In Bedlington terriers copper toxicosis (CT) is an inherited disease. Copper is present quite normally in the diet and drinking water. It is absorbed into the dog and has some essential uses especially relating to the blood and the nervous system. Any excess is excreted in the bile. In copper toxicosis this excretion is reduced, which causes a build up of copper in the liver. The liver is damaged by this.

Signs of disease

1.      No signs are seen until the copper builds to a toxic level, though damage is occurring. Some affected dogs do live to old age, most progress in one of the following ways.
2.      Acute liver failure: Sudden severe illness with jaundice (due to breakdown of red blood cells as well as liver damage), diarrhea, vomiting and commonly death within 2-5 days. Often this is seen in young adults.
3.      Chronic liver disease: Slow progressive loss of weight and condition. There may be loss of appetite, excess thirst, vomiting and even nervous symptoms. Sometimes jaundice is seen. This is commonly what is seen in older dogs, eventually the liver fails and the dog will probably die.

Preventing illness in affected dogs
1.      Low copper diet, either commercial or homemade.
2.      Liver support diet with increased levels of antioxidants and vitamins and relatively low in fat and protein. A diet such as Hills L/D combines these first two aims. If fed at an early stage a low copper diet may prevent disease.
3.      Chelating agents (e.g. D-penicillamine = Distamine) bind to copper so it can be excreted in the urine. Another benefit is an anti-inflammatory effect, which may help to reduce cirrhosis (fibrous tissue which is formed in chronic disease and further damages the liver function). Distamine can have side effects in high percentage of dogs, usually nausea and vomiting.
4.      Zinc can be added to the diet, although care is needed as excess zinc can be toxic.

Treatment of an ill dog
1. Acute hepatitis requires hospitalization by your vet for intensive care.
2. Chronic disease. As well as the preventative measures mentioned above antibiotics, steroids and other drugs may be needed.

Tests

a.      C04107 Marker Test was the first genetic test. Two types of marker 1 or 2 are commonly seen. A dog could be:
i.      1:1 Clear, a healthy dog
ii.      1:2 Carrier (a healthy dog, but carrying the defect) which when mated to another carrier (or an affected dog) can produce affected offspring
iii.      2:2 Affected, a dog with CT.

This marker is a piece of DNA near to the gene in question not the actual gene so this test is not 100% accurate.

Conclusion: This test has to be used alongside biopsy results to give a fuller picture of the status of any dog.

b.      COMMD1 Gene Test. A defective form of this gene has been identified as the principle cause of CT in Bedlingtons. The cause is a deletion (a large piece of DNA from the COMMD1 gene is missing). A dog has two copies of the COMMD1 gene. Dogs can be:
1.      “Affected” dogs which have the disease. Two deletions are present.
2.      “Carriers” (a healthy dog, but carrying the defect) which when mated to another carrier (or an affected dog) can produce affected offspring. The dog has one deletion and one normal copy of COMMD1.
3.      “Clear” dogs (which are healthy and cannot produce affected offspring) Two normal copies of the gene.

The advent of this test means that the Marker Test is no longer necessary as the COMMD1 test is 100% accurate, the dog either has a deletion or not. However, as dogs which have no deletion have been found affected with CT it is not quite that simple. Another gene or factor not directly related to COMMD1 deletion must be involved and recent efforts are being made to track down the cause.

Conclusion: Biopsies still needed to be taken or affected Bedlingtons will continue to be produced and die from CT! Relying on the genetic tests available at present is not sufficient. If dogs that may be carrying a second gene are bred from then the numbers of affected dogs will increase and we will return to the level of disease seen previously. In the 1980s a large percentage of Bedlingtons were affected dogs. Even in 2004 a Kennel Club survey found 12.5% of Bedlingtons died of liver problems, though not necessarily CT.

A possible second Copper Toxicosis Gene

Last year a young Bedlington terrier had a routine blood sample prior to neutering. The ALT result was high. Further tests suggested a liver problem; therefore a liver biopsy was taken when the bitch was spayed. The biopsy diagnosed CT. This bitch was shown by DNA testing not to have the gene defect currently known to cause CT. It has been speculated that a second gene for CT is involved in this and several other anomalous results.

Since then more than thirty other Bedlingtons, some closely related, some not, have been blood tested to determine if this result was a one off. Sadly it was not. Some of the results could be considered normal, but a large number were abnormal. Whilst none of these dogs had ever shown any signs of being unwell, their blood results suggested liver problems, though not necessarily CT. Some have now been liver biopsied to see if CT is present. Although some proved not to be affected with CT, several were. In some of the others different causes were identified.

To get a better picture of what we may be dealing with we need to blood test as many Bedlingtons as possible, that have been DNA tested clear or carrier (1-1 or 1-2) for the known CT gene COMMD1 and should theoretically have normal liver function. This will hopefully determine whether there is a major problem in the breed or not and identify dogs which would benefit from liver biopsy immediately, which would be useful in four ways:

1. Early diagnosis would allow treatment, so that hopefully the dog will remain healthy.

2. To identify any CT related problems before breeding from a Bedlington and reduce the chances of producing affected offspring.

3. To help others with related Bedlingtons which may be carriers, as only affected dogs are likely to be identified even on biopsy, knowing more about closely related dogs would help predict carrier status in any biopsied normal dog which was genetically tested to be free of deletions.

4. For the good of the breed as a whole, eventually leading to identifying the cause of the anomaly i.e. identifying a possible second CT gene.

Samples from dogs with anomalies and related individuals should be made available for genetic sequencing. Dr Susan Haywood at the University of Liverpool is currently running the research project to investigate the anomalous results.

If you or your vet require more information or would like to discuss this further contact me:
Roger Bannister rb@lindenhousevets.com or 01379 783245 or
Dr Susan Haywood shaywood@tiscali.co.uk

The problem can be controlled with selective breeding. The National Bedlington Terrier Club is committed to this object.

In 2002 the three breed clubs agreed to form a Bedlington Terrier Health Group, consisting of two committee members from each club and one other who would represent the working side of the breed. The health group are in contact with researchers and geneticists and regularly report their findings to the clubs.

The Animal Health Test announces an updated DNA test for copper toxicosis in Bedlington Terriers. The research underlying this test was carried out jointly by a team led by Dr Mike Boursnell at the Animal Health Trust and at the University of Nottingham in the laboratory of Dr Paul Jones (Masterfoods Ltd.). This basic science was developed into a diagnostic test at the Animal Health Trust with funding from the American Kennel Club Canine Health Foundation.

Copper toxicosis is an hereditary disease in which failure of the liver to expel dietary copper leads to a build-up of this toxic metal causing illness and death. It is inherited as an autosomal recessive trait. As such, two copies of the defective gene, one inherited from each parent, need to be present before an individual displays clinical signs. Dogs with one copy of the defective gene and one copy of the normal gene (carriers), will not show clinical signs, but will be able to transmit the defective gene to their offspring. A reservoir of symptomless carriers exists in the population and when two carriers are bred, affected dogs may be thrown up in the litter. Unlike liver biopsy, DNA testing has the potential to pick out carriers as well as affected dogs so that all dogs bearing the defective gene can now be identified and the disease gene eventually eradicated from the population.

The previous DNA test detected changes in a DNA marker. Recent research has identified the mutation as a massive deletion of part of the DNA of a gene called COMMD 1. Studies at the AHT and the University of Nottingham have now identified the limits of this deletion, enabling us to devise a new diagnostic test. This research has been published as. "Characterisation of the COMMD1 (MURR1) mutation causing copper toxicosis in Bedlington terriers" (2005). O. P. Forman, M.E.G. Boursnell, B. J. Dunmore, N. Stendall, B. van der Sluis, N. Fretwell, C. Jones, C. Wijmenga, J. Rothuizen, B. A. van Oost, N. G. Holmes, M. M. Binns and P. Jones. Animal Genetics Vol 36 pp497-501.

The results from the new test will be definitive for this mutation and will identify the dog as CLEAR of, a CARRIER of or AFFECTED by copper toxicosis caused by the deletion in the gene COMMD1.

CLEAR: the dog has 2 copies of the normal gene and will neither develop copper toxicosis caused by the known deletion in the COMMD I gene, nor pass this mutation to its offspring.

CARRIER: the dog has one copy of the normal gene and one copy of the mutated COMMD 1 gene. It will not develop copper toxicosis caused by this mutation but if bred from will pass on the mutation to (on average) 50% of its offspring.

This test is an extension of the previous test offered for this disease, which used the DNA marker C04107. The new test is not subject to the element of doubt which existed in the old test. However, results from the old test are still valid. The Table below compares results from the old test with the results from the new COMMD1 deletion test.

C04107 Test	COMMD1 deletion test

1-1	clear
1-2	carrier or clear
1-3	clear
2-2	affected or carrier or clear
2-3	carrier or clear

Dogs with 1-2 status are most likely to be carriers, however, there is a small possibility that they could be clear of the disease gene. For dogs of 2-2 status, there is a small possibility that they could be carriers - and even, very rarely, clear of the disease gene.

Whilst the test is definitive for this mutation, it is possible that there are other genetic causes of copper toxicosis in Bedlingtons, as yet unidentified, which will not be detected by this test.

The DNA marker test using C04107 is still available, but by special arrangement only.

Samples should be submitted as cheek swabs, available free of charge from the AHT. Enquiries should be made to Mrs Vikki Lett (08700 509144 (telephone) or via e-mail to vikki.lett@aht.org.uk). Four-generation pedigrees are not required for the new test.

Samples for testing should be sent, together with a completed DNA Testing form and a cheque for £50-00 (including VAT) for each sample to Genetic Services, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk CB8 7UU.

*****************************************************************************************************

Notes for Guidance — Breeding and the role of Copper Toxicosis Test Result.

A number of different tests have been used to determine the copper toxicosis status of Bedlington terriers. The most recently available test; the 'DNA deletion test' aims to establish the presence/absence of a mutation within the COMMD1 gene. This mutation is the result of the loss of a considerable `chunk' of the gene - a deletion

To be categorised as 'affected', a dog must inherit the mutated gene from both parents, i.e. have two copies of the deletion. On the other hand, a dog that inherits a mutated gene from one parent will only have one copy of the deletion and will be categorised as a – ‘carrier'. A ‘normal (clear)' dog will have no deletions

The ‘ideal' mating would obviously be a ‘normal x normal', i e where both parents have tested 1.1 (linked marker test) or have been classified as `normal (COMMD1 - DNA deletion test). In this case there is generally no need to have the puppies tested -- they should all test as 'normal'

However. bearing in mind the need to maintain breed type and to keep the gene pool as wide as possible, it may be prudent, in some circumstances, to use a – ‘normal x carrier', or even a ‘normal x affected', mating. Such matings will result in puppies with the `carrier' status – in the case of a `normal x affected' mating ALL the puppies will be ‘carriers' whereas statistically only 50% of puppies from a `normal x carrier' mating will be 'carriers’. Obviously, puppies from either of these types of matings must he tested to determine their status. The breeder may do this prior to Sale or, alternatively, the breeder may advise the purchaser to have their puppy tested - this is particularly important if a puppy is likely to be used for breeding in the future.

A useful tactic is for the breeder to have the KC put "not to be used for breeding” endorsements on registration documents. Prospective owners can then be advised when collecting their puppy that if at any time in the future, they wish to use the dog for breeding they can contact the breeder, who will advise them and arrange for the endorsement to be rescinded.

Stress is considered to be a pre-disposing factor in the onset of clinical symptoms of copper toxicosis in dogs that have tested 'affected'. The stress associated with pregnancy and particularly with whelping, is important in this respect and must always be borne in mind.

A ‘carrier x carrier' or a `carrier x affected' mating can result in puppies that are ‘affected' i.e. have two deletions. Because of this, such a mating should he avoided

An `affected x affected' mating cannot be justified and should NEVER be contemplated

Likewise, for the long-term good of the breed, the use of untested dogs for breeding should be avoided.

Summary Points.
a. Bear in mind that the long-term aim is the elimination of the mutated gene from the breed.
b. Be aware of the need to maintain breed type.
c. Consider breeding policy well in advance in order to allow time to choose a suitable stud dog and for any testing to be done.
d. Be prepared to ask for advice.
e. It is incumbent on a breeder to inform a prospective purchaser of a puppy about its likely copper toxocosis status and to provide written information to support this. Likewise, stud dog owners should provide the relevant information.
f. At least one parent in a mating should be classified as ‘normal’. This will ensure that, at worst, the progeny will be carriers’, i.e. will only have one copy of the mutant gene (one deletion) and will not develop copper toxicosis.

Testing.
Samples for testing should be submitted as cheek swabs, These are available free of charge.
Currently, there are two centres that undertake testing for copper toxicosis,

a. The Animal Health Trust (AHT).
Enquiries should be made by telephone (08700 509144) to Mrs Vikki Lett or bye- mail (vikki.lett@aht.org.uk). Samples for testing should be sent to Genetic Services, Animal Health Trust, Lanwades Park, Kentford, NEWMARKET, Suffolk CB8 7UU. together with a completed DNA Testing form and a cheque for £50.00 for each sample.
Currently, only the DNA deletion test is offered although the linked marker test is still available by special arrangement.

b. VetGen (an American company).
Enquiries for test kits should be made by telephone (01234 851647) to Susan Santoriello. the VetGen liaison officer in the UK. Questions relating to costs, method of payment etc. can be answered at this time. The samples are posted direct to VetGen in America.
At the present time the cost, which obviously relates to the exchange rate, is lower than that charged by the AHT and the sample results are available quicker. Moreover. VetGen offer both the DNA deletion test and the linked marker test on a routine basis.

Note.
Research evidence suggests that some cases of copper toxicosis may be caused by another, as yet unidentified, gene. However, the COMMD 1 mutation is thought to be responsible for over 80% of cases and that the judicious application of this test will result in a progressive reduction in the incidence of copper toxicosis,

COPPER TOXICOSIS REVISITED : UNFINISHED BUSINESS by Susan Haywood, BVSc,PhD,MRCVS (July 2007)

Some of you who read this will know that I have a long association with Bedlington terrier owners and their dogs in our mutual search for the diagnosis and eradication of copper toxicosis(CT). Over the years I have learnt much about the presentation and pathology of this disease and also about things that puzzle you as dog owners when confronted by scientific ‘jargon’. I am grateful for this opportunity to review and perhaps to ‘clear the air’ with respect to some of these misconceptions. Also to give you a report of work in progress.

As long ago as 1984 when we first reported CT in an affected Bedlington terrier (1) I continued to monitor the livers of young Bedlingtons for this disease on the basis of a liver copper analysis (amount of copper in the liver) and histopathology (microscopic examination of the liver) in liver biopsies. With the identification of the DNA marker C04107 in close proximity to the CT locus by scientists (“the DNA marker test”) in both US (1997) and UK (1998) and despite the recognition that this was only 95% accurate, the situation was transformed and biopsies dried up to very small numbers and we thought our job was completed.

However to my surprise we continued to receive small numbers of liver biopsies from Bedlingtons which did not conform to the DNA marker test and which nevertheless had CT. It is important to emphasise that the disease in these 1-1 (theoretically “clear”dogs), 1-2 (theoretically “carrier”) dogs was indistinguishable from CT identified in dogs homozygous for the DNA marker allele 2-2 (theoretically “affected” dogs) (and later found to be lacking the MURR1/COMMD1 deletion – van de Sluis and co workers 2002) There was a wide spectrum of clinical presentation and pathological changes which ranged from a fatal acute (sudden onset) haemolytic crisis with jaundice often leading to death within several days and massive hepatic cell death to a cirrhosis (fibrous tissue being laid down in the liver affecting its function) and chronic (slow progressive) liver dysfunction with all stages in between! Liver copper levels ranged from 500 - 8000 mg/g dry weight. In some animals high liver copper occurred without clinical signs and yet others progressed to intermediate and seemingly stable levels. All these features were highly recognisable scenarios from our early work with the disease, if not fully understood.

A digression at this point is worthwhile: Unfortunately copper concentrations in biological tissues are measured in a variety of different units which can make for confusion. In the liver the gold standard is measured in micrograms (0.001G) of copper per Gram of DRIED tissue and is given as such mg/g dry weight DW. If WET weight is substituted then the copper (Cu) concentration is diluted by a factor of 3-4 and appears so much less (i.e. Cu DW=3-4xWW). A second misunderstood concept is the normal copper to be expected in the liver, this is given usually as<400 mg/g DW. In my own experience of well over 100 livers the normal range has been 20-385mg/g DW. The regulatory mechanisms do not allow deviation above this figure unless faulty in some way and so this is a strict upper limit. Above this level the liver begins to show signs of stress which may manifest as disease. Even at a copper concentration of 403mg/g DW I have once seen evidence of liver injury!

With accruing evidence of CT unassociated with DNA marker 2-2 we published our findings in 2001 (2) and hypothesised the existence of a 2^nd gene and slowly other groups in US and later Australia followed suit. Dr van den Sluis and I joined forces to try to identify this 2^nd CT gene and obtained KC funding in 2006. We needed more UK samples to make up our cohort due to some we had stored having become unavailable to us. In the autumn of 2006 I became aware of a young dog identified as CT affected by a routine blood (ALT) test followed by liver biopsy and the vet responsible and myself wrote to the Veterinary Record in an attempt to identify other dogs likewise affected by offering the inducement of reimbursement for blood tests and free liver biopsies (3).

A second digression here: Some owners have queried as to whether a needle biopsy would not be preferable to the wedge biopsy we prefer on the grounds that the former would be much less traumatic for the dog and as such more ‘attractive’ to owners. The simple answer to that is that the very few fatalities that have occurred following biopsies have been as a result of needle biopsies on account of the ‘blind’ penetration of a blood vessel.

Following our request I was surprised to get a rapid response and identified several dogs with raised liver enzymes and abnormal BAST (bile stimulation test). Unfortunately at the present only a very few of these dogs have gone on to have a liver biopsy to assess whether or not they had CT and in these few cases I was able to report causes other than CT which were responsible for the abnormal blood tests.

To expand a little on the blood tests performed: Alanine amino transferase (ALT) is a liver enzyme released into the blood stream from damaged liver cells and together with other liver enzymes (GLDH and AST) is a very sensitive indicator of early liver disease. Whereas the bile stimulation test (BAST )is a test of a particular aspect of liver function and early indicator also of liver disease. Neither test is a specific indicator of CT and liver cell injury can be caused by a wide variety of insults such as bacteria and viruses which may gain access to the blood stream or bile ducts from time to time and may lead to either to a temporary disturbance or more progressive disease. Alternatively these tests may indicate a hormonal disturbance such as Cushings disease or Diabetes which can have serious consequences.

From this it is important that owners do not jump to conclusions that a dog with an abnormal blood profile has CT and put the dog on a low copper diet. Copper is an essential element and deficiency can have deleterious effects on general well being. (Concern is currently being expressed in human health that supposedly adequate dietary copper is not so and over the long term can have deleterious effects on brain and locomotor function - the same might be so for dogs). Far better to identify the cause of the liver disturbance to be able to give specific treatment as opposed to non specific treatment for liver damage and monitoring the results by blood test, which can only be done by further tests including liver biopsy.

This now is the present position. I can still offer owners reimbursement for blood tests of their DNA marker 1-1, 1-2 dogs (but would be happy if they repeat what others have done and bear the cost of the initial blood test themselves). Further I am able to offer a free liver biopsy to owners of dogs which have an ALT >200U/L which would include copper analysis and a histopathological examination.

I do urge Bedlington owners to take up this offer. It is a unique opportunity to identify dogs with a 2^nd CT gene and remove them from the breeding pool before the gene becomes widely disseminated. There is a limited time available before I report to the Kennel Club of the success or otherwise of my search for dogs with the putative 2^nd CT gene. If I do not receive the necessary number of samples before the end of the year I shall foreclose on this research and my association with the Bedlington terriers and their owners will cease. I do hope this will not be the case and that owners and breeders of Bedlington terriers can rise to the challenge so that in the near future together we may be able to say ‘mission accomplished’!

1. Kelly DF, Haywood S & Bennett AM (1984) Copper toxicosis in Bedlington Terriers in the United Kingdom. J. Small Anim. Pract. 25, 293-298

2. Haywood, S., Fuentealba, I.C., Kemp, S.J., Trafford, J. (2001) Copper toxicosis in the Bedlington terrier: a diagnostic dilemma. J. Small Anim. Practice. 42,181-185.

3. Haywood S and Jones J (2007) Hunt for a second copper toxicosis gene. Vet Rec 160 (21) 743

Bedlington Terrier Health Group Chairman: Mr D Taylor. Tel: 01909 515815 Email: taylor.david@virgin.net

National Bedlington Terrier Club Secretary: Mrs A M Emsley. Tel: 01274 788773 Email: secretary@bedlingtons.org.uk

Bedlington Terrier Association Secretary: Mrs J Hurley Tel: 01980 882600 Email: Jacqui@fralex.co.uk

Midland Bedlington Terrier Club Secretary: Mrs D Owen. Tel: 0115 9816018 Email: bisbee@btinterent.com

Copper Toxicosis

Signs of disease

Treatment of an ill dog 1. Acute hepatitis requires hospitalization by your vet for intensive care. 2. Chronic disease. As well as the preventative measures mentioned above antibiotics, steroids and other drugs may be needed.

Tests

A possible second Copper Toxicosis Gene

Treatment of an ill dog
1. Acute hepatitis requires hospitalization by your vet for intensive care.
2. Chronic disease. As well as the preventative measures mentioned above antibiotics, steroids and other drugs may be needed.