Poodle Forum banner
1 - 20 of 24 Posts

·
Registered
Joined
·
8,520 Posts
Discussion Starter · #1 ·
I found this on Facebook, where Barbara is a huge source of information about poodle genetics.

***
Barbara Hoopes

Everyone keeps asking me about Merle poodles, so I am summarizing literature research I did below. I am making this post public so it can be shared. I am a professor of Molecular Biology at Colgate University, have a PhD in Biochemistry from Harvard University and do molecular genetics research in dog body size and some coat colors in dogs. In addition I am a breeder of toy poodles.

Merle poodles have only been observed for the last two decades. Merle poodles must have resulted from the introduction of the dominant Merle mutation from a Merle containing breed, probably a herding breed or breeds. Merle does not occur in purebed poodles naturally. The arguments for natural Merle in poodles don't hold up in the light of what we know about Merle and are discussed below.

False claim 1. "Merle has been present forever, but was hidden in white dogs." Yes, Merle can be “hidden” in white and cream dogs. However, extensive crossing of white and colored poodles since 1900 has occurred--this would have “unmasked” hidden Merle early in breed history, since it is a dominant mutation (see reference 1). This was not observed.

False claim 2. "The Merle mutation simply arose spontaneously in poodles recently." No. The Merle mutation is very unusual at the DNA level, and the Merle found in poodles is identical to that found in herding breeds. It is not possible that the exact same unusual mutation occurred more than once in different breeds of dogs (see reference 2).

False claim 3. "Merle poodles arose from 'cryptic Merles' present in the breed." No. Although “cryptic Merles” that do not show Merle coloring exists in Merle containing breeds, this cannot explain the sudden appearance of Merle Poodles. Active Merle can produce “cryptic Merle”, due to the unusual nature of the mutation, but the reverse has NEVER been observed (see reference 3). In addition this would predict a lot of cryptic Merles in non-Merle poodles, which are not observed.

Since these arguments are not supported scientifically, the most reasonable conclusion is that Merle must have been introduced from a different Merle containing breed, which means that Merle poodles have pedigrees that were falsified at some point.

Why is Merle "bad"? Well in addition to falsified pedigrees, Merle carries with it health risks. Merle dogs have a higher risk of deafness than non-Merle dogs when there is loss of pigment on the head, and dogs containing two copies of the Merle mutation (“double Merles”) not only have an even higher risk for deafness but a risk of improper eye development and blindness (see reference 4).

This is bad for poodles, where a lot of dogs are white and cream, where Merle can be "hidden". Breeding a “hidden Merle” to a Merle dog will result in the production of “double Merles”, which will have a significant risk for hearing and vision loss. Genetic testing to detect the presence or absence of Merle in colors where Merle would be hidden would be required to prevent this unfortunate result.

1 Mackey J. Irick, Jr. “The New Poodle 6th Edition”, Chapter Howell Book House, New York, NY 1986
2 Clark, L.A., Wahl, J.M., Rees, C.A. and K. E. Murphy (2006). Retrotransposon insertion in SILV is responsible for merle patterning of the domestic dog. Proc Natl Aca Sci USA 103(5):1376-1381.
3 Langevin, M., Synkova, H., Jancuskova, T., and S. Pekova. (2018). Merle phenotypes in dogs—SILV SINE insertions from Mc to Mh. PLoS One 13(9):e0198536
4 Strain, G.M., Clark, L.A., Wahl, J.M., Turner, A. E. and K.E. Murphy (2009). Prevalence of deafness in dogs heterozygous or homozygous for the merle allele. J. Vet. Intern. Med. 23:282-286.
 

·
Registered
Joined
·
10,468 Posts
Excellent post, very clear, thanks for finding and posting this.
 
  • Like
Reactions: Deere and Dechi

·
Registered
Joined
·
2,767 Posts
I found this on Facebook, where Barbara is a huge source of information about poodle genetics.

***
Barbara Hoopes

Everyone keeps asking me about Merle poodles, so I am summarizing literature research I did below. I am making this post public so it can be shared. I am a professor of Molecular Biology at Colgate University, have a PhD in Biochemistry from Harvard University and do molecular genetics research in dog body size and some coat colors in dogs. In addition I am a breeder of toy poodles.

Merle poodles have only been observed for the last two decades. Merle poodles must have resulted from the introduction of the dominant Merle mutation from a Merle containing breed, probably a herding breed or breeds. Merle does not occur in purebed poodles naturally. The arguments for natural Merle in poodles don't hold up in the light of what we know about Merle and are discussed below.

False claim 1. "Merle has been present forever, but was hidden in white dogs." Yes, Merle can be “hidden” in white and cream dogs. However, extensive crossing of white and colored poodles since 1900 has occurred--this would have “unmasked” hidden Merle early in breed history, since it is a dominant mutation (see reference 1). This was not observed.

False claim 2. "The Merle mutation simply arose spontaneously in poodles recently." No. The Merle mutation is very unusual at the DNA level, and the Merle found in poodles is identical to that found in herding breeds. It is not possible that the exact same unusual mutation occurred more than once in different breeds of dogs (see reference 2).

False claim 3. "Merle poodles arose from 'cryptic Merles' present in the breed." No. Although “cryptic Merles” that do not show Merle coloring exists in Merle containing breeds, this cannot explain the sudden appearance of Merle Poodles. Active Merle can produce “cryptic Merle”, due to the unusual nature of the mutation, but the reverse has NEVER been observed (see reference 3). In addition this would predict a lot of cryptic Merles in non-Merle poodles, which are not observed.

Since these arguments are not supported scientifically, the most reasonable conclusion is that Merle must have been introduced from a different Merle containing breed, which means that Merle poodles have pedigrees that were falsified at some point.

Why is Merle "bad"? Well in addition to falsified pedigrees, Merle carries with it health risks. Merle dogs have a higher risk of deafness than non-Merle dogs when there is loss of pigment on the head, and dogs containing two copies of the Merle mutation (“double Merles”) not only have an even higher risk for deafness but a risk of improper eye development and blindness (see reference 4).

This is bad for poodles, where a lot of dogs are white and cream, where Merle can be "hidden". Breeding a “hidden Merle” to a Merle dog will result in the production of “double Merles”, which will have a significant risk for hearing and vision loss. Genetic testing to detect the presence or absence of Merle in colors where Merle would be hidden would be required to prevent this unfortunate result.
Thanks so much for a clear presentation of this issue.
 

·
Super Moderator
Joined
·
5,293 Posts
Barbara is a fount of information. It would be really interesting to see if unique genetic markers in merle poodles could be found in certain herding dog lines. Probably a hugely expensive project, though.
 

·
Registered
Joined
·
685 Posts
Merle anything makes me nervous. Seen too many merle dachshunds bred together with horrific results.
I saw what looked like an oversized merle french bulldog....

I don't know what terrifies me more that someone had the audacity to breed that or trying to imagine what the owners must have paid for that pup...
 

·
Premium Member
Joined
·
25,464 Posts
This should be a sticky!
 
  • Like
Reactions: Dechi

·
Premium Member
Joined
·
25,464 Posts
Thank you again Dechi for hving found and posted this and to cowpony for making sure it will always stay high on the list of discussions on this topic. We have talked about this topic many many times and it will be great to have an authoritative and evidence driven way for people to find answers to their questions and concerns.
 
  • Love
Reactions: Dechi

·
Registered
Joined
·
633 Posts
My poodle pup was the only sable in the litter. The rest were merles. I dont want to breed from him (I usually rescue but have been looking for about 8 years with no success as they go so fast) but am guessing that he would carry the merle gene.

When we first got him at 12 weeks and now at nearly 5 months.
Vertebrate Water dog Carnivore Fawn Dog breed
Dog Water dog Dog breed Carnivore Fawn
 

·
Registered
Joined
·
10,468 Posts
My poodle pup was the only sable in the litter. The rest were merles. I dont want to breed from him (I usually rescue but have been looking for about 8 years with no success as they go so fast) but am guessing that he would carry the merle gene.
Cute puppy

Have you had your puppy tested for Multidrug Resistance Mutation (MDR1)? It’s is a very serious problem found in many herding breeds. Many common drugs prescribed for dogs, such as heart and tick medication, seizure treatments etc. if prescribed for a dog with MDR1 could make it sick or dead. Your dog may or may not carry the merle gene but it could carry MDR1 and should be tested for it.

It’s not a mutation found in poodles so if you told your vet your puppy is 100% poodle they wouldn’t recommend testing.

 

·
Registered
Joined
·
633 Posts
I was told by the people who bred him that he is toy x miniature. Mum being the toy (strange). She was lovely. Black with a kind of brindle pattern on her. Very dainty and gentle. I didnt see dad but was told that he was also black.

Who knows if he is oure poodle, he looks like he is, but I am no expert. I will let my vet know about his merleness (!) just in case.
 

·
Registered
Joined
·
10,468 Posts
I was told by the people who bred him that he is toy x miniature. Mum being the toy (strange). She was lovely. Black with a kind of brindle pattern on her. Very dainty and gentle. I didnt see dad but was told that he was also black.

Who knows if he is oure poodle, he looks like he is, but I am no expert. I will let my vet know about his merleness (!) just in case.
Tulsi, with a history of merle, your dog is not pure poodle. Your dog may look 100% poodle but you and your vet should be aware that your dog is not pure poodle - it's got a herding breed mixed in - maybe grandmother or grandfather. That is why I recommend you get your dog tested MDR1.
 

·
Registered
Joined
·
633 Posts
Oh thank you. Will definately explain/discuss with my vet.

I love herding breeds, recently had my soul mate collie pts ... cancer.

Shame about byb and the recent merle craze.

Couch Furniture Vertebrate Blue Comfort
 

·
Registered
Joined
·
633 Posts
Thank you Liz. I got Rusty on the 5th of June and Tass (collie) was diagnosed with cancer 3 days later ... Rusty respected her and always went to her for comfort. She tolerated him!
 

·
Registered
Joined
·
2,767 Posts
Tulsi, with a history of merle, your dog is not pure poodle. Your dog may look 100% poodle but you and your vet should be aware that your dog is not pure poodle - it's got a herding breed mixed in - maybe grandmother or grandfather. That is why I recommend you get your dog tested MDR1.
Tulsi, this is really important - some herding breeds have a serious issue with certain medications (ivermectin is one). I agree with Skylar that you should get your dog tested and let your vet know what breeds are behind it.
 

·
Registered
Joined
·
10,468 Posts
Tulsi, I’m so sorry for your loss. Rusty was lucky to be welcomed into your family by Tass. What a sweet collie.

My daughter has a gorgeous roughy collie and she had to get dog tested, that’s why I’m aware of this genetic test.
 
  • Like
Reactions: Tulsi

·
Registered
Joined
·
4,039 Posts
Cute puppy

Have you had your puppy tested for Multidrug Resistance Mutation (MDR1)? It’s is a very serious problem found in many herding breeds. Many common drugs prescribed for dogs, such as heart and tick medication, seizure treatments etc. if prescribed for a dog with MDR1 could make it sick or dead. Your dog may or may not carry the merle gene but it could carry MDR1 and should be tested for it.

It’s not a mutation found in poodles so if you told your vet your puppy is 100% poodle they wouldn’t recommend testing.

Cute puppy

Have you had your puppy tested for Multidrug Resistance Mutation (MDR1)? It’s is a very serious problem found in many herding breeds. Many common drugs prescribed for dogs, such as heart and tick medication, seizure treatments etc. if prescribed for a dog with MDR1 could make it sick or dead. Your dog may or may not carry the merle gene but it could carry MDR1 and should be tested for it.

It’s not a mutation found in poodles so if you told your vet your puppy is 100% poodle they wouldn’t recommend testing.

Skylar, decades ago, I remember reading a research article that identified MDR1 as being present in a very few white Standard Poodles. I had been looking for information because my white male Standard became very ill after being exposed to Ivermectin. I had Australian Shepherd owning friends and they were quick to tell me to research MDR1. I thought the article came out of Washington state, but my memory isn't as good as it used to be. I thought it was interesting that only white Standards were noted. Also, for what it's worth, my male did really well on his herding instinct test.
 
1 - 20 of 24 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top