Detomidine-diazepam-ketamine anaesthesia in buffalo (Bubalus bubalis) calves

Eight buffalo calves (8-12 months, 70-100 kg) were randomly assigned to two groups of four animals each. Animals of group I were given detomidine (100 micrograms/kg), whereas animals of group II received a mixture of detomidine (100 micrograms/kg), diazepam (100 micrograms/kg) and ketamine (3 mg/kg) (DDK) intravenously. Various clinical parameters, such as weak time, down time, pedal and pinprick reflexes, muscle relaxation and extent of sedation, as well as heart and respiratory rates and electrocardiograms were measured before (time 0) and 15, 30, 45, 60, 75 and 90 min after treatment. In all the animals of group II (DDK), the pedal reflex was completely abolished (score: 3.00 +/- 0.00) within 5 min, the pinprick response was either very weak or it was completely abolished at this interval. Muscle relaxation and sedation were excellent within 5 min of DDK administration. The depth of sedation and analgesia was maximum from 5 to 15 min postinjection. Detomidine alone, however, failed to produce appropriate depression of the pedal and pinprick reflexes, sedation was mild and muscle relaxation was inadequate. Heart rate showed a significant (P < 0.05) decrease in group I, but the decrease was non-significant in group II. A more pronounced increase in respiratory rate was observed in group I as compared to group II. Animals of both groups recovered within 90 min without any complication. Minimal changes in the cardiovascular system in the group given the DDK combination were an advantage over the group given detomidine. The results indicated that DDK combination is safe and suitable for 15 min of anaesthesia with excellent muscle relaxation and has only limited cardiorespiratory effects in buffaloes.     

Propofol infusion anaesthesia in dogs pre-medicated with medetomidine

Ten laboratory beagles pre-medicated with medetomidine (40 μg/kg bodyweight [bwt]) were anaesthetised using a rapid injection of propofol, followed by propofol infusion. A loading dose of 4 mg/kg bwt of propofol was administered intravenously (iv) as a bolus and, immediately after, a 60 min iv propofol infusion (150 μg/kg bwt/min) was initiated. After a transient increase, mean arterial blood pressure decreased significantly below the pre-propofol level. However, the lowest values recorded (115 ± 11 mmHg) remained within the physiological limits. Heart rate increased significantly (from 41 ± 7.3 to 58 ± 11 beats/min) after initiation of the propofol infusion. No significant changes were seen in respiratory frequency; pO₂ decreased transiently; minimum values (10 ± 2.3 kPa) recorded 5 mins after initiation of the propofol infusion differed significantly from the starting level. pCO₂ increased significantly and the highest values recorded were 6.1 ± 0.35 kPa. Accordingly, pH decreased reaching the lowest level (pH 7.29) 15 mins after initiation of the propofol infusion. The analgesic effect of the present combination was not studied, but the absence of the palpebral and pedal reflexes suggested a surgical stage of anaesthesia. Therefore, propofol infusion in beagles pre-medicated with medetomidine proved to be a promising anaesthetic regimen but, if used clinically, oxygen-enriched inspired air should be used.     

Physiological and biochemical effects of glyceryl guaiacolate-thiopentone sodium anaesthesia in buffalo calves

Glyceryl guaiacolate was used with thiopentone sodium for general anaesthesia in 10 clinically healthy male buffalo calves. When the animals were in the stage of surgical anaesthesia, there was marked hypotension and tachycardia along with a decrease in central venous pressure, tidal volume, partial pressure of oxygen in arterial blood and venous plasma potassium. Hyperglycaemia was another consistent feature. The changes in the acid base status were mild and inconsistent.     

The therapeutic effects of 2,3-butanedione monoxime and atropine in severe dichlorvos intoxication in buffalo calves

2,3-Butanedione monoxime and atropine alone or in combination were evaluated for their ability to alleviate the toxicity and to reverse the biochemical changes induced by dichlorvos in the blood of buffalo calves. Treatment with 2,3-butanedione monoxime plus atropine 30 min after oral administration of dichlorvos (160 mg/kg) eliminated the apparent toxic signs within 10–15 min, completely prevented lethality, and reversed the dichlorvos-induced alterations in the concentrations of serum carboxylesterase, total plasma proteins, blood glucose and plasma cholinesterase within 2, 4, 12 and 168 h, respectively. Treatment with either 2,3-butanedione monoxime or atropine alone was less effective but the former was the more potent of the two in counteracting the biochemical effects of dichlorvos. These antidotal studies suggest that 2,3-butanedione monoxime in conjunction with atropine would provide effective therapy against severe dichlorvos intoxication in buffalo.     

Experimental toxoplasmosis in buffalo calves

Eight buffalo calves were inoculated with infectious oocysts of a virulent strain of Toxoplasma gondii, five with 1 × 10⁵, and the other three with 5 × 10⁵ oocysts each while two more were kept as non-inoculated controls. Infected animals developed pyrexia, anorexia, conjunctivitis and dyspnoea. The clinical symptoms, haematological changes and serological response were of a low order. The appearance of haemagglutinating antibodies at significant levels (? 1:64) was first observed at 21 days after inoculation (DAI), peaked at 42 DAI and rapidly declined after 63 DAI. The inoculated calves were killed (or died) at intervals from 11 DAI to 110 DAI. The organism could be recovered from several times of a calf that died 11 DAI, but was rapidly removed subsequently. Only the lymph nodes were infective till 32 DAI. Parasitism of the retina was demonstrated in one calf. The significance of these findings is discussed.     

Pharmacokinetics and bioavailability of moxifloxacin in buffalo calves

The pharmacokinetics of moxifloxacin were investigated in buffalo calves following a single intravenous and intramuscular administration of moxifloxacin (5 mg kg⁻¹ body wt.). Moxifloxacin concentrations in plasma and urine were determined by microbiological assay. Pharmacokinetic analysis of disposition data indicated that intravenous administration data were best described by a two compartment open model, whereas intramuscular administration data were best described by a one compartment open model. Following intravenous administration, the elimination half life (t_1/2β), volume of distribution (Vd_(area)) and total body clearance were 2.69 ± 0.14 h, 1.43 ± 0.08 L kg⁻¹ and 371.2 ± 11.2 ml kg⁻¹ h⁻¹, respectively. Following intramuscular administration, the absorption half life (t_1/2ka) was 0.83 ± 0.20 h. The systemic bioavailability (F) of moxifloxacin in buffalo calves was 80.0 ± 4.08%. Urinary excretion of moxifloxacin was less than 14% after 24 h of administration of drug. In vitro binding of moxifloxacin to plasma proteins of buffalo calves was 28.4 ± 3.77%. From the data of surrogate markers (AUC/MIC, C_max/MIC), it was determined in the buffalo calves that when administered by intravenous or intramuscular route at 5 mg kg⁻¹, moxifloxacin is likely to be effective against bacterial isolates with MIC ? 0.1 μg ml⁻¹.     

Experimental Sarcocystis levinei infection in buffalo calves

Six buffalo calves were orally inoculated with 3 graded doses of sporocysts of Sarcocystis levinei (0.5, 1.0 and 2.0 million sporocysts; 2 calves for each dose) while two more calves were kept as uninoculated controls. One calf from each group was killed at 30 days post infection (DPI) and the other at 80 DPI. Inoculated calves showed a dose dependent response. The calves inoculated with 0.5 and 1.0 million sporocysts did not manifest any clinical signs of disease up to 80 DPI. One of the two calves inoculated with 2.0 million sporocysts showed clinical signs of weakness, emaciation and anaemia during the 5th week post infection. The other calf remained healthy until it was killed at 30 DPI. Pale liver tissue, gelatinization of fat and haemorrhages in the heart were observed in one calf inoculated with 2.0 million sporocysts; only microscopic lesions were seen in other calves. Schizonts and merozoites were not observed in any calf. Mature sarcocysts were observed in cardiac and skeletal muscle of calves killed at 80 DPI whereas no sarcocysts were seen in calves killed at 30 DPI.     

Rotavirus-associated diarrhoea in buffalo calves in Sri Lanka

Faecal samples from 150 buffalo calves, one to 150 days old, located in various districts of Sri Lanka, were examined for group A rotavirus antigen by a screening enzyme linked immunosorbent assay (ELISA). Positive samples were confirmed by the blocking ELISA. In the calves studied 27·3 per cent were diarrhoeic, and the rest were non-diarrhoeic but were in contact with the animals showing diarrhoea. Antigen was detected in 36·6 per cent of the diarrhoeic animals and in 11·9 per cent of the nondiarrhoeic animals. There was a strong association between the presence of antigen in faeces and diarrhoea in these animals (ξ² = 46·98; P<0·001). Of the 146 serum samples examined for antirotaviral antibodies, by the blocking ELISA at a single serum dilution (1:20) against a constant dose of antigen (8 units), 68·5 per cent were positive indicating a widespread infection with the virus in the population studied. This is the first record of the detection of rotavirus and its association with diarrhoea in buffalo calves in Sri Lanka.     

Pharmacokinetics and urinary excretion of sulphadimidine in buffalo calves

Pharmacokinetics and urinary excretion of sulphadimidine (SDI) were determined in buffalo calves following single oral administration (150 mg/kg). The plasma levels of free sulphadimidine were above minimum effective therapeutic concentration (> 40 micrograms/ml) between 4 and 12 h and the N4-acetylated form of the drug was in the range of 7.2-19.3%. Kinetic evaluation of plasma levels was performed using a two-compartment open model. The absorption and elimination half-lives of SDI were 3.01 and 11.94 h, respectively. Based on this study, an optimal dosage regimen of sulphadimidine in buffalo calves would be 100 mg/kg, followed by 50 mg/kg at 12 h intervals. Sulphadimidine was mainly excreted in the urine as free amine. The percentage of N4-acetyl sulphadimidine in urine was comparatively higher than in plasma.     

Trypanosoma evansi infection in bovine and buffalo calves in Indonesia.

Fifteen bovine and 11 buffalo calves born on different farms in a Trypanosoma evansi-endemic area of West Java were monitored for the presence of T. evansi and T. evansi antibody at monthly intervals until they were 12 months of age. Fifty percent of the bovine and 83% of the buffalo calves sampled in the first month of life were antibody positive. This antibody was considered to be of colostral origin. Antibody developing later in life persisted for up to 12 months and was considered to have arisen in response to T. evansi infection. No protective function could be ascribed to the colostral antibody.     

The kinetic disposition and dosage regimen for carbenicillin in buffalo calves

The distribution half-life, elimination half-life, apparent volume of distribution and total body clearance of carbenicillin in healthy buffalo calves following a single intravenous administration (50 mg/kg) were 0.057±0.005 h, 1.688±0.11 h, 0.185±0.021 L kg^-1 and 75.97±6.519 ml kg^-1 h^-1 respectively. A satisfactory dosage regimen for carbenicillin in buffalo calves was calculated to be 56 mg/kg followed by 52 mg/kg body weight repeated at 6 h intervals.     

Pharmacokinetics following intravenous administration and pharmacodynamics of cefquinome in buffalo calves

Disposition following single intravenous injection (2 mg/kg) and pharmacodynamics of cefquinome were investigated in buffalo calves 6–8 months of age. Drug levels in plasma were estimated by high-performance liquid chromatography. The plasma concentration–time profile following intravenous administration was best described by a two-compartment open model. Rapid distribution of cefquinome was evident from the short distribution half-life (t _½α ?=?0.36?±?0.01 h), and small apparent volume of distribution (Vd_area?=?0.31?±?0.008 L/kg) indicated limited drug distribution in buffalo calves. The values of area under plasma concentration–time curve, elimination half-life (t _½β ), total body clearance (Cl_B), and mean residence time were 32.9?±?0.56 μg·h/mL, 3.56?±?0.05 h, 60.9?±?1.09 mL/h/kg, and 4.24?±?0.09 h, respectively. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration of cefquinome were 0.035–0.07 and 0.05–0.09 μg/mL, respectively. A single intravenous injection of 2 mg/kg may be effective to maintain the MIC up to 12 h in buffalo calves against the pathogens for which cefquinome is indicated.