Promoting veterinary medication safety - Exploring the competencies of community pharmacy professionals in veterinary pharmacotherapy

The science of veterinary medicine is currently lacking studies on medication safety, although its importance in protecting animals from medication errors is central. Pharmacy professionals have an important role in ensuring medication safety of both prescription and over-the-counter medications of animals. However, this requires adequate competencies of pharmacy professionals in veterinary pharmacotherapy. The present study aimed to explore the competencies of pharmaceutical staff in community pharmacies in veterinary pharmacotherapy, which factors influence these competencies and what kind of information sources they typically use on veterinary pharmacotherapy. The study was conducted as a cross-sectional online survey targeted to pharmacy professionals in the Finnish community pharmacies, providing 596 responses. Less than half of the respondents (41%, n = 246) are considered to possess good competencies in veterinary pharmacotherapy. A third of the respondents (35%, n = 211) would dispense an anti-inflammatory drug for an animal off-label, whereas 24% (n = 145) would not interview the pet owner to discover the need for internal parasite medication before dispensing the drug. A small proportion (<1%, n = 5) would have dispensed a broad-spectrum internal parasite medication. Approximately a quarter of the respondents (27%, n = 159) stated that they acquired information on pharmacotherapy only from the material produced by the manufacturers of veterinary drugs. The competencies of pharmacy professionals in veterinary pharmacotherapy need to be strengthened in many areas to better promote veterinary medication safety. It should also be ensured that pharmacy professionals can access and use independent, high-quality information on veterinary pharmacotherapy.

Effects of general anaesthesia in dorsal recumbency with and without vatinoxan on bronchoalveolar lavage cytology of healthy horses

Pneumonia is one of the potential complications of general anaesthesia in horses. Anaesthesia is known to increase neutrophils in bronchoalveolar lavage fluid (BALF) of horses after lateral recumbency, but studies after dorsal recumbency are lacking. Our primary aim was to determine when lung inflammation reaches its maximum and how rapidly BALF cytology returns to baseline after anaesthesia in dorsal recumbency. A secondary aim was to investigate the possible effect of vatinoxan, a novel drug, on the BALF cytology results. Six healthy experimental horses were enrolled in this observational crossover study. The horses were subject to repeated BALF and blood sampling for 7 days after general anaesthesia with two treatment protocols, and without anaesthesia (control). During the two treatments, the horses received either medetomidine-vatinoxan or medetomidine-placebo as premedication, and anaesthesia was induced with ketamine-midazolam and maintained with isoflurane for 1h in dorsal recumbency. The differences in BALF and blood variables between the two anaesthesia protocols and control were analysed with repeated measures analysis of variance models. In this study, anaesthesia in dorsal recumbency resulted in no clinically relevant changes in airway cytology that could be differentiated from the effect of repeated BALF sampling. No differences in BALF matrix metalloproteinase gelatinolytic activity could be detected between the two treatments or the control series. Marked increase in serum amyloid A was detected in some animals. Vatinoxan as premedication did not consistently affect lung cytology or blood inflammatory markers after anaesthesia.

Acceptability of flavoured pharmaceutically non-active mini-tablets in pet cats tested with a rapid 3-portal acceptance test with and without food

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The palatability of synthetically flavoured mini-tablets in cats was investigated.

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3-portal acceptance tests were carried out on 10–19 pet cats in their homes.

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The mini-tablets were not accepted voluntarily without food by most of the cats.

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Amino acids were not palatable to cats, which did not support the earlier studies.

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Most of the cats ate the mini-tablets concealed inside a palatable food item.

Palatable oral pharmaceuticals are crucial for feline medication. The pharmaceutical industry prefers synthetic flavours over organic ones because of hygiene and regulatory issues. The aim of this study was to find a palatable synthetic flavour for future taste-masking of feline pharmaceuticals. The hypothesis was that synthetic meat aromas and free amino acids would be palatable to cats. The palatability of 18 synthetically flavoured mini-tablets was screened with 10–19 pet cats using a rapid 3-portal acceptance test with and without food. The tested flavours were synthetic amino acids (L-carnitine, l-glutamic acid monosodium salt hydrate, l-leucine, l-methionine, l-phenylalanine, l-proline, and taurine), d-(+)-Maltose monohydrate and thiamine hydrochloride. Furthermore, thiamine hydrochloride was combined with amino acids (l-cysteine, l-leucine, l-methionine and l-proline) and synthetic meat flavours (2-acetylpyridine, 2-acetylthiazole, 2-pentylpyridine and 4-hydroxy-5-methyl-3(2H)-furanone). The negative control was a non-flavoured placebo mini-tablet, while positive controls were an organic yeast-flavoured mini-tablet and a yeast- and fish-based commercial vitamin tablet in mini-tablet form. No significant differences were detected between palatable synthetic flavours and the placebo, nor between the synthetic flavours and the yeast flavour. In general, the mini-tablet seemed to be small enough to be accepted inside a food item. These results differ from the earlier literature about the taste preferences of cats for amino acids, and hence free amino acids should not be considered palatable to cats based purely on previous findings.

Difficulties in administration of oral medication formulations to pet cats: an e-survey of cat owners

The purpose here was to determine the problems cat owners encounter in medicating their cats with orally administered drugs at home. The study was carried out as an open e-questionnaire survey addressed to cat owners in which the authors focused on the oral administration route. A total of 46 completed questionnaires were included in the survey. In the study, 46 cats received 67 orally administered drugs. Approximately half of the drugs were registered for use in cats by the European Medicines Agency (54 per cent), and there were also off-label drugs registered for human (36 per cent) and canine medication (7.4 per cent) and an ex tempore drug (3.0 per cent). The owners were unable to give the doses as prescribed for their cats for one-fourth of the medications (16/67). Drugs that were registered for feline medication were significantly more palatable than drugs registered for other species (odds ratio (OR) 4.9), and liquid formulations were significantly more palatable than solid formulations (OR 4.8). However, most of the owners (22/38) preferred a solid dosage form, while few (4/38) chose a liquid formulation. The results indicate that there is still a need for more palatable and easily administered oral drugs for cats.

Dose-response investigation of oral ketoprofen in pigs challenged with Escherichia coli endotoxin

In order to determine the effective dose, the effects of orally administered ketoprofen were evaluated in pigs following intravenous challenge with Escherichia coli endotoxin. One hour after the challenge, five groups of pigs were treated with either tap water or ketoprofen (0.5 mg/kg, 1 mg/kg, 2 mg/kg or 4 mg/kg). The body temperature was measured and a total clinical score was calculated after assessing the general behaviour, respiratory rate and locomotion of the pigs. Thromboxane B(2) and ketoprofen concentrations were analysed from blood samples. Ketoprofen treatment significantly reduced the rectal temperature and total clinical scores, and lowered blood thromboxane B(2) concentrations when compared with the control group. Ketoprofen plasma concentrations were lower than previously reported in healthy pigs after similar doses. The appropriate dose of orally administered ketoprofen in pigs in this model is 2 mg/kg, as the higher dose of 4 mg/kg failed to provide an additional benefit.

Plasma glucose, insulin, free fatty acids, lactate and cortisol concentrations in dexmedetomidine-sedated dogs with or without MK-467: a peripheral α-2 adrenoceptor antagonist

Six healthy laboratory Beagles were treated IV with 10 μg/kg dexmedetomidine (DEX) or 10 μg/kg dexmedetomidine combined with 500 μg/kg MK-467 in the same syringe (DMK) in a randomised cross-over design with a 14 day washout. Blood was collected immediately before treatment and 35, 60 and 120 min post-injection through a central venous catheter. The plasma concentrations of glucose, insulin, non-esterified free fatty acids (NEFAs), lactate and cortisol were determined. A repeated-measures ANOVA test was used to compare treatments and effects for each sample time point. Significant differences between treatments were found for plasma glucose (P=0.037) and insulin (P=0.009). DEX significantly increased plasma glucose at 120 min, but reduced plasma insulin at 35 and 60 min. NEFA decreased for both treatments at 35 min. This reduction was transient for DMK, whereas it persisted during the follow up period for DEX. Plasma lactate concentrations increased at 35 and 60 min with DEX. Neither treatment altered plasma cortisol concentrations. The addition of MK-467 to dexmedetomidine prevented or abolished most metabolic changes in healthy Beagles.

MCT1 and CD147 gene polymorphisms in Standardbred horses

REASONS FOR PERFORMING STUDY

Transport of lactate across membranes is facilitated by proton-monocarboxylate transporters (MCT). The most widely distributed isoform is MCT1, which needs an ancillary protein CD147. Studies on erythrocytes have shown that high activity of MCT1 is inherited as the dominant allele and that activity is regulated through CD147. Mutations of human MCT1 have been described that appear to impair lactate transport in muscles and cause exertional rhabdomyolysis. There are no reports of this potential relationship in the horse.

OBJECTIVES

To obtain sequences of equine MCT1 and CD147 to examine differences between horses with high and low lactate transport activity in their erythrocytes.

METHODS

Muscle biopsy samples were taken from 3 healthy Standardbred horses and from 7 horses which according to the owners had signs of myopathy after intense exercise. DNA and RNA were isolated and PCR analysis and sequencing performed.

RESULTS

Currently, PCR fragments covering 100% of MCT1 and 70% of CD147 coding region are retained and sequence analysis has demonstrated one single nucleotide polymorphism (SNP) in the C-terminal area of MCT1 and one SNP in the extracellular domain of CD147. Both cause an amino acid change. The SNPs found are not related to lactate transport activity in erythrocytes or signs of myopathy.

CONCLUSIONS

More samples need to be analysed to make conclusions on the significance of the polymorphisms found. Furthermore, full sequence coverage of the coding region of CD147 is needed.

POTENTIAL RELEVANCE

The molecular probes produced could be used as tools to study gene regulation of lactate transport.

Coralline hydroxyapatite reinforced with polylactide fibres in lumbar interbody implantation

Porous hydroxyapatite HA blocks reinforced with poly-l/dl-lactide fibres were used to maintain the lumbar disc space and to start to create intercorporeal fusion in 23 growing pigs. In four pigs two emptied non adjacent disc spaces were left open. After 3, 6, 12 and 16 weeks the implanted disc blocks were studied radiologically, histologically, histomorphometrically, microradiographically, and with oxytetracycline fluorescence. In plain films slight to moderate ossification of the implanted disc spaces was detected at 12 and 16 weeks. Resorption of the implants was seen radiologically from 3 weeks and fragmentation from 12 weeks onwards. In microradiographs disintegration of the coralline inner structure started at 3 weeks. Histologically, connective tissue ingrowth was seen inside the porous structure from three weeks onwards. Small amounts of new bone were visible and connective tissue inside the implant increased from a mean of 65.6% at 3 weeks to a mean of 79.4% at 16 weeks histomorphometrically. The bone ingrowth varied from 0.7 to 1.7%. A loss of height in the implanted disc spaces was seen (p < 0.05, linear regression analysis). In control pigs the emptied disc spaces lost their height similarly. The implants used were not strong enough to maintain the lumbar disc height.

A comparison of propofol infusion and propofol/isoflurane anaesthesia in dexmedetomidine premedicated dogs

The effects of propofol infusion were compared with propofol/isoflurane anaesthesia in six beagles premedicated with 10 microg/kg intramuscular (i.m.) dexmedetomidine. The suitability of a cold pressor test (CPT) as a stress stimulus in dogs was also studied. Each dog received isoflurane (end tidal 1.0%, induction with propofol) with and without CPT; propofol (200 microg/kg/min, induction with propofol) with and without CPT; premedication alone with and without CPT in a randomized block study in six separate sessions. Heart rate and arterial blood pressures and gases were monitored. Plasma catecholamine, beta-endorphin and cortisol concentrations were measured. Recovery profile was observed. Blood pressures stayed within normal reference range but the dogs were bradycardic (mean heart rate < 70 bpm). PaCO2 concentration during anaesthesia was higher in the propofol group (mean > 57 mmHg) when compared with isoflurane (mean < 52 mmHg). Recovery times were longer with propofol than when compared with the other treatments. The mean extubation times were 8 +/- 3.4 and 23 +/- 6.3 min after propofol/isoflurane and propofol anaesthesia, respectively. The endocrine stress response was similar in all treatments except for lower adrenaline level after propofol infusion at the end of the recovery period. Cold pressor test produced variable responses and was not a reliable stress stimulus in the present study. Propofol/isoflurane anaesthesia was considered more useful than propofol infusion because of milder degree of respiratory depression and faster recovery.

Pain alleviation in animals: attitudes and practices of Finnish veterinarians

A questionnaire was sent to 911 Finnish veterinarians to assess their attitudes and practices to pain relief in animals. Responses to statements about recognition and treatment of pain were either to agree or to disagree. The pain caused by specified surgical and clinical conditions was rated. Inquiries were also posed about the number of analgesics available and their use in specific surgical procedures and clinical situations. The questionnaires were returned by 441 respondents. Women and younger veterinarians generally rated pain higher and treated it more frequently than men and older colleagues. Younger veterinarians and those in larger practices also had more analgesics available than older veterinarians and those in smaller practices. Respondents agreed with the statement that relieving pain is beneficial for animals. However, large differences were present in the frequency of use of pain alleviation between different animal species undergoing similar operations and between clinical conditions scored equally in the numerical rating of pain. The severity and clinical relevance of feline pain is probably often underestimated, as cats were less likely to receive analgesics than dogs after similar operations.

24-hour Holter-monitoring in the perianaesthetic period in dogs premedicated with dexmedetomidine

Baseline and perianaesthetic 24-hour Holter recordings were carried out in six healthy beagles. After dexmedetomidine premedication anaesthesia was induced with propofol and maintained with propofol infusion or isoflurane for one hour. Dexmedetomidine alone was used as control. The recordings were analysed for ventricular premature complexes (VPC), atrioventricular (AV) blocks and mean heart rate/hour (HR). In most recordings, no ventricular arrhythmias were detected, the maximum frequency being two VPCs/24 h. VPCs were not seen during anaesthesia or during the recovery period. The development of second-degree AV-blocks varied from dog to dog. Most of the heart blocks were seen during the premedication period when bradycardia was most prominent. During the subsequent night, HR was similar between treatments and did not differ from that seen on the baseline recordings. In beagles treated with dexmedetomidine alone or combined with propofol or propofol/isoflurane, ventricular arrhythmias were not detected more frequently than those reported in healthy non-anaesthetised dogs.

Some factors influencing the level of clinical sedation induced by medetomidine in rabbits

Rabbits (n=23) received intravenous bolus medetomidine at 100 mug/kg. Prior to medetomidine administration, heart and respiratory rates were measured, arterial blood was collected and analysed for plasma cortisol, glucose and albumin concentrations. Fifteen minutes after medetomidine administration, heart and respiratory rates were measured again and sedation was scored. The rabbit was afterwards anaesthetized with 20 mg/kg ketamine administered intravenously to enable spinal tap and heart puncture. Cerebrospinal fluid (CSF) was collected (this occurred 20 min post medetomidine administration) and analysed for medetomidine concentration. Blood was collected by heart puncture immediately after the spinal tap and analysed for serum medetomidine concentration. Cerebrospinal fluid medetomidine concentration correlated negatively with sedation. Serum medetomidine correlated positively with CSF medetomidine concentration. Cerebro-spinal fluid medetomidine was 17 +/- 13% of serum medetomidine concentration. Plasma cortisol and glucose concentrations correlated negatively with serum medetomidine. We conclude that after an intravenous bolus administration of a low sedative dose of medetomidine to rabbits; CSF concentration of the drug correlate negatively with sedation and that this may be because of the fact that only the free and unbound medetomidine may be available for detection in the CSF, the concentration of medetomidine detected in the CSF was much lower than that in blood and a positive correlation exists between CSF and serum medetomidine concentrations. Stress may have some effect on the distribution or metabolism of medetomidine in rabbits.

Double-blind evaluation of implants of gold wire at acupuncture points in the dog as a treatment for osteoarthritis induced by hip dysplasia

Thirty-eight dogs with hip dysplasia were studied to evaluate the use of gold wire implants at acupuncture points around the hip joints. They were assigned at random into two groups of 19. In the treated group, gold wire was inserted through hypodermic needles at electrically found acupuncture points around both hips. In the control group, the areas were prepared in the same way but had only the skin pierced at sites which were not acupuncture points, with a needle of the same size as that used in the treated group. Over a period of six months the dogs were studied repeatedly by two veterinarians and by the dogs' owners who were unaware of the treatments the dogs had received; they assessed the dogs' locomotion, hip function and signs of pain. Radiographs were taken at the beginning and end of the study. Although the data collected from both groups by the veterinarians and the owners showed a significant improvement of locomotion and reduction in signs of pain (P=0.036 for the veterinary evaluation and locomotion and P=0.0001 and P=0.0034 for the owners' evaluation of locomotion and pain, respectively), there were no statistically significant differences between the treated and control groups (P=0.19 and P=0.41, P=0.24, respectively).

Comparison of medetomidine and dexmedetomidine as premedicants in dogs undergoing propofol-isoflurane anesthesia

OBJECTIVE

To compare 3 dose levels of medetomidine and dexmedetomidine for use as premedicants in dogs undergoing propofol-isoflurane anesthesia.

ANIMALS

6 healthy Beagles.

PROCEDURE

Dogs received medetomidine or dexmedetomidine intravenously at the following dose levels: 0.4 microg of medetomidine or 0.2 microg of dexmedetomidine/kg of body weight (M0.4/D0.2), 4.0 microg of medetomidine or 2.0 microg of dexmedetomidine/kg (M4/D2), and 40 microg of medetomidine or 20 microg of dexmedetomidine/kg (M40/D20). Sedation and analgesia were scored before induction. Anesthesia was induced with propofol and maintained with isoflurane. End-tidal isoflurane concentration, heart rate, and arterial blood pressures and gases were measured.

RESULTS

Degrees of sedation and analgesia were significantly affected by dose level but not drug. Combined mean end-tidal isoflurane concentration for all dose levels was higher in dogs that received medetomidine, compared with dexmedetomidine. Recovery time was significantly prolonged in dogs treated at the M40/D20 dose level, compared with the other dose levels. After induction, blood pressure decreased below reference range and heart rate increased in dogs treated at the M0.4/D0.2 dose level, whereas blood pressure was preserved in dogs treated at the M40/D20 dose level. However, dogs in these latter groups developed profound bradycardia and mild metabolic acidosis during anesthesia. Treatment at the M4/D2 dose level resulted in more stable cardiovascular effects, compared with the other dose levels. In addition, PaCO2 was similar among dose levels.

CONCLUSIONS AND CLINICAL RELEVANCE

Dexmedetomidine is at least as safe and effective as medetomidine for use as a premedicant in dogs undergoing propofol-isoflurane anesthesia.

Sedative, analgesic, and cardiovascular effects of levomedetomidine alone and in combination with dexmedetomidine in dogs

OBJECTIVE

To determine whether a high dose of levomedetomidine had any pharmacologic activity or would antagonize the sedative and analgesic effects of dexmedetomidine in dogs.

ANIMALS

6 healthy Beagles.

PROCEDURE

Each dog received the following treatments on separate days: a low dose of levomedetomidine (10 microg/kg), IV, as a bolus, followed by continuous infusion at a dose of 25 microg/kg/h; a high dose of levomedetomidine (80 microg/kg), IV, as a bolus, followed by continuous infusion at a dose of 200 microg/kg/h; and a dose of isotonic saline (0.9% NaCl) solution, IV, as a bolus, followed by continuous infusion (control). For all 3 treatments, the infusion was continued for 120 minutes. After 60 minutes, a single dose of dexmedetomidine (10 microg/kg) was administered IV. Sedation and analgesia were scored subjectively, and heart rate, blood pressure, respiratory rate, arterial blood gas partial pressures, and rectal temperatures were monitored.

RESULTS

Administration of levomedetomidine did not cause any behavioral changes. However, administration of the higher dose of levomedetomidine enhanced the bradycardia and reduced the sedative and analgesic effects associated with administration of dexmedetomidine.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggest that administration of dexmedetomidine alone may have some cardiovascular benefits over administration of medetomidine, which contains both dexmedetomidine and levomedetomidine. Further studies are needed to confirm the clinical importance of the effects of levomedetomidine in dogs.

Abdominal radiography in monitoring the resolution of sand accumulations from the large colon of horses treated medically

This retrospective study consisted of 14 horses (age 6 weeks-12 years) with radiographically evident sand accumulations cranioventrally in the abdomen and clinical signs suggestive of sand enteropathy. The horses were treated medically and resolution of sand was monitored radiographically. Routine treatment consisted of psyllium mucilloid, combined with magnesium sulphate and/or mineral oilif needed. Initially, the number, size and shape of the sand accumulations showed large variation and the response to therapy was not predictable based on the initial appearance of the accumulation. In 2 foals, some of the sand was passed and the rest was mixed with other intestinal contents within 2-4 days. Even large accumulations disappeared in 2-4 days with psyllium alone or combined with mineral oil in 4 horses. In another 4 horses, the size of the accumulations decreased but varying amounts remained approximately at the same site, despite treatment for 1-4 weeks, and all these horses also had either gastric or large colon impaction. Three horses had a limited response to psyllium treatment, but the accumulation resolved with repeated doses of magnesium sulphate, with or without mineral oil. One horse did not respond to prolonged laxative treatment but the accumulation resolved on pasture. Clinical improvement was not necessarily related to the resolution of sand. Radiography of the cranioventral abdomen was found to be a useful means for monitoring the resolution of sand and confirming the effect of medical treatment in removing sand from the large colon in the horse.

Correlation between serum concentrations following continuous intravenous infusion of dexmedetomidine or medetomidine in cats and their sedative and analgesic effects

Dexmedetomidine (DEX) may have some therapeutic advantages over the racemate medetomidine (MED). Here we have examined how serum concentrations of DEX correlate with some of its anaesthetic effects. Cats (n = 6) were administered with a continuous stepwise intravenous (i.v.) infusion of DEX or MED on different occasions in a cross-over design. Maintenance infusion rates (mg/kg/min) used were: DEX = 0.25 (MED = 0.50); DEX = 1 (MED = 2) and DEX = 4 (MED = 8) for infusion steps 1, 2 and 3, respectively. Each maintenance infusion lasted at least 50 min and was preceded with a loading dose. There was no significant difference between serum DEX and 0.5 serum MED concentrations at any dose level nor was there a significant difference between serum DEX and the (entire) serum MED concentrations. There was no significant difference between DEX and MED for sedation, analgesia, muscular relaxation and heart and respiratory rates. For both DEX and MED, serum drug concentration and analgesia were dose-dependent and sedation increased until the end of infusion step 2 (dose level 2) and decreased at the end of step 3 (dose level 3). Muscular relaxation was not dose-dependent. We conclude that increasing the blood concentration of DEX or MED beyond a certain level decreases the level of sedation instead of increasing it even though analgesia increases. The rate at which DEX and MED are metabolized in cats may not be the same.

Clinical effects and pharmacokinetics of medetomidine and its enantiomers in dogs

The clinical effects and pharmacokinetics of medetomidine (MED) and its enanti-omers, dexmedetomidine (DEX) and levomedetomidine (LEVO) were compared in a group of six beagle dogs. The dogs received intravenously (i.v.) a bolus of MED (40 microg/kg), DEX (20 and 10 microg/kg), LEVO (20 and 10 microg/kg), and saline placebo in a blinded, randomized block study in six separate sessions. Sedation and analgesia were scored subjectively, and the dogs were monitored for heart rate, ECG lead II, direct blood pressure, respiratory rate, arterial blood gases, and rectal body temperature. Blood samples for drug analysis were taken. Peak sedative and analgesic effects were observed at mean (+/- SD) plasma levels of 18.5 +/- 4.7 ng/mL for MED40, 14.0 +/- 4.5 ng/mL for DEX20, and 5.5 +/- 1.3 ng/mL for DEX10. The overall level of sedation and cardiorespiratory effects did not differ between MED40, DEX20 and DEX10 during the first hour, apparently due to a ceiling effect. However, the analgesic effect of DEX20 lasted longer than the effect of the corresponding dose of racemic medetomidine, suggesting greater potency for dexmedetomidine in dogs. Levomedetomidine had no effect on cardio-vascular parameters and caused no apparent sedation or analgesia. The pharmacokinetics of dexmedetomidine and racemic medetomidine were similar, but clearance of levomedetomidine was more rapid (4.07 +/- 0.69 L/h/kg for LEVO20 and 3.52 +/- 1.03 for LEVO10) than of the other drugs (1.26 +/- 0.44 L/h/kg for MED40, 1.24 +/- 0.48 for DEX20, and 0.97 +/- 0.33 for DEX10).

Comparison of three doses of dexmedetomidine with medetomidine in cats following intramuscular administration

Cats (n = 6) were administered dexmedetomidine (DEX) and medetomidine (MED) at three different dose levels in a randomized, blinded, cross-over study. DEX was administered at 25, 50 and 75 microg/kg (D25, D50 and D75), corresponding to MED 50, 100 and 150 microg/kg (M50, M100 and M150). Sedation, analgesia and muscular relaxation were scored subjectively. Heart and respiratory rates and rectal temperature were measured. Corresponding doses of DEX and MED were compared. Effects were also compared between dose levels for each compound. At dose level 2 (D50-M100), the duration of effective clinical sedation was significantly shorter after DEX (202.5 +/- 16.0 min) than after MED (230.0 +/- 41.2 min). Proceeding from D50-M100 to D75-M150, the duration of effective clinical sedation was increased more after DEX (by 57.5 +/- 38.4 min) than after MED (by 14.2 +/- 41.9 min) Increasing from D50-M100 to D75-M150, heart rate was further decreased after DEX (by 8.1 +/- 13.4%) but not after MED. There was no statistically significant difference between corresponding doses of DEX and MED for any of the other parameters studied. Changes in sedation, analgesia and muscular relaxation were dose-dependent. It was concluded that anaesthetic effects of medetomidine in cats are probably due entirely to its d-isomer and that dexmedetomidine at 25, 50 and 75 microg/kg induces dose-dependent sedation, analgesia and muscular relaxation of clinical significance in cats.

Medetomidine-midazolam sedation in sheep

Seven sheep were sedated 3 times: with medetomidine (15 micrograms kg-1), with midazolam (0.1 mg kg-1) and with a combination of the drugs. All drugs were administered intravenously. Heart and respiratory rates were measured. Arterial blood samples were collected, and PaO2, PaCO2, pH, haemoglobin concentration and saturation, and base excess were determined. Systolic and mean arterial pressures were recorded before and after the treatment with medetomidine-midazolam. Midazolam increased the time of recumbency induced by medetomidine. After administration of midazolam alone, 4 of the 7 sheep were sedated and the other 3 were excited. Heart rate decreased after both medetomidine and medetomidine-midazolam. One sheep suffered a cardiac arrest after medetomidine-midazolam injection, and it required resuscitation. PaO2 and haemoglobin oxygen saturation decreased after medetomidine, and medetomidine-midazolam caused a marked hypoxaemia. PaCO2 increased after medetomidine, both alone and combined with midazolam, but arterial pH was within the reference values after all drug administrations. Systolic and mean arterial pressures decreased after medetomidine-midazolam. This study indicates that though in sheep midazolam potentiates the sedative effect of medetomidine, the combination of medetomidine and midazolam also reduces the in PaO2 and haemoglobin oxygen saturation more than medetomidine alone. The results indicate that a medetomidine-midazolam combination is unsafe for sheep at the doses studied.

Medetomidine-midazolam sedation in sheep

Seven sheep were sedated 3 times: with medetomidine (15 micrograms kg-1), with midazolam (0.1 mg kg-1) and with a combination of the drugs. All drugs were administered intravenously. Heart and respiratory rates were measured. Arterial blood samples were collected, and PaO2, PaCO2, pH, haemoglobin concentration and saturation, and base excess were determined. Systolic and mean arterial pressures were recorded before and after the treatment with medetomidine-midazolam. Midazolam increased the time of recumbency induced by medetomidine. After administration of midazolam alone, 4 of the 7 sheep were sedated and the other 3 were excited. Heart rate decreased after both medetomidine and medetomidine-midazolam. One sheep suffered a cardiac arrest after medetomidine-midazolam injection, and it required resuscitation. PaO2 and haemoglobin oxygen saturation decreased after medetomidine, and medetomidine-midazolam caused a marked hypoxaemia. PaCO2 increased after medetomidine, both alone and combined with midazolam, but arterial pH was within the reference values after all drug administrations. Systolic and mean arterial pressures decreased after medetomidine-midazolam. This study indicates that though in sheep midazolam potentiates the sedative effect of medetomidine, the combination of medetomidine and midazolam also reduces the in PaO2 and haemoglobin oxygen saturation more than medetomidine alone. The results indicate that a medetomidine-midazolam combination is unsafe for sheep at the doses studied.

Preliminary investigations of pain and analgesia assessment in horses administered phenylbutazone or placebo after arthroscopic surgery

Twenty-five horses undergoing arthroscopic surgery were studied to develop a scheme for assessing pain in horses while investigating the effects of phenylbutazone (PBZ) analgesia. Fifteen of the 25 horses received PBZ 4 mg/kg intravenously (IV) before surgery and 2 mg/kg (IV) every 12 hours thereafter until 60 hours; the remaining 10 (placebo group) were given a corresponding volume of saline. In both groups, venous blood samples were collected for catecholamine, beta-endorphin, and cortisol assays before premedication and up to 72 hours after surgery. Postoperative pain was evaluated by measuring predefined behavioral and physiological variables. A total postoperative pain severity index (TPPSI) was calculated using all variables. There were no differences between PBZ and placebo groups in plasma beta-endorphin or catecholamine concentrations, but the TPPSI was higher in the placebo group than in the PBZ group, suggesting that perioperative treatment with PBZ has some analgesic benefit. This study shows the difficulties associated with pain assessment in horses.

Relationship between ossification of the cartilages of the foot and conformation and radiographic measurements of the front feet in Finnhorses

One hundred Finnhorse cadaver front feet were measured and examined both radiographically and visually to report the incidence of various foot problems and their relationship to ossification of the cartilages of the foot. Ossification extending above the proximal border of the navicular bone and/or separate centres of ossification were found in 36 feet, and the lateral cartilages showed more ossification than the medial cartilages. The feet were generally broad with well developed frogs, but the long toe-low heel syndrome was a relatively common finding. Ossification of the cartilages correlated with the length of the heels but was not related to any clinically significant foot abnormalities such as contracted or under-run heels or signs of unequal weightbearing. Ossification of the cartilages did not seem to be either the cause or the result of general conformational adaptations of the front feet.

Intra-articular morphine and saline injections induce release of large molecular weight proteoglycans into equine synovial fluid

Both morphine and physiologic saline injected intra-articularly into healthy equine tarsocrural joints induced a release of large molecular size proteoglycan (PG) subunits into the synovial fluid (SF) analysed 24 h postinjection. High-performance liquid chromatography (HPLC) with a size-exclusion column was used to assess the high molecular weight proteoglycans in equine synovial fluid (SF). The PG peaks of SF samples eluated separately from SF hyaluronate and other molecular components of the SF in the HPLC chromatographies indicating no interaction between hyaluronate and PG in the SF. Individual elution profiles varied between joints and horses. The amount of PG release was measured by relative area index from the HPLC chromatograms. The synovial fluid PG content was significantly increased (P < 0.05) after morphine but not in saline injected joints compared with pretreatment but there were no significant differences between the two groups. It was concluded that intra-articular injections of both morphine and physiologic saline are able to elicit a marked PG release into the SF from articular cartilage within 24 h of injection.

Influence of medetomidine on acid-base balance and urine excretion in goats

Seven goats were given medetomidine 5 micrograms/kg as an iv bolus injection. Venous blood samples were taken repeatedly and urine was collected continuously via a catheter up to 7h after the injection. Medetomidine caused deep clinical sedation. Base excess, pH and PCO2 in venous blood rose after medetomidine administration. There were no significant changes in plasma concentrations of sodium, calcium, magnesium, creatinine or osmolality, whereas potassium and bicarbonate concentrations increased, and phosphate and chloride decreased. Medetomidine increased plasma glucose concentration, and in 4 of 7 goats glucose could also be detected in urine. Medetomidine did not influence urine flow rate, free water clearance, bicarbonate and phosphate excretion or pH, but renal chloride, sodium, potassium, calcium, magnesium and creatinine excretion were reduced. The results suggest that the metabolic alkalosis recorded after medetomidine administration is not caused by increased renal acid excretion.

Influence of medetomidine on acid-base balance and urine excretion in goats

Seven goats were given medetomidine 5 micrograms/kg as an iv bolus injection. Venous blood samples were taken repeatedly and urine was collected continuously via a catheter up to 7h after the injection. Medetomidine caused deep clinical sedation. Base excess, pH and PCO2 in venous blood rose after medetomidine administration. There were no significant changes in plasma concentrations of sodium, calcium, magnesium, creatinine or osmolality, whereas potassium and bicarbonate concentrations increased, and phosphate and chloride decreased. Medetomidine increased plasma glucose concentration, and in 4 of 7 goats glucose could also be detected in urine. Medetomidine did not influence urine flow rate, free water clearance, bicarbonate and phosphate excretion or pH, but renal chloride, sodium, potassium, calcium, magnesium and creatinine excretion were reduced. The results suggest that the metabolic alkalosis recorded after medetomidine administration is not caused by increased renal acid excretion.

Sympatho-adrenal activity and the clinical sedative effect of detomidine in horses

Thirty-nine horses were given detomidine 10 micrograms/kg bodyweight (bwt) intravenously (iv) and six horses were given a corresponding volume of saline solution before minor procedures. Venous blood samples were collected for catecholamine and cortisol determination immediately before the detomidine or saline injection and 20 mins after it. The behaviour of the horse at the time of detomidine injection and the extent of sedation were evaluated. Plasma adrenaline, noradrenaline and the catecholamine metabolites, 3,4-dihydroxyphenylglycol (DHPG) and 3,4-dihydroxyphenylacetic acid (DOPAC), and cortisol concentrations decreased significantly after administration of detomidine, but they remained unchanged in the control group. A high plasma adrenaline concentration before detomidine injection, indicative of a high level of stress, seemed to correspond with a reduced sedative effect of detomidine. The extent of sedation also was related to the concentrations of adrenaline, noradrenaline and DHPG in plasma after the detomidine injection. The reductions in the plasma catecholamine concentrations may have been caused, in part, by decreased secretion of catecholamines due to the sedative effects of detomidine; but detomidine also influences the plasma catecholamine concentrations by reducing directly sympatho-adrenal activity.

Long term ECG recording with Holter monitoring in clinically healthy horses

The electrocardiogram of 9 horses was continuously recorded for 24 h with Holter monitoring to examine the variations in heart rate and rhythm during daily routine procedures and at night. Three horses had transient sinus bradycardia, and 3 had periods of sinus tachycardia. Heart blocks were detected in 3 horses, and all horses had periods of sinus arrhythmia. These changes in the heart rate and rhythm were apparently caused by variations in autonomic nervous system tone and they are probably "normal" findings in resting, undisturbed horses. Ventricular premature depolarisations were not observed in any horse, but some single supraventricular premature contractions were detected. There was preliminary evidence that in order to register the real resting heart rate and rhythm of a horse the ECG should be recorded over a long period, and also at night and without the presence of the investigator.

The Influence of Detomidine and Epinephrine on Heart Rate, Arterial Blood Pressure, and Cardiac Arrhythmia in Horses

Detomidine (10 micrograms/kg and 20 micrograms/kg) was administered to seven horses with and without epinephrine infusion (0.1 microgram/kg/min) from 5 minutes before to 5 minutes after detomidine injection. One or more single supraventricular premature heartbeats were observed in three horses after detomidine administration. Epinephrine infusion did not modify the incidence of cardiac arrhythmias in detomidine-treated horses at the doses tested. Relatively high momentary peak systolic pressures were registered in some horses after detomidine administration during epinephrine infusion. The highest systolic arterial blood pressure was 290 mm Hg, but this value was not higher than that reported in horses during maximum physical exercise. Epinephrine infusion did not alter blood gases, arterial pH, or base excess.

Preliminary study of porous hydroxylapatite particle containment with a curved biodegradable implant in the sheep mandible

A conventional augmentation method without a splint was compared with the use of a biodegradable polyglycolide (PGA) splint as a container of hydroxylapatite (HA) particles. With the PGA splint there was a 35% rate of dehiscence of the incision, leading to loss of HA particles. Based on microradiographic measurements, the HA was retained better on the side augmented by the conventional technique. Toward the end of 24 weeks, however, a decrease of augmentation and in the quantity of HA was seen with both methods. According to the histologic studies, there was evidence of HA phagocytosis by osteoclast-type cells. In the histomorphometric studies after 24 weeks of follow-up, new bone ingrowth was 12% without and 10% with the PGA splint. Although the planimetric studies showed the PGA splint to be a good container, the material still requires further development.

Detomidine reduces the plasma catecholamine, but not cortisol concentrations in horses

Single doses of the alpha 2-adrenergic sedative-analgesic drug, detomidine (10 micrograms/kg, n = 7; 20 micrograms/kg, n = 9), were administered IV to adult horses. Plasma concentrations of adrenaline, noradrenaline, the catecholamine metabolites 3,4-dihydroxyphenylglycol (DHPG) and 3,4-dihydroxyphenylacetic acid (DOPAC), and cortisol were determined before the medication and 30 minutes after it. The plasma concentrations of noradrenaline and the catecholamine metabolites decreased significantly after administration of both 10 micrograms/kg and 20 micrograms/kg of detomidine. Plasma adrenaline level had a tendency to decrease, but plasma cortisol levels were not influenced. The findings suggest a reduction in sympatho-adrenal activity in horses treated with detomidine.

Lumbar spine interbody fusion with reinforced hydroxyapatite implants

Porous coralline and synthetic hydroxyapatite blocks reinforced with either self-reinforced polyactide or polyglycolide were implanted into 15 lumbar intervertebral disc spaces in five minipigs in order to determine whether they could provide an osteoconductive bridge for interbody fusion. Histological examination and radiological analysis with plain films, computed tomography and magnetic resonance imaging were carried out. The osteoconductive properties were promising; creeping bone formation could be observed, although no complete fusion had been achieved at 24 weeks.

N-acetyl-beta-D-glucosaminidase (NAGase) in porcine milk

Sow milk contains a high basal level of the lysosomal enzyme N-acetyl-β-D-glucosaminidase (NAGase). The level is extremely high in colostrum. High basal levels seem to hide inflammatory changes. Therefore NAGase did not prove to be as good an indicator for porcine agalactia syndrome as reported for mastitic bovine or ovine milk.

Enhanced growth of E. coli in whey from sows with agalactia syndrome

E. coli strains were inoculated into porcine whey samples. Replication rates and the final number of bacteria increased when grown in samples collected from sows affected by the agalactiae syndrome as compared with control samples from healthy ones. The bacteria grew especially well in samples collected on the day of farrowing.

The results suggest that milk collected at the very early stages of lactation and from sows affected by agalactia supports growth of E. coli. This might make the mammary glands more sensitive to infections caused by coliform bacteria although the causal relationship remains to be resolved.