Copper Toxicosis

Belle Starr's Battle:

 After a long battle we lost our precious Belle Starr.  She truly was a  unique Labrador Retriever.  She was smart, loved her people, the best dog mommy ever, sweet, and was my companion.  She carried a beautiful curly coat, was stocky in build, and had the cutest face ever.  She got along well with the other dogs and loved her Shadow. It was heart breaking to lose her, but we have her little girl Sophia whom we kept from her last litter.  After the diagnosis, we now know why she battled her health and had problems with her delivery.  We are so fortunate to have her pups that carry on her legacy.  Thank you Belle Starr for what you have given us.  You are missed by all.  Humans and Fur Family

They believe that she died from Copper Toxicosis.  This can be a genetic factor or also could be environmental.  She was the second dog who recently died here in this area.  The other was also a young female who had delivered pups 5 weeks before her death. Belle Starr hung in there as best she could until her litter was 10 weeks old.  She first started with signs of sickness when they turned 4 weeks old. Copper Toxicosis tends to hit female Labradors between the ages of 3 and 6.  I am attaching a paper that explains the genetic copper toxicosis.  Many vets haven’t even heard of this to my surprise. They say it is a rare condition, but I wonder how rare for if they don’t know much about it at this point.  I have had many conversations with genetics from a couple of DNA testing centers.  The one problem I have came across is that I was not able to have Belle Starr’s DNA test done for Copper Toxicosis.  The vet who did her second surgery was also the vet that diagnosed the other lab with this disease.  The other lab that passed away from this, they had done the test and she came back with the genetic disposition for CT.  After Belle Starr’s surgery they took a biopsy of her liver and were going to run several different tests on her.  To my unknowing they cancelled the tests when she passed on the next day.  Their  thinking was to save Fred and I lots of money ($3,000).  A week later when I called to check on her tests results was when I found out that they hadn’t run the tests.  I talked to the vet for a lengthy time and he apologized several times as making a mistake.  I stated that the only test I was interested in was the genetic test for CT.  Belle Starr and and this other young female had the same issues: (They had drained 2 liters of fluid from both girls, they drank lots of water, and both girls had very abnormal livers.  They were both about the same age and each just had a litter of pups.)  So my next step was to have Shadow and Sophia tested and I did Cassiopeia as well.  Sophia’s tests came back as carrying the 2 ATP7A which is the “good” mutation and both of her ATP7B genes were normal. So this tells me that Belle Starr had to have at least one good ATP7A and at least one of the ATP7B had to have been normal.  Shadow came out with the “good” mutation on his X chromosome, and both of his ATP7B are normal. So genetically Belle Starr’s and Shadow’s pups should be fine.  If ever in doubt you can order a DNA test from Paw Prints to check for CT.  I haven’t gotten the results back from Hawk yet, but will only contact you if I feel there is a problem. Now the other factor is environmental.  This is the food and water intake.  I checked the food, but don’t see copper listed.  Also our bodies need some copper and zinc helps control the levels.  My next step is to have our water tested for copper levels. So this is a very complicated aspect of genetics and how our bodies work.  And I learned that humans as well can have copper toxicosis.  Interesting…  One of the signs that dogs show with this is they stop eating.  Belle tried to eat, but her body wasn't digesting it and then she would end up throwing up.  Another thing that I noticed was that she was drinking lots and lots of water.  That had started before she even got pregnant with the last litter.  I had her tested for diabetes along with her thyroid tested and all other tests.  Her bloodwork always came back normal.  The thing is that copper toxicosis doesn't show up in blood work.  The more you read about it the more mysterious it is. The good news is, if they are diagnosed at an early stage, there is medications that can help the situation and they can live a long life. 

 

I hope I have answered any questions you might have had about Belle Starr’s condition.So

as for Belle Starr’s pups go, they shouldn’t have any issues with CT. 


 

CT - Copper Toxicosis (Labrador Type)

 

Copper Toxicosis in the Labrador Retriever is similar to the disease found in other breeds in

that it manifests itself as a build up of copper in the liver of affected animals. Unlike the

disease seen in Bedlington Terriers, the Labrador form is not inherited as a strictly recessive

trait. The mutant genes have an additive affect, so one copy of the mutation increases

copper levels, and a second copy when present increases levels even further. This affect is

somewhat more extreme in females than in males. We know very little of the frequency of

the disease itself. It is an uncommon diagnosis, but that may be due to the fact that it is a

relatively late onset disease (middle aged or older dogs) and may have variable, difficult

to diagnose, symptoms. The mutation responsible for copper toxicosis in Labradors has

been identified by researchers at the University of Utrecht. Our test is based on their

findings.

The primary cause of copper toxicosis in Labrador Retrievers is a mutant form of ATP7B. Dogs that inherit two normal versions of the gene (one from each parent) will have normal levels of copper in their livers. Dogs that inherit one normal copy and one mutant copy will have somewhat elevated levels of copper in their liver, while those that inherit two mutant copies will have the highest levels. Generally speaking, it is those dogs with two mutant copies that are at the highest risk for the disease, although there have been some dogs reported that only had one copy and still had dangerously high copper levels.

The second gene involved in the Labrador disease is a mutated form of ATP7A. This is a "good" mutation which helps minimize the accumulation of copper in the liver. Since this gene is located on the X chromosome, the mutation is inherited as a sex-linked recessive. Males inherit only a single copy of the gene either normal or mutant from their mother, while females inherit two copies, one on the x chromosome of each parent. Therefore, males only need to inherit one copy of the mutant gene to help with their copper levels, while females need to inherit two. This is why females are more commonly diagnosed with the disease than males.

Since the frequency of the ATP7B CT mutation is relatively high, we do not recommend breeding completely away from it, but rather avoiding pairings that might produce two-copy offspring.

 

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