The aim of the study was to describe the process of neuron death in the cerebral cortex caused by embryonic carbofuran exposure. 81 mouse foetuses from 27 breeding mice were used in the study. Carbofuran was administered by gavage from the 6ᵗʰ to the 15ᵗʰ day of gestation to two groups: one at 0.0208 and the other at 0.0417 mg/kg b.w. On the 17ᵗʰ day, the mice were sacrificed and the foetuses were taken to measure the ROS (malondialdehyde/MDA and superoxide dismutase/SOD) activity in brain tissue, the number of apoptotic embryonic cerebral cortex neurons using a TUNEL assay, and necrotic cells using HE staining. Examination of p53 and caspase 3 expression was done by immunohistochemistry. Data were analysed using analysis of variance (ANOVA) and Duncan’s test. Increased activity of cerebral ROS characterised by significant elevation of the MDA level (P < 0.05), decreased SOD (P < 0.01), increased p53 and caspase 3 expression, and cerebral cortical neuron death either by necrosis or apoptosis (P < 0.05) were found. At the low dose carbofuran increased expression of p53, caspase 3, and apoptosis. At the high dose it increased levels of MDA and necrosis. Increased expression of p53 and caspase 3 and apoptosis indicated that carbofuran may cause apoptosis through the intrinsic pathway. The increased apoptosis grants an opportunity to prevent and treat the effect of ROS due to gestational carbofuran exposure.

Boophilus microplus engorged females stored at 4 C for up to 5 days and females kept at room temperature for 1 day and then at 4 C for 1 day showed no significant differences in their response to an organophosphate (dioxathion) as determined by the Drummond adult test

Psoroptes ovis, cattle (exper.), residual effectiveness of ivermectin injections against establishment of scabies, comparison with toxaphene dip

Objective--To evaluate the efficacy of coumaphos, an organophosphate (OP) acaricide, at concentrations up to 2 times higher than the highest concentration required by the US Eradication Program against all stages of an OP-resistant strain of Boophilus microplusin experimentally infested cattle. Animals--16 tick-naïve 200-kg female Hereford calves. Procedure--Four groups of cattle (4 calves/group) were all infested with Boophilus ticks 3 times before treatment. Each group was treated with coumaphos as follows: group 1, at 0.165% active ingredient (AI); group 2, at 0.299% AI; group 3, at 0.566% AI; and group 4, not treated. Following treatment, ticks were collected for 21 days. Ticks collected 1 to 7, 8 to 14, and 15 to 21 days after treatment were considered adults, nymphs, and larvae, respectively, at time of treatment. Results--Overall control at 0.165, 0.299, and 0.566% AI was 52.9, 75.8, and 89.7%, respectively. Control of adults ranged from 4.3% at 0.165% AI to 73.5% at 0.566% AI. Control of nymphs ranged from 60.6% at 0.165% AI to 97.3% at 0.566% AI. Control of larvae was > 98% at all coumaphos concentrations. Conclusions and Clinical Relevance--All coumaphos concentrations failed to provide acceptable control for use in the US Eradication Program against OPresistant ticks. Treatment was least effective against adults and most effective against larvae. Even at 0.566% AI (2 times higher than required by the US Eradication Program), ticks were not eradicated, placing the United States at risk from dispersing cattle harboring viable ticks to uninfested areas.

Twenty-four, adult, female Beagles were arranged by body weight from greatest to least and allocated to 2 groups of 12 dogs, using random numbers. Dogs were housed collectively in 2 adjacent metal buildings, each divided into 4 rooms measuring 2.1 X3.7 m. Each room was paneled and carpeted and had an access door to the outside with a connecting run that measured 2.1 X 9.1 m. Each run had a surface consisting of 5 cm of pea gravel overlayng 5 cm of sand, and was partially covered by an awning that provided shade at its proximal end. For placement in room/run units, dogs in each of the treated and control groups were allotted to 4 subgroups of 3 dogs each. Each subgroup of dogs was placed in a separate room/run unit. Units containing treatment or control subgroups were alternated to avoid placing identically treated subgroups adjacent to each other. Dogs of subgroups A, C, E, and G were treated with lufenuron monthly at a minimal target dosage of 10 mg/kg of body weight; those of subgroups B, D, F, and H were treated with excipient tablets. Dogs were treated on study days 7, 37, 68, and 98. Each dog was infested with 100 newly emerged, unfed, insectary-reared adult Ctenocephalides felis on each of study days 0 and 2. Thereafter, infestations on all dogs were dependent on continued development of fleas either in the indoor or outdoor environment. Numbers of fleas on each of the treated and control dogs were determined, using a nondestructive counting technique on days 6, 14, 21, 28, 35, 56, 70, 84, 98, 112, and 119. On study day 21 and on each collection day thereafter, numbers of adult fleas recovered from treated dogs were significantly (P < 0.05) fewer than those recovered from control dogs. Proportion reduction of fleas on treated vs control dogs exceeded 90% by study day 35 and 95% by study day 56. Efficacies exceeded 95% on all remaining study days except days 98 (94.4% and 119 (90%). Results of this study indicate that control of flea populations can be achieved in treated dogs approximately 4 to 5 weeks after initial treatment with lufenuron, and that continued monthly treatments will maintain effective control of flea infestations. Adverse reactions or side effects to treatment with lufenuron were not observed in dogs after treatment at any time throughout the study.

Psoroptes ovis, calves, control with ivermectin, dosages and routes of administration; effect on Bovicola bovis; Otobius megnini not affected

The present study was carried out to investigate the potential adverse effects of amitraz on pregnant dams after maternal exposure during the gestational days (GD) 1 through 19 in Sprague-Dawley rats. The test chemical was administered orally to pregnant rats at dose levels of 0, 3, 10, or 30 mg/kg/day. During the test period, clinical signs, mortality, body weights, food consumption, serum biochemistry, gross findings, organ weights and reproductive findings on GD 20 were examined. In the 30 mg/kg group, an increase in the incidence of abnormal clinical signs and death, a suppression in the body weight gain, and a decrease in the food consumption were observed.

Thirty-two mixed-breed male and female cats were blocked by sex, arranged by body weight from greatest to least, and allocated to 4 groups of 8 (4 male, 4 female) cats, using random numbers. Cats in each of 3 groups were treated orally with a 7% suspension formulation of lufenuron at dosage of 15, 30, or 45 mg/kg of body weight. Cats in the fourth group were treated orally with an excipient suspension without lufenuron. Cats were infested with newly emerged, unfed cat fleas (Ctenocephalides felis felis) on days -7 and -3 before treatment and at approximately weekly intervals after treatment. Flea eggs were collected from beneath each cat on selected days before and after treatment and placed in an artificial rearing medium. Flea eggs and medium were kept for 35 days in an insectary to determine effects of lufenuron or excipient suspension on emergence of adults of the F1 generation. Lufenuron was 100% effective in inhibiting development of C felis at all dosages for 11 days after treatment. Thereafter, efficacy exceeded 92% in all dosages groups, On day 32, when the study was terminated, efficacy for each of the dosage groups was: 15 mg/kg, 95.2%; 30 mg/kg, 98.2%; and 45 mg/kg, 99.6%. Adverse reactions or side effects were not observed in cats, regardless of treatment dosage.

Angora goats heavily infested with Chorioptes bovis were dipped one time in either 0.05% amitraz, 0.27% coumaphos, 0.05% fenvalerate, or 0.03% lindane, Control of the mites by the single dips was evaluated for 21 days. Amitraz caused 98% mortality of the mites initially. Both coumaphos and lindane caused greater than 85% mortality at 3 days, but mite numbers increased rapidly thereafter. Only fenvalerate killed all of the mites.