The length of BTV-8 viraemia in cattle according to infection doses and diagnostic techniques

Four groups of BTV free Frisian and cross bred calves were used to determine the length of viraemia following infection with different doses of BTV-8 Italian isolate. The first group of five animals was infected with 10 TCID₅₀ of BTV-8, the second group of four animals with 10³ TCID₅₀ and the third group, which also included four animals, was infected with 10⁶ TCID₅₀. A placebo containing uninfected tissue culture medium was given to the four animals of the fourth group. The viraemia was evaluated by real time RT-PCR and virus isolation. In all infected groups, virus isolation was able to detect infectious virus up to 39 days post infection (dpi) while RT-PCR was positive up to 151–157 dpi. Infectious dose did influence neither the length nor the pattern of BTV-8 viraemia and confirmed that real time RT-PCR remains positive although no circulating virus is detectable in the peripheral circulation.     

CLINICAL ASSESSMENT OF RENAL FUNCTION IN THE DOG WITH A REDUCTION IN NEPHRON NUMBER*

The viewpoint presented is that, because compensatory functional adjustment of the residual nephrons occurs in chronic renal disease, reduction in nephron number usually exceeds 70% before a diagnosis is made. The case that earlier diagnoses are likely if laboratory medicine values are measured and interpreted with a maximum of efficiency is then made. The laboratory data more commonly used in practice for the clinical assessment of renal function in the dog are presented and some comparisons with findings in man are made. The information originates from clinical and experimental observations of the authors, as well as from a literature review. The laboratory data presented and discussed includes glomerular filtration rate and the clearance of nitrogenous waste (urea and creatinine), plasma protein concentration, plasma osmolality, renal concentrating capacity, and urinary constituents, particularly its protein concentration and sediment (centrifuge deposit). All parameters recommended for the clinical assessment of chronic renal failure are considered qualitatively, and some are also dealt with quantitatively.     

RESPONSE OF CATTLE TO INOCULATION WITH ATYPICAL MYCOBACTERIA ISOLATED FROM SOIL

Nine strains of atypical mycobacteria and a strain of the rhodochrous taxon, originally isolated from soil samples collected on the subcoastal plains of the Northern Territory, were inoculated into cattle. Each strain was injected subcutaneously into one animal and into a mesenteric lymph node of another. At 4 and 10 weeks after inoculation, the cattle were tuberculin tested with bovine PPD tuberculin, avian PPD tuberculin and the appropriate homologous PPD tuberculin. Six strains induced a significant level of sensitivity to bovine PPD at the 4-week test, but only one animal gave a similar response at the 10-week test. In general, the level of sensitivity to all tuberculins declined between the 4-week and 10-week tests. At both tests the response to avian PPD was equal to, or exceeded, that to bovine PPD. The inoculation of each of the 10 strains resulted in the production of tuberculous granulomas at the subcutaneous sites and similar lesions were produced at the mesenteric lymph node site in response to 2 strains. Mycobacteria were re-isolated from 11 cattle and represented 7 strains. The significance of the soil as a reservoir of atypical mycobacteria and other organisms capable of inducing sensitivity to bovine PPD is discussed.     

Critical remarks on the investigation methods of coergistic effects of acute oral toxicity of combination insecticides

Often the application of fractions of the LD50 (e.g. 1/4 LD50, 1/2 LD50) is unavoidable due to technical conditions in the experiment (e.g. in case of substances with low toxicity and in case of very steep slope functions). But if ever possible, dosage of equitoxic amounts (LD10, LD50 etc.) should be prefered, because of higher reliability in the choice of dosage and evaluation of the results. Benefits and disadvantages of the two experimental principles are demonstrated by results of own investigations.     

The irritancy of chlorhexidine gluconate in the genital tract of the mare

Uterine irrigation was carried out in eight Welsh pony mares using 50 ml of chlorhexidine gluconate solution diluted to give active ingredient concentrations of 0.25 per cent to 2 per cent. Treatment was repeated up to twice in mares showing no adverse effects and irritancy of treatment judged on clinical symptoms and uterine biopsy. Results indicated the inadvisability of using a higher concentration than 0.25 per cent. Three daily applications of a diluted surgical scub solution containing 2 per cent chlorhexidine gluconate to the penis of an arab stallion failed to produce symptoms or irritation. An in vitro minimum inhibitory concentration test performed with the contagious equine metritis organism confirmed its high sensitivity to both chlorhexidine gluconate preparations.     

Mycotic pneumonia in mariculture-reared green sea turtles

Microbiologic examination of 29 juvenile green sea turtles with a buoyancy abnormality revealed pulmonary infection with Sporotrichium sp, Cladosporium sp, and Paecilomyces sp. Histologic examination of the lungs revealed granulomatous lesions containing branching septate hyphae. The diagnosis was mycotic pneumonia.     

Trichlorfon-induced congenital cerebellar hypoplasia in neonatal pigs

The neuroteratogenicity of trichlorfon was evaluated in 3 groups of pregnant sows (8/group). The treatments were: control (no trichlorfon), trichlorfon (60 mg/kg of body weight) in the feed only on day 55 of gestation, or trichlorfon (60 mg/kg of body weight) in the feed on day 55 and day 70 of gestation. One week after farrowing, all newborn pigs were removed from the sows and were euthanatized. Brain and cerebellum weights of the newborn pigs were recorded. Mean cerebellum weights and cerebellum/total brain weight ratios of the neonatal pigs were 3.780 and 0.106 (group 1, n = 26), 3.183 and 0.098 (group 2, n = 42), and 2.986 and 0.088 (group 3, n = 61). Although trichlorfon interfered with cerebellar development and the severity of the trichlorfon-induced cerebellar hypoplasia was dosage-related, ataxia did not develop in the neonatal pigs.