A comparison of the postoperative analgesic and sedative effects of flimixin and pap aver etum in the dog

Twenty-nine dogs undergoing a variety of surgical procedures were assigned randomly to one of two groups. All animals were premedicated with acepromazine (0–05 mg/kg) intramuscularly. Induction of anaesthesia was achieved with thiopentone sodium, or propofol in the case of sight hounds, and maintained with halothane in an oxygen/nitrous oxide mixture using a non-rebreathing circuit. Dogs in group 1 were given flunixin (1 mg/kg made up to 5 ml with 0–9 per cent saline) slowly intravenously 10 minutes before the halothane was switched off. Group 2 dogs received papaveretum (0–2 mg/kg made up to 5 ml with saline] administered as before. Using a visual analogue scale, the dogs were scored for sedation and for pain by trained theatre staff who were unaware of the analgesic used. Scoring was at 15, 30, 60, 120 , 240 and 360 minutes after analgesic administration. Seven dogs were withdrawn from the trial (three from the papaveretum group and four from the group which received flunixin) because analgesia was deemed unsatisfactory and these animals were given pethidine (3 mg/kg intramuscularly) which produced adequate analgesia within 15 minutes in all cases. Clinically, flunixin proved to be as effective a postoperative analgesic as papaveretum for up to six hours and was associated with less sedation, Pain scores were significantly different at two and four hours with flunixin providing more analgesia than papaveretum and at the four hour time point, flunixin was associated with significantly less sedation than papaveretum. From this study it was concluded that flunixin has a place in the treatment of acute post surgical pain, either alone or in combination with opioid analgesics where pain is refractory to treatment with clinical doses of opioids alone.     

Analgesic, behavioural and cardiopulmonary effects of epidurally injected medetomidine (Domitor) in goats

This study was carried out in order to evaluate the analgesic, sedative, immobilizing and cardiopulmonary effects of medetomidine in goats after lumbosacral epidural injection of three (10, 20 and 30 micrograms/kg body weight) doses. The volume of the injection for all three medetomidine doses was 5 ml in sterile water. Seventeen clinically healthy, Small East African goats of either sex and weighing between 12 and 22 kg (mean +/- SD; 14.8 +/- 2.5 kg body weight) were used. The animals were randomly assigned to two groups. Seven goats were used for evaluating analgesic, behavioural and cardiopulmonary effects while 10 were used for experimental surgery. The cardiopulmonary values and rectal temperature were determined and recorded at time 0 (preinjection) and at 5, 10, 15, 20 and 30 min, and thereafter at 15-min intervals up to 180 min after injection. Analgesia of the flank and perineum was determined at time 0 (preinjection) and at 5, 10, 15, 30, 60, 120 and 180 min using a scoring system. The spread of analgesia to the thorax, neck, forelimbs and head was also determined and recorded. The onset and duration of lateral recumbency was noted and recorded. Medetomidine at the given doses induced variable cardiopulmonary depression, which was not detrimental to the animals. All three doses (10, 20 and 30 micrograms/kg) of medetomidine induced adequate analgesia of the flank and perineum. Analgesia extended to the thorax, forelimbs, neck and head. The duration of lateral recumbency was 136 and 166 min for the 20 and 30 micrograms/kg medetomidine doses, respectively. The duration of lateral recumbency was not determined for the animal given 10 micrograms/kg medetomidine. Signs of sedation (lowering of the head, drooping of the lower lip, partial to complete closure of the eyes and salivation) were noted after administration of all three doses. It can be concluded from this study that all three doses induced adequate analgesia of the flank and perineum. Surgical analgesia of the flank of goats was achieved after lumbosacral epidural administration of 20 micrograms medetomidine/kg, diluted in 5 ml of sterile water. Surgery was not performed with the other doses (10 and 30 micrograms/kg) of medetomidine.     

Carprofen as an analgesic for postoperative pain in cats: Dose titration and assessment of efficacy in comparison to pethidine hydrochloride

The aim of this study was to titrate the optimal dose of carprofen for single dose usage, for alleviating postoperative pain, under a double-blind and randomised protocol, using both negative and positive controls. Renal tolerance was assessed by screening plasma urea and creatinine. Pre- and postoperative assessment of pain and sedation was made using a dynamic and interactive visual analogue scoring system in 60 cats undergoing ovariohysterectomy. The cats were randomly assigned to one of six groups: (1) carprofen at 1-0 mg/kg subcutaneously (sc); (2) carprofen at 2-0 mg/kg sc; (3) carprofen at 4-0 mg/kg sc; (4) pethidine at 5-0 mg/kg intramuscularly (im), (5) pethidine at 10-0 mg/kg im; and (6) no analgesics (injection of saline). All injections were given postoperatively on tracheal extuba-tion and administered in a double-blind manner. Assessments were made up to 20 hours post extubation. Prior to induction and at 20 hours post extubation, blood samples were taken for laboratory analysis of the urea and creatinine content to check for any adverse effect on renal function. Cats given pethidine did not appear more sedated than the groups receiving carprofen or saline. Cats receiving carprofen were in less pain postoperatively overall, with 4-0 mg/kg being the most effective dose rate (significantly better than the other doses of carprofen at four and eight hours post extubation). The highest dose of pethidine provided significantly better analgesia than the highest dose of carprofen up to two hours post extubation, but from two to 20 hours post extubation carprofen at 4-0 mg/kg provided significantly better analgesia than the pethidine. None of the analgesic regimens appeared to affect renal function adversely, as measured by urea and creatinine levels.     

Oral and intravenous immunoglobulin therapy in neonatal foals

Newborn foals, deprived of colostrum and its rich supply of immunoglobulin G (IgG), were supplemented both orally and intravenously with purified equine immunoglobulin G (Lyphomune^®). Data were obtained from 18 foals given oral administration of IgG at Colorado State University and 26 foals given IgG intravenously at the Jockey Club de Sao Paulo in Brazil.Oral administration of 10-gm doses of Lyphomune^® in 18 colostrum-deprived Arabian foals, at various intervals within the first 24 hours after birth, resulted in increased serum concentrations of IgG. Administration of one 10-gm dose of Lyphomune^® immediately following birth provided a mean serum IgG level of 125 mg/dl after two hours. The recommended dosage of two 10-gm doses per 15 kg of body weight produced mean IgG serum concentrations of approximately 400 mg/dl by 14 hours. It was determined that an early bolus of IgG was most effective, although administration at any period during the first 24 hours would increase IgG levels significantly and in direct relationship to grams of Lyphomune^® administered.After the 24-hour study period, colostrum from each respective mare was provided by bottle feeding (200 ml) to 10 of the foals that were then allowed to nurse their dams normally. Significant increases in circulating IgG were observed in nine of these ten animals at four and eight hours after colostrum administration. No interfering effect was noted when colostrum and Lyphomune^® were given to the same foal.Intravenous administration of 10-gm doses of Lyphomune^® in Thoroughbred foals, immediately after birth, resulted in serum concentrations of IgG of 200–300 mg/dl six hours later. A second intravenous dose, at six hours after the initial dose, resulted in an additional average increase of 184 mg/dl. Four of six foals administered 10 gm of Lyphomune^® for each 15 kg of body weight reached serum concentrations greater than 400 mg/dl. It was demonstrated that Lyphomune^® was able to increase circulating levels of IgG, by either oral or intravenous administration, to levels considered protective in the newborn foal.     

Safety and efficacy of an oil-adjuvant vaccine against haemorrhagic septicaemia in buffalo calves: cross-protection between the serotypes B:2,5 and E:2,5.

The safety, efficacy and duration of immunity of an improved oil-adjuvant vaccine against haemorrhagic septicaemia, containing inactivated cells of Pasteurella multocida serotype B:2,5, were tested in young buffalo calves in Pakistan. For safety testing, five buffalo calves were vaccinated intramuscularly with twice the normal dose, and six weeks later with a normal dose. Except for a transient rise in rectal temperature at six hours after the vaccinations, no systemic reactions were observed. The buffaloes remained in good condition and had a normal appetite. No local reactions were observed at the injection site. For efficacy testing two trials were carried out. In the first, buffalo calves were vaccinated intramuscularly either with two doses two-and-a-half months apart, or with a single dose, or left unvaccinated. They were challenged subcutaneously with virulent P multocida after eight, 13 or 15 months. After challenge at eight months the four buffaloes given two doses and the buffalo given one dose were protected, whereas the control animal developed the typical signs of the disease. After the challenges at 13 and 15 months, the vaccinated animals were still protected whereas the control animals died. In the second trial, buffalo calves were vaccinated intramuscularly either with two doses two months apart, or with a single dose at two months or left unvaccinated. The buffaloes were challenged after eight or 14 months. After challenge at eight months the four control animals died, whereas three of the four buffaloes given a single dose were protected. After challenge at 14 months, the three control animals died, whereas four of the five buffaloes given two doses and both the buffaloes given a single dose were protected. To test for cross-protection against the heterologous serotypes E:2,5 and B:3,4, groups of mice were vaccinated once or left unvaccinated. Four weeks later, the vaccinated and control groups were challenged with a dilution series of the different challenge cultures. The vaccine appeared to induce protection against challenge with different strains of serotypes B:2,5 and E:2,5 but not against strains of serotype B:3,4.     

Avian paramyxovirus type 1 infections of racing pigeons: 4 laboratory assessment of vaccination

The immune response and protection from challenge afforded to adult pigeons by four different vaccination schedules were assessed. Intravenous challenge with a field pigeon isolate was done four weeks after the second of two doses of vaccine given four weeks apart. Little difference in protection was seen between two 0.25 ml and two 0.5 ml doses of oil emulsion vaccine, although the latter produced a slightly higher immune response. In both cases one of 10 challenged pigeons became sick and died. One dose of Newcastle disease virus B1 live vaccine followed four weeks later by 0.5 ml oil emulsion vaccine gave a comparable immune response to two 0.25 ml doses of oil emulsion but only six birds survived challenge. Two doses of Newcastle disease virus B1 vaccine gave a poor immune response and little protection from challenge; all 10 birds became sick and eight died. Assessment of the onset of protection following one dose of either 0.5 ml oil emulsion vaccine or Newcastle disease virus B1 indicated some partial protection in the latter group as early as five days after vaccination. Both groups showed protection at 10 days but by 21 days, although protection was sustained in the oil emulsion group, birds receiving live vaccine were fully susceptible. Measurement of the duration of protection in pigeons given two 0.5 ml doses of oil emulsion vaccine indicated that protection had begun to wane by 40 weeks after the first dose.     

Effects of perineural dexmedetomidine combined with ropivacaine on postoperative methadone requirements in dogs after tibial plateau levelling osteotomy: a two-centre study

ObjectiveTo evaluate the efficacy of a perineural injection of dexmedetomidine combined with ropivacaine for reducing postoperative methadone requirements in dogs after tibial plateau levelling osteotomy (TPLO).Study designA prospective, clinical, randomized and blinded trial.AnimalsA total of 58 client-owned dogs.MethodsUltrasound-guided midfemoral sciatic and inguinal femoral nerve blocks with ropivacaine (1 mg kg^–1 per nerve block) combined with either dexmedetomidine (0.5 μg kg^–1 per nerve block; group DEX) or the same volume of saline (group CON) were performed in dogs undergoing TPLO. Pain was assessed 30 minutes, 2 hours and then every 4 hours for 24 hours after surgery with a validated pain scale (4AVet). Meloxicam (0.15 mg kg^–1) was administered intravenously (IV) at recovery. Rescue methadone (0.2 mg kg^–1 IV) was administered if a score ≥ 6 (maximal score 18) was recorded and the number of postoperative doses was analysed by Fisher exact tests. The study was performed in parallel at a Veterinary Teaching Hospital (VTH) and a private Veterinary Referral Centre (VRC).ResultsDogs received a total of 22 and 31 postoperative doses of methadone in groups DEX (14 doses at VRC, eight doses at VTH) and CON (28 doses at VRC, three doses at VTH), respectively. Overall, there was no difference in the postoperative rescue analgesia requirements between groups (p = 0.244). At the VRC, dogs received less methadone (p = 0.026) in group DEX compared with group CON, whereas at the VTH, there was no difference between groups (p = 0.216).Conclusions and clinical relevancePerineural dexmedetomidine combined with ropivacaine did not reduce postoperative methadone requirements in dogs after TPLO, but results may differ from one centre to another. This discrepancy might be linked to variations in clinical practices and questions the validity of results obtained from single-centre randomized controlled trials but applied to different clinical settings.     

Analgesic efficacy of butorphanol and morphine in bearded dragons and corn snakes

OBJECTIVE: To test the hypothesis that administration of butorphanol or morphine induces antinociception in bearded dragons and corn snakes. DESIGN: Prospective crossover study. ANIMALS: 12 juvenile and adult bearded dragons and 13 corn snakes. PROCEDURES: Infrared heat stimuli were applied to the plantar surface of bearded dragon hind limbs or the ventral surface of corn snake tails. Thermal withdrawal latencies (TWDLs) were measured before (baseline) and after SC administration of physiologic saline (0.9% NaCl) solution (equivalent volume to opioid volumes), butorphanol tartrate (2 or 20 mg/kg [0.91 or 9.1 mg/lb]), or morphine sulfate (1, 5, 10, 20, or 40 mg/kg [0.45, 2.27, 4.5, 9.1, or 18.2 mg/lb]). RESULTS: For bearded dragons, butorphanol (2 or 20 mg/kg) did not alter hind limb TWDLs at 2 to 24 hours after administration. However, at 8 hours after administration, morphine (10 and 20 mg/kg) significantly increased hind limb TWDLs from baseline values (mean +/- SEM maximum increase, 2.7+/-0.4 seconds and 2.8+/-0.9 seconds, respectively). For corn snakes, butorphanol (20 mg/kg) significantly increased tail TWDLs at 8 hours after administration (maximum increase from baseline value, 3.0+/-0.8 seconds); the low dose had no effect. Morphine injections did not increase tail TWDLs at 2 to 24 hours after administration. CONCLUSIONS AND CLINICAL RELEVANCE: Compared with doses used in most mammalian species, high doses of morphine (but not butorphanol) induced analgesia in bearded dragons, whereas high doses of butorphanol (but not morphine) induced analgesia in corn snakes.     

Effects of two doses of buprenorphine four or six hours apart on nociceptive thresholds, pain and sedation in dogs after castration

Twenty-eight dogs were randomly allocated into two groups. They were premedicated with either 10 or 20 microg/kg buprenorphine and 0.05 mg/kg acepromazine administered intramuscularly, and then anaesthetised with intravenous thiopentone to effect and maintained with isoflurane in 100 per cent oxygen. The dogs underwent routine castration, and a second dose of 10 microg/kg buprenorphine was administered four hours after the first or 20 microg/kg six hours after the first dose. Levels of pain and sedation were scored on a visual analogue scale and in terms of the dogs' requirement for rescue analgesia, and mechanical nociceptive thresholds were measured at the hock and wound at premedication and one, two, three, four, five, six, seven, 10 and 21 to 22 hours later. Pain scores were low in both groups, with a trend for lower scores in the high dose group; administration of the second dose of buprenorphine further decreased the pain scores. Buprenorphine produced good preoperative sedation and the level of sedation decreased over time after surgery. Administration of the second high dose of buprenorphine did not increase the level of sedation. Both doses of buprenorphine prevented hyperalgesia at the wound and hock postoperatively. Three dogs given the low dose and one dog given the high dose required rescue analgesia with carprofen.     

Interaction between epidurally administered ketamine and pethidine in dogs

The present study was designed to test the hypothesis that a synergistic interaction could be recorded after epidural administration of ketamine-an N-methyl-D-aspartate (NMDA) antagonist and pethidine--an opioid agonist. Twelve adult mongrel dogs of either sex were randomly divided in three groups A, B and C of four animals each. Ketamine (5%) at 2.5 mg/kg and pethidine (3%) 2 mg/kg were injected at lumbosacral epidural space in animals of groups A and B, respectively. In animals of group C ketamine (2.5 mg/kg) and pethidine (2 mg/kg) were injected. Heart rate increased significantly up to 15 min in group A, whereas in groups B and C, the increase was non-significant for a period of 10 and 45 min, respectively. Respiration increased gradually up to 45-60 min in group A and for 15-20 min in group B. However, in animals of group C respiration fell below the baseline during the first 10-15 min and then returned near the baseline. Rectal temperature decreased only marginally in all the groups. Ketamine alone produced complete analgesia at tail and perineal region for a period of 5-10 min and then moderate analgesia for the next 20-30 min. Analgesia at the flank was moderate to complete between 5 and 15 min. In group B complete analgesia was only moderate at the tail and perineal region up to 30 min. In animals of group C, complete analgesia was observed only at perineal region for a very short period (5 min). Analgesia was not associated with sedation in any of the groups but animals of groups A and C showed signs of motor incoordination. Results of the study suggest rather antagonistic than synergistic interaction between epidurally administered ketamine and pethidine. Further studies are needed to confirm the antagonistic interaction between the two drugs.     

Efficacy of intranasal vaccination of field buffaloes against haemorrhagic septicaemia with a live gdhA derivative Pasteurella multocida B:2

The efficacy of an intranasal haemorrhagic septicaemia vaccine containing live gdhA derivative Pasteurella multocida B:2 was tested in buffaloes in Sabah. Sixty buffaloes, kept grazing in the field with minimal human intervention were devided into three groups of 20 buffaloes per group. Buffaloes of group 1 were exposed intranasal to 5 ml vaccine containing 10(6) CFU/ml of live gdhA derivative P multocida B:2. Buffaloes of group 2 were not exposed to the vaccine but exposed to PBS and were allowed to commingle and graze in the same field as the buffaloes of group 1 while buffaloes of group 3 were similarly exposed to PBS and were grazing separately. Booster was on group 1, two weeks later. Twelve months after the first vaccination, three buffaloes from each group were brought into the experimental house and challenged subcutaneously with 10(9) CFU/ml of live wild-type P multocida B:2. All challenged buffaloes of groups 1 and 2 survived with only mild, transient signs while all control unvaccinated buffaloes developed severe signs of haemorrhagic septicaemia and were euthanased between 28 hours and 38 hours postchallenge with signs and lesions typical of haemorrhagic septicaemia. These data showed that the gdhA mutant strain, given intranasally as two doses two weeks apart, successfully induced systemic immunity in exposed buffaloes and also led to spread of vaccine strain to the in-contact animals, where it acted as an effective live vaccine to protect both exposed buffaloes and in-contact buffaloes against challenge with the virulent parent strain.     

Assessment of dose and time responses to TRH and thyrotropin in healthy dogs

Changes in total thyroxine (T₄ [TT₄]), free T₄(FT₄) and total tri-iodothyronine (T₃ [TT₃]) in serum after the intravenous administration of different doses of thyrotropin (TSH) and thy-rotropin-releasing hormone (TRH) were measured in six healthy beagles. Significant (P<0·05) elevations in serum TT₄, FT₄ and TT₃ were observed at each sampling time (two, four, five, six, seven, eight and 10 hours) after administration of 1, 3 or 5 iu (total dose) TSH and peak mean responses were observed six to eight hours after injection. At six hours after injection the mean TT₄, FT₄ and TT₃ levels were approximately 2·6, 3·9 and 1·5 times basal levels, respectively, and there were no significant differences between the three doses of TSH. Significant (P<0·05) elevations in serum TT₄ and FT₄ but not TT₃ were observed at each sampling time (two, four, five, six, seven and eight hours) after the administration of TRH. Peak mean responses were observed at four hours after injection at which time TT₄ and FT₄ levels were approximately 1·7 and 1·9 times basal levels, respectively. No significant differences were observed between the four doses of TRH used (100, 200, 300 and 600 μg total dose). Concentrations of TT₄, FT₄ and TT₃ were significantly (P<0·05) higher following the administration of TSH compared with TRH, and the response to TRH showed greater individual variation.     

Influence of liver fat on experimental Escherichia coli mastitis in periparturient cows

Eleven cows with a wide range of liver fat (5.7 to 51.4 per cent) at seven days post partum were experimentally infected in a single quarter with a capsular Escherichia coli at 10 days post partum. The results suggested that a fatty liver in itself does not influence the severity of mastitis. All animals had clinical mastitis 10 hours after infection but no animals became severely ill and no treatment was given. Four out of five animals in the group with less than 20.2 per cent liver fat had bacteria in their milk at 10 hours after infection but these bacteria were eliminated by 12 hours. The six animals in the group with more than 28.3 per cent fat in their liver retained viable bacteria in the udder for much longer; with two animals bacteria were shed and abnormal milk was secreted for up to four months despite antibiotic therapy.     

Experimental infection of newborn piglets with Yersinia enterocolitica: an animal model of enteritis

Newborn, colostrum-deprived Large White piglets infected with a human isolate of Yersinia enterocolitica biotype 4 serotype 0:3 were used as an animal model of yersiniosis. Within 3 hours of birth and before being fed, 14 piglets were inoculated orogastrically with 10 ml of bacterial suspension containing about 3 x 10(10) colony forming units of Y. enterocolitica, followed by 10 ml of 10% NaHCO3 solution. A further 14 litter mates acted as controls. The animals were reared on an artificial milk formula and humanely killed at 3 or 5 days after infection. Of the 14 infected piglets, 11 became anorexic, five vomited and 13 developed diarrhoea. Yersinia enterocolitica was isolated from their faeces and small intestinal contents. Body weight gains and the plasma glucose concentrations were significantly lower in the infected piglets than in the controls. Damage to the mucosa was observed in the whole gastro-intestinal tract, but was more severe in the small intestine and caecum. Micro-abscesses surrounding bacteria were present at the base of the villi in all parts of the small intestine, particularly in the distal ileum. Lesions were present in the small intestine in all infected piglets by day 3 and were more extensive by day 5. The liver was damaged by day 5, but not day 3. Similar lesions were seen in the mucosa of the stomach in one of six piglets at 3 days and in two of eight piglets at 5 days. It is hypothesised that the hypoacidity in the newborn stomach, as well as the administration of the NaHCO3 solution, may have produced favourable conditions for bacterial invasion.     

Changes in thermal threshold response in eight cats after administration of buprenorphine, butorphanol and morphine

Thermal thresholds were measured in eight cats after the intramuscular administration of morphine (0.2 mg/kg), buprenorphine (0.01 mg/kg) or butorphanol (0.2 mg/kg), doses commonly used in clinical practice; 0.9 per cent saline (0.3 ml) was injected as a control. Groups of six cats were used and each cat participated in at least two treatments, according to a randomised design. The investigator was blinded to the treatments. The thermal thresholds were measured with a testing device developed specifically for cats, and measurements were made before and five, 30, 45 and 60 minutes and two, four, six, 12 and 24 hours after the injections. There was no significant change in thermal threshold after the injection of saline. With butorphanol, the threshold was increased only at five minutes after the injection and was decreased two hours after the injection; with morphine it was increased from between four and six hours after the injection, and with buprenorphine it was increased from between four and 12 hours after the injection.     

Effect of probenecid on disposition kinetics of ampicillin in horses.

The effect of an oral dose of probenecid on the disposition kinetics of ampicillin was determined in four horses. An intravenous bolus dose (10 mg/kg) of ampicillin sodium was administered to the horses on two occasions. On the first occasion the antibiotic was administered on its own, and on the second occasion it was administered one hour after an oral dose of 75 mg/kg probenecid. The plasma concentration of probenecid reached a mean (+/- se) maximum concentration (Cmax) of 188-6 +/- 19.3 micrograms/ml after 120.0 +/- 21.2 minutes and concentrations greater than 15 micrograms/ml were present 25 hours after it was administered. The disposition kinetics of ampicillin were altered by the presence of probenecid and as a result the antibiotic had a slower body clearance (ClB; 109.4 +/- 6.71 ml/kg hours compared with 208.9 +/- 26.2 ml/kg hours) a longer elimination half-life (t1/2 beta 1.198 hours compared with 0.701 hours) and consequently a larger area under the plasma concentration versus time curve (AUC 92.3 +/- 5.09 mg/ml hours compared with 35.95 +/- 3.45 mg/ml hours) when compared with animals to which ampicillin was administered alone. The ampicillin concentrations observed suggest that the dosing interval for horses may be increased from between six and eight hours to 12 hours when probenecid is administered in conjunction with the ampicillin.     

Comparison of xylazine and lidocaine effects for analgesia and cardiopulmonary functions following lumbosacral epidural injection in goats

The present study was carried out in order to compare the effects of xylazine and lidocaine on analgesia and cardiopulmonary parameters following epidural injection in goats. Twelve healthy Small East African goats of both sexes (mean +/- SD; 15.6 +/- 1.9 kg body weight) were used. The goats were randomly assigned to two groups of five and seven animals. The first group (n = 5) was given 2% lidocaine-HCl at 4400 micrograms/kg body weight. The second group (n = 7) was administered 2% xylazine-HCl at 150 micrograms/kg body weight. All drugs were diluted in 5 ml of sterile water and were injected epidurally through the lumbosacral interspace with the injection taking over 20 s. Both drugs induced analgesia within 5 min. Signs of sedation, cardiopulmonary changes and lateral recumbency developed within 5-7 min after administration of epidural xylazine. Tail flaccidity and hind limb paralysis developed 3 min after epidural administration of lidocaine. The time from recumbency to regaining normal stance was 60 and 158 min for xylazine- and lidocaine-treated animals respectively. Xylazine induced adequate analgesia of the flank and perineum, which extended to the head and forelimbs. In contrast, lidocaine induced adequate bilateral flank and perineal analgesia extending up to the third thoracic vertebra. For both drugs, analgesia of the flank and perineum persisted for the entire 180-min observational period. Epidural injection of xylazine and lidocaine caused variable depression effects on the cardiopulmonary values but was not so low as to cause concern. It is concluded that lumbosacral epidural injection of xylazine at 150 micrograms/kg body weight in 5 ml of water for injection offers the most desirable sedation and analgesia of the flank and perineum. The longer duration of analgesia may be useful for postoperative analgesia and relief of continuous straining in goats.     

Coronavirus infections in the laboratory rat: degree of cross protection following immunization with a heterologous strain.

One hundred and twenty-one specific pathogen-free male Wistar rats eight to ten weeks of age were used to evaluate the efficacy of Parker's rat coronavirus (PRC) in affording cross protection on subsequent challenge with virulent sialodacryoadenitis (SDA) virus. Sixty-two animals were inoculated intranasally on day 0 and 21 days later with approximately 10(2) median tissue culture infective doses (TCID50) of the tenth passage of PRC replicated in L-2 cells. Animals were selected at random postvaccination to evaluate the safety and efficacy of PRC by histopathology, immunohistochemistry and serology. At three and six months postvaccination (PV), vaccinated and seronegative control rats were inoculated intranasally with approximately 10(3) TCID50 doses of virulent SDA virus. Challenged rats were then killed at 6, 10 and 14 days postchallenge and necropsied. Evaluations were based on lesion indices in lacrimal and salivary glands and respiratory tract, the presence of viral antigen by immunohistochemistry, and antibody response. Lesions were observed in rats killed PV, but in general, they were significantly reduced compared with those present in seronegative animals post-exposure to virulent SDA virus (p < or = 0.05). However, they were still considered to be an unacceptable level for a routine vaccination procedure. Potvaccination antibody titers to rat coronavirus were evident in all animals tested at three or six months prior to challenge with SDA virus.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparison of ropivacaine with a combination of ropivacaine and fentanyl for the caudal epidural anaesthesia of mares

Two groups of six mares aged from eight to 18 years were anaesthetised by caudal epidural injections of ropivacaine (0.5 per cent, 0.1 mg/kg) or a combination of ripovacaine (0.08 mg/kg) and fentanyl (100 microg) in a randomised study. The onset of anaesthesia was significantly more rapid (P<0.001) and it lasted significantly longer (P<0.001) in the group anaesthetised with the combination of drugs. The surgical comfort scores of the group anaesthetised with the combination were higher than those of the group anaesthetised with ropivacaine alone (P<0.001), and the quality of intraoperative analgesia, as assessed by the surgeon, was significantly improved. There were no differences between the groups in their average scores for the levels of ataxia and sedation, in their behaviour, or in the incidence of side effects.