The toxicity of Castanospermum australe seeds for cattle

Two calves given a mean of 16.1 g and 16.4 g ripe Castanospermum australe seeds/kg body weight daily for 13 and 16 days respectively developed haemorrhagic gastroenteritis. The first calf died. The second calf had mild myocardial degeneration and necrosis and mild nephrosis at necropsy. Two calves given a mean of 16.8 g unripe C. australe seeds/kg body weight daily for 18 days remained clinically normal and had mild gastritis at necropsy. The activity of alpha-glucosidase was reduced in the mononuclear cells of peripheral blood and in skeletal muscle. This was attributed to the presence of the indolizidine alkaloid, castanospermine, in the seeds. The toxin causing the gastroenteritis and other lesions is unknown.     

Occurrence of organochlorine residues in Australian meat

In spite of several quality control procedures used by Australia to ensure the wholesomeness of export meat, a number of pesticide residue violations were identified in the Australian product exported to the USA in May 1987. The pesticides involved were the organochlorines, dieldrin and heptachlor. The problems were caused by the persistence of organochlorines in soils and their illicit use or contamination of storage facilities. Animals grazing contaminated pasture, ingesting contaminated feed or held in contaminated yards over a period, bioaccumulated residues in their adipose tissues which eventually exceeded maximum residue limits (MRL) and caused violations. Though there was no immediate public health risk, the Australian Quarantine and Inspection Service (AQIS) of the Commonwealth Department of Primary Industries and Energy (DPIE), acted expeditiously to determine and eliminate the factors causing these problems, which threatened Australia's beef export industry worth in excess of two billion dollars annually. An overall strategic plan, "The Integrated Action Plan", was formulated and implemented by AQIS with the assistance of the relevant Departments of the States and the Northern Territory (NT), meat processing and export industries and livestock producer bodies. As a result of this action, the likely sources of contamination were identified and controlled. The National Residue Survey (NRS) was enhanced, a National Residue Data Base (NRDB) was established and a centralised computer system interactive with abattoirs, laboratories and animal health authorities developed. The cattle farm identity tail tag system already in place, capable of tracing cattle to the farm of origin was refined and trace back systems for sheep and pigs were utilised.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of potting mix texture on farm tree seedling survival in heavy soils

The importance of compatibility of potting mix and soil type for increasing the survival of tree seedlings planted in heavy soils is indicated by the results of this preliminary trial.     

Efficacy against Fasciola hepatica and the pharmacokinetics of triclabendazole administered by oral and topical routes

Objective   To determine the efficacy of triclabendazole (TCBZ) against 28-day-old, early immature liver fluke in cattle and its pharmacokinetics following administration by the oral or topical (pour-on) route.
Procedures   Cattle (n = 18) were infected with 500 TCBZ-susceptible liver fluke metacercariae and randomly allocated to three groups. At 28 days after infection, the groups were: (1) untreated controls; (2) treated with oral TCBZ at 12 mg/kg in combination with oxfendazole and selenium (TOS); (3) treated with pour-on TCBZ at 30 mg/kg in combination with abamectin (TA). Blood samples were taken immediately prior to treatment and serially after treatment to assess the plasma profile of TCBZ metabolites. Ten weeks after treatment all animals were slaughtered and total liver fluke counts, fluke egg counts and liver pathology were assessed.
Results   Both the TOS and TA treatments resulted in significant reductions of 28-day-old liver fluke, as assessed by fluke counts and fluke egg counts at slaughter, and the reductions following TOS treatment were significantly greater than those following TA treatment. The blood profile of TCBZ metabolites in TOS-treated animals showed a significantly greater area under the plasma concentration time curve and a higher maximum observed concentration than those treated with TA. There was significantly less liver pathology in TOS-treated animals than in the TA-treated animals.
Conclusion   TCBZ administered orally at 12 mg/kg resulted in greater efficacy against 28-day-old, early immature liver fluke than was achieved by topical administration at 30 mg/kg. Plasma metabolites of TCBZ were higher and liver pathology was less in TOS-treated animals than in TA-treated animals.     

Fluoroquinolone resistance in Staphylococcus intermedius

Four canine isolates of S. intermedius resistant to enrofloxacin were isolated amongst a total of 429 screened. Two of these were shown to exhibit resistance also to marbofloxacin and ciprofloxacin. Whilst molecular studies have shown the mechanism of resistance to these quinolone antibiotics to be similar in a number of staphylococcal species, it was not possible to confirm this mechanism in Staphylococcus intermedius .     

Unusual vascular ring anomaly associated with a persistent right aortic arch in two dogs

An unusual vascular ring anomaly consisting of a persistent right aortic arch and a left ligamentum arteriosum extending from the main pulmonary artery to an aberrant left subclavian artery and left aortic arch remnant complex was identified in a German shepherd dog and a great Dane. The left subclavian artery and left aortic arch remnant complex originated at the junction between the right distal aortic arch and the descending aorta and coursed dorsal to the oesophagus in a cranial direction. The attachment of the ligamentum arteriosum to the aberrant left subclavian artery was approximately 5 cm cranial to the point of origin of the aberrant left subclavian artery and left aortic arch remnant complex from the descending aorta in both dogs. This anomaly observed in both dogs is similar to an anomaly reported in humans, in which a persistent right aortic arch is found in conjunction with an aberrant left subclavian artery and a left aortic arch remnant (Kommerell's diverticulum). Surgical ligation and division of the left ligamentum arteriosum in both dogs, along with division of the left subclavian artery in the great Dane, resulted in resolution of clinical signs in both of the dogs in this report.     

Comparative cell morphology in the peripheral blood film from exotic and native animalsa

Haematological investigation is an important part of disease diagnosis. This is particularly so when investigating individual animal disease. It may also be important when investigating diseases in groups of animals, but the opportunity to perform necropsies to directly detect disease processes often diminishes its usefulness. Haematological investigation is essentially similar for all species. The presence of nucleated erythrocytes and thrombocytes in nonmammals requires alteration of haemoglobin measurement and cell counting. In addition, it may cause some confusion in identification of cells in peripheral blood films. Examination of blood films is an important component of haematological investigation and provides useful information on erythroid, leukocytic and platelet/thrombocytic alterations. Interpretation of alterations is essentially similar for all species. However, cell identification can at times be difficult. There are five basic leukocytes in all species: neutrophil (mammals) or heterophil (nonmammals), eosinophil, basophil, lymphocyte and monocyte. In nonmammals it may be difficult at times to distinguish between heterophils and eosinophils. In addition, lymphocytes may be confused with thrombocytes. However, a common-sense approach to the examination of the peripheral blood film will minimise this confusion.