The

The Veterinary Journal 168 (2004) 110–111

Veterinary Journalwww.elsevier.com/locate/tvjl

Guest editorial

Do animals suffer like us? – the assessment of animal welfare

Do animals suffer in the way that humans do? Theboring academic answer is that it depends. Clearly,

chimpanzees are much more likely candidates than ants

to suffer as humans do and ants more so than jellyfish.

And even chimpanzees may be unable to reflect on their

own mortality in the ways that humans do from time to

time and suffer accordingly. The intrinsic difficulty,

though, is that suffering is a subjective state and no

person can be sure that another would, in the samecircumstances, suffer as he or she does. The usual way of

dodging this ancient philosophical catch is to rely on the

similarities between people. So if I suffer when I am

burnt, I assume that you too will suffer in much the same

way when you are burnt. Undoubtedly, this is the im-

plicit assumption of most veterinarians when dealing

with the issue of pain in animals. If the animal has the

same neural equipment for detecting damage and pro-cessing the information in its central nervous system as a

human and if it behaves in situations that humans would

find painful in much the same way as a human, the in-

tuitive rule is that the animal should be treated hu-

manely (Bateson, 1991). Identical arguments are

mounted for other aspects of suffering by those con-

cerned about animal welfare.

Unfortunately, the debates about welfare are fraughtwith many problems, not least being that those who seek

to legislate about such matters want categorical answers

to questions of the ‘‘Yes or No?’’ type. The reality of

neural and behavioural complexity in the animal king-

dom is that gradations of all kinds abound. What should

be done about Octopus? It might be dismissed as just a

large snail with a nervous system quite different in

character from those of vertebrates. Yet it is an animalof extraordinary behavioural complexity and intelli-

gence. A Home Office committee deliberated and even-

tually decided that Octopus vulgaris should be treated as

an honorary vertebrate and given the protection of UK

law. Paradoxically, the Home Office officials did not

recommend that the same protection be given to any

other species of cephalopod.

In a similar vein, politicians would like scientists toprovide incontrovertible evidence for welfare problems

generated by human activity. Nothing in science is in-

controvertible – even if those who controvert may be

way out on a limb from the central trunk of scientific

1090-0233/$ - see front matter � 2003 Elsevier Ltd. All rights reserved.

doi:10.1016/j.tvjl.2003.12.002

opinion. Many of the judgements about poor welfare inanimals have been disputed by Bermond (2001) who

believes that animals do not have the necessary neural

equipment to suffer in the way that humans do. My own

view is that this attempt to adjudicate about what ani-

mals feel on the basis of a very incomplete under-

standing of the brain is treading on treacherous ground.

In the past many surgeons took the view that the central

nervous systems of human babies was so immature thatthey could not feel pain. Therefore, they argued that

babies undergoing surgery should not be treated with

potentially dangerous analgesic drugs or anaesthesia.

Wall (1999) described how endless philosophical mus-

ings were brought to an end by a rigorous empirical

examination of the fate of babies that had been given

analgesics or anaesthesia during surgery and those who

had not. Those who had not been protected from thepain of surgery were much less likely to survive. That

terrifying story should generate a measure of thought-

fulness in anybody who is tempted to pontificate on

what animals do and do not feel.

In their excellent paper on ‘‘Animal welfare implica-

tions of neonatal mortality and morbidity in farm ani-

mals’’ in the current issue of The Veterinary Journal,

David Mellor and Kevin Stafford largely draw on evi-dence from humans when assessing the impact of a par-

ticular experience on the well being of young animals

(Mellor and Stafford, 2004).While their conclusions seem

entirely reasonable, it is as well to remember that there is

no royal road to establishing the case for poor welfare.

Ideally assessments should be made in a variety of ways

and the case for poor welfare will be strongest when all

the indicators point in the same direction. Mellor andStafford back up their assessments with mortality data

and it is striking that as welfare has improved according

to their assessments, mortality has fallen.

Behavioural biologists who have entered the debate

on welfare have argued that proper account should be

taken of the special adaptations to ecological conditions

in which the animal evolved (Barnard and Hurst, 1996).

When an animal does not behave as humans would inthe same circumstances, scientists should be sensitive to

its requirements, its evolutionary history and the details

of its social life. Therefore, it is argued that assessments

of suffering will also depend on good observational data

Guest editorial / The Veterinary Journal 168 (2004) 110–111 111

about the natural behaviour of the species in question,its normal requirements, its vulnerability to damage and

the ecological conditions in which it lives. The quality of

an animal�s welfare may be also determined by judging

the animal�s ‘‘state as regards its attempts to cope with

its environment’’ (Broom, 1986). Animals maintain their

internal state within certain limits. A change in their

environment taking any value, such as body tempera-

ture, outside those limits is countered by a behaviouraland/or physiological reaction that operates against the

effects of the environmental change. Stress is thought to

arise when attempts to bring the internal state to the

optimum persistently fail (Toates, 1995).

One way to penetrate the motivation of the animal is

to question it by behavioural means (Dawkins, 1980).

Colpaert et al. (1980) tested the responses of animals to

analgesics when in a state that might be expected to bepainful on the basis of what is known about humans.

They knew that normal rats drink sugar solution rather

than water containing an analgesic. When their joints

were chronically inflamed, they preferred to drink the

solution containing the analgesic. Cooper and Mason

(2001) made mink work for a variety of resources by

requiring them to pushing a heavily weighted access

door. They varied the weight of the door to see howmuch the mink would pay to reach different resources

such as extra space, an extra nest site, novel objects, toys

and a water bath. The mink pushed against heavy doors

particularly to reach swimming water. Indeed, so keen

were they that they would push a door with 2 kg of

weight added to them.

The scientific approach to the problems of assessing

suffering in animals has to be evidence based and col-lecting evidence requires orderly methods. Many de-

bates about what should and should not be measured in

welfare studies suggest that a variety of approaches are

more likely to benefit understanding than a single ap-

proach (Mason and Mendl, 1993). All of the following

approaches contribute to an assessment of adverse

welfare: (a) measurements of physical damage to the

animal; (b) measurement of the extent to which it hasbeen required to operate chronically homeostatic

mechanisms that would normally operate acutely; (c)measurements of physiological states that would be

found in suffering humans; (d) measurement of the an-

imal�s preferences; and (e) considerations of the condi-

tions to which the animal is adapted and its normal

social structure. When all these things are done, judge-

ments about the quality of an animal�s welfare are much

more likely to win widespread agreement than if only

one approach had been used.

Patrick Bateson

Sub-Department of Animal Behaviour

University of Cambridge

Madingley Road

Cambridge CB3 8AA, UK

E-mail address: ppgb@cam.ac.uk

References

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