Te Maitho

Comparative efficacy of pyrethrum marc with albendazole against sheep gastrointestinal nematodes

The efficacies of pyrethrum marc and of albendazole against experimental sheep gastrointestinal nematode infection were compared. Sheep were infected orally with 10000 larvae (Haemonchus spp. (60.1%), Oesophagostomum spp. (13.9%), Trichostrongylus spp. (13.2%), Cooperia spp. (8.3%), Nematodirus spp. (3.5%), Strongyloides spp. (0.8%) and Ostertagia spp. (0.2%)). Faecal egg count reduction in albendazole-treated sheep was 100% by day 4 following treatment, compared to 37.03%, 31.3%, 38.9% and 51.8% on days 4, 6, 8 and 10 in pyrethrum marc-treated sheep. These reductions were statistically significant on days 8 and 10 post-treatment (p<0.05). The potential for using pyrethrins for helminth treatment is discussed.

Fluoride levels in water and fish from Lake Magadi (Kenya)

Water entering Lake Magadi from a spring contained 73 mg fluoride (F)1-1, while samples taken 100 and 400 m from the spring were estimated to contain 110 and 140 mg F 1-1. Evaporation apparently increased the F and salt concentrations to levels at which the common method of F analyses became unreliable, even after dilution. It is recommended to re-examine the very high F levels reported in the saline lakes of Rift Valley. The F levels of Tilapia grahami living in water with about 110 mg F 1-1 averaged (mg F kg-1 dry weight): fillet 68, skin 819, gills 1,366 and bones 1,661. The variation was highest in fillet and skin. There was no positive correlation between tissue F levels and fish size (range 3–20 g). It remains uncertain whether the fish bone was saturated at this concentration of F or if some mechanism of elimination hindered higher F accumulation in the skeletal structures.

The pharmacokinetics of pyrethrins in lactating and non-lactating ewes after oral and subcutaneous administration

Pyrethrins were administered orally and subcutaneously (SC) at 150 mg/kg body weight to 10 lactating and nonlactating ewes in a cross over experimental design. A gas chromatographic method was used for analysis of Pyrethrins in serum and milk samples from the experimental animals. The disposition curves were bi-exponential after first-order absorption and fitted 1 and 2 compartmental models. The maximum plasma concentration (Cmax) of Pyrethrins following oral and SC administration was 0.08 μg/ml and 0.13 μg/ml respectively with the corresponding time to maximum concentrations (Tmax) being 1 hr and 2 hrs respectively. At 48 hours, serum Pyrethrins levels were below the limit of detection of 0.005 μg/ml. Absorption was significantly higher for SC route compared to oral routes (p 0.05). The mean residence time (MRT) was 9.7 hours. Total clearance was 4,337 and 3,180 litres/ kg/hr for oral and SC routes respectively. Pyrethrins were secreted in milk at levels of up to 0.005 μg/ml. It was concluded that in ewes, Pyrethrins are rapidly absorbed after orally and SC, widely distributed and eliminated from the body within 24 hours. Secretion into milk occurs in ewes but the residues in milk are too low to toxic effects in humans.