Anti-Docking Alliance (A.D.A.)

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The Campaign Against the Docking of Dogs' Tails

 
The Wansbrough Report
Cosmetic Tail Docking of Dogs’ Tails.

ROBERT K WANSBROUGH    Picasso Crescent, Old Toongabbie, New South Wales 2146        

This article was published in the Australian Veterinary Journal Vol 74, No. 1, July 1996.   
 It has been reproduced, by kind permission of the Author.
       

SUMMARY :

The anatomy of the canine tail and its relationship to the physiological functions of the tail are
described and the effect of tail docking on these is discussed. Current knowledge on the
physiology and anatomy of pain is described with  particular reference to cosmetic tail
docking in the neonatal puppy. Recent advances in knowledge about pain and the changes
in approach to pain management refute the premise that 'Puppies do not feel pain therefore
tail docking is not Inhumane', and also the premise that 'the pain and the effects of tail docking
are insignificant.' Six criteria to tell the 'necessity' to dock dogs are presented. The article
shows that the reasons advanced for tail docking do not satisfy these criteria and so that
docking dogs' tails cannot be justified.    

Tail docking is an old custom, which is entrenched in certain dog breeds. This article aims
to provide scientific information relevant to the cosmetic tail docking of dogs.        

There have been no scientific studies or double blind trials conducted to compare the effects
of tail docking in one sample of dogs with a similar sample of undocked dogs. Similarly there
have been no studies that measure the initial pain and the ongoing pathological pain inflicted
on docked dogs. Due to the phenomena of deafferentation (suppression of afferent  nerve
impulses) and phantom limb pain, scientific regulatory bodies would not permit such inhumane
research. Even without this information from specific scientific research, our current knowledge
is sufficient to show the canine tail is an anatomically and physiologically important organ which
should not be docked simply because tradition dictates it. Cosmetic tail docking cannot be
justified  medically or scientifically and recent advances in our knowledge about pain indicate
that it should he regarded as an inhumane act.        

CRITERIA TO TEST THE 'NECESSITY TO REMOVE OR MODIFY ANY PART OF A DOG.        

The following questions have been proposed by Morton (1992) to test the necessity to modify
or remove any part of a dog.
       

1. Is there evidence that leaving the dog intact predisposes them to harmful consequences?        

2. Is there evidence that the interference is in the best interests of the dog and will be
beneficial to the dog?        

3. would the harmful consequences or the benefit occur in a significant proportion of dogs
and therefore justify the procedure on all dogs of a particular breed?        

4. Does the proposed interference cause greatest harm to the dog than the damage one is
trying to prevent?        

5. Is there another way with no, or lesser adverse effects that would achieve the same end?        

6. Does the increase in 'value' as a result of the interference justify the harm done to the dog?        

ANATOMICAL CONSIDERATIONS.        

An understanding of the importance of the tail and the con-ditions to which docking can
predispose is gained by reviewing the anatomy and the physiology of the tail and the pelvic
region.    The canine tail usually consists of 20 (6 to 23) highly mobile vertebrae largely
enclosed by a very versatile musculature  making the various segments, especially the tip
capable of finely graded movements. Part of the musculature is formed from muscles
associated with the rectum, the anus, and the pelvic diaphragm. The tail is served by 4 to 7,
paired coccygeal nerves. On leaving the spinal canal the branches of these  nerves
anastomose to form the left and right dorsal and ventral coccygeal trunks which lie on their
respective surfaces of the transverse processes of the vertebrae. The dorsal muscles of the
tail are direct continuations of the epiaxial musculature of the trunk. The dorsal
sacrococcygeal muscles are extensors, while the sacrococcygeus ventralis lateralis and
medialis muscles act as flexors or depressors of the  tail. These muscles have many
tendons that insert from the 5th or 6th coccygeal vertebra then onto the next vertebra and so
on to the end of the tail. The coccygeus, levator ani, and the inter-transversarius caudac
muscles are lateral flexors of the tail.

The rectococcygeus muscle is composed of external fibres from each side of the rectum
with the left and right portions fusing at the level of the 3rd coccygeal vertebra then inserting
on the 5th and 6th coccygeal vertebrae. This attachment on the tail serves to support, anchor
and stabilise the anal canal and the rectum, preventing them from being pulled cranially by a
peristaltic wave. By its contraction, the rectococcygeus muscle can move the anal canal and
rectum caudally thus evacuating faecal material (Miller 1969). The pelvic diaphragm is the
vertical closure of the pelvic cavity formed by the coccygeal muscles. The coccygeal muscle
originates on the ischiatic spine, extends to the lateral surface of the tail and inserts on the
2nd to 5th coccygeal vertebrae The levator ani muscle (m coccygeus medialis) originates
on the ilium, pubis and pelvic symphysis, radiates upwards surrounding the genitalia and the
rectum and ends on the 4th to 7th coccygeal vertebrae. Besides helping to contain the contents
of the pelvic cavity the levator ani muscle moves the tail cranially and laterally, presses the tail
against the anus and the external genitalia, compresses the rectum and causes the sharp
angulation between the 6th arid 7th coccygeal vertebrae which is characteristic for defecation.
Only in carnivores does the levator muscle reach the vertebrae of the tail, thus the detri-mental
effect of tail docking on the role of this muscle will be  more significant in the dog compared
with other domestic species.         

PHYSIOLOGICAL ASPECTS.
LOCOMOTION.    

The tail is important as a means of counter-balance when the dog is carrying out complicated
movements such as leaping, walking along narrow structures, or climbing. Tail muscles are
also important in stabilising the vertebral column and supporting the action of the extensor
muscles of the back as well as those of the croup and buttocks.         

DEFÆCATION.    

Normally the rectum, anus, and anal canal are devoid of faecal material with the walls in
apposition. During defecation the dog assumes a squatting position with elevation of the tail
and subsequent relaxation of the coccygeus, the levator ani, and the rectococcygeus muscles.
This allows the migrating contractions in the colon to push the faeces distally into the rectum
with defecation ensuing. The movement of the tail during the act of defecation has a direct
influence in evacuating the rectum and anal canal of the last part of the faecal bolus. The
coccygeus and levator ani muscles cross the rectum laterally tending to compress the tube,
while the recto- coccygeus shortens the tube. After defecation the muscles return to their
normal position with oncomitant obliteration of the empty lumen. If the tail is removed from an
immature puppy the muscles of the tail and pelvis may fail to develop to their full  potential.
Removal of the tail in the mature dog may lead to atrophy and degeneration of these muscles,
in addition, if these muscles lose their distal attachments there may be a lessening of the
support and anchorage of the rectum and anus. An absence of adequate function of these
muscles may result in rectal dilatation, rectal sacculation and faecal incontinence.
   

PELVIC DIAPHRAGM INTEGRITY.    

Perineal hernia involves a breaching of the caudal wall of the pelvic cavity with herniation of the
rectum, the abdominal contents or the pelvic contents through an opening bordered by the anal
sphincter medially, the coccygeal muscle laterally and the internal obturator ventrolaterally. Any
process resultmg in fascial weakening, muscle atrophy, or muscle degeneration may
predispose to this weakness in the pelvic diaphragm.  Often perineal hernias occur secondary
to medical conditions which cause tenesmus with resultant weakening of the pelvic diaphragm.  
  Burrows and Ellison (1989) recorded a predisposition to perineal hernia in those
brachycephalic breeds,
which  traditionally have their tails docked, and suggested that inherent
conformational deficiencies may contribute to the  disease in these breeds.Canfield (1986)
compared long-tailed and docked Corgis and found that the levator ani and the coccygeus
muscles did not develop fully in the docked dogs. A relationship with perineal hernia potentially
exists, but she considered that further research was required before a categorical statement
could be made.         

ACQUIRED URINARY INCONTINENCE.    

Urinary incontinence in bitches caused by urethral sphincter mechanism ncompetence (SMI),
is a multi factorial condition. A recent study (Holt and Thrusfield 1993) noted the increased risk
of SMI developing in large breeds but it also concluded that bitches belonging to small breeds
had a reduced risk and medium breeds had no increased risk. Breeds identified in this study
as having significantly increased risk of developing SMI were the Old English Sheepdog,
Rottweiler, Doberman Pinscher, Weimaraner and Irish Setter. A reduced  risk was
demonstrated in the Labrador Retriever, and, although the result was not statistically
significant, a low risk was observed in the German shepherd. This agreed with the
observations of Arnold et al (1989).Holt and Thrusfield (1993) noted 2 consistent association
between SMI and tail docking which they interpreted as an indication that docked breeds of
whatever size are more likely to develop incontinence than undocked dogs of the same breed.
It is well recognised in women that the risk of developing genuine stress incontinence (GSI) is
related to pelvic floor muscle damage during labour. In the bitch the equivalent 'pelvic floor'
muscles are the levator
ani and coccygeus muscles both of which attach to the tail base, and it
is possible that these muscles are atrophied and/or damaged in docked breeds reducing
urethral resistance. A similar relationship may exist
between tail docking and submissive
urinary incontinence in puppies.Holt and Thrusfield (1993) conclude that their results provide
some evidence to support the arguments against tail docking and that it would be interesting
to determine if the predisposition to urinary incontinence in currently docked breeds such as
the Old English Sheepdog and Doberman Pinscher would be reduced if they cease to be
docked.        

COMMUNICATION AND CANINE BEHAVIOUR.    

The position of the tail and the way it is moved can signal pleasure, fear, friendliness,
dominance, playfulness, defensiveness, inquisitiveness, aggression, nervousness and
submissiveness. Thus tail docking can affect the interaction of dogs with other animals and
man. Some behaviourists believe the absence of a tail may predispose a dog to show
unwarranted aggression to other dogs and man, or that they may be the victim of attacks by
other dogs due to their failure to communicate (RJ Holmes personal communication)    Dogs
are playing an increasingly significant role as pets and companion animals. Their role in the
reduction of emotion and stress related diseases in western society is well recognised, as is
their important role in companion animal therapy with children, the handicapped and the elderly.
Therefore, good, clear communication with 'man's best friend' is of paramount importance
and anything that may impair this  communication should he avoided. Tail docking is one
such thing.       

PAIN    

Recent advances in our knowledge of pain physiology and anatomy are relevant to the
discussion of cosmetic tail docking. Pain is a feeling, a complex summation of nociceptive
input, emotion
and state of arousal. Physiological pain is normal, has a short duration and
can be protective, but pathological pain is abnormal, is often  persistent and can be 
debilitating and counterproductive. Pathological pain is the sensation perceived from the
inflammation that accompanies tissue injury or the sensation perceived from damage directly
to the nervous system. Clinically, pathological pain is characterised by one or more of the
following :

  • The presence of sponataneous pain - pain that occurs in the absence of a
    demonstrable stimulus.    
  • Widening of the painful area - 'flare reaction.'    
  • Hyperalgesia - where (the response to a painful stimulus is exaggerated)   
  • Allodynia - where a normally innocuous stimulus is painful.     
  • Referred pain - where the pain from injured tissues spreads to intact tissues.   
  • Sympathetic dystrophy - a pathological interaction between the sensory and the
    sympathetic nervous systems
    .    

Unlike physiological pain, pathological pain has no thresh-hold.  The nervous system is a
plastic, modifiable system with a propensity for adaptation and maladaptation and peripheral
and central sensitisation are the mechanisms underlying the generation of pathological pain
(Dart 1994).        

PERIPHERAL SENSITISATION.    

Nociceptors (pain receptors) are activated directly by mechanical and thermal stimuli and
also by endogenous substances released from inflamed, traumatised and   ischaemic
tissues. Serotonin, products of the arachidonic cascade, histamine, kinins and acetylcholine
are all algogenic (directly pain producing). Prostaglandins and nor-adrenalin may not be
directly painful, but sensitise the nociceptors and potentiate the effect of other algogenic
substances. Substance P is secreted from the excited or sensitised nociceptors and induces
vasodilation, increased vascular permeability, mast cell degranularion and production of
unstored inflammatory substances. The formation of this 'sensitising soup' leads to
sensitisation of adjacent nociceptors and so the vicious cycle of 'peripheral sensitisation' is
set in motion.  Sensitised nociceptors can become spontaneously active causing
depolarisation of 'dorsal' horn neurons, and thus peripheral sensitisation is one of the
phenomena involved in the development of pathological pain.          

CENTRAL SENSITISATION.    

At the spinal cord level, the balance between the afferent stimuli reaching the dorsal horn and
the degree of activity of inhibitory interneurons will determine the strength and frequency of the
stimuli registering in the brain. A cascade of  intracellular events is initiated and as a result
identical but repeated stimuli can evoke a larger and larger response because the potentials
are summated. The dorsal horn neurons become hyperexcitable this reaction is termed 'dorsal
horn wind up'.  The hyperexcitability of the dorsal horn neurons increases the activity in
preganglionic sympathetic neurons and as a result postganglionic sympathetic efferents
release noradrenalin which sensitises primary afferent terminals. These in turn  initiate central
sensitisation, which further increases  sympathetic outflow and this increases afferent input.
So another vicious cycle is set in motion. Pathological pain can he seen to he the result of
peripheral  and central sensitisation.        

INCORRECT MYTHS ABOUT PAIN.    

Several myths about pain have been propagated for years and  form the basis on which
cosmetic tail docking has been justified and allowed to he perpetuated.        

MYTH 1 - Animals don't feel pain like humans.    This is illogical. Anatomically and
physiologically mammals (and possibly all vertebrates) have the same neural transmitters,
receptors, pathways and higher brain centres. Whilst it is true that animals may show
different signs of pain,  we cannot deny that they feel pain in the same way humans do
(Fleeman 1995). Because of the physiological similarity between mammals, it is valid to use
animals, including dogs, as models for human medical research. The converse applies in that
man can be used as a model for advancing veterinary knowledge. Similarity between the
human and canine nervous systems means that we can assume that anything causing pain
in man will cause a painful sensation of similar intensity in the dog.The pain threshold has
been determined to be approximately equal in humans and animals (Fleeman 1995).   

MYTH 2 - Lack of myelination is an index of immaturity in the neonatal nervous system
and therefore neonates are not capable of pain perception. We know this is no longer correct,
in fact the contrary occurs. Anatomical studies have shown that the density of cutaneous
nociceptive nerve endings in the late foetus and newborn animal may equal or exceed that of
adult skin (Anand and Cart 1989).    Nociceptive impulses are conducted via unmyelinated
and thinly myelinated fibres. The slower conduction velocity in neonatal nerves resulting from
incomplete myelination is offset by the shorter interneuronal and neuromuscular distances that
the impulse has to travel. It has been shown, using quantitative neuroanatomical methods, that
nerve tracts associated with nociception in the spinal cord and brain stem are completely
myelinated up to the thalamus during gestation (Anand and Cart 1989).    Further development
of the pain pathways occurs during puppyhood when there is a high degree of 'brain plasticity
.'The development of descending inhibitory pain pathways in the dorsal horn of the spinal cord
and the sensory brain stem nuclei also occurs during this period, therefore painful and other
experiences during this period may determine the final architecture of the adult pain system.        

THE PAIN OF TAIL DOCKING.    

Tail docking involves the removal of all or part of the tail using cutting or crushing instruments.
Muscles, tendons, 4 to 7 pairs of nerves and sometimes bone or cartilage are severed. The
initial pain from the direct injury to the nervous system would be intense and at a level that
would not be permitted to be inflicted on humans. The subsequent tissue injury and
inflammation, especially if the tail is left to heal as an open wound will produce the algogenic
substances, the 'sensitising soup' and the 'dorsal horn wind up' required for peripheral and
central sensitisation and the development of ongoing pathological pain.  Puppies are usually
subjected to this pain and trauma at 2 to 5 days of age when the level of pain would he much
greater than an adult would experience because the afferent stimuli  reaching the dorsal horn
from a greater density of sensitised cutaneous nociceptors will exceed that of the adult and
the strength and frequency of painful stimuli reaching the brain will be greater because
inhibitory pain pathways will not be developed.

  • The whimpering and the 'escape response' (continual movements) exhibited
    by most puppies following tail docking, are evidence that they are feeling
    substantial pain. Animals tend to be more stoic than humans due to an inherent
    preservation instinct.
  • Because some puppies do not show signs of intense suffering, it does not mean
    that the pain inflicted on them has not registered in their central nervous system.

Cosmetic tail docking is most often performed without any anaesthesia or analgesia and
only manual restraint is used. General anaesthesia, if used, produces  unconsciousness and
muscle relaxation but does not affect the sensory nerves and will not necessarily prevent
'dorsal horn wind' up or the development of pathological pain. Movement of the patient may
be controlled, but sensory stimuli will still register in the higher centres of the central nervous
system. On recovery from anaesthesia peripheral and central sensitisation, the mechanisms 
underlying the generation
of pathological pain will still he present.

General anaesthesia in very young animals entails a high degree of risk  Local anaesthesia,
because of the practical difficulties of injecting into such a small area and the potential for
systemic toxicosis, also has a high risk. The maximum dose of lignocaine in the dog is
5 mg/kg making use
of the 2% (20 mg/ml.) solution urealistic in the average puppy up to a
week of age.  Use of local anaesthetics to which adrenalin has been added could increase the
risk of cardiovascular and CNS problems occurring, although some proponents of tail docking
recommend the use of these solutions to prolong analgesia and to help control haemorrhage
(RA Zammit in a submission prepared for the New South Wales Canine Council).
Understanding the phenomena of peripheral and central sensitisation and their role in the
generation of pathological pain, has changed the approach to pain management. The
emphasis is now on preventing pain and treating pain before it occurs.

About 90% of human amputees suffer pathological pain in the form of phantom limb pain.
Docked dogs similarly may suffer phantom limb pain but, if their inherent stoicism masks the
symptoms, this may he misdiagnosed or go undiagnosed. The currently  recommended
anaesthetic procedure for  a human undergoing surgery where major peripheral nerves are
to he severed, would involve epidural anaesthesia for 48 h before surgery and 24 h after
surgery.local anaesthesia around the surgical site at the time of surgery and for 24 h after
surgery.


OTHER POTENTIAL SEQUELAE FROM TAIL DOCKING.        

Other sequelae that may result from tail docking are :-       

  • Haemorrhage or ischaemia.        
  • Infection, gangrene, toxaemia/septicaemia.        
  • Meningitis.        
  • Hypoglycaemia or hyperglycaemia.        
  • Amputation neuroma formation.        
  • Caudal adhesions with neurodermatitis.        
  • Deafferentation, causing loss of sensory perception from the tail.        

Many of these can potentially produce a state of shock which may prove fatal to the neonatal puppy.


SOME REASONS FOR TAIL DOCKING PRIOR TO THE 19TH CENTURY     

  • To produce bobtail puppies - Lamarcks theory of acquired characteristics was still widely
    believed and people thought the new born puppies would look like their parents.    
  • To prevent rabies - it was thought that docked dogs were less likely to develop rabies.    
  • To avoid tax - docked dogs did not attract tax.     
  • To strengthen the back and increase speed.    
  • To prevent being bitten when ratting or fighting.    
  • To make better 'sport' of bear baiting and dog fighting.    

These reasons from which the custom of tail docking evolved are no longer valid. (Note - Have
they ever been valid?)
       

REASONS GIVEN TO JUSTIFY TAIL DOCKING TODAY

  • Prevention of injury in hunting and working dogs.    

Most dogs in the breeds that are generally docked are kept as pets and companion animals
and are never used for hunting or working. The most popular breeds used in the field or
paddock are Labradors, Kelpies, Border Collies and Cattle dogs, none of  which are
required to have their tails docked.    

  • Prevention of injury in short coated dogs especially those with exuberant and
    ebullient temperaments

This is inconsistent because not all breeds in this category are required to be docked, for
example the Dalmatian and the Labrador. The boxer is often cited a dog requiring docking
for   this reason, but some professional dog trainers note a difference  in the behaviour of this
and other traditionally docked breeds when they are left undocked and 'urge and encourage
all breeders  to forget about what has happened in the past and now change to keep their
dogs' tails on" (Tucker 1994).        

A survey in Edinburgh by Darke et al (1985) over a 7 year period showed that there was
insufficient evidence of statistical significance, to suggest that there is a positive association
between tail injuries and an undocked tail and that tail docking could not be recommended
as a measure to prevent tail injuries in any dog population similar to the predominantly urban
population surveyed.        

Of the first 1000 consultations at the North West Animal Emergency Clinic in Sydney none
involved tail injury cases. Between December 1991 and September 1992 there were 2350
consultations only 3 of which involved tail injuries. All three of these cases were related to tail
docking, the first case involved 12 three day old Rottweiler pups which were still haemorrhaging
6 hours after being docked and required suturing.    The other two cases involved single pups
one of which was bleeding and the other had become infected (From records of the North West
Animal Emergency Centre, Baulkharn Hills, NSW.)        

Not all tail injuries require amputation, so tail docking may be routinely performed on 100% of
puppies of certain breeds as a measure to prevent injuries that would only require a bandage,
some antiseptic or simply natural healing.        

  • Hygiene

Dogs such as the Old English sheepdog, poodle and  silky terrier would foul themselves and
the average pet owner would not have the time, patience or skill to carry out proper coat care. 
This is inconsistent because other breeds with the same potential problem (for  example the
Bearded collie, Pekingese, Maltese terrier and Afghan) are not required to be docked.    
 Regular clipping of long-haired areas and 'feathers' is far less  invasive and painful than tail
docking and has far fewer adverse  effects. Poor breed selection, lack of education in dog
husbandry or irresponsible pet ownership should not be justification for tail docking.        

TRADITION OR CUSTOM  

Submitting dogs to a procedure known to be painful and which may have harmful
consequences, just to satisfy a centuries old custom, cannot he justified in a humane society.        

CONCLUSION

Cosmetic tail docking cannot be justified on scientific or medical grounds. Unless pecuniary
or traditional reasons are to take priority over the welfare of the animal, then the criteria to
justify removal of a dogs tail are not satisfied.  The tail is not merely an inconsequential
appendage. It is an anatomically and physiologically sign significant structure which has
many biological functions that should not he underestimated. Tail docking can predispose the
dog to detrimental consequences including intense, initial pain and continuing pain related,
neurological problems. Tail amputation should only be performed on those dogs whose tail
or associated structures have been injured or where there is occult pathology of this
appendage. If tail amputation is indicated as a therapeutic measure, appropriate anaesthetic
and surgical techniques should be employed. The neonate is anatomically and  physiologically
able to and in fact does feel pain. Therefore veterinarians who wish to be seen as caring
professionals and as the guardians of animal welfare must stop cosmetic tail docking and
actively oppose anyone else continuing the painful practice.

REFERENCES        

Anand KJS and Carr DB (1989) Paediatric Clinics Of North Am.     36:795        

Arnold S, Arnold P. Hubler M, Casal M and Rusch P (1989)  Schwelzer Archiv fur Tierheilkunde 131: 259.
(English translation European J. of Companion Anim Practice (1992) 2:65)       

Burrows C and Elilson G (1989) In Textbook of Veterinary  Internal Medicine, 3rd edn, edited by Ettinger SW,
Saunders Philadelphia. p1559.        

Canfield R (1986) Anatomical Aspects of Perineal Hernia in the  Dog, PhD Doctoral thesis, University of
Sydney        

Darke PGG, Thrusfield MVand Aitken CGG (1985) Vet Rec 116:409        

Dart CM (1994) In Pain and its Control University of Sydney Post Graduate Commitee In Veterinary Science,
Proceedings No 226. p333.       

Fleeman L (1995) Control of Pain - What's the  Latest? University of Melboume Veterinary Clinic and Hospital.         

Holt PE and Thruslield MV (1993) Vet rec 133:177       

 Miller M (1969) Anatomy of the Dog, Saunders, Philadelphia. p 189       

 Morton D(1992) Vet Rec 131:301        

Tucker M (1994) AVA News Oct p 16

 
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