Reference values on hematologic parameters of the Brazilian donkey (Equus asinus) breed

Thirteen hematologic measurements were performed on 38 healthy donkeys of the Brazilian breed (32 females and 6 males) aged 3 to 19 years. Mean ±SD (minimum-maximum) values were as follows: red blood cells (RBC) 6.82 ± 0.67 (5.46−8.17) × 10⁶/μL; packed cell volume (PCV) 37.63 ± 2.76 (32.00−44.00) %; hemoglobin (Hb) 12.87 ± 0.98 (10.70−14.50) g/dL; mean corpuscular volume (MCV) 55.45 ± 4.06 (48.90−62.70) fL; mean corpuscular hemoglobin (MCH) 18.85 ± 1.14 (17.40−21.60) pg; mean corpuscular hemoglobin concentration 34.20 ± 1.24 (31.50−36.40) g/dL; white blood cells (WBC) 8.22 ± 1.49 (4.60−11.50) × 10³/μL; bands 1.77 ± 2.00 (0.00−9.00) %; segmented neutrophils 41.18 ± 5.98 (30.50−53.20) %; lymphocytes 50.53 ± 6.25 (35.30−63.50) %; monocytes 1.57 ± 1.30 (0.00−4.60) %; eosinophils, 4.64 ± 2.17 (1.00−10.00) %; basophils 0.33 ± 0.58 (0.00−2.90) %. It was demonstrated that values of some blood parameters of the Brazilian donkey breed were similar to results obtained for other donkey breeds. The results of this study serve as reference ranges for donkey populations and can be useful for health control, which in turn helps in the diagnosis and prognosis of diseases.

Introduction

Blood examination has been performed for several reasons: as a screening procedure to assess general health; as an adjunct to patient's infection; and to evaluate the progress of certain disease states.[1] However, there are important differences in physiology, behavior, and management that influence the common diseases encountered in donkeys. Successful diagnosis and treatment often depend on recognizing these differences. [2] Unfortunately, a limited number of observations have been reported on the hematologic values for donkey breeds and populations and these studies are far from complete. [3, 4, 5, 6, 7, 8 and 9] Hematologic variation values for donkey breeds and populations should be associated with the age, sex, and the time of sampling in relation to exercise, geographic, and nutritional factors. Perhaps some of the variations observed among different authors were also associated with different techniques and methods. [4]Apart from the investigations by Perdigão de Oliveira et al,[3] Gacek et al, [10] and Mori et al, [11] we could find no published record of blood values of the Brazilian donkey breed. The aim of this investigation was to determine reference ranges for hematologic analyses in the Brazilian donkey breed to establish a baseline for further scientific and clinical use.

Materials and methods

The material for the present study consisted of 38 adult donkeys of the Brazilian breed (32 females and 6 males), ranging between 3 and 19 years of age (mean ±SD: 8.3 ± 3.5 years), from the Estação Experimental de Colina do Instituto de Zootecnia da Secretaria de Agricultura do Estado de São Paulo, and kept under similar feeding and management conditions. All animals were apparently healthy, and they were handled carefully to reduce any possible effects of stress on the parameters analyzed.Blood samples were draw from the jugular vein into 5 mL evacuated glass tubes containing EDTA as anticoagulant. Blood smears were prepared immediately after being collected from whole blood and then were air-dried. The collected blood samples were immediately stored at 4°C and processed within 6 hours.RBC and WBC counts were performed using an electronic counter (Serono Baker). Hb concentration was determined by the cyanmethemoglobin method. PCV was determined after the blood had been transferred to microhematocrit tubes and centrifuged at 10,000 g for 5 minutes. MCV, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration were calculated from PCV, Hb concentration, and RBC count.[1] Blood smears were stained with modified May-Grunwald Giemsa stain for determination of the differential WBC count. At least 200 WBCs were counted for differential WBC determinations.All analyses were performed within the Departamento de Clinica Médica da Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo.Data analysis was performed using a statistical software (Graph Pad InStat version 3.01, 32 bit for Windows 95/NT). Each parameter was tested for normality applying the Kolmogorov and Smirnov methods. The reference ranges for the hematologic analyses were given as mean ±SD and the interval from minimum and maximum values.Unpaired t-tests were used to determine the effect of sex (female versus male) on hematologic values, for data normally distributed. If data did not seem to be normally distributed, non-parametric tests (Mann-Whitney U test) were used. The level of statistical significance was set at P < .05.

Results

Reference ranges of hematologic constituents of the blood of the Brazilian donkey breed determined in the current study are shown in Table 1 and Table 2. Most of the values had Gaussian distribution (P < .10). Only basophils did not seem to be normally distributed (P < .05). Comparisons of hematologic ranges of the Brazilian donkeys with other donkey breeds and populations are shown in Table 1 and Table 2.     

Comparative Effect of Epidural Administration of Xylazine or Dexmedetomidine on Echocardiographic Dimensions and Cardiac Indices in Clinically Healthy Donkeys (Equus asinus)

The aim of the present study was to assess and compare the changes of the echocardiographic dimensions and cardiac function indices after epidural injection of xylazine or dexmedetomidine in clinically healthy donkeys. In an experimental prospective randomized cross-over study, 10 healthy adult donkeys were injected with saline solution, xylazine (0.20 mg kg⁻¹), and dexmedetomidine (0.005 mg kg⁻¹) into the epidural space between the second and third coccygeal vertebrae. Echocardiographic dimensions as well as cardiac function indices were assessed using a 2–3.9 MHz sector transducer, at the left paracostal ultrasonographic window, at zero, 15, 30, 60, 90, 120, and 180 minutes after administration of these medications. Epidural injection of xylazine or dexmedetomidine produced moderate sedation, complete bilateral perineal analgesia, and mild ataxia in all studied donkeys. There was a significant (P < .05) decrease in the interventricular septum thickness at end systole 60 minutes, stroke volume 30–120 minutes, fractional shortening 120 minutes, and ejection fraction 90–120 minutes after administration of xylazine or dexmedetomidine when compared with saline solution. Left ventricular end diastolic volume was significantly (P < .05) increased 60 minutes following epidural injection of dexmedetomidine compared with xylazine and saline solution. There was a significant (P < .05) increase in the left ventricular internal diameter at end diastole 90–120 minutes and left ventricular end systolic volume 60–180 minutes after administration of xylazine or dexmedetomidine in comparison with saline solution. In conclusion, epidural use of xylazine or dexmedetomidine in donkeys induced mild and transient effect on echocardiographic dimensions as well as cardiac function indices. Therefore, care should be taken when such medications are to be administered into the epidural space in donkeys with a pre-anesthetic cardiovascular compromise.     

Assessment of the accuracy of testicular dysfunction detection in male donkey (Equus asinus) with the aid of colour-spectral Doppler in relation to plasma testosterone and serum nitric oxide levels

This study aimed to determine the usefulness of colour and pulsed Doppler modes for the accurate diagnosis of donkeys suffering from subfertility to determine whether testicular vascularity assessment could be an indicator for sperm functionality. The study sample was composed of 10 male donkeys with normospermia (control group) and 10 donkeys with hypospermia. Animals underwent scrotal circumference measurement, testicular Doppler examination, seminal evaluation, blood sampling and hormonal assay. Semen volume and concentration were significantly (p ≤ .05) lower in the subfertile group (30.25 ± 1.22 ml and 89.44 ± 2.55 × 10⁶/ml) as compared with the control group (82.76 ± 1.65 ml and 452.78 ± 1.25 × 10⁶/ml), and total sperm/ejaculation was significantly (p ≤ .05) higher in the normal donkeys (28.30 ± 2.32 × 10⁹/total ejaculated) as compared with the subfertile group. Intratesticular coloured area showed a marked decline in the hypospermic males. There was no significant difference between the two groups in testosterone level, although the normal group showed an increase in nitric oxide metabolites. Both Doppler indices of the three branches of the testicular artery were elevated significantly (p ≤ .05) in abnormal donkeys, whereas Doppler peak systolic and end-diastolic velocities were increased in the normal group. Male donkeys with subfertility demonstrated lower arterial vascularity parameters in the form of intratesticular coloured area and blood flow rate; therefore, the most optimal parameters for differentiating subfertile hypospermic from normospermic donkeys were found to be the two Doppler indices, velocities parameters, testicular blood flow rate and nitric oxide levels.     

Serological Prevalence of Brucellosis among Donkeys (Equus asinus) in Some Local Government Areas of Yobe State,Nigeria

A cross-sectional study of prevalence of antibody against Brucella organisms was conducted among donkeys in three local government areas of Yobe State, northeastern Nigeria. Three hundred adult donkeys of both sexes were sampled, with 100 samples each from local government areas Bursari, Gaidam, and Machina. The overall serological prevalence of brucellosis among donkeys in the three local government areas by both rose bengal plate test (RBPT) and microtiter serum agglutination test (MSAT) was 15 (5.0%), of which five (1.7%) were male and 10 (3.3%) were female donkeys. The overall prevalence by competitive enzyme-linked immunosorbent assay (cELISA) was 10 (3.3%), of which four (1.33%) were male and six (2.0%) were female donkeys. There was a significant association between the female sex of the donkeys and the serological reaction to RBPT, MSAT, and cELISA (P < .05). Of the 100 sera sampled from Bursari, five (5%) were positive by RBPT/MSAT, which comprised two (2%) male and three (3.0%) female donkeys. There was no significant association between the sex of the donkeys and the serological reaction (P > .05). Of the 100 samples from Gaidam, four (4.0%) tested positive by RBPT/MSAT, of which one (1.0%) was male and three (3.0%) were female donkeys (P < .05). Six (6.0%) of the 100 donkey sera samples from Machina tested positive by both RBPT and MSAT, which comprised two (2.0%) male and four (4.0%) female donkeys. There was no significant association between the male sex of the donkeys and the serological reaction (P > .05); however, there was a significant association between the female sex of the donkeys and the serological reaction to both RBPT and MSAT (P < .05). Of the 100 samples from Bursari and the 100 samples from Gaidam, three (3%) from each were positive by cELISA, which comprised one (1%) male and two (2%) female donkeys. There was no statistically significant association between the sex of donkeys and the serological reaction (P > .05). Of the 100 samples tested from Machina, two (2%) male and two (2%) female donkeys were positive for Brucella antibodies by cELISA. No statistically significant association was demonstrated between the sex of the donkeys and the serological reaction to cELISA (P > .05). Because of the importance of donkeys to humans as a source of draft power, infected donkeys could be a source of Brucella infection to humans through close contact, through the respiratory system via contaminated dust or droplets, and through aborted fetuses and discharges from the genitalia.     

Comparison of carprofen and flunixin meglumine asadjunctive therapy in bovine respiratory disease

In an open, controlled, multi-centre clinical field trial, seven ‘naturally occurring’ outbreaks of acutefebrile (rectal temperature ≥ 39·5°C) respiratory disease in housed calves were treated with a single antimicrobial agent, and either the non-steroidal anti-inflammatory drug (NSAID) carprofen (n=95) or flunixin meghunine (n=92) on an alternate basis. Carprofen was administered as a single subcutaneous injection at a mean dosage of 1·4 mg kg⁻¹ (range 1·2 to 1·9 mg kg⁻¹) body weight on the first day and flunixin meglumine by intravenous injection at a mean dosage of 2·0 mg kg⁻¹ (range 1·2 to 2·6 mg kg⁻¹) body weight on the first 3 consecutive days. All calves were examined clinically immediately prior to initial treatment and on three occasions up to 1 week after the end of treatment. There were no statistically significant differences between NSAID groups in reduction of clinical parameters between examinations, or in overall efficacy. This trial demonstrated that a single dose of carprofen was equally effective as three daily closes of flunixin meglumine as adjunctive therapy to antimicrobial treatment in acute respiratory disease in calves.     

Guaifenesin-Ketamine-Xylazine Infusions to Provide Anesthesia in Donkeys

The purpose of this study was to determine a satisfactory combination of guaifenesin, ketamine, and xylazine (GKX) that would produce safe and satisfactory total intravenous anesthesia in donkeys for use under field conditions. Donkeys require higher amounts of ketamine in GKX to achieve satisfactory anesthetic levels without producing excessive depression with guaifenesin. Five adult standard donkeys (average weight, 264 kg) were anesthetized with 1.5 mg/mL ketamine, 0.5 mg/mL xylazine, 50 mg/mL guaifenesin (GKX-1); 2.0 mg/mL ketamine, 0.5 mg/mL xylazine, 50 mg/mL guaifenesin (GKX-2); or 2.0 mg/mL ketamine, 0.75 mg/mL xylazine, 50 mg/mL guaifenesin (GKX-3). For the first trial, two donkeys received GKX-1, two received GKX-2, and one received GKX-3. One donkey received GKX-1, one received GKX-2, and three received GKX-3 for the second trial. In the final trial, two received GKX-1, two received GKX-2, and one received GKX-3. Donkeys were sedated with xylazine (1.1 mg/kg body weight) intravenously, and anesthesia was induced using intravenous GKX-1, GKX-2, or GKX-3. Anesthesia was maintained for 45 minutes; temperature, respiration rate, heart rate, hemoglobin saturation, partial pressure of arterial oxygen (PaO₂), partial pressure of carbon dioxide in arterial gas (PaCO₂), and pH were measured. There was no significant difference between combinations for temperature, respiration rate, heart rate, hemoglobin saturation, PaCO₂, or pH. At 30 and 45 minutes, GKX-3 produced significantly (P < .05) lower PaO₂ values than GKX-1 and GKX-2. GKX-3 is not recommended for field use in donkeys because of respiratory depression (PaO₂= 48.7 [±5.84] and 46.0 ± 3.11 mmHg at 30 and 45 minutes, respectively), whereas more voluntary movement was apparent with GKX-1. GKX-2 produced satisfactory anesthesia without significant respiratory depression in donkeys and should produce safe and effective anesthesia in donkeys under field conditions.     

Verapamil administration for acute termination of supraventricular tachycardia in dogs

Verapamil, a calcium channel-blocking drug, was administered IV at a dosage that ranged from 0.05 to 0.15 mg/kg of body weight to 14 dogs with supraventricular tachycardia. The dosage was titrated, administering 0.05 mg/kg every 5 to 30 minutes following the initial 0.05 mg/kg dose in all but 1 dog. The drug terminated the arrhythmia in 12 dogs and slowed the ventricular rate in 1 dog. One dog was unresponsive to verapamil administration and became transiently hypotensive after the administration of a total dose of 0.15 mg/kg over 5 to 6 minutes. Various arrhythmias occurred after verapamil administration, but none required additional treatment or caused serious sequelae. Verapamil was an effective treatment for acutely converting supraventricular tachycardia to sinus rhythm in these dogs. It appears to be safe when administered in the aforementioned dosage range.     

The anatomy of the atrioventricular bundle in the heart of camels (Camelus dromedarius)

The anatomy and histology of the atrioventricular bundle (AVB) was studied in the heart of six camels (Camelus dromedarius). The trunk of the atrioventricular bundle (bundle of His) was a direct continuation of the atrioventricular (AV) node with no sharp line of demarcation between the node and the bundle. The atrioventricular bundle ran through the fibrous trigone and entered the lower part of the interventricular membranous septum, beneath the right endocardium, then lay over or slightly to the side of the centre of the muscular interventricular crest. The AVB of camels measured 4.12±1.00 mm in length, 3.66±1.13 mm in width and 1.13±1.85 mm in thickness, its maximum sectional area being 12.68±6.13 mm².Histologically, the AVB in the heart of camels comprised multiple strands of Purkinje cells separated by collagen fibres and surrounded by connective tissue. It resembled that in human beings and dogs except that, in camels, intercalated discs were present at the intercellular connections in the AVB.Abbreviations AVB trunk of the atrioventricular bundle - AV node atrioventricular node     

Pharmacokinetic, metabolism and withdrawal time of orphenadrine in camels (Camelus dromedarius) after intravenous administration

The pharmacokinetics of orphenadrine (ORPH) following a single intravenous (i.v.) dose was investigated in six camels (Camelus dormedarius). Orphenadrine was extracted from the plasma using a simple sensitive liquid–liquid extraction method and determined by gas chromatography/mass spectrometry (GC/MS). Following i.v. administration plasma concentrations of ORPH decline bi-exponentially with distribution half-life (t_1/2α) of 0.50 ± 0.07 h, elimination half-life (t_1/2β) of 3.57 ± 0.55 h, area under the time concentration curve (AUC) of 1.03 ± 0.10 g/h l⁻¹. The volume of distribution at steady state (Vd_ss) 1.92 ± 0.22 l kg⁻¹, volume of the central compartment of the two compartment pharmacokinetic model (V_c) 0.87 ± 0.09 l kg⁻¹, and total body clearance (Cl_T) of 0.60 ± 0.09 l/h kg⁻¹. Three orphenadrine metabolites were identified in urine samples of camels. The first metabolite N-desmethyl-orphenadrine resulted from N-dealkylation of ORPH with molecular ion m/z 255. The second N,N-didesmethyl-orphenadrine, resulted from N-didesmethylation with molecular ion m/z 241. The third metabolite, hydroxyl-orphenadrine, resulted from the hydroxylation of ORPH with molecular ion m/z 285. ORPH and its metabolites in camel were extensively eliminated in conjugated form. ORPH remains detectable in camel urine for three days after i.v. administration of a single dose of 350 mg orphenadrine aspartate.     

Autologous Platelet Concentrates as a Treatment of Horses with Osteoarthritis: A Preliminary Pilot Clinical Study

The clinical effect of the intra-articular injection of an autologous platelet concentrate (PC) in four horses with osteoarthritis was evaluated. The degree of lameness and joint effusion and clinical follow-up were recorded. Three injections of PC were performed at 2-week intervals. Horses were evaluated before each injection and two months after the last treatment. Clinical follow-up was conducted for 1 year. Count of platelets, leukocytes, and determination of transforming growth factor beta-1 (TGF-β₁) levels per milliliter PC were performed, as well as leukocyte count, cytology, and protein levels in synovial fluid. PC produced a statistically significant improvement in both the degree of lameness and joint effusion (P < .05). The most marked improvement was observed 2 months after the last treatment and apparently persisted for 8 months. A mean of 250 ± 71.8 × 10⁶ platelets, 8.68 ± 3.78 leukocytes × 10⁶, and 12,515 ± 2,443 pg of TGF-β₁ per milliliter PC were obtained. The evaluated synovial fluid parameters remained between normal values. No adverse clinical signs resulted from this treatment. Despite the seemingly positive effects of this substance, the clinical use of PC cannot be recommended until further studies with higher numbers of cases and longer follow-up can be undertaken.     

Comparative endocrinological responses to short transportation of Equidae (Equus asinus and Equus caballus)

In order to evaluate the effects of short transportation on β‐endorphin, adrenocorticotropic hormone (ACTH) and cortisol changes, 12 healthy stallions of Equidae (Equus asinus and Equus caballus) were studied before and after transportation of 50 km. Blood samples were collected 1 week before transportation in basal conditions, immediately before loading and after transportation and unloading, on their arrival at the breeding station. Compared to basal and before values, donkeys showed an increase in circulating ACTH (P < 0.001) and cortisol (P < 0.0005) levels after transportation and higher ACTH (P < 0.01) levels than horses after transportation. A positive and significant correlation (r = 0.885; P < 0.01) between ACTH and cortisol levels after transportation was found. No significant differences were observed for β‐endorphin levels. Compared to basal and before values, horses showed higher cortisol (P < 0.005) levels after transportation and no significant differences were observed for ACTH and β‐endorphin levels in donkeys. Horses facing forward (direction of travel) showed higher (P < 0.01) β‐endorphin levels after transportation than donkeys; horses facing backward (the opposite direction of travel) showed lower (P < 0.05) ACTH levels after transportation. The results indicate that short transportation induces a preferential activation of the hypothalamus‐pituitary‐axis (HPA), with significant release of ACTH and cortisol in donkeys and only of cortisol in horses, suggesting that transportation for donkeys may be more stressful than horses.     

Biological suppression of aflatoxicosis in Japanese quail (Coturnix coturnix japonica) by dietary addition of yeast (Saccharomyces cerevisiae)

The amelioration of aflatoxicosis in Japanese quails was examined by the dietary addition of live yeast (Saccharomyces cerevisiae; SCE). Yeast incorporated into the diet at 1 g kg⁻¹was evaluated for its ability to reduce the deleterious effects of 2·5 mg total aflatoxin ( ; 82·30 per cent ₁ , 2·06 per cent ₂, 7·68 per cent ₁and 7·96 per cent ₂) kg⁻¹diet on growing Japanese quail chicks from 10 days to 45 days of age. Forty 10-day-old Japanese quail chicks were assigned to 2×2 factorial arrangement of treatments (control, , , plus ) each consisting of 10 quails. The performances of birds were evaluated. The treatment significantly and dramatically decreased food consumption and body-weight gain from the first week onwards. The significant adverse effect of on the food conversion ratio was also determined from week 1 to the end of the experiments. The addition of to the -containing diet significantly reduced these deleterious effects of on food consumption, body-weight gain and food conversion ratio. Compared to controls, the cumulative body weight gain was reduced by 37 per cent among the quails consuming without , but increased 15 per cent for the birds fed plus . Interestingly, the single inclusion of to the -free diet provided significant improvements in all the investigated growth performances of birds (approximately 40 per cent) compared to controls.     

Arrhythmias in newborn thoroughbred foals.

Foetal electrocardiograms (ECG) were obtained from 39 of 50 Thoroughbred foaling mares close to delivery. The 50 newborn foals were studied electrocardiographically during their adaptive period, immediately after birth. In 48 foals there were paroxysmal arrhythmias or mixed arrhythmias. The most common arrhythmias were sinus arrhythmias including wandering pacemaker (32/50) and atrial premature contraction (30/50). The others observed were atrial fibrillation (15/50), ventricular premature contraction (10/50), partial atrioventricular block (7/50), ventricular tachycardia (4/50), atrial tachycardia (3/50) and idioventricular rhythm (1/50). The duration of the arrhythmias was approximately 5 min, and in all cases the arrhythmia disappeared within 15 min of birth. From foetal ECG recordings, no indication of the likelihood of neonatal arrhythmias was detected. With the exception of 2 cases, all foals have continued to grow and develop normally. These arrhythmias are considered normal physiological processes in newborn Thoroughbred foals during the adaptive period to extra-uterine life. High vagal tone and hypoxaemia at birth are probably the main contributing factors.     

Effect of housing system on reproductive behaviour and on some endocrinological and seminal parameters of donkey stallions

Reproductive management of male donkeys employed for artificial breeding has been poorly studied. The aim of this study was to evaluate the effect of housing system, with the animals grouped together in a paddock or kept in individual boxes, on sexual behaviour, cortisol and testosterone concentration and seminal characteristics of adult male donkeys. The study included four Amiata donkey jacks (stallions) from which ejaculates, saliva and blood were collected during two distinct 3 weeks periods, one in the group and one in the box housing system. Time needed for semen collection was shorter when donkeys were kept in paddocks compared to when they were kept in single boxes (14:57 ± 07:27 and 20:52 ± 09:31 min, p < .05). Native semen characteristics were not influenced by housing system, while cooled preservation in an Equitainer^® showed that sperm motility parameters were significantly higher during the paddock period compared to the box period. Salivary cortisol was influenced by housing system, both before and 60 min after ejaculation, being statistically higher when donkeys were housed in paddocks. On the contrary, overall and basal testosterone concentrations were significantly higher when animals were kept in boxes. In conclusion, in the present study, good quality semen could be successfully collected from donkeys irrespective of the housing system despite some differences in hormone concentrations.     

Centrally administered verapamil prevents the autonomic reaction to visceral pain in sheep

The significant role of voltage gated calcium channels (VGCC) L-type antagonists used concomitantly with opioids in attenuation of clinical pain has been confirmed. The aim of this study was to evaluate the effect of centrally administered verapamil on behavior and biochemical parameters in sheep that have undergone experimental duodenal distension (DD) and to determine whether verapamil exerts any anti-nociceptive effects under these conditions. The study was carried out using 24 mature crossbred ewes, each weighing 38-43 kg. Verapamil, a VGCC blocker, was administered through an intracerebroventricular cannula at the following doses: 0.25, 0.5, 1.0 and 2.0 mg in toto. Ten minutes later experimental DD was conducted by insertion and the distension of rubber balloon (containing 40 ml of warm water) inserted into sheep duodenum. After 5 min of mechanical DD the following reactions were then observed: the significant increase in behavioral pain responses, i.e. tachycardia, hyperventilation, inhibition of reticulo-ruminal contractions (70% approximately, during 15 min), an increase of plasma catecholamine concentration (over 7-fold increase of epinephrine during 2 h following DD, 2-times norepinephrine and ±80% increase of dopamine). Verapamil infusion administered 10 min prior to DD decreased intensity of visceral pain responses, such as: behavioral changes, tachycardia, hyperventilation, inhibition of the reticulo-rumen motility and efficiently prevented the appearance of catecholamine release. These data demonstrated that the development and persistence of duodenal hyperalgesia depends on the activation of Ca²⁺ ion flux leading to neurotransmitters release and modulation of membrane excitability. The observed antinociceptive action of VGCCs type-L blockers suggests that these channels play a crucial role in the modulation of acute visceral hyperalgesia in sheep.     

Effect of stage of gestation and foetal number on plasma concentrations of a pregnancy serum protein (PSP-60) in cattle

This study characterised the peripheral plasma concentration of PSP-60 throughout gestation, and examined the effect of stage of gestation and foetal number on this protein in Holstein cows after non-surgical embryo transfer. Cows (n=12) were divided into two groups; Group 1 contained single embryo recipient cows (n=5), Group 2 contained twin-embryo recipient cows (n=7). Blood was collected approximately every third day from day 0 (first day of standing oestrus), then daily for the last 10 days of gestation and until one day post-partum. Two of the twin-embryo recipient cows had abnormal pregnancies, consequently data from them was considered separately. In both groups PSP-60 increased progressively from about day 20 post-oestrus to 20 days pre-partum (from 0·9 ± 0·2 to 49·7 ± 8·7 ng ml⁻¹, and from 1·3 ± 0·6 to 115 ± 34·9 ng ml⁻¹ (mean ± SEM), in singleton and twin-bearing groups, respectively). The mean concentrations between 20 and 10 days pre-partum increased dramatically by about six-fold (P<0·001) in singleton-bearing cows (from 49·7 ± 8·7 ng ml⁻¹ to 2838 ± 73·7 ng ml⁻¹) to over two-fold in twin-bearing cows (from 115 ± 34·9 ng ml⁻¹ to 284 ± 98·2 ng ml^-1). The mean concentrations of the two groups were indistinguishable between 10 days pre-parturn and parturition. Cows giving birth prematurely to stillborn calves or to a schistosomus reflexus calf exhibited abnormal PSP-60 profiles. Our findings indicate that peripheral plasma PSP-60 concentrations are correlated to the stage of gestation and foetal number, and assist in predicting foeto-placental viability.     

Plasma glucose and cortisol responses to exogenous insulin in fasted donkeys

Susceptibility to equine hyperlipaemia is increased by poor food intake. To assess the contribution of changes in insulin sensitivity, plasma glucose and cortisol responses to an intravenous insulin challenge (0·4 kg⁻¹ bodyweight) were compared with those observed after saline administration in six donkeys fasted either overnight or for three days. Three days of fasting decreased both the rate of insulin-induced hypoglycemia and the maximal hypoglycemic response. A transitory increase in plasma cortisol which peaked within one to four hours of insulin administration was observed in three of the six overnight-fasted donkeys and in all of the three-day fasted donkeys; inter-animal variation appeared to exist in the responsiveness of the hypothalamic-pituitary-adrenocortical ( ) axis to stimulation by insulin-induced hypoglycemia. Fasting is likely to present a risk of equine hyperlipaemia, at least in part, by the reduction in tissue sensitivity to the glucoregulatory action of insulin.     

Pharmacokinetics of marbofloxacin after a single oral dose to loggerhead sea turtles (Caretta caretta)

The single-dose disposition kinetics of marbofloxacin (MBX) were determined in clinically healthy loggerhead sea turtles (n = 5) after oral (PO) administration of 2 mg kg⁻¹ bodyweight. Marbofloxacin plasma concentrations were determined by DAD–HPLC (LOD/LOQ 0.015/0.05 μg ml⁻¹). Data were subjected to non-compartmental analysis. Following PO administration, marbofloxacin achieved maximum plasma concentrations of 11.66 ± 2.53 mg L⁻¹ at 15.00 ± 3.00 h. The absence of general adverse reactions in the turtles of the study, and the favourable pharmacokinetic properties (long half-life and high maximum plasma concentration) of MBX administered PO at the single-dose of 2 mg kg⁻¹ suggest the possibility of its safe and effective clinical use in loggerhead sea turtles.     

Comparison of Caudal Epidural Anesthesia with Lidocaine-distilled Water and Lidocaine-MgSO4 Mixture in Horses

This study was performed to compare the onset and duration of analgesia produced by either a lidocaine−MgSO₄ or lidocaine−distilled water combination administration in the caudal epidural space of horse. Seven healthy adult horses, aged 11.7 ± 1.4 years (mean ± SD), body weight (kg) 567 ± 32.5 (mean ± SD), were selected for this study. Caudal epidural anesthesia was produced in all horses by administering 2% lidocaine (0.22 mg/kg) diluted in 1 mL distilled water and repeated with 2% lidocaine (0.22 mg/kg) diluted in 1 mL 10% MgSO₄ 2 weeks later. Time to onset (minutes), duration (minutes), and cranial spread of epidural analgesia were recorded. Heart rate (HR), respiratory rate (RR), and body temperature (°C) were recorded. Measurements were taken at 0 (as a baseline value before epidural administrations) and at 5, 10, 15, 30, 60, and 75 minutes after the epidural administrations of each treatment. Statistical analyses included paired Student t test and analysis of variance (computer program SPSS, Analytical Software, version 15.00). Statistical significance was set at P < .05. Onset of analgesia was significantly different (P < .001) between lidocaine-distilled water (2.38 ± 0.47 minutes) and lidocaine−MgSO₄ (4.62 ± 0.54 minutes). Duration of analgesia after lidocaine−MgSO₄ (186.0 ± 7.0 minutes) was longer than lidocaine-distilled water (54.5 ± 7.3 minutes). No significant differences were recorded for HR, RR, and body temperature in comparison with baseline values for each group. Using the lidocaine−MgSO₄ combination for obstetric and surgical procedures could commence relatively soon after epidural injection and could be completed without readministration of anesthetic agent.     

Pharmacokinetics of fluconazole in cats after intravenous and oral administration

Fluconazole (100 mg) was administered to six adult cats as an intravenous infusion over 30 minutes, and the same cats received 100 mg of the drug orally 16 weeks later. The cats were bled repeatedly through an indwelling jugular catheter, the plasma fluconazole concentrations were assayed by high performance liquid chromatography, and the concentration-time data were subjected to a non-compartmental pharmacokinetic analysis. The mean (SD) intravenous half-life (13·8 [2·6] hours) was similar to that observed after oral dosing (12·4 [3·0] hours). The plasma clearances (intravenous 0·9 [0·1], oral 0·9 [0·2] ml min⁻¹ kg⁻¹) and the volumes of distribution at steady state (intravenous 1·1 [0·1], oral 1·0 [0·1] litre kg⁻¹) were also similar after the two routes of dosing. The peak plasma concentration was reached 2·6 hours after oral dosing and the drug was completely bioavailable (1·09 [0·05]). On the basis of this single dose study, the administration of 50 mg fluconazole every eight hours to a 4 kg cat should produce average steady state plasma fluconazole concentrations of approximately 33 mg litre⁻¹.