Article: Inbreeding and health

[sandgrubber]

https://cgejournal.biomedcentral.com/articles/10.1186/s40575-021-00111-4

 

First article I've seen that relates a DNA based measurement of genetic diversity to health outcomes.   Raises questions about the mantra "improving the breed".

 

Impressive dataset. AND NOT BEHIND A PAY WALL

 

Extracted from the article

Abstract

Background

Dog breeds are known for their distinctive body shape, size, coat color, head type and behaviors, features that are relatively similar across members of a breed. Unfortunately, dog breeds are also characterized by distinct predispositions to disease. We explored the relationships between inbreeding, morphology and health using genotype based inbreeding estimates, body weight and insurance data for morbidity.

Results

The average inbreeding based on genotype across 227 breeds was F_adj = 0.249 (95% CI 0.235–0.263). There were significant differences in morbidity between breeds with low and high inbreeding (H = 16.49, P = 0.0004). There was also a significant difference in morbidity between brachycephalic breeds and non-brachycephalic breeds (P = 0.0048) and between functionally distinct groups of breeds (H = 14.95 P < 0.0001). Morbidity was modeled using robust regression analysis and both body weight (P < 0.0001) and inbreeding (P = 0.013) were significant (r² = 0.77). Smaller less inbred breeds were healthier than larger more inbred breeds.

Conclusions

In this study, body size and inbreeding along with deleterious morphologies contributed to increases in necessary health care in dogs.

Edited December 3, 2021 by sandgrubber

[Redsonic]

I enjoyed reading this article; thanks for posting. Buried in the text is a link to a chart of inbreeding coefficients calculated for each breed using genotype (not pedigrees). Quite variable depending on individual breed, but overall far too high. The average for the breeds tested was 0.249, which is equivalent to a brother-sister mating. I have attached this chart below, taken from Dataset 1 in the article linked to above and here: The effect of inbreeding, body size and morphology on health in dog breeds

The dogs tested were from Scandinavian countries, so we could expect some variation here.

 

 

 

DogBreedInbreeding.xlsx

Edited December 9, 2021 by Redsonic

[Deeds]

I have been watching a British Documentary set in 1969.  The police dogs i.e. German Shepherds looked so different from what is bred today. They all looked healthy with no sloping on the back or back  legs at all.  Very nice looking German Shepherds.

[coneye]

Interesting . you mention GSD  remember years ago  , probably 20 --- 25 years ago ,, out of curiosity going to a show of sorts Shepards only ,I was looking for one to buy , 95% of the dogs i was looking at , too be honest looked wrong , hump backs ,  too much of a slope ,  narrow skinny faces ,,, then i come across two absolutly beutiful  strong  excellent looking dogs  they were not together , , i aproached  the owner of this big male ,  had a discusion  ,  with him , and he then told me the other one i admired was his dogs pups , ,, HE  TOOK ME RND TO HIS HOUSE AND SHOWN ME HIS OTHERS , HE HAD ABOUT 5-6 ,  the big male was a german import ,, he shown me the mother  she also was a german import   marvelous looking dogs , unfortunatly for me no pups available ,  he  only bred the one litter  ,,

 

Anyway i said to him , bet you get sick of winning these shows , ,, never won one he said ,  i was shocked ,   what about that pup he's marvelous i said surely he'll win today ,, never do he said thats why i'm getting out of it ,, he said ,,,  i said to him most these other shepards don't even look like a proper shepard ,  more like skinny jackals ,  his answer was ,,  they tell me there looking for fine dogs like them ,, i spoke to a few other owners  who said we breed them fine nowadays ,, this was bred with that  and that was bred with this ,,, i quickly relized  , that most these people did'nt have the money and recources to bring in good stock , so  bred with there mates and then started to change the  awards to suit themselves ,,, make of this what you will , but i can honestly tell you ,  EVERDAY  of the week , i watch people  walk past my house ,  with shepards  i live right opposite the dog beach ,  and everyday i look at the poor things and think they look deformed  , most have skinny snouts and  bigger hunchbacks than  the fella who rings the bells ,, shame really , then i watch  a police dog  , on tele and think thats a shepard , .

 

Another thing with them  , the very things that made them  a great dog seem to being bred out of them ,  ,,, Not meaning to start a argument here ,  but  i believe its all to do with  breeders playing police , taking dogs of main registar  , and why ,, to save the world or to protect there income ,   different people different views i suppose

[Deeds]

I think GSD's were the only dogs they used for Police work in Britain back in 1969.

[Paul777]

On 09/12/2021 at 1:01 PM, Deeds said:

I have been watching a British Documentary set in 1969.  The police dogs i.e. German Shepherds looked so different from what is bred today. They all looked healthy with no sloping on the back or back  legs at all.  Very nice looking German Shepherds.

That's interesting considering that the English Alsatian was a result of inbreeding. 
Many will argue that the Alsatian is the same as a GSD.
Originally they were.

Due to hostilities with Germany, English breeders sourced GSDs from two French towns [Alsace and Sebastian IIRC] and called them Alsatian to dissociate them from German Shepherds. [Alsatian being an amalgamation of the names of the two French towns] 
Unfortunately the breeding stock was too narrow. Due to inbreeding, the Alsatian became a smaller dog in stature, had a narrower head and often had yellowish eyes.
They also had a reputation [whether fair or not I'm unable to say] of turning on their masters.

I'm not sure when English breeders rectified the issue - by bringing in new stock from OS - but pics I've seen of todays English bred GSDs now look like a GSD should. 
The GSDs in that doco you mentioned must have been a result of that reform of the breed in England. 

[sandgrubber]

For anyone that isn't up to reading the original article you can find a short verse here

https://www.sciencedaily.com/releases/2021/12/211202162148.htm