Tail docking in horses: a review of the issues.

Routinely performed painful procedures are of increasing interest and, in 2001 (Royal Order, May 17), Belgium prohibited docking in several vertebrates including horses. In 2004, opponents to this decision submitted a Bill (Doc51 0969/001) to Parliament, intending to obtain derogation for Belgian draught horses, which were traditionally docked. The Animal Welfare Council of Belgium, an official body advising the Minister of Public Health, was asked to evaluate this complex question, including biological, ethical and socio-economic aspects, on the basis of the available peer-reviewed studies. In this context, this study reviews legal aspects (overview of the European legislation), zootechnic aspects (uses of the Belgian draught horse) and biological aspects (pain potentially related to docking; horses' welfare linked to insect harassment and hygiene, communication and reproduction) of tail docking in draught horses. We conclude that (1) there is no benefit for horses in tail docking, including Belgian draught horses, (2) potential advantages of docking are essentially in favour of humans and these advantages could be scrupulously re-evaluated, taking into account practices of other countries. Therefore, there is no need to dock any horse other than for veterinary reasons.

A stereotaxic atlas of the forebrain of the bank vole (Clethrionomys glareolus).

In this article part of the forebrain of the bank vole (Clethrionomys glareolus) is presented in stereotaxic coordinates. The stereotaxic procedure was performed as follows. With the vole's head mounted in a stereotaxic adaptor, internal reference tracks were made with a 0.5-mm diameter microdialysis cannula and India ink, 2 mm in front and 2.6 mm behind the skull landmark bregma. Brains were fixed for 72 h in 4% commercial formaldehyde in sodiumcacodylate buffer containing 1% CaCl2. To determine shrinkage they were weighed before and after fixation. After embedding in paraffin they were sectioned at 25 microm and stained with Nissl. Photomicrographs were taken from the brain of one animal while its frontal (antero-posterior) coordinates of five neural structures were compared with those of 12 other voles. Variability was also checked in lateral and vertical directions at frontal level -1.0 mm (relative to bregma). The results show that the distance between the two skull landmarks bregma and lambda correlates significantly and negatively with the antero-posterior position of each of the brain areas. On the basis of these results an equation is proposed to improve accuracy in locating neural structures that deviate due to biological variability.

The development of equestrianism from the baroque period to the present day and its consequences for the welfare of horses.

Many saddle horses are slaughtered at a young age which could be indicative of a welfare problem. Bad riding is probably an underestimated source of poor welfare. Widespread knowledge of 'academic' riding should be encouraged and should be beneficial to all horses, at all schooling levels, for all purposes. In particular, 18th century principles tend to be forgotten and in this article the authors illustrate some differences to modern dressage. Various suggestions are made in order to improve welfare.

Heart rate and behavioural responses of crib-biting horses to two acute stressors.

The heart rate and behaviour of 14 adult saddle horses, eight crib-biters and six normal controls, were investigated. Initially, the relationship between crib-biting and heart rate was investigated while the horses were undisturbed. The horses were tested when restrained with a lip twitch, and assessed when they were exposed suddenly to the rapid inflation of a balloon. The heart rate of the crib-biters during crib-biting was lower than during other behaviours. The crib-biters had a higher overall mean heart rate (P<0.05) suggesting that they may have had a higher basal sympathetic activity. After the application of the twitch, all the horses had a transient increase in heart rate which returned to basal values more rapidly in the crib-biters. The crib-biters were less reactive to the lip twitch, five of the six investigated remaining calm, and after the release of the twitch, they spent more time nibbling (P<0.05) than the control horses. The crib-biters reacted more strongly to the inflation of the balloon (three of the six reacted), and after it had been inflated they spent more time walking in the box.

Dissociation between MK-801- and captivity-induced stereotypies in bank voles.

Pharmacologically induced stereotypies (PHIS) following dopamine agonists and, more recently, the non-competitive NMDA antagonist dizocilpine (MK-801), are used to study human psychopathology and for screening potential neuroleptic drugs. On the other hand, bank voles (Clethrionomys glareolus) spontaneously develop stereotyped jumping in barren cages, already before the age of 1 month (= captivity-induced stereotypies or CIS). Large interindividual differences in the level of jumping exist. In this study, the effect of MK-801 on various behaviours of bank voles, and in particular the relationship between CIS and PHIS, was investigated by repeated administration of MK-801 to stereotyping (ST) and non-stereotyping (NST) voles. The animals received nine daily s.c. injections of, respectively, saline and 0.3 mg/kg MK-801, with a 48-h break between both treatments. Their behaviour was visually recorded every 4 days. The results showed that jumping was neither evoked in NST, nor intensified in ST. Instead, in both ST and NST, PHIS consisting of intensive sniffing and locomotor stereotypy characterised by running in unidirectional circles were elicited. Furthermore, ST showed behavioural sensitisation for locomotor stereotypy, while in NST intensive sniffing was progressively enhanced. These results suggest that CIS and PHIS induced by MK-801 in bank voles are regulated, at least in part, by different neuronal mechanisms and that ST and NST could be predisposed to develop more easily one given PHIS than the other.

Effect of apomorphine on the conflict-induced jumping stereotypy in bank voles.

In conventional laboratory cages, bank voles (Clethrionomys glareolus) develop a jumping up-and-down stereotypy already before the age of one month. Central DA systems are thought to be involved in the expression of these conflict-induced stereotypies (CIS). Stereotypies can also be elicited pharmacologically, most commonly by amphetamine and apomorphine. Hence, administration of apomorphine to jumping bank voles provides the opportunity to compare pharmacologically-induced stereotypies (PHIS) and CIS in that species. A pilot study showed that apomorphine induced stereotyped licking that is qualitatively different from the CIS elicited by captivity. The present study investigated whether apomorphine has an effect on CIS-levels. The lowest dose (0.625 mg/kg) did not elicit licking but neither influenced jumping levels. Higher doses (0.938 and 1.094 mg/kg) lead to the occurrence of licking but also suppressed CIS-levels. However, the discordance in time profiles of licking and jumping argues against a shift from jumping to licking due to further stimulation of already activated DA systems. Therefore, expression of jumping seems to depend on stimulation of other DA receptor subtypes or jumping may even be DA independent.

A combined stereotaxic adaptor and anaesthesia apparatus for microdialysis studies in small rodents.

Intracerebral microdialysis in the bank vole (Clethrionomys glareolus) challenges the accuracy and precision of the stereotaxic implantation technique because of the small brain size. In this paper, a miniaturized stereotaxic head holder is described that allows precise alignment of bone landmarks on the skull and prevents all movement after fixation by clamping the skull symmetrically at the os parietale and at the os nasale. In addition, the head holder is adapted for inhalation anaesthetic delivery in order to ensure stable anaesthetic depth over several hours. The system is not restricted to bank voles but can be readily applied to other small experimental animals, which could lead to a more widespread use of the microdialysis technique in mice.

Changes in naloxone and haloperidol effects during the development of captivity-induced jumping stereotypy in bank voles.

Captivity-induced stereotypies in bank voles (Clethrionomys glareolus) were inhibited at the age of 1, 2, 4, 6, 8 and 10 months by 0.2 mg/kg haloperidol s.c., while 35 mg/kg naloxone s.c. only inhibited them at the age of 4-6 months. Other activities were not significantly inhibited. The change in the naloxone effect was not due to desensitization as animals treated only at 6 or 8 months reacted similarly. It is suggested that the expression of such stereotypies is influenced by endogeneous brain opioid peptides during an early stage of their development, but that thereafter only motoric automatisms remain, essentially under dopaminergic control.

The effect of interference in catecholamine biosynthesis on captivity-induced jumping stereotypy in bank voles (Clethrionomys glareolus).

The level of the captivity-induced jumping stereotypy in bank voles was significantly decreased by 150 and 200 mg/kg alpha-methyl-para-tyrosine and increased by 200 mg/kg L-DOPA while 20 and 40 mg/kg fusaric acid had no effect. None of the other movements were affected by these drugs (as measured by a general activity meter), except for a nonsignificant decrease after treatment with fusaric acid. These results suggest that cerebral dopaminergic neuronal systems and not noradrenergic neuronal systems are involved in the expression of that stereotypy in bank voles.

The influence of cage size and environmental enrichment on the development of stereotypies in bank voles (Clethrionomys glareolus).

Bank voles were bred and lived in 4 different environments: small barren cages (SB), small enriched cages (SR), big barren cages (BB) and big enriched ones (BR). Ten different behaviours were recorded at the age of 30, 45, 60, 61, 75 and 90 days. Between day 60 and 61, within each experimental environment, the group of voles performing stereotypies (ST) and the group of those which did not (NST) were each split in two, one part being transferred to a new environment, the other remaining in the same as control. For each of the 10 behaviours, differences between the 4 environments and therein differences between the ST and the NST animals and between the age groups were analysed with a split-plot ANOVA. The results indicated that enrichment is more determinant than cage size, as more voles developed stereotypies in SB and BB than in SR and BR. Improving the environment after day 60 inhibited the stereotypies in most ST animals, while smaller and/or barren environments elicited them in very few NST. ST voles performed significantly more rearing and walking-sniffing and showed significantly less immobility than NST ones. These differences remained linked to the ST/NST status when an animal reversed it after day 60. Within different environments, some individuals are more prone to react actively to frustration, including the development of stereotypies. The performance of stereotypies is associated with a more general behavioural activation.

Some data on the fertility of bank voles (Clethrionomys glareolus britannicus) in the laboratory supporting the hypothesis of induced ovulation.

83 (40%) litters with an average of 3.42 pups and unbiased sex ratio were born of 207 couples. Fertility and litter average were higher in summer and autumn. Most females were fertilized on the 1st day spent with a male, which supports the mating-induced ovulation hypothesis. Infantile mortality was highest at birth and during the 1st 5 days of life. 26% of the pups died before weaning (day 25), i.e. an average of 1 per litter.

A study of the hearing ability of horses.

The ability of 10 horses to hear frequencies between 14 and 25 Kc/s was tested. The horses appeared to perceive ultrasounds by showing either fright reactions or Pryer reflexes to all of the 12 frequencies. The highest frequencies were heard less by older animals, and elicited more reactions in geldings than in mares.