Abstract: Ivermectin and abamectin are two members of the group of parasiticides known as the avermectins; ivermectin was first registered as an injectable treatment for cattle in 1981. Since then, abamectin has been registered for cattle and ivermectin for horses. The relative popularity of the avermectins amongst farmers and veterinarians can be attributed to their spectrum of activity, convenience, wide margin of safety and the improved health and performance of stock following their use. Patterns of use in grazing animals apply equally to the avermectins as to other antiparasitics, particularly anthelmintics; these are based on a knowledge of epidemiology integrated with practical management considerations. For cattle, programs are commonly aimed at control of abomasal nematodes of the genera Ostertagia and Haemonchus. Use of avermectins is largely strategic in cattle, treatments being favored at the end of the period of transmission of these parasites; this frequently coincides with housing, entry into a feedlot or movement to another pasture. Simultaneous control of important ectoparasites at this time is an added benefit. Prophylactic use of avermectins at pasture is primarily targeted at the young first season grazing animal. In horses, a bimonthly treatment schedule during the period of risk has proved effective in helping prevent adverse effects of the main target parasites, including large and small strongyles and stomach bots. These patterns of use can be applied to the evaluation of the potential for avermectin residues in feces to have impact on pasture ecology. The evidence presented suggests that any effects are temporally and spatially limited. After more than a decade of practical use, there is no indication that avermectins have had a significant impact on pasture ecology and the environment.

Abstract: Intense and persistent use of DDT for malaria control has increased resistance and induced exophilic behavior of Anopheles pseudopunctipennis. An evaluation of bendiocarb and DDT to control this species in Sinaloa, Mexico, showed that, in spite of DDT-resistance, both insecticides produced similar effects. Feeding patterns were analyzed to explain these results. Resting mosquitoes were collected over the dry and wet seasons. Anophelines were tested in an ELISA to determine the source of the meals. The human blood index (HBI) ranged from 3.3 to 6.8% in DDT- and from 12.7 to 26.9% in bendiocarb-sprayed houses. Irritability and repellency in DDT-sprayed houses could explain the reduced HBI. In contrast, bendiocarb produced higher mortality. These effects could have affected different components of the vectorial capacity and similarly reduced malaria.

Abstract: From observations of intra-specific social grooming in cattle and studies on human stroking in other species, we hypothesised that cows' reactions to human stroking differ depending on the body regions being stroked. Moreover, we tested, whether cows `reactions to stroking change with the animals' experience of stroking. Sixty dairy cows were stroked in three different body regions, i.e. the withers, W, neck ventral, NV (both licked often in social grooming) and the lateral chest, LC (licked rarely), in a balanced order during 10-min sessions. Behavioural reactions and heart rate during stroking as well as reactions to the human just after stroking were recorded. Two test sessions were carried out with 3 weeks of treatment in-between. During this period, the cows were randomly allocated to four treatment groups: three groups received 5 min of daily stroking in either W, NV or LC and the last one (control group) was exposed to simple human presence. During stroking W and NV, cows showed longer neck stretching and ear hanging than during stroking LC (P < 0.001). Moreover, ear hanging was shown longer when W was stroked as compared to NV (P < 0.001), but neck stretching was observed longer during stroking NV as compared to W only after the treatment period (P < 0.01). In the first test session, more animals showed head shaking and head throwing during stroking W and NV than LC (P < 0.01), whereas in the second test session these behaviours were observed only in few animals. In the first test session heart rate was higher during stroking W than the other body regions (P <= 0.01). In the second test session, the lowest heart rate was found during stroking NV (P < 0.05). Finally, contact with the experimenter following stroking differed for the three body regions stroked in both test sessions (first: P = 0.06, second: P < 0.01); contact was shortest for LC. When comparing both test sessions, stretching the neck and ear hanging increased (P < 0.001), while head shaking and head throwing decreased (P < 0.05); there was no difference for heart rate and contact with the experimenter. The four treatments had no influence on reactions to stroking. To conclude, stroking of body regions often licked during social grooming led to more responses than stroking the one licked rarely. Some reactions, such as stretching the neck, are also observed during social licking. This suggests that cows may in part perceive human stroking of body regions often licked similarly to social licking. This knowledge could be of interest for an improvement in quality of human-cattle interactions.

Abstract: Determined behavioral audiograms for 3 horses and 2 cows. Horses' hearing ranged from 55 Hz to 33.3 kHz, with a region of best sensitivity from 1 to 16 kHz. Cattle hearing ranged from 23 Hz to 35 kHz, with a well-defined point of best sensitivity at 8 kHz. Of the 2 species, cattle proved to have more acute hearing, with a lowest threshold of –21 db (re 20 μN/m–2) compared with the horses' lowest threshold of 7 db. Comparative analysis of the hearing abilities of these 2 species with those of other mammals provides further support for the relation between interaural distance and high-frequency hearing and between high- and low-frequency hearing. (39 ref) (PsycINFO Database Record (c) 2012 APA, all rights reserved)

Abstract: Anthropophagic horses have been described in classical mythology. From a current perspective, two such instances are worth mentioning and describing: Glaucus of Potniae, King of Efyra, and Diomedes, King of Thrace, who were both devoured by their horses. In both cases, the horses' extreme aggression and their subsequent anthropophagic behaviour were attributed to their madness (hippomania) induced by the custom of feeding them with flesh. The current problem of 'mad cow' disease (bovine spongiform encephalopathy) is apparently related to a similar feed pattern. Aggressive behaviour in horses can be triggered by both biological and psychological factors. In the cases cited here, it is rather unlikely that the former were the cause. On the other hand, the multiple abuses imposed on the horses, coupled with people's fantasies and largely unconscious fears (hippophobia), may possibly explain these mythological descriptions of 'horse-monsters'.