Frequency of canine hip and elbow dysplasia decreasing in Finland

 |  Koiran terveys, Terveystarkastukset

Genetic trends for hip and elbow dysplasia were assessed for the dogs born during the years 1993-2012. In hip dysplasia, the largest improvement can be seen in the Saint Bernard, the Smooth Collie, the Newfoundlander, the Beauceron and the Bordercollie. In elbow dysplasia, the Rottweiler and the St.Bernard have improved the most.

Genetic trends for hip and elbow dysplasia were assessed from the mean EBVs of the dogs born during the years 1993-2012. EBVs are being estimated for about 55 breeds in the Finnish Kennel Club, and these breeds were included in the assessment. Improvement in the mean EBVs was proportioned to the phenotypic screening results (Tables 1 and 3). A change of one point means that the breed average has moved one letter (hip dysplasia) or number (elbow dysplasia) to either a better or a worse direction.

Most of the assessed breeds are improving in hip dysplasia

Genetic improvement in hip dysplasia had taken place in almost every breed studied (Table 2). The largest improvement could be seen in the Saint Bernard, the Smooth Collie, the Newfoundlander, the Beauceron and the Bordercollie. An average hip joint of the Saint Bernard in the 1990s was in the middle of C and D. In the 2010s it is only slightly worse than B.

Genetic gain in the Smooth Collie is very interesting: in the 1990s, 99 % of the dogs screened had A or B hips. Despite of this very good situation, this breed has improved further by increasing the frequency of dogs with A hips and decreasing the frequency of dogs with B hips. An average hip joint of the Smooth Collie is currently the best of all breeds studied: a clear A.

An average hip of the Newfoundlander in the 1990s was only slightly better than D. In the 2010s it is in between B and C. The Beauceron and the Border Collie had the same average hip score in the 1990s: the score was in the middle of B and C. Now an average hip in these two breeds is in the middle of A and B, as the breeds have both improved 1.1 hip score points.

The breeds which had not improved or improved only a little included for example the Shorthaired German Pointer and Belgian Shepherds (Malinois and Groenendael). Their hip health is already so good, that not much improvement can be expected. However, there are also breeds, such as the Bullmastiff, the Boxer and the Brittany, which would greatly benefit from an improved situation.

The Wheaten Terrier and the Bouvier were the only breeds which had clearly changed for the worse when compared to the dogs born in the 1990s. Both breeds had got a half score worse, moving from the better side of B to slightly worse than B.

Rottweiler and Saint Bernard best improvers in elbow dysplasia

In elbow dysplasia, clear genetic improvement has taken place in seven breeds (Table 4). The Rottweiler and the St.Bernard had improved the most, 0.6 scores both. All three Belgian Shepherd varieties had on average a good elbow health already in the 1990s, so only a little improvement has been made, or the situation has remained unchanged in these breeds.

 

Table 1. Hip dysplasia letters and their numbering (scores) in the EBV estimation.

 Hip dysplasia letter

Explanation

Numbering in the EBV estimation (scores)

A

No signs of hip dysplasia

0

B

Near normal hip joints

1

C

Mild hip dysplasia

2

D

Moderate hip dysplasia

3

E

Severe hip dysplasia

4.5

 

Table 2. Change of the hip score in the dogs born during 1993-2012, and an average hip score of the dogs born during 2009-2012. A negative change means moving to a healthier direction.

Breed

Change in hip score

1993-2012

Average hip score

2009-2012

St. Bernard

-1.3

1.2 (slightly worse than B)

Collie, Smooth

-1.2

0.1 (A)

Newfoundlander

-1.2

1.6 (in the middle of B and C)

Beauceron

-1.1

0.5 (in the middle of A and B)

Border Collie

-1.1

0.5 (in the middle of A and B)

Labrador Retriever

-0.9

0.6 (in the middle of A and B)

Welsh Corgi Pembroke

-0.9

2.0 (C)

Novascotia Duck Tolling Retriever

-0.9

0.6 (in the middle of A and B)

German Shepherd

-0.9

1.0 (B)

Bearded Collie

-0.8

0.4 (in the middle of A and B)

Leonberger

-0.8

0.7 (nearer to B than A)

English Springerspaniel

-0.8

0.6 (in the middle of A and B)

Bernese Mountain Dog

-0.8

1.1 (B)

Spanish Water Dog

-0.8

0.9 (B)

Golden Retriever

-0.7

1.1 (B)

Rottweiler

-0.7

0.7 (nearer to B than A)

Collie, Rough

-0.6

0.7 (nearer to B than A)

Finnish Hound

-0.6

0.9 (B)

Red Irish Setter

-0.6

1.0 (B)

Samoyed

-0.6

0.9 (B)

Old English Sheepdog

-0.6

1.0 (B)

Belgian Shepherd Tervueren

-0.6

0.3 (slightly worse than A)

Norwegian Elkhound Grey

-0.6

0.5 (in the middle of A and B)

Dalmatian

-0.6

0.8 (slightly better than B)

Landseer                 

-0.6

0.8 (slightly better than B)

Finnish Lapphund

-0.5

1.0 (B)

Karelian Bear Dog

-0.5

1.2 (slightly worse than B)

Welsh Springerspaniel

-0.5

0.7 (nearer to B than A)

Jämthund

-0.5

0.4 (in the middle of A and B)

German Wirehaired Pointer

-0.5

0.5 (in the middle of A and B)

Hovawart

-0.4

0.5 (in the middle of A and B)

Australian Shepherd

-0.4

0.5 (in the middle of A and B)

Staffordshire Bullterrier

-0.4

1.5 (in the middle of B and C)

English Cockerspaniel

-0.4

0.6 (in the middle of A and B)

Airedale Terrier

-0.4

1.0 (B)

Flatcoated Retriever

-0.4

0.4 (in the middle of A and B)

Lapponian Herder

-0.4

0.6 (in the middle of A and B)

Alaskan Malamute

-0.3

0.6 (in the middle of A and B)

Lagotto Romagnolo

-0.3

1.3 (slightly worse than B)

American Staffordshire Terrier

-0.3

1.5 (in the middle of B and C)

Schnauzer

-0.3

1.0 (B)

German Shorthaired Pointer

-0.2

0.3 (slightly worse than A)

Swedish Vallhund

-0.2

1.0 (B)

Boxer

-0.2

1.2 (slightly worse than B)

Brittany

-0.2

1.4 (in the middle of B and C)

Giant Schnauzer

-0.2

0.8 (slightly better than B)

Great Dane

-0.2

0.9 (B)

English Setter

-0.1

0.7 (nearer to B than A)

Belgian Shepherd Malinois

-0.1

0.4 (in the middle of A and B)

Dobermann

0

0.8 (slightly better than B)

Briard

0

1.0 (B)

Belgian Shepherd Groenendael

+0.1

0.4 (in the middle of A and B)

Shetland Sheepdog

+0.1

0.6 (in the middle of A and B)

Chow Chow

+0.1

1.2 (slightly worse than B)

Bullmastiff

+0.2

1.9 (C)

Wheaten Terrier

+0.4

0.7 (nearer to B than A)

Bouvier

+0.4

0.7 (nearer to B than A)

 

Table 3. Elbow scores.

Elbow score

Explanation

0

Normal

1

Mild arthrosis

2

Moderate arthrosis

3

Severe arthrosis

 

Table 4. Change of the elbow score in the dogs born during 1993-2012, and an average elbow score of the dogs born during 2009-2012. A negative change means moving to a healthier direction.

Breed

Change in elbow score

1993-2012

Average elbow score

2009-2012

Rottweiler

-0.6

0.33

St.Bernard

-0.6

0.24

Chow chow

-0.5

1.19

Labrador Retriever

-0.5

0.17

Bernese Mountain Dog

-0.4

0.31

Golden Retriever

-0.4

0.20

German Shepherd

-0.4

0.23

Belgian Shepherd Malinois

-0.1

0.09

Bullmastiff

-0.1

0.23

Belgian Shepherd Tervueren

0.0

0.13

Belgian Shepherd Groenendael

0.0

0.07

Newfoundlander

+0.1

0.43