A new study was published last week, The effect of inbreeding, body size and morphology on health in dog breeds (link below), which included a bit of data for the Mudi.
Health data was collected from Agria pet insurance, mostly based on dogs insured in Sweden, while “the heterozygosity values were obtained from worldwide sample collection centered in the Scandinavian countries”, using DNA samples sent to MyDogDNA™/Optimal Selection™/(both products of Wisdom Health). They refer to the level of inbreeding used in the study as “genotype-based coefficient of inbreeding”, also known as genetic coefficient of inbreeding, or GCOI.
Number of
Mudi used in the study = 141
Heterozygosity
minimum = 27.6
Heterozygosity
median = 40.4
Heterozygosity
maximum = 47.6
Adjusted
inbreeding level = 0.096 (9.6%)
Mid range body
weight was calculated using AKC breed standards: 10.66 kilos (FCI = 10.5 kilos)
Breeds were
sorted into groups based on FCI grouping = No group was listed for the Mudi (although
it is listed as belonging to Group 1 in FCI)
Health
Insurance Count = none listed
Morbidity =
none listed
Brachycephaly
yes or no = not listed (the Mudi is not brachycephalic)
The Mudi did
not have any health insurance data listed in the data sets, which leaves one to
assume they did not have any health data.
The missing health data is not due to the low sample size of Mudis as
there were 85 other breeds with a lower count that did have health data (85
breeds have 141 or less dogs and have insurance, morbidity, brachy designation
and FCI group information). As a comparison, 222 Pumis and 36 Pulis, were also
included in this study and they had insurance, morbidity, brachy data and FCI group
listed.
The only mention of the Mudi in the study can be found in this one sentence and Dataset 1:
“The breeds with low inbreeding included recent cross breeds (Tamaskan Dog, Barbet and Australian Labradoodle) and landrace breeds (Danish-Swedish Farmdog, Mudi and Koolie), supporting the notion that high inbreeding is a result of closed stud books or small numbers of founders or both.”
The authors mention landrace breeds once more: “The breeds with the lowest levels of inbreeding were mostly landrace breeds or breeds with recent cross breeding.”
The study states that low inbreeding is less than 10%, the Mudi is 9.6% in their study, if 9.6 is rounded up, it is no longer low, this rounding note will be of some importance later in this post. From the study: “Strikingly few breeds (N = 12) had low inbreeding values (< 0.10)”.
They write
that the Mudi is a landrace breed and I agree with that, but so are the Pumi
and the Puli. But the Pumi/Puli
inbreeding levels are not below 10%, they are: Puli = 13.6% and the Pumi = 12.1%,
according to their DNA sampling.
They infer that
the low inbreeding level in the Mudi is due to the stud book being kept open or
from having a high number of founders. I
disagree with the high number of founders existing in the Mudi, it is simply
not the case and several of the original founder lines have already been lost,
while others were in critical danger of extinction the last time I did a Mudi founder
study.
Yes the stud
book is still open in Hungary and therefore other FCI countries, but this is
not the case already in Canada (CKC stud book has been closed since 2015) and
eventually the USA as the stud book closing clock will start to tick January 1,
2022, as that is when the Mudi will become a fully recognized breed with AKC, which
means only 3 full generation pedigree Mudis can be registered. The AKC will leave a window open until 12/2026
for some further registration of less than 3 full generation pedigreed Mudis,
via a domestic registry solution, but the details of which domestic registry
they will allow are still undetermined, which is quite worrisome. It is also unknown if they can extend this
window after 2026. This means the Mudi breed
will eventually experience an interesting trial between USA/Canada and the rest
of the world in terms of inbreeding levels.
Having an
open stud book is only valuable if the dogs that are being brought in are truly
representative of new or lost lines and the July 23, 2021 Mudi Directions post,
The Neglected Hungarian Treasure, already explained how that has not been the case
for quite a long time now.
So how has
the Mudi kept inbreeding levels low? Are
they actually low? Good questions I will
research answers to when I have a chance.
I used to publish periodic reports about the levels of inbreeding, but
no one seemed to care, so I stopped wasting my time.
I do not
disagree that inbreeding levels are connected to health, reproduction and
longevity in animals, as many studies have shown it. As for the other breed data used in the
study, I have no quarrel as I am not familiar with their status.
However, inferring
the Mudi is healthy because it has a lower level of inbreeding, is not a
correct assumption. The lack of supporting
health insurance data is also not an indicator of the health status of the
Mudi. The Mudi data used in this study
is not relevant to the purpose of the study.
Regardless
of my opinion, I urge you to read the entire study and make your own conclusions.
INBREEDING
VALUES ARE NOT CREATED EQUAL
I have been
recording the Embark GCOI Mudi data for quite a while. I also tracked the Wisdom/MyDog/Optimal
Select GCOI, but there was a problem with the information they provided. Wisdom does not give a usable GCOI, they give
a percentage of heterozygosity (photo example below). Therefore, it is not
comparable to my pedigree COI, nor the GCOI that Embark gives which is based on
homozygosity. I can compare the GCOI of
Embark to my pedigree database, and my pedigree COI is surprisingly close to Embarks GCOI in most cases I have compared thus far (50+).
Why do I do this? It’s more than
just curiosity or data collecting, I want to check the reliability of the
pedigree COI I give. In many cases Embarks GCOI and my pedigree COI are often
within 1-4%. The difference can be due to rounding (I don’t round the COI’s I calculate)
and the number of empty spaces on the pedigree.
In a few cases it can be from less common things such as parents being
incorrectly reported on pedigrees, accidental breeding with multiple sires, and
other breeder/pedigree record mismanagement.
It should be
noted that Embark uses the rounding principle with their GCOI’s, for example,
if the GCOI is 5.7, they round it up to 6%.
I assume they also round down.
Embark has
DNA tested more than 100 Mudis, possibly more than 150. And these are not just Mudis in the USA or Scandinavia,
but Mudis from many parts of the world. I
have just now asked Embark if they can tell me how many Mudis they have tested,
if I get a response, I will update this post.
As indicated
on a recent Embark results report (see photo at the top of this post), the range of GCOI in the
Mudis tested with Embark is between 1% and 30%. What the Mudi breed average is, I cannot tell from
the graph. It appears that the bulk of Mudis tested are in the 6-10% range, if
the bars indicate that by their height.
Of course,
much depends on the gene set each DNA lab is using as a baseline indicator of
homo-heterozygosity for a breed and most likely Wisdom and Embark are not using
the same gene set for comparison. Several Mudis have been tested by both labs, with the test
results sometimes showing differences, which further indicates testing
parameters are not the same.
LET’S
HERD SOME DUCKS TO ROWS
Even with
all the data both labs offer, it is still unknown how representative it is of
the Mudi breed in actuality, as a whole. That is, does their GCOI average speak
for the whole breed? Or due to the
number and relationship of Mudis tested, is the GCOI average actually much
higher or lower?
I had an idea
today to see what kinds of statistics I can make using the data I constantly
collect. I decided to compare the GCOI
of Embark, to my pedigree COI, to health issues affecting the tested dogs. I also
used the rounding function on my pedigree COI to be more in line with the Embark
GCOI.
Number of
Mudis in my database with Embark GCOI = 50
Embark GCOI
range and average of these 50 Mudis: 2-29%;
Average GCOI: 11%
USA living
Mudis (40) GCOI = 11%; Canada + Europe living Mudis (10) GCOI = 11%
Pedigree COI
range and average of these 50 Mudis: 0-21%;
Average COI: 8%
Year of
Birth/Age range of these 50 Mudis: 2008 to 2021; Aged 13 to less than 1 year
28 Mudis are
aged 2 or younger, this means health data is likely not available for these
Mudis yet
Country
these 50 tested Mudis live in: USA = 40; Canada, UK, Austria, Hungary, Poland =
10
How many of
the 50 Mudis produced a litter: 12, between 1 and 4 times
LITTERMATE
SPREAD IS NOT FOR BREAD
What was
also interesting in this GCOI data, is the effect of littermate spread.
Among this set of 50 GCOI tested Mudis, there
are 8 litters containing two or more tested littermates. The range of the littermates GCOI’s I call
littermate spread, the gap is the difference between highest and lowest GCOI of
the tested littermates. For example, the
largest set of littermates in this group of 50 is 6 puppies. Their GCOI’s were 6, 8, 10, 11, 12 (two
puppies had 6% each). The spread is 6-12%, with a gap of 6%, which is equal to
a 50% difference between the 6% and 12% littermates. That is a significant
difference. However, it is not
unexpected for a gap this large to occur in lower GCOI litters. As the GCOI level increases, it is expected
the gap between littermates will decrease.
That is, when the GCOI for a litter reaches the 12.5% and higher range,
the gap between littermates GCOI’s should narrow. Why? Because as the GCOI level rises, the genes
shared between puppies in a litter become more and more similarly shared, that
is, they have less variation between them, which allows a more similar GCOI. Less variation in genes creates both good and
bad points for a breed, but that is a topic for another post.
In case you
are still not sure what littermate spread is and why it is important to
understand, think of it this way: the lower the GCOI for a litter, the greater
the chance the GCOI for each puppy in the litter to have a very different GCOI from
the other puppies in the litter – there can be a big range of GCOI’s among the
littermates, this is not unexpected.
As the GCOI
level increases, the diversity decreases among the littermates making the differences
between puppies smaller – thereby equalizing the GCOI more closely among
littermates.
GCOI level
is low = higher gap between GCOI’s in littermates
GCOI level
is high = lower gap between GCOI’s in littermates
The gap for
the 8 groups of littermates found in this group of 50 Mudis, ranges from 0% to
12%, with 5 litters having a 1-4% difference in their GCOI. The other 3 litters had a gap of 6, 7 and
12%.
As time goes
on, it will be interesting to see more of these littermate spreads and if they
can be correlated to health issues or longevity between littermates.
HEALTH
ISSUES AND GCOI
Now for the
list you’ve probably been waiting for most.
The following health issues affect these 50 Embark tested Mudis / how many are
affected / and the GCOI. Order is alphabetical.
Allergy / 2 /
13%, 15%
Anal Gland
Issue / 1 / 7%
Bite: 1
over, 1 under / 2 / 9%, 14%
Distichiasis
/ 1 / 7%
Elbow
Dysplasia / 1 / 7%
Epilepsy / 1
/ 9%
Hip Dysplasia
/ 1 / 14%
Patella
Luxation / 2 / 9%, 23%
Teeth Issue
/ 1 / 9%
Testicles,
Missing / 1 / 9%
Thyroid / 1
/ 13%
Trichiasis /
1 / 23%
12 health
issues in 15 Mudis, GCOI range: 7 – 23%
Percentage
of 50 Mudis affected: 30% (15 affected from 50)
Number of
affecteds with 10% GCOI or above: 7
Number of
affecteds with 9% GCOI or lower: 8
Of course, this
is a very small study using only 50 Mudis.
However, a 30% rate of health issues is not small. It does not appear to be biased towards high
or low levels of inbreeding as 7 vs 8 affecteds is not a significant difference. Perhaps with more Mudis a difference might be
seen.
I do hope to
expand this study, however I will need cooperation from the Mudi owners that
have done Embark DNA testing. Please
consider sharing your Embarked Mudis results with me. I will not give subject names to the data, it
is anonymous as you can see, and it will always be that way.
If you would
like to see the comparison chart between the Embark GCOI and my pedigree COI
for these 50 Mudis, I can add it to this post, send me a message that you would
like to see it included.
I would like
to thank the 49 Mudi owners and breeders that shared their Embark data with me as they made
this small starter study possible. The
50th Mudi is mine.
If you have
any questions, or other statistics or data you would like to see, just ask!
REFERENCES:
Embark report notes, in reference to the chart at the top of this post:Genetic Diversity and Inbreeding
Inbreeding is a measure of how closely related your dog's
parents were. Dogs that are less inbred tend to live longer, healthier lives.
Coefficient
of Inbreeding (COI)
Genetic COI measures the proportion of your dog's genes that
are identical on the mother's and father's side. The higher the number, the
more inbred your dog is.
Wisdom DNA Inbreeding Level Report, photo below:
ARTICLE LINK:
The
effect of inbreeding, body size and morphology on health in dog breeds
https://cgejournal.biomedcentral.com/articles/10.1186/s40575-021-00111-4
