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- Author or Editor: Rebecca A. Johnson x
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Abstract
OBJECTIVE To assess effects of buprenorphine hydrochloride (BH), sustained-release buprenorphine (SRB), and high-concentration buprenorphine (HCB) formulations in healthy rats.
ANIMALS 8 Sprague-Dawley rats.
PROCEDURES In a crossover-design study, rats received BH (0.05 mg/kg), SRB (1.2 mg/kg), HCB (0.30 mg/kg), or 5% dextrose solution (0.2 mL/kg), SC, once. Self-injurious behavior and thermal sensitivity (hind limb withdrawal latencies) were assessed prior to injection (time 0) and 1, 4, 8, 12, and 24 hours after injection. Food intake, kaolin intake, and fecal output were measured over 12-hour light and dark periods before and after each treatment. Values were compared among treatments and time points.
RESULTS Self-injurious behavior was detected with all buprenorphine treatments; scores were greater at all time points during the 12 hours after HCB and 24 hours after SRB administration than at time 0. Percentage change in hind limb withdrawal latencies from time 0 was higher with BH and HCB 1 hour after injection than at other time points. Postinjection light-period food intake was higher (BH and HCB) and dark-period food intake was lower (BH, HCB, and SRB), compared with preinjection values for the same treatments. For SRB, postinjection light-period kaolin intake was greater than the preinjection value, and postinjection light- and dark-period kaolin intake was greater than that for other treatments.
CONCLUSIONS AND CLINICAL RELEVANCE Hypoalgesic effects were briefly observed after administration of BH or HCB in healthy rats; adverse effects were detected in some rats with all buprenorphine formulations. Studies comparing effects of BH, SRB, and HCB in rats undergoing surgery or other noxious stimuli are indicated to determine clinical benefits in this species.
Abstract
OBJECTIVE To evaluate effects of high-concentration buprenorphine (HCB) on self-injurious behavior, food intake, fecal output, and thermal withdrawal latencies in healthy rats.
ANIMALS 8 Sprague-Dawley rats.
PROCEDURES Rats received 4 SC treatments (HCB at 0.075, 0.15, or 0.30 mg/kg [HCB0.075, HCB0.15, and HCB0.30, respectively] or 5% dextrose solution [0.20 mL/kg]) in a randomized, crossover-design study. Self-injurious behavior was assessed for 8 hours after injection. Food intake and fecal output were assessed for predetermined periods before and after treatment and separated into 12-hour light and dark periods for further analysis. Withdrawal latencies were assessed before (time 0) and at predetermined times after injection. Data were compared among treatments and time points.
RESULTS Self-injurious behavior was observed up to 8 hours after injection for all HCB, but not dextrose, treatments. Preinjection food intake and fecal output amounts were similar among groups and higher during the dark period than during the light period. Food intake after all HCB treatments was higher during the light period and lower during the dark period, compared with preinjection results for the same treatments and with postinjection results for dextrose administration. Light-period fecal output was lower after HCB0.15 and HCB0.30 administration, compared with preinjection values for the same treatments and postinjection values for dextrose administration. Percentage change in withdrawal latency was significantly higher than that at time 0 (ie, 0%) for only 1 treatment (HCB0.30) at 1 time point (1 hour after injection).
CONCLUSIONS AND CLINICAL RELEVANCE Although HCB0.30 produced a degree of thermal hypoalgesia in healthy rats, self-injurious behavior and alterations in food intake and fecal output were detected, potentially affecting clinical utility of the treatment.
Abstract
OBJECTIVE To quantify nausea and sedation scores, gastric emptying time, and gastrointestinal transit time after IV administration of a lidocaine hydrochloride bolus followed by a constant rate infusion (CRI) in clinically normal dogs.
ANIMALS 6 Beagles.
PROCEDURES In a crossover study, dogs were fed thirty 1.5-mm barium-impregnated spheres (BIPS) and received a saline (0.9% NaCl) solution bolus (0.05 mL/kg) IV (time 0) followed by a CRI at 10 mL/h, a lidocaine bolus (1 mg/kg) IV followed by a CRI at 25 μg/kg/min, or a lidocaine bolus (1 mg/kg) IV followed by a CRI at 50 μg/kg/min; CRIs were for 12 hours. Nausea and sedation scores were assessed and abdominal radiographs obtained immediately after feeding of BIPS and every hour for 12 hours and again 16 hours after CRI start. Percentage of BIPSs in the small and large intestines, gastric emptying time, and gastrointestinal transit time were assessed.
RESULTS Gastric emptying time did not differ significantly among treatments. Significantly more BIPS were in the large intestine 4 to 7 hours after treatment start for the 50-μg/kg/min treatment than for the other 2 treatments. Six hours after treatment start, significantly more BIPS were in the large intestine for the 25-μg/kg/min treatment than for the saline solution treatment. Higher sedation and nausea scores were associated with the 50-μg/kg/min CRI.
CONCLUSIONS AND CLINICAL RELEVANCE In clinically normal dogs, lidocaine CRI did not significantly affect gastric emptying. However, gastrointestinal transit time was mildly decreased and sedation and nausea scores increased in dogs administered a lidocaine CRI at clinically used doses.
Abstract
OBJECTIVE
To determine whether previous corrective upper airway surgery in brachycephalic dogs would decrease perianesthetic complications in subsequent anesthetic events.
ANIMALS
45 client-owned dogs.
PROCEDURES
Brachycephalic dogs undergoing any combination of staphylectomy, nasal alaplasty, or laryngeal sacculectomy that were anesthetized at a later date for additional surgical procedures or imaging from August 2, 2007, to February 8, 2019, had their medical records reviewed during both anesthetic events for signalment, American Society of Anesthesiologists status, perianesthetic drug administration, anesthetic duration, presence and total time of positive-pressure ventilation, procedure invasiveness, and perianesthetic complications such as bradycardia, hypothermia, hypotension, cardiac arrhythmias, hypertension, vomiting or regurgitation, dysphoria, respiratory distress, hypoxemia, reintubation, and prolonged periods of recovery.
RESULTS
The odds of having complications during the postanesthetic period following subsequent anesthetic events were decreased by 79% in dogs having previous surgical intervention to correct clinical signs of brachycephalic airway syndrome. Intra-anesthetic bradycardia increased the odds of developing a postanesthetic complication by 4.56 times. Every 15-minute increase in anesthetic duration increased the odds of having a postanesthetic complication by 12% and having an intra-anesthetic complication by 11%.
CONCLUSIONS AND CLINICAL RELEVANCE
Previous corrective upper airway surgery decreased odds of postanesthetic complications in brachycephalic dogs that underwent subsequent anesthetic events. Findings in this study indicated that corrective upper airway surgery for brachycephalic dogs may reduce postanesthetic complications following subsequent anesthetic events, which may reduce perianesthetic morbidity in patients undergoing multiple surgical or diagnostic imaging procedures.
Abstract
Objective—To elucidate the ultrastructural details of calcium oxalate-containing urinary calculi from dogs.
Sample Population—38 specimens selected from a collection of 8,297 oxalate-containing urinary calculi from dogs: 22 specimens composed of calcium oxalate (calcium oxalate monohydrate [COM], calcium oxalate dihydrate [COD], or COM and COD) and 16 specimens composed of calcium oxalate with amorphous calcium phosphate.
Procedure—Analyses of specimens included use of plain, reflected, and polarized light microscopy, X-ray diffractometry, scanning electron microscopy (SEM) with backscattered electron (BSE) imagery, and electron microprobe analysis.
Results—Four texture types were observed in calcium oxalate calculi; 4 texture types of calcium oxalatecalcium phosphate-mixed calculi were recognized. Texture types were delineated through differences in calcium oxalate crystal sizes, which were affected by urine supersaturation and abundance of crystal nucleation sites. Segregation of calcium oxalate from calcium phosphate indicated they do not precipitate under the same conditions. Deposition of calcium phosphate between calcium oxalate crystals decreased the volume of pore spaces within calculi. Porosity was observed along boundaries between COM and COD. Minute pores increased the surface area of calculi exposed to urine, and this increase in liquid-solid interface promotes interaction of crystals with the surrounding urine.
Conclusions and Clinical Relevance—Calcium oxalate urolithiasis is of major concern, because it is often a recurrent disease among dogs, principally treated by surgical removal of calculi, with few effective dissolution strategies. Understanding the ultrastructure and mineralogic content of calcium oxalate and its association with amorphous calcium phosphate is a step toward the solution of this increasingly important medical problem. (Am J Vet Res 2001;62:237–247)
Abstract
OBJECTIVE To determine the prevalence of Alaria infection in cats and dogs in north central Oklahoma over various periods and investigate whether wild animal species in this region were also infected.
DESIGN Combined cross-sectional study and case series.
SAMPLE Results of parasitological testing of fecal samples from 5,417 client-owned dogs and 1,246 client-owned cats (2006 through 2014); fecal samples from 837 shelter or rescue dogs and 331 shelter or rescue cats (2013 and 2014) and 268 feral cats (2015); tongue or jowl samples from cadavers of 43 wild pigs, 3 opossums, and 1 raccoon; and intestinal tract segments from cadavers of 48 cats and 5 coyotes.
PROCEDURES Various parasite recovery techniques were performed to detect various Alaria stages in samples. Recovered adult trematodes and mesocercariae were used for PCR assay and sequencing of the 28S rRNA gene.
RESULTS Prevalence of Alaria infection was significantly higher in feral cats (9.0%) than in shelter or rescue cats (0.6%) and client-owned cats (1.4%) and in shelter or rescue dogs (1.8%) than in client-owned dogs (0.2%). Mesocercariae were recovered from tissue samples from 11 (26%) wild pigs and 1 opossum. Amplicon sequences from adult trematodes and mesocercariae were 100% identical to each other and 99% homologous to GenBank sequences of Alaria alata and Alaria mustelae.
CONCLUSIONS AND CLINICAL RELEVANCE Prevalence of Alaria infection in the study area has increased in dogs and cats since 1990, when infections were rare. Prevalence in wild pigs was similar to that in Eurasia, where A alata is considered an emerging zoonotic parasite.
Abstract
Objective—To evaluate diagnostic tests used for detection of bovine viral diarrhea virus (BVDV) and determine the prevalence of BVDV subtypes 1a, 1b, and 2a in persistently infected (PI) cattle entering a feedlot.
Design—Prospective study.
Animals—21,743 calves.
Procedures—Samples were obtained from calves initially testing positive via antigen capture ELISA (ACE) performed on fresh skin (ear notch) specimens, and ACE was repeated. Additionally, immunohistochemistry (IHC) was performed on skin specimens fixed in neutral-buffered 10% formalin, and reverse transcriptase PCR (RT-PCR) assay and virus isolation were performed on serum samples. Virus was subtyped via sequencing of the 5′ untranslated region of the viral genome.
Results—Initial ACE results were positive for BVDV in 88 calves. After subsequent testing, results of ACE, IHC, RT-PCR assay, and viral isolation were positive in 86 of 88 calves; results of all subsequent tests were negative in 2 calves. Those 2 calves had false-positive test results. On the basis of IHC results, 86 of 21,743 calves were PI with BVDV, resulting in a prevalence of 0.4%. Distribution of BVDV subtypes was BVDV1b (77.9%), BVDV1a (11.6%), and BVDV2a (10.5%).
Conclusions and Clinical Relevance—Rapid tests such as ACE permit identification and segregation of PI cattle pending results of further tests, thus reducing their contact with the rest of the feedlot population. Although vaccines with BVDV1a and 2a components are given to cattle entering feedlots, these vaccines may not provide adequate protection against BVDV1b.
