Scielo RSS <![CDATA[Journal of the South African Veterinary Association ]]> vol. 79 num. 4 lang. es <![CDATA[SciELO Logo]]> <![CDATA[<b>Provisional clinical chemistry parameters in the African Sharptooth catfish <i>(Clarias gariepinus)</i></b>]]> Pollution affects aquatic systems worldwide and there is an urgent need for efficient monitoring. Fish are generally sensitive to their environment and are thus considered to be valuable bioindicator species. The African Sharptooth catfish (Clarias gariepinus)is particularly important in this respect because of its very wide distribution. In order to use C. gariepinus as a bioindicator species its baseline clinical chemistry must be defined. Existing data are scarce, and the objective of this work was therefore to establish clinical chemistry parameters for C. gariepinus. Blood was collected from male and female catfish and a number of clinical chemistry parameters were determined. Plasma protein values, but particularly those of plasma albumin, were found to be very low, approximately half the value for dogs, but similar to the values in Channel catfish (Ictalurus punctatus). Plasma urea values in Sharptooth catfish were found to be much lower than in dogs, but only marginally lower than in Channel catfish. Plasma creatinine in Sharptooth catfish, however, was only a quarter of that of dogs and one third of that found in Channel catfish. These findings may have implications for using urea and/or creatinine as an index of renal glomerular filtration, as is done in mammals. Plasma enzyme activity ranges were much lower in Sharptooth catfish than in dogs, particularly for alkaline phosphatase (ALP) and alanine amino-transferase (ALT). By comparison, Channel catfish have an even lower ALT activity range but an ALP range that is very similar to dogs. The implications for using these enzymes as markers for liver disease are not clear from these data, as factors such as plasma half-life and tissue distribution remain tobe determined. The very lowplasma thyroxine (T4) levels have important implications for laboratory personnel, who will have to set up calibration and standardisation adaptations for the methods that are generally designed for human samples. Although the sample size was too small for reliable comparisons, it appeared that there was little difference in the parameters measured between male and female fish. The values obtained are a useful startingpoint for using C. gariepinus as abioindicator species. <![CDATA[<b>Antimicrobial drug resistance of <i>Escherichia coli</i> isolated from poultry abattoir workers at risk and broilers on antimicrobials</b>]]> Antimicrobial usage in food animals increases the prevalence of antimicrobial drug resistance among their enteric bacteria. It has been suggested that this resistance can in turn be transferred to people working with such animals, e.g. abattoir workers. Antimicrobial drug resistance was investigated for Escherichia coli from broilers raised on feed supplemented with antimicrobials, and the people who carry out evisceration, washing and packing of intestines in a high-throughput poultry abattoir in Gauteng, South Africa. Broiler carcasses were sampled from 6 farms, on each of which broilers are produced in a separate 'grow-out cycle'. Per farm, 100 caeca were randomly collected 5 minutes after slaughter and the contents of each were selectively cultured for E. coli. The minimum inhibitory concentration (MIC) of each isolate was determined for the following antimicrobials: doxycycline, trimethoprim, sulphamethoxazole, ampicillin, enrofloxacin, fosfomycin, ceftriaxone and nalidixic acid. The same was determined for the faeces of 29 abattoir workers and 28 persons used as controls. The majority of isolates from broilers were resistant, especially to antimicrobials that were used on the farms in the study. Overall median MICs and the number of resistant isolates from abattoir workers (packers plus eviscerators) tended to be higher than for the control group. However, no statistically significant differences were observed when the median MICs of antimicrobials used regularly in poultry and percentage resistance were compared, nor could an association between resistance among the enteric E. coli from packers and those from broilers be demonstrated. <![CDATA[<b>First isolation of <i>Escherichia coli</i> O157:H7 from faecal and milk specimens from Anatolian water buffaloes <i>(Bubalus bubalus)</i> in Turkey</b>]]> Three hundred rectal faecal samples and 213 raw milk samples obtained from the tanks and containers were examined using standard cultural methods. Escherichia coli O157:H7 was isolated from 11 (3.7 %) of 300 faecal samples and 3 (1.4 %) of 213 raw milk samples. It was determined that 8 (73 %) of E. coli O157:H7 strains isolated from faecal samples originated from water buffaloes younger than 2 years of age and 3 (27 %) from 2-year-old and older water buffaloes. This is the 1st isolation of Escherichia coli O157:H7 from faecal and milk samples of water buffaloes in Turkey. <![CDATA[<b>Is the current dose of a conventional oxytetracycline formulation adequate for the management of infections in sheep?</b>]]> In the veterinary industry, short-acting or conventional Oxytetracycline formulations are recommended for use once a day for 4 days, at a dose of 10 mg/kg. With the large degree of antimicrobial resistance reported, the efficacy of this dose was assessed using pharmacodynamic modelling. The specific parameters evaluated were based on the time-dependent activity of the tetracycline class of antimicrobials according to the total time above minimal inhibitory concentration (T > MIC) and the ratio of the total exposure in 24 hours, represented by area under the curve (AUC24), to the minimal inhibitory concentration (AUC24:MIC). The current pharmacokinetic study examined whether the prevailing antimicrobial resistance could be overcome by doubling the recommended conventional dose. Using reported MIC data for South Africa and elsewhere, modelling indicated the presence of a large degree of resistance. In general, doubling the dose only overcame resistance of 2 bacterial species in South Africa. <![CDATA[<b>Canine hip extension range during gait</b>]]> Assessment of canine gait is frequently used by veterinary clinicians to establish the presence of orthopaedic pain. As up to 30 % of canine orthopaedic conditions affect the pelvic limb, knowledge of pelvic limb biomechanics during gait is very important. Previous studies have investigated the biomechanics at the tarsus and stifle, but little information is available regarding hip motion during gait. The aim of this study was to determine the maximum hip extension range achieved during the stance phase of gait in normal canines. In addition, this study aimed to determine the difference between maximum passive hip extension and maximum hip extension during gait. Using a sample of 30 morphologically similar normal dogs, mean maximum passive hip extension was measured using a goniometer and mean maximum hip extension range during gait was determined videographically. Inter- and intra-assessor reliability studies performed at the start of the study showed that the measurement tools and techniques used in this study were valid and reliable. The goniometric data showed that mean maximum passive hip extension range was 162.44° (±3.94) with no significant difference between the left and the right hind limbs. The videographic data showed that mean maximum hip extension range during gait was 119.97° (±9.26) with no significant difference between the left and right hind limbs. The results of this study provided reference values for active and passive hip extension range and showed that the degree of hip extension range required for normal gait is significantly less than maximum passive hip extension range. <![CDATA[<b>Changes in sheep oesophageal diameter and function during <i>Geigeria ornativa</i> (vermeerbos) poisoning and subsequent recovery</b>]]> Changes in the oesophageal diameter and function together with changes in body weight, feed intake and the cardiac pulmonary flow index were investigated during experimentally induced poisoning with Geigeria ornativa and subsequent recovery. This was performed under varying conditions for individual sheep. Results showed an increase in the oesophageal diameter index (ODI) during vermeersiekte, accompanied with a decrease in oesophageal function (OF). Cessation of G. ornativa intake resulted in a considerable although incomplete recovery of the ODI. Recovery of the OF for the different sheep, however, varied between 0 and 100 %. Detrimental changes in the oesophageal diameter and function were also measured in sheep receiving only subclinical doses of G. ornativa. Decreases in body weight and feed intake commenced 1 to 3 weeks before the onset of vermeersiekte, while indications of a decline in these 2 parameters were also noticed with ingestion of subclinical amounts of G. ornativa. An increase in the cardiac pulmonary flow index (CPFI) to a value indicating the onset of heart failure was found in 1 of the sheep showing clinical signs of vermeersiekte. The CPFIreturned to normal after termination of G. ornativa intake. <![CDATA[<b>Three cases of osteoma and an osseous fibroma of the paranasal sinuses of horses in South Africa</b>]]> Four horses were presented to the Onderstepoort Veterinary Academic Hospital with histories of facial asymmetry, nasal discharge or obstruction of normal nasal passage airflow. Radiographic examination of the maxillary sinuses of 2 cases revealed well circumscribed, unilateral, mineralised masses; the other 2 cases showed less mineralisation. The masses were accessed for further investigation by surgically created frontonasal bone flaps or trephination of the maxillary sinuses. Diagnosis of osteoma was confirmed histopathologically in 3 of the cases and of ossifying fibroma in the 4th. Two horses were euthanased directly after surgical intervention due to poor prognosis. Osteomas are by nature expansile tumours andfollow the complex communication of the sinuses, and therefore are not all amenable to surgical removal. Osseous fibromas are large, solitary, expansile lesions that are rare in all species but reported most frequently in horses. They have an apparent predilection for the rostral mandible of the horse. <![CDATA[<b>Review of idiopathic eosinophilic meningitis in dogs and cats, with a detailed description of two recent cases in dogs</b>]]> Eosinophilic meningoencephalitis (EME) has been described in various species of animals and in humans. In dogs it has been associated with protozoal infections, cuterebral myiasis and various other aetiologies. Ten cases of idiopathic eosinophilic meningoencephalitis have been reported in dogs and one in a cat where the origin was uncertain or unknown. The dogs were all males, of various breeds but with a predominance of Golden Retrievers and Rottweilers; they generally had a young age of onset. Two cases with no apparent underlying aetiology were diagnosed on post mortem examination. The 18-month-old, male Boerboel presented with sudden onset of cerebellar ataxia, as well as various asymmetrical cranial nerve deficits of 2 weeks' duration and without progression. Haematology revealed a peripheral eosinophilia. Necropsy showed extreme generalised congestion especially of the meninges and blood smear and histological sections of various tissues showed intravascular erythrocyte fragmentation with the formation of microcytes. Histopathology revealed severe diffuse cerebrocortical subarachnoidal meningitis and submeningeal encephalitis, the exudate containing variable numbers of eosinophils together with neutrophils and mononuclear cells. There was also deeper white matter and hippocampal multifocal perivascular mononuclear encephalitis and multifocal periventricular malacia, gliosis and phagocytosis of white matter. The cerebellum, brain stem and spinal cord showed only mild multifocal oedema or scattered occasional axon and myelin degeneration respectively, with no inflammation. Immunohistochemical staining of central nervous tissue for Toxoplasma gondii failed to show any antigen in the central nervous tissue. Ultrastructure of a single submeningeal suspected parasitic cyst showed it to be chromatin clumping within a neuron nucleus indicating karyorrhexis. Gram stain provided no evidence of an aetiological agent. The 3-year-old Beagle bitch had a Caesarian section after developing a non-responsive inertia 8 days prior to presentation. This animal's clinical signs included status epilepticus seizures unrelated to hypocalcaemia and warranted induction of a barbiturate coma. She died 4 hours later. Post mortem and histopathological findings in the brain were almost identical to those of the Boerboel and she also showed histological evidence of recent active intravascular haemolysis with microcyte formation. Rabies, distemper and Neospora caninum immunohistochemical stains were negative in the brains of both dogs. Immunohistochemical staining of the cerebral and meningeal exudates of the Beagle for T- and B-lymphocyte (CD3 and CD79a) markers showed a predominance of T-lymphocytes with fewer scattered B lymphocytes. A possible allergic response to amoxicillin/clavulanate is considered, as this appeared to be the only feature common to the recent history of both animals. An overview of EME in humans, dogs and cats is given and the previously published cases of idiopathic EME in dogs and the single published cat case are briefly reviewed. <![CDATA[<b>Increasing ketamine dose enhances the anaesthetic properties of ketamine-xylazine-midazolam combinations in growing pigs</b>]]> The influence of increasing the dosage of ketamine on anaesthesia induced by a combination of ketamine, xylazine and midazolam in pigs was determined by assessing the onset of action (OAN), duration of analgesia (DAN), anaesthesia time (ANT), and recovery time (RCT) in 10 growing pigs (Mean weight: 18.2 ± 1.65 kg) receiving either 10 mg/kg intramuscular (i.m) injection of 10 % ketamine, 2 mg/kg i.m injection of 2 % xylazine and 0.25 mg/kg i.m injection of 0.1 % midazolam (K10XM) or 20 mg/kgi.m injection of ketamine and 2 mg/kg i.m injection of xylazine and 0.25 mg/kg i.m injection of 0.1 % midazolam (K20XM). In addition, the heart rates (HR), respiratory rates (RR) and rectal temperatures (RT) were determined immediately after drug administration and at 10 minute intervals over a period of 60 minutes. Analgesia was assessed by the response of the pigs to artery forceps applied at the interdigital space. Recovery was determined as pigs' ability to stand without ataxia. Data were expressed as mean ± SEM while anaesthetic indices were compared using Student's t-tests. A P value of 0.05 was accepted as significant in all cases. In this study, both the OAN and RCT were significantly (P < 0.05) shorter in K10XM (1.4 ± 0.2 min; 7.8 ± 2.2 min) than in K20XM (2.2 ± 0.2; 18.6 ± 1.4 min) respectively. Similarly, the duration of anaesthesia was significantly (P < 0.05) shorter in K10XM (55.4 ± 8.4 min) than in K20XM (92.0 ± 13.6 min). The pigs that received K20XM combination had analgesia of duration of 41.4 ± 12.6 min while those that received K10XM combination had no analgesia. However, the HR, RR, and RT were not significantly (P &gt; 0.05) different between K10XM and K20XM. It was therefore concluded that the lower dose ketamine combination is better for the induction of anaesthesia, while the higher dose ketamine combination is preferable for surgery of short duration in pigs.