Assessment of Levels and Potential Health Risk of Heavy Metals in Water and Selected Fish Species from the Benue-Niger River Confluence,Lokoja, Nigeria

The concentrations of cadmium (Cd), lead (Pb), chromium (Cr), copper (Cu), zinc (Zn), and iron (Fe) in water and selected fish species (Oreochromis nilzinc (oticus and Clarias gariepinus) from Benue-Niger River Confluence, Nigeria were investigated. The water and fish sample digests were quantified using an atomic absorption spectrophotometer. The study aimed to assess any possible human health risk associated with water and fish consumption from the selected geographical area. The concentration of the metals in the surface water ranged from 0.007 to 0.039, 0.106 to 0.240, 0.092 to 0.0164, 0.682 to 0.878, 0.058 to 0.309, and 0.136 to 1.645 mg/L for Cd, Cr, Cu, Fe, Pb, and Zn, respectively, while the concentrations of the metals, Cd, Pb, Cr, Cu, Zn, and Fe in these fish species ranged from 0.034 to 0.679, 0.500 to 1.75, 0.152 to 0.351, 0.36 to 1.01, 5.32 to 7.41, and 4.25 to 9.17 mg/kg, respectively. Cd, Cr, and Pb levels in fish were higher than the provisional tolerable weekly intake of 7, 1.5, and 25 μg/kg bw, respectively, according to the World Health Organization. Dry season values of the metals in water samples were higher, and sharptooth catfish had higher amounts of the metals. The hazard quotient (HQ) for Cd indicated a possible potential health concern with fish consumption from this area.     

Macrozamia toxicosis in a dog

A case of Macrozamia riedlei seed poisoning is described in a young Dachshund. Vomiting and depression commenced within 6 h of ingestion; other signs that developed included severe hepatopathy, jaundice, abdominal pain that was unresponsive to analgesics, severe gastro-intestinal haemorrhage and thrombocytopenia as well as crystalluria and marrow dyserythropoiesis. The dog was euthanased 6 days after ingestion of the seeds.     

Serological evidence of exposure to tick fever organisms in young cattle on Queensland dairy farms

OBJECTIVES: To compare the features of farms on which the exposure of young cattle to tick fever organisms is sufficient to ensure that immunity is high and the risk of clinical disease is low (endemic stability) with those of farms on which exposure is insufficient to induce widespread immunity (hence without endemic stability); to examine the relationships between the management of ticks and tick fever, and endemic stability to Babesia bovis, B. bigemina and Anaplasma marginale. DESIGN: Cross-sectional study of 874 cattle between the ages of 6 and 15 months on 64 dairy farms, from three centres in south-eastern Queensland (Mutdapilly, Dayboro and Kenilworth) and one centre in far-north Queensland (Malanda). PROCEDURE: Blood samples collected from between 5 and 20 calves from each farm were submitted for serological assay to determine exposure to B. bovis, B. bigemina and A. marginale. A questionnaire about the farm characteristics and the management of ticks and tick fever was completed with each farmer. RESULTS: On 73% of farms, confirmed clinical cases of tick fever were recalled by the farmer, indicating that tick fever was a threat on most farms. The majority of herds in the study (54 of 64) did not have sufficient numbers of seropositive animals aged between 6 and 15 months to have a low risk of tick fever. Region had an effect on the likelihood of endemic stability for all tick fever organisms. Cattle near Malanda in Far-north Queensland were more likely to be seropositive to B. bovis and B. bigemina. The method, strategy and intensity of tick control were not related to the likelihood of endemic stability when the effect of region was considered. The decision to leave a few ticks on cattle in an effort to induce endemic stability did increase the likelihood of endemic stability to A. marginale. However, in practical terms, it was ineffective, because only 26% of these farms had endemic stability against all three organisms. CONCLUSIONS: Given the low proportion of farms that have endemic stability to the tick fever organisms and the high likelihood of clinical disease, vaccination is recommended to protect dairy cattle from tick fever throughout the tick infested area of Queensland. However, further work is required to determine the economic value of vaccination, taking into account the costs of vaccination, of outbreaks and the protective value of vaccination.