Assessing pain in farm animals

European Commission Directorate-General For Agriculture And Rural Development Directorate-General For The Information Society And Media

Description

Agricultural and fisheries research
Animal production

Sujets

• Livestock
• Medical research
• Veterinary medicine

Informations

• Publié par: EUROPEAN-COMMISSION-DIRECTORATE-GENERAL-FOR-AGRICULTURE-AND-RURAL-DEVELOPMENT-DI
• Nombre de lectures: 72
• Langue: English
• Poids de l'ouvrage: 1 Mo

Extrait

Commission of the European Communities
AGRICULTURE
Assessing pain in farm animals
Report
EUR 9742 EN Commission of the European Communities
AGRICULTURE
Assessing pain in farm animals
Proceedings of a workshop held ¡n Roslin, Scotland, 25 and 26 October 1984
Edited by
I.J.H. Duncan V. Molony
AFRC Poultry Research Centre Department of Veterinary Physiology
Roslin Royal (Dick) School of Veterinary
Midlothian EH25 9PS Studies
United Kingdom Summerhall
Edinburgh EH9 1QH
United Kingdom
Sponsored by the
Commission of the European Communities
Directorate-General for Agriculture
Coordination of Agricultural Research
1986 EUR 9742 EN Published by the
COMMISSION OF THE EUROPEAN COMMUNITIES
Directorate-General
Telecommunications, Information Industries and Innovation
Bâtiment Jean Monnet
LUXEMBOURG
LEGAL NOTICE
Neither the Commission of the European Communities nor any person acting on behalf
of then is responsible for the use which might be made of the following
information
Cataloguing data can be found at the end of this publication
Luxembourg: Office for Official Publications of the European Communities, 1986
ISBN 92-825-6518-1 __
© ECSC-EEC-EAEC, Brussels · Luxembourg, 1986
Printed in Luxembourg PREFACE
The papers and accompanying synopses of discussion are the product of a
workshop held on October 25th and 26th 1984 at the AFRC Poultry Research
Centre, Roslin, Scotland. The workshop is part of the continuing programme
of meetings and research co-ordinated by the Commission of the European Com­
munities (CEC) as part of a Programme on Farm Animal Welfare.
Previous meetings in this Programme have highlighted the need to be
able to detect the presence and assess the intensity of pain in farm ani­
mals, and although there has been a considerable improvement in understand­
ing of the basic mechanisms of nociception and in the assessment and treat­
ment of pain in man, the assessment of pain in animals has yet to receive
the necessary attention.
The general aim of this workshop was to raise awareness of the subject
and to encourage its adoption as a viable and attractive research field.
Specific aims were: to discuss the use, or potential use, of a variety of
methods of assessing pain in animals, to comment upon their application in
farm animals, and to make recommendations for future research in this field.
Participation in the workshop was restricted to representatives of the
countries of the European Economic Community (EEC) and a few individuals who
attended at their own expense. Short papers of six approaches to the asses­
sment of pain were precirculated and were briefly reviewed by their authors
prior to discussion which was formally initiated by another of the partici­
pants. The precirculated papers and a summary of the discussants' comments
are included in the proceedings together with synopses of the discussions
which followed. Where possible the authors of particular comments are ac­
knowledged but no attempt has been made to quote all of the discussion
verbatim.
There was considerable concern to establish an acceptable basis for
work on "pain" in animals, since pain is a word which describes a human
experience and it is a continuing problem to establish the existence of an
equivalent experience in animals. This fundamental problem has not been
overcome but we have extracted from the proceedings a view of pain in ani­
mals which can act as target for improvement. We suggest that intact animals
are capable of an experience which they avoid, given the opportunity, and
which can dominate their physiology .and behaviour in a similar way to the
experience of pain in man. This we contrast with the view that the
experiences and perceptual capacity of intact animals are so different from
those of manthat it is not possible to describe any experience that they
might have as pain. Discussion of this view is expected to continue, but the
III welfare of farm animals cannot wait for a conclusion, nor will animal
welfare be improved directly by concentrating all of our attention and
resources on this aspect of the problem. The protection from and elimination
of pain in farm animals is a primary concern of our society and is expected
to remain so for the foreseeable future.
Direct measurement of pain in animals was not considered feasible with
current techniques and with the present understanding of the neurophysiolo-
gical basis of mental activity. Our concern must therefore be to review phy­
siological and behavioural changes which occur when pain can be expected to
be present. The changes that are of interest in the first place being those
seen to accompany pain in intact humans. These must, however, be supplement­
ed with observation of changes which are characteristic for each species.
Pain assessment must be accomplished in two dissimilar circumstances:
in the experimental situation, sophisticated measuring techniques can be ap­
plied both to the study of pain induced by various noxious interferences and
to the efficiency of methods for its relief; in the clinical situation the
existence of pain and its intensity must be assessed, relatively quickly,
without sophisticated measuring techniques and in most cases without prior
training of or prior knowledge of the animal concerned.
A wide variety of methods for use in both situations were discussed,
and it was clear that although many of the criteria were used with reasona­
ble confidence, different criteria were often used by different people. Sys­
tematic comparisons of the various criteria have not been carried out and
there has been little published discussions of them. It is therefore recom­
mended that future research should be directed at pain evoked by well defi­
ned noxious interferences in particular species, to obtain detailed analyses
of the relative value ofr physiological and behavioural measure­
ments under both laboratory and field conditions.
It has become much more clearly appreciated in the last few years that
noxious interference, such as traumatic injury to tissue, does not necessa­
rily elicit either continuing reflex responses or the experience of pain. In
intact animals antinociceptive mechanisms can operate to modify both physio­
logical and behavioural responses according to circumstances. Thus in some
situations the exhibitions of obvious external signs, in response to noxious
interference, may be avoided, because they would increase the chances of
detection by a potential predator. In other situations external signs of
pain are advantageous because they elicit help from other of the same spe­
cies or even from other species.
IV -If antinociceptive mechanisms eliminate physiological and behavioural
responses to noxious interference, it seems reasonable to assume that the
experience of pain is eliminated at the same time. The significance of any e accompanying noxious interference in animals should be interpret­
ed in the light of their physiological and behavioural responses, anthropo­
morphic interpretation should be undertaken with caution.
The use of analgesics to eliminate physiological and behavioural res­
ponses associated with noxious interference was considered to be a valuable
experimental and diagnostic tool. For example, the self administration of
analgesics by trained animals was considered to be one of the most powerful
methods for assessing pain under laboratory conditions. The development and
application of analgesics for the investigation, diagnosis and treatment of
pain in farm animals should therefore receive particular attention.
Even when more detailed information is available, it will still be ne­
cessary for experienced workers to make judgements about the presence and
intensity of pain, and if these are clearly reported in appropriate scienti­
fic journals it will permit development and continuous reassessment of the
criteria used to determine what constitutes unacceptable pain in farm
animals.
It is hoped that meetings such as this workshop, and that on "Animal
Pain" held in the Federation of American Societies for Experimental Biology
in 19R2, will highlight the problems, will promote investment in research
and that the detailed information required will rapidly become available.
As organisers of the workshops, we would like to thank the participants
for the papers presented for discussion and for their energetic contribut­
ions to the discussions. We would also like to thank Professor Ainsley Iggo
for his masterly job as chairman; the director of the Poultry Research Con­
tre, Dr. David Shannon, and his staff for their help in organising the mee­
ting; and the CEC for supporting the workshop. We would like to give parti­
cular thanks to Miss Carlisle and Miss Slee who have helped in the prepara­
tion of these proceedings for publication.
This workshop has again shown that international collaboration in the
scientific community provides an excellent means for developing and suppor­
ting the friendly personal relation