1:400,000, 1:1,600,000 and 1:6,400,000 were compared, there were no significant differences between sedative types. Moreover, the percentage agreement when comparing subjective interpretation of all histamine dilutions between sedations was high (κ = 0.90). However, there was only 69% agreement beyond chance when objective and subjective interpretations of all antigens were compared between sedative groups. CONCLUSIONS: Although butorphanol resulted in significantly smaller wheal size in comparison to dexmedetomidine, it did not affect the overall subjective interpretation of the results of IDT.

The effect of fentanyl on the end-tidal sevoflurane concentration needed to prevent motor movement in dogs.

OBJECTIVE: The objectives of this study were to determine the effects of fentanyl on the end-tidal concentration of sevoflurane needed to prevent motor movement (MACNM ) in response to noxious stimulation, and to evaluate if acute tolerance develops. STUDY DESIGN: Randomized cross-over experimental study. ANIMALS: Six healthy, adult (2-3 years old), intact male, mixed-breed dogs weighing 16.2 ± 1.1 kg. METHODS: Six dogs were randomly assigned to receive one of three separate treatments over a 3 week period. After baseline sevoflurane MACNM (MACNM-B) determination, fentanyl treatments (T) were administered as a loading dose (Ld) and constant rate infusion (CRI) as follows: T1-Ld of 7.5 µg kg(-1) and CRI at 3 µg kg(-1) hour(-1); T2-Ld of 15 µg kg(-1) and CRI at 6.0 µg kg (-1) hour(-1); T3-Ld of 30 µg kg(-1) and CRI at 12 µg kg(-1) hour(-1). The MACNM was defined as the minimum end-tidal sevoflurane concentration preventing motor movement. The first post-treatment MACNM (MACNM-I) determination was initiated 90 minutes after the start of the CRI, and a second MACNM (MACNM - II) determination was initiated 3 hours after MACNM-I was established. RESULTS: The overall least square mean MACNM-B for all groups was 2.66%. All treatments decreased (p < 0.05) MACNM, and the decrease from baseline was 22%, 35% and 41% for T1, T2 and T3, respectively. Percentage change in T1 differed (p < 0.05) from T2 and T3; however, T2 did not differ from T3. MACNM-I was not significantly different from MACNM-II within treatments. CONCLUSIONS AND CLINICAL RELEVANCE: Fentanyl doses in the range of 3-12 µg kg(-1) hour(-1) significantly decreased the sevoflurane MACNM. Clinically significant tolerance to fentanyl did not occur under the study conditions.

Treatment outcome of dogs with meticillin-resistant and meticillin-susceptible Staphylococcus pseudintermedius pyoderma.

BACKGROUND: The prevalence of meticillin- and multidrug-resistant Staphylococcus pseudintermedius (MRSP) in canine pyoderma has been increasing in recent years; thus, treatment of these cases has become challenging. HYPOTHESIS/OBJECTIVES: To compare treatment outcome (clinical resolution and treatment duration), adverse effects of medication, and concurrent diseases and medications in dogs with meticillin-susceptible S. pseudintermedius (MSSP) and MRSP pyoderma. ANIMALS/METHODS: Medical records were reviewed retrospectively, and 123 MSSP and 93 MRSP clinical cases between January 2008 and April 2010 were included. RESULTS: In MSSP infections, cefalexin and cefpodoxime were the most commonly prescribed antimicrobials, accounting for 43.2 and 34.4% of cases, respectively. In MRSP infections, chloramphenicol and doxycycline were most commonly prescribed, accounting for 52.6 and 14.4% of cases, respectively. Adverse effects were reported in seven MSSP and 31 MRSP cases. The most commonly reported adverse effects were gastrointestinal, prompting antibiotic discontinuation in three MSSP and 20 MRSP cases. Chloramphenicol was associated with the highest incidence of adverse reactions (27 of 51 cases). Of 164 cases with follow up, 43 of 88 MSSP infections and 29 of 76 MRSP infections achieved complete clinical resolution at the first recheck examination. Three MSSP and seven MRSP cases failed to improve or resolve at subsequent visits assessed at 3-4 week intervals. CONCLUSIONS AND CLINICAL IMPORTANCE: Results from this study showed that the majority of pyodermas resolved regardless of meticillin susceptibility. Although some cases of MRSP pyoderma took longer to treat, this is likely to be because of chronicity and not the organism. In addition, adverse effects were frequently associated with chloramphenicol administration.

Denervating the pelvic suspensory ligaments of horses causes morphological and histological changes in the ligaments.

OBJECTIVE: To examine changes occurring in normal pelvic suspensory ligaments (SLs) of horses after denervating these ligaments and to investigate the effect chronic inflammation might have on these changes. ANIMALS: 10 horses. PROCEDURES: The SL of 1 randomly selected pelvic limb of each of 5 horses was injected with collagenase to induce desmitis, and 42 days later, the proximal aspect of both pelvic SLs were denervated. The SLs were harvested 120 days after being denervated, and the morphological and histological characteristics of each collagenase-injected, denervated SL were compared with those of the contralateral, non-injected, denervated SL. All denervated SLs were compared with non-denervated pelvic SLs harvested from 5 horses similar in weight and age. RESULTS: The mean width and the cross-sectional area of the musculature of all denervated SLs were significantly less than that of the non-denervated ligaments. The mean thickness of collagenase-injected denervated ligaments, but not that of the non-injected denervated ligaments, was significantly less than that of the non-denervated ligaments. Histological abnormalities typical of neurogenic muscular atrophy were observed in all denervated ligaments. CLINICAL RELEVANCE: Loss of motor neuronal input to the proximal aspect of the SL of the pelvic limb of horses causes neurogenic atrophy of the musculature in that portion of the ligament. Denervating a SL of a pelvic limb may weaken the ligament, increasing its risk of injury. Chronic inflammation of the SL before neurectomy may exacerbate atrophy of the musculature after neurectomy.

Risk factors associated with failure of heartworm prophylaxis among members of a national hunting dog club.

OBJECTIVE: To identify practices associated with failure of heartworm prophylaxis among dog and kennel owners and dog trainers. DESIGN: Online survey and mail-in questionnaire. Sample-708 members of a national hunting dog club. PROCEDURES: Heartworm prevention practices used by respondents that reported failure of prophylaxis were compared with practices used by respondents that reported success. RESULTS: Univariate analyses indicated failure of heartworm prophylaxis was inversely related to the number of dogs under a respondent's care. Year-round prophylactic practice was not significantly associated with reduced odds of failure, and efforts to control exposure to mosquitoes were similar among the comparison groups. Respondents reporting prophylaxis failure were more likely to test for heartworm infection ≥ 1 time/y, compared with those reporting success. In a multivariable analysis, residence south of the Virginia-North Carolina state line (ie, the 37th geographic parallel), testing for heartworm infection < once a year when the test was administered prior to April 1, and keeping dogs outdoors for longer periods at dusk, at dawn, or after dark were associated with increased odds of prophylaxis failure. CONCLUSIONS AND CLINICAL RELEVANCE: Veterinarians should stress the importance of annual heartworm testing 6 to 7 months after the last possible date of exposure to heartworm, regardless of whether a dog receives prophylactic treatment year-round. Reducing the number of hours dogs spend outdoors at dusk, at dawn, or after dark may reduce the odds of heartworm disease even when dogs are given preventive treatment.

The effect of midazolam on the end-tidal concentration of isoflurane necessary to prevent movement in dogs.

OBJECTIVE: To determine the possible additive effect of midazolam, a GABA(A) agonist, on the end-tidal concentration of isoflurane that prevents movement (MAC(NM) ) in response to noxious stimulation. STUDY DESIGN: Randomized cross-over experimental study. ANIMALS: Six healthy, adult intact male, mixed-breed dogs. METHODS: After baseline isoflurane MAC(NM) (MAC(NM-B) ) determination, midazolam was administered as a low (LDS), medium (MDS) or high (HDS) dose series of midazolam. Each series consisted of two dose levels, low and high. The LDS was a loading dose (Ld) of 0.2 mg kg(-1) and constant rate infusion (CRI) (2.5 µg kg(-1) minute(-1)) (LDL), followed by an Ld (0.4 mg kg(-1)) and CRI (5 µg kg(-1) minute(-1)) (LDH). The MDS was an Ld (0.8 mg kg(-1)) and CRI (10 µg kg(-1) minute(-1)) (MDL) followed by an Ld (1.6 mg kg(-1)) and CRI (20 µg kg(-1) minute(-1)) (MDH). The HDS was an Ld (3.2 mg kg(-1)) and CRI (40 µg kg(-1) minute(-1)) (HDL) followed by an Ld (6.4 mg kg(-1)) and CRI (80 µg kg(-1) minute(-1)) (HDH). MAC(NM) was re-determined after each dose in each series (MAC(NM-T)). RESULTS: The median MAC(NM-B) was 1.42. MAC(NM-B) did not differ among groups (p > 0.05). Percentage reduction in MAC(NM) was significantly less in the LDS (11 ± 5%) compared with MDS (30 ± 5%) and HDS (32 ± 5%). There was a weak correlation between the plasma midazolam concentration and percentage MAC(NM) reduction (r = 0.36). CONCLUSION AND CLINICAL RELEVANCE: Midazolam doses in the range of 10-80 µg kg(-1) minute(-1) significantly reduced the isoflurane MAC(NM) . However, doses greater than 10 µg kg(-1) minute(-1) did not further decrease MAC(NM) indicating a ceiling effect.

Survey of heartworm prevention practices among members of a national hunting dog club.

Surveillance data indicate that failures have been reported for virtually all heartworm prevention product categories. Resistance of third and fourth stage larvae of Dirofilaria immitis to macrocyclic lactones, lack of compliance, other unknown factors, or a combination of these reasons may be the cause of failure. A survey of members of a national hunting dog club was conducted to identify practices used to prevent canine heartworm infections. Questionnaires were completed by 708 dog owners. Year-round administration of heartworm preventive medication was reported by 208 (88%) respondents residing north of the 37th parallel. Dosing was based on the estimated weight of the dog by 54 (7%) respondents, 389 (55%) did not record the date prophylaxis was administered, and 89 (13%) observed the dogs spit out pills. Heartworm testing at least once per year was done by 556 (79%) respondents and test dates were spread throughout the year. Only 448 (64%) respondents tested newly acquired dogs for heartworm. These findings suggest that veterinarians should place a greater emphasis on the frequency and timing of heartworm diagnostic tests, the importance of weighing dogs, duration of administration, recording the date monthly heartworm prophylaxis is given, and observing dogs to ensure that oral medication is retained.

Variability of estradiol concentration in normal dogs.

Estradiol concentrations are evaluated in canine serum as part of an adrenal panel used to diagnose atypical Cushing's syndrome and other endocrine abnormalities. Estradiol concentrations are often elevated in dogs without clinical signs of hyperestrogenism, and the significance of this elevation is unknown. The purpose of this study was to estimate the variation in estradiol concentrations in normal dogs. Ten neutered male and female dogs were enrolled in the study. Blood was collected from each dog at 2 h intervals, four times during a given day. This was repeated approximately 1 (week 2) and 5 weeks later (week 6). There was no attempt for a given dog to be started at the exact time or day each week. Results showed that estradiol concentrations ranged from 44.6 to 120.3 pg/mL with a mean of 70.4 pg/mL, which is greater than the upper limit of normal for our laboratory (69 pg/mL). The mean difference between the highest and lowest concentrations for each dog was 28.8 pg/mL, with a range of 12.5-53.5 pg/mL. Mean estradiol concentrations from week 6 (63.2 pg/mL) were significantly lower than those from week 1 (71.4 pg/mL; P=0.015) and week 2 (76.5 pg/mL; P=0.0004). These data show a wide range of variability in estradiol concentration both within and between dogs and that these measurements often exceed the normal ranges established by the laboratory. Therefore, diagnosis of hyperestrogenism or atypical Cushing's syndrome based on increased estradiol concentrations should require compatible clinical presentation of hyperestrogenism together with elevated serum estradiol.

Postoperative complications and survival after enterolith removal from the ascending or descending colon in horses.

OBJECTIVE: To compare incidence of postoperative complications and survival of horses that had surgery for enterolithiasis of the ascending (AC) or descending (DC) colon. STUDY DESIGN: Case series ANIMALS: Horses (n=236) that had celiotomy for AC (n=97) or DC (n=139) enterolithiasis. METHODS: Medical records (1999-2005) were reviewed for signalment, presenting clinical signs, surgical findings, postoperative complications, and short-term survival until discharge. Information on performance and survival > or = 1 year was obtained by telephone or mailed questionnaire. RESULTS: Number of postoperative complications did not differ between groups (P=.76). The most frequently identified short-term complications for all horses were incisional problems, gastric ulceration, ileus, diarrhea, fever, and anorexia. Horses with DC enteroliths had a significantly higher incidence of anorexia (P=.04) and fever (P=.01). The most common complications after hospital discharge were incisional problems, laminitis, weight loss, and colic. Although more DC horses were euthanatized intraoperatively (P=.02), no differences were detected for horses that survived until discharge (P=.18) or > or = 1 year after discharge (P=.47). CONCLUSIONS: Number or type of postsurgical complications or survival after surgery was not influenced by enterolith location and horses have a favorable prognosis for long-term survival after enterolith removal, regardless of site of obstruction in the colon. CLINICAL RELEVANCE: Incidence of postoperative complications and survival are not affected by the site of enterolith obstruction in the colon.

Effect of intravenous administration of tramadol hydrochloride on the minimum alveolar concentration of isoflurane in rabbits.

OBJECTIVE: To evaluate the effect of IV administration of tramadol hydrochloride on the minimum alveolar concentration of isoflurane (ISOMAC) that prevented purposeful movement of rabbits in response to a noxious stimulus. ANIMALS: Six 6- to 12-month-old female New Zealand White rabbits. PROCEDURES: Anesthesia was induced and maintained with isoflurane in oxygen. A baseline ISOMAC was determined by clamping a pedal digit with sponge forceps until gross purposeful movement was detected or a period of 60 seconds elapsed. Subsequently, tramadol (4.4 mg/kg) was administered IV and the posttreatment ISOMAC (ISOMAC(T)) was measured. RESULTS: Mean +/- SD ISOMAC and ISOMAC(T) values were 2.33 +/- 0.13% and 2.12 +/- 0.17%, respectively. The ISOMAC value decreased by 9 +/- 4% after tramadol was administered. Plasma tramadol and its major metabolite (M1) concentrations at the time of ISOMAC(T) determination varied widely (ranges, 181 to 636 ng/mL and 32 to 61 ng/mL, respectively). Intervals to determination of ISOMAC(T) and plasma tramadol and M1 concentrations were not correlated with percentage change in the ISOMAC. Heart rate decreased significantly immediately after tramadol administration but by 10 minutes afterward was not different from the pretreatment value. Systolic arterial blood pressure decreased to approximately 60 mm Hg for approximately 5 minutes in 3 rabbits after tramadol administration. No adverse effects were detected. CONCLUSIONS AND CLINICAL RELEVANCE: As administered, tramadol had a significant but clinically unimportant effect on the ISOMAC in rabbits. Higher doses of tramadol may provide clinically important reductions but may result in a greater degree of cardiovascular depression.

Effects of tramadol on the minimum alveolar concentration of sevoflurane in dogs.

OBJECTIVE: To evaluate the effect of tramadol on sevoflurane minimum alveolar concentration (MAC(SEVO)) in dogs. It was hypothesized that tramadol would dose-dependently decrease MAC(SEVO). STUDY DESIGN: Randomized crossover experimental study. ANIMALS: Six healthy, adult female mixed-breed dogs (24.2 +/- 2.6 kg). METHODS: Each dog was studied on two occasions with a 7-day washout period. Anesthesia was induced using sevoflurane delivered via a mask. Baseline MAC (MAC(B)) was determined starting 45 minutes after tracheal intubation. A noxious stimulus (50 V, 50 Hz, 10 ms) was applied subcutaneously over the mid-humeral area. If purposeful movement occurred, the end-tidal sevoflurane was increased by 0.1%; otherwise, it was decreased by 0.1%, and the stimulus was re-applied after a 20-minute equilibration. After MAC(B) determination, dogs randomly received a tramadol loading dose of either 1.5 mg kg(-1) followed by a continuous rate infusion (CRI) of 1.3 mg kg(-1 )hour(-1) (T1) or 3 mg kg(-1) followed by a 2.6 mg kg(-1 )hour(-1) CRI (T2). Post-treatment MAC determination (MAC(T)) began 45 minutes after starting the CRI. Data were analyzed using a mixed model anova to determine the effect of treatment on percentage change in baseline MAC(SEVO) (p < 0.05). RESULTS: The MAC(B) values were 1.80 +/- 0.3 and 1.75 +/- 0.2 for T1 and T2, respectively, and did not differ significantly. MAC(T) decreased by 26 +/- 8% for T1 and 36 +/- 12% for T2. However, there was no statistically significant difference in the decrease between the two treatments. CONCLUSION AND CLINICAL RELEVANCE: Tramadol significantly reduced MAC(SEVO) but this was not dose dependent at the doses studied.

Effects of acepromazine and butorphanol on tiletamine-zolazepam anesthesia in llamas.

OBJECTIVE: To evaluate sedative, antinociceptive, and physiologic effects of acepromazine and butorphanol during tiletamine-zolazepam (TZ) anesthesia in llamas. ANIMALS: 5 young adult llamas. PROCEDURES: Llamas received each of 5 treatments IM (1-week intervals): A (acepromazine, 0.05 mg/kg), B1 (butorphanol, 0.1 mg/kg), AB (acepromazine, 0.05 mg/kg, and butorphanol, 0.1 mg/kg), B2 (butorphanol, 0.2 mg/kg), or C (saline [0.9% NaCl] solution). Sedation was evaluated during a 30-minute period prior to anesthesia with TZ (2 mg/kg, IM). Anesthesia and recovery characteristics and selected cardiorespiratory variables were recorded at intervals. Antinociception was assessed via a toe-clamp technique. RESULTS: Sedation was not evident following any treatment. Times to sternal and lateral recumbency did not differ among treatments. Duration of lateral recumbency was significantly longer for treatment AB than for treatment C. Duration of antinociception was significantly longer for treatments A and AB, compared with treatment C, and longer for treatment AB, compared with treatment B2. Treatment B1 resulted in a significant decrease in respiratory rate, compared with treatment C. Compared with treatment C, diastolic and mean blood pressures were lower after treatment A. Heart rate was increased with treatment A, compared with treatment B1 or treatment C. Although severe hypoxemia developed in llamas anesthetized with TZ alone and with each treatment-TZ combination, hemoglobin saturation remained high and the hypoxemia was not considered clinically important. CONCLUSIONS AND CLINICAL RELEVANCE: Sedation or changes in heart and respiratory rates were not detected with any treatment before administration of TZ. Acepromazine alone and acepromazine with butorphanol (0.1 mg/kg) prolonged the duration of antinociception in TZ-treated llamas.

Effects of hyperbaric oxygen on full-thickness meshed sheet skin grafts applied to fresh and granulating wounds in horses.

OBJECTIVE: To determine the effects of hyperbaric oxygen therapy (HBOT) on full-thickness skin grafts applied to fresh and granulating wounds of horses. ANIMALS: 6 horses. PROCEDURES: On day 0, two 4-cm-diameter circular sections of full-thickness skin were removed from each of 2 randomly selected limbs of each horse, and two 4-cm-diameter circular skin grafts were harvested from the pectoral region. A skin graft was applied to 1 randomly selected wound on each limb, leaving the 2 nongrafted wounds to heal by second intention. On day 7, 2 grafts were harvested from the pectoral region and applied to the granulating wounds, and wounds grafted on day 0 were biopsied. On day 14, 1 wound was created on each of the 2 unwounded limbs, and the wounds that were grafted on day 7 were biopsied. All 4 ungrafted wounds (ie, 2 fresh wounds and 2 wounds with 1-week-old granulation beds) were grafted. The horses then received HBOT for 1 hour daily at 23 PSI for 7 days. On day 21, the grafts applied on day 14 were biopsied. RESULTS: Histologic examination of biopsy specimens revealed that grafts treated with HBOT developed less granulation tissue, edema, and neovascularization, but more inflammation. The superficial portion of the graft was also less viable than the superficial portion of those not treated with HBOT. CONCLUSIONS AND CLINICAL RELEVANCE: The use of HBOT after full-thickness skin grafting of uncompromised fresh and granulating wounds of horses is not indicated.

Influence of inflammation and coat type on oestrogen receptor immunohistochemistry.

The purpose of this study was to evaluate oestrogen receptor alpha staining in a variety of breeds and skin conditions. The influence of inflammation and coat type on the presence and intensity of oestrogen receptor alpha staining was evaluated. Approximately 1700 haematoxylin and eosin (H&E)-stained slides of skin biopsies were screened for presence of small hair bulbs. Slides from 94 cases were submitted for oestrogen receptor alpha immunohistochemistry. H&E-stained skin biopsy tissues were examined for inflammation and hair follicle stages. Oestrogen receptor alpha staining characteristics of telogen follicles, flame follicles, large anagen bulbs, small hair bulbs and early anagen hairs (capped bulbs) were recorded. To assess the influence of inflammation and coat type on oestrogen receptor staining of hair follicle types, chi-square tests, Fisher's exact tests and logistic regression models were performed. Slides were classified as inflammatory (65) and noninflammatory (29). There were no statistically significant differences in oestrogen receptor staining when comparing inflammatory to noninflammatory skin biopsies or skin biopsies from dogs with different coat types. A subset of 13 noninflammatory biopsies from alopecic skin was identified. There was a statistically significant increase in the number of flame follicles in this subset as compared to all others. Comparison of oestrogen receptor staining of hair follicle types from these biopsies and all other biopsies revealed a statistically significant increase in the number of mature telogen hair follicles stained in this subset. No statistical difference in staining of early follicle stages was noted. Therefore, the oestrogen receptor is unlikely to be the controlling factor for the transition from telogen to anagen in the dog.

Comparative evaluation of the liver in dogs with a splenic mass by using ultrasonography and contrast-enhanced computed tomography.

Evaluation of dogs with splenic masses to better educate owners as to the extent of the disease is a goal of many research studies. We compared the use of ultrasonography (US) and contrast-enhanced computed tomography (CT) to evaluate the accuracy of detecting hepatic neoplasia in dogs with splenic masses, independently, in series, or in parallel. No significant difference was found between US and CT. If the presence or absence of ascites, as detected with US, was used as a pretest probability of disease in our population, the positive predictive value increased to 94% if the tests were run in series, and the negative predictive value increased to 95% if the tests were run in parallel. The study showed that CT combined with US could be a valuable tool in evaluation of dogs with splenic masses.

Effect of adjunctive treatment with intravenously administered Propionibacterium acnes on reproductive performance in mares with persistent endometritis.

OBJECTIVE: To determine whether treatment with a preparation of Propionibacterium acnes would improve pregnancy and live foal rates in mares with persistent endometritis. DESIGN: Randomized placebo-controlled clinical trial. ANIMALS: 95 mares with a cytologic diagnosis of persistent endometritis. PROCEDURES: Mares were treated with P acnes or placebo (both administered IV) on days 0, 2, and 6. No attempt was made to alter additional treatments administered by attending veterinarians. Information on breeding history, physical examination findings, results of cytologic examination and microbial culture of uterine samples, additional treatments administered, breeding dates, results of pregnancy examinations, whether a live foal was produced, and reactions to treatment was recorded. RESULTS: In multivariate logistic regression models, mare age, year of entry into the study, and first breeding within 8 days after first treatment with P acnes or placebo were significantly associated with pregnancy. Fewer number of cycles bred and younger age were significantly associated with delivery of a live foal in a separate multivariate analysis. Results of multivariate logistic regression modeling indicated that mares treated with P acnes were more likely to become pregnant and to deliver a live foal, compared with placebo-treated controls. CONCLUSIONS AND CLINICAL RELEVANCE: IV administration of P acnes as an adjunct to conventional treatments in mares with a cytologic diagnosis of persistent endometritis improved pregnancy and live foal rates. The optimal effect was detected in mares bred during the interval extending from 2 days before to 8 days after first treatment with P acnes.

Prevalence of oxacillin- and multidrug-resistant staphylococci in clinical samples from dogs: 1,772 samples (2001-2005).

OBJECTIVE: To determine whether resistance to oxacillin and other antimicrobials in 3 Staphylococcus spp commonly isolated from dogs increased from 2001 to 2005. DESIGN: Retrospective case series. SAMPLE POPULATION: 1,772 clinical samples of various types obtained from dogs examined at the University of Tennessee Veterinary Teaching Hospital or at regional veterinary hospitals and submitted to the bacteriology and mycology laboratories associated with the teaching hospital. PROCEDURES: Samples were submitted by attending veterinarians to the bacteriology and mycology laboratories for routine aerobic microbial culture. Identification and antimicrobial susceptibility procedures were performed on all isolates. Susceptibility reports for each antimicrobial and Staphylococcus spp were determined from aggregate electronically archived test results. Oxacillin and multidrug resistance for Staphylococcus intermedius was analyzed by reviewing disk diffusion zone measurements. RESULTS: Oxacillin resistance increased among S. intermedius isolates during the past 5 years, and the increase was associated with multidrug resistance. In 2005, 1 in 5 Staphylococcus spp isolates from canine clinical samples was resistant to oxacillin. The most common staphylococcal species isolated were S. intermedius (n = 37), Staphylococcus schleiferi (21), and Staphylococcus aureus (4), and frequencies of oxacillin resistance in isolates of these species were 15.6%, 46.6%, and 23.5%, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Veterinarians should be aware of the potential for empiric drug treatment failures in instances where Staphylococcus spp infections are common (eg, pyoderma). Judicious use of bacterial culture and susceptibility testing is recommended.

Incidence of incompatible crossmatch results in dogs admitted to a veterinary teaching hospital with no history of prior red blood cell transfusion.

OBJECTIVE To determine the incidence of incompatible crossmatch results in dogs without a history of prior RBC transfusion and to evaluate changes in Hct following RBC administration for transfusion-naïve dogs that did and did not have crossmatching performed. DESIGN Retrospective study. ANIMALS 169 client-owned dogs. PROCEDURES Information obtained from the medical records included signalment, pretransfusion Hct or PCV, and crossmatching results where applicable. Dogs that underwent major crossmatching (n = 149) as part of pretransfusion screening were each crossmatched with 3 potential donors. Donor blood was obtained from a commercial source and tested negative for dog erythrocyte antigens (DEAs) 1.1, 1.2, and 7 but positive for DEA 4. Mean change in Hct after transfusion was compared between crossmatch-tested dogs (57/91 that subsequently underwent RBC transfusion) and 20 other dogs that underwent RBC transfusion without prior crossmatching by statistical methods. RESULTS 25 of 149 (17%) dogs evaluated by crossmatching were incompatible with 1 or 2 of the 3 potential donors. All 149 dogs were compatible with ≥ 1 potential donor. Mean ± SD change in Hct after transfusion was significantly higher in dogs that had crossmatching performed (12.5 ± 8.6%) than in dogs that did not undergo crossmatching (9.0 ± 4.3%). CONCLUSIONS AND CLINICAL RELEVANCE Results indicated immunologic incompatibility can exist between first-time transfusion recipients and potential blood donor dogs. The clinical importance of these findings could not be evaluated, but considering the potential for immediate or delayed hemolytic transfusion reactions or shortened RBC life span, the authors suggest veterinarians consider crossmatching all dogs prior to transfusion when possible.

Effect of fentanyl and lidocaine on the end-tidal sevoflurane concentration preventing motor movement in dogs.

OBJECTIVE To determine effects of fentanyl, lidocaine, and a fentanyl-lidocaine combination on the minimum alveolar concentration of sevoflurane preventing motor movement (MACNM) in dogs. ANIMALS 6 adult Beagles. PROCEDURES Dogs were anesthetized with sevoflurane in oxygen 3 times (1-week intervals). Baseline MACNM (MACNM-B) was determined starting 45 minutes after induction of anesthesia. Dogs then received 1 of 3 treatments IV: fentanyl (loading dose, 15 µg/kg; constant rate infusion [CRI], 6 µg/kg/h), lidocaine (loading dose, 2 mg/kg; CRI, 6 mg/kg/h), and the fentanyl-lidocaine combination at the same doses. Determination of treatment MACNM (MACNM-T) was initiated 90 minutes after start of the CRI. Venous blood samples were collected at the time of each treatment MACNM measurement for determination of plasma concentrations of fentanyl and lidocaine. RESULTS Mean ± SEM overall MACNM-B for the 3 treatments was 2.70 ± 0.27 vol%. The MACNM decreased from MACNM-B to MACNM-T by 39%, 21%, and 55% for fentanyl, lidocaine, and the fentanyl-lidocaine combination, respectively. This decrease differed significantly among treatments. Plasma fentanyl concentration was 3.25 and 2.94 ng/mL for fentanyl and the fentanyl-lidocaine combination, respectively. Plasma lidocaine concentration was 2,570 and 2,417 ng/mL for lidocaine and the fentanyl-lidocaine combination, respectively. Plasma fentanyl and lidocaine concentrations did not differ significantly between fentanyl and the fentanyl-lidocaine combination or between lidocaine and the fentanyl-lidocaine combination. CONCLUSIONS AND CLINICAL RELEVANCE CRIs of fentanyl, lidocaine, and the fentanyl-lidocaine combination at the doses used were associated with clinically important and significant decreases in the MACNM of sevoflurane in dogs.