Health testing

BVA- Joint assessing (all research for this page has been used from the BVA website with my own interpretation and rewording to make the information more digestible)

The BVA joint assessing schemes for hips and elbows assess how well those joints are constructed. This is done through x-raying the dog in question. For hips one x-ray is needed. For elbows two are needed at different angles. The lower the score the tighter the joint is, hips are graded up to 53 of each hip (right and left), elbows are graded up to 3 on each elbow (right and left). A score of 0-0 is the lowest for both hips and elbows. These assessments show the current state of the joints. Dogs, humans and mammals all have joints which degrade over time, therefore an older animal will have a higher score than a younger one. The BVA assessment for hips assesses nine different areas of the hip structure:

Norberg angle

Subluxation

Cranial acetabular edge

Dorsal acetabular edge

Cranial effective acetabular rim

Acetabular fossa

Caudal acetabular edge

Femoaral head/neck exostosis

Femoral head recontouring

In the diagram of a hip seven of these can be seen and where they relate to the hip joint. The below table is an explanation as to the scoring of each section. In basic terms the top parts of a score concentrate on how the joint fits into the socket, the third section depicts the wideness of this joint (how tight the ball fits into the socket). The rest of the sections depict the make and shape of the ball and socket. A score in the later six sections are what can lead to arthritis. Not every dog with a score in these areas will have arthritis, equally a dog with no score in these areas may not be free of arthritis, it is just more likely (a dog with a higher hip score will develop arthritis).

Each section of the hip and its scoring process are described.

Norberg angle

This is calculated by measuring from the centre of the femoral head to the cranial effective acetabular rim. The larger this angle is the better the score. 90° is 0 therefor +15 to 90° is 105° this is an angle which shows the joint is tight.

Subluxation

This is where the centre femoral head sits in relation to the dorsal acetabular edge (far side of the hip x-ray). The further over this line the femoral head is the tighter the hip joint will be. This part of the joint can change through the day (it may become worse with weight being on the joint), therefore assessment on this may not be 100% accurate the actual score may be one point higher. [scores of 1, 2 and 3 are most common]

Cranial acetabular edge

This is the curved part of the socket that faces the femoral head. Ideally this should be one continuous curve with a small uniform gap to the femoral head. a higher score can be indicated through straightening of the curve, a high score in this area will lead to scores in the subsequent areas of the hip. [A score of 2 is most common]

Dorsal acetabular edge

This is at the back of the x-ray behind the femoral head. Ideally there should be a slight s shaped curve to this section. Variations to this will cause a higher score also any blurring will cause a higher score. A score of 3 or above indicates a score in every other area of the hip.

Cranial effective acetabular rim

This is where the dorsal acetabular edge meets the cranial acetabular edge, it in effect holds the ball in the socket. This should be a clearly defined area of the hip. A score of up to two can still be a perfectly good hip, above two and the hip has abnormal wear and tear.

Acetabular fossa

This should be a clearly defined gap in the bone, this is where a ligament that controls the hip is located. If this is smaller or blurred it will be scored and subsequently all other areas of the hip will also have a score. This part of the hip will eventually fill in completely.

Caudal acetabular edge

Like the acetabular fossa any blurring in this area will cause a score in all other areas. This should be a smooth continuous curve with a uniform gap to the femoral head.

Femoaral head/neck exostosis

This is toward the top of the femur this should be a smooth bone. Any abnormal growth on this bone will cause a higher score and could lead to arthritis. If there is any abnormality it will worsen with age.

Femoral head recontouring

This is the top of the femur, the shape may change with age gradually wearing down with use. There may also be a development issue with a dog where the bone will not form properly. Again a score here will result in a score in all other areas.

Scores of each hip:

0-4 is a perfect to near perfect hip

5-10 borderline changes that are unlikely to worsen with age

11-20 mild changes that may worsen with age, sometimes developing into arthritis

21-50 moderate to marked hip dysplasia in which arthritis is probably prominent.

>50 very severe hip dysplasia with arthritis

When there is a difference in hips the score of the higher hip should be doubled and used to have an understanding of the hips i.e. 0-20 and 10-10 are both in the total score of 11-20, but realistically a score of 20 on one hip is fairly high. This hip score on one leg, means the total relative score should be considered in the 21-50 (total of 40 by doubling the higher leg) to gain an understanding of the state of that hip.

Elbows are graded differently to hips. With a score only going up to three on each side. As the scoring has such a small range there is more variation between each number i.e. between 1 and 2 will be a large difference with elbows but not with hips. A low score is needed with elbows.

Comparison charts

FCI	OFA	UK (single hip)	Germany	Sweden
A- normal hip	Excellent	0	A1	0
	Good	1-3	A2
B- Borderline	Fair	4-6	B1
	Borderline	7-8	B2
C Mild HD	Mild	9-12	C1	1
		13-18	C2
D Moderate	Moderate	19-20	D1	2
			D2
E Severe	Severe	>30	E1	3
			E2	4

Hip Scores	Number Tested	BMS	Range	Median
All Chows 20/01/2019	308	16.1	0-106	9
Our chows 02/10/2019	54	13.7	0-98	6.8
Current Breeding 02/10/2019	NA	8.9	2-22	4.5

Elbow Dysplasia

Information on Elbow Dysplasia (ED), read and adapted from the BVA website.

In my opinion there is far less information available on ED that there is on hip dysplasia. This is equally displayed in the scoring system for Elbows opposed to Hips, within the elbow test the results are 0-3 whereas hips are 0-53 on each hip. As shown above there are numerous areas which are looked at within hip scoring and the results are freely displayed for the owner. Elbow results just give the score, as such there is less information available to us as breeders. ED regards the ligament growth on the elbow, knowledge as to what area is affected would be beneficial in my opinion. I do value the scores, as it assists in giving me more information on the dog.

In simple terms ED is abnormal development of an elbow. This term includes numerous abnormalities that affect different sites within the joint, causing problems by affecting the growth of cartilage on the surface of the joint of the structure around it.

Some breeds are more prone to ED- these tend to be larger breeds and cross breeds, and Chows are not one of these breeds. ED tends to be begin at puppyhood, and can affect the dog for life. One sign of ED is lameness, however all lameness is not ED. Screening can assist in showing where there is an issue and subsequently where to breed away from.

Causes of ED can be- Genetic, Diet, Growth rate, Levels of exercise. Genetic ED is controlled by different genes as such there is not one gene that controls it. A score of 0 has less of these genes and should therefore have less probability of passing on ED, but it can still be passed on by any dog. If there were a genetic test for ED puppies could be sorted at a younger age and kept by ED values, as things stand the only test is an adult x-ray. Grading is based on the presence of primary lesions and the size and extent of secondary lesions. The overall grade is based upon the higher value.

Dogs with a higher score (3) should be avoided in a breeding program, equally the whole dog needs to be considered. Screening assists in providing information to move forward with. A higher score in ED but lower in hips, and overall good conformation could be a good dog in general. ED should be bred away from, there are far more dogs which aren’t scored and bred with which could be all have higher scores.

Elbow Scores	Number tested	0	>0	1	2	3
All chows 01/20/2019	133	54 (40.6%)	79 (59.4%)	21 (15.8%)	33 (24.8%)	29 (18.8%)
Our dogs 02/10/2019	28	11 (39.3%)	17 (60.7%)	9 (32.1%)	6 (21.4%)	2 (7.1%)
Current breeding 02/10/2019		43%	57%	43%	7%	7%

Coefficient of Inbreeding

With all dog breeding the COI should be considered. COI (coefficient of inbreeding) basically looks at how many common ancestors a dog has. When a COI is higher in a proposed mating both parents will share more common ancestors, thus the puppies born have greater a potential of having the genetics of those common ancestors. This will mean the good and the bad attributes are more likely to be in existence. If the common ancestor had excellent ears the likelihood is that the puppies will also have good ears, equally is it had poor bone the puppy could also have poor bone. In effect the probability of inheriting attributes increases.

If two unrelated dogs are mated together, their puppies will have a 0% COI. If two of these puppies are mated together they will produce subsequent puppies with a 25% COI. Equally there are simple COI of the following:

· Parent – Offspring 25%

· Grandparent- Grandchild 12.5%

· Half sibling 12.5%

· Great grandparent- Great grandchild 6.25%

· First cousins 6.25%

A higher COI can assist in enhancing certain attributes, but could equally assist in exhibiting the negative. A higher COI is also commonly associated with smaller litter sizes, less viable puppies and fertility issues. Life expectancy can also be altered by COI, with dogs over 25% COI living up to 4 years less than those under 6.25% COI. At the same time, two completely unrelated dogs can die prematurely and their resultant puppies could also with a COI of 0%. Personally I have had dogs with 0% COI dying prematurely and those with 17.1% (the highest I have bought in) dying at the same age.

Like will all things in dog breeding, this should be taking into account, a higher COI will increase the probability of puppies exhibiting ancestral features- the good, the bad and the ugly.

COI Annual Breed Average	Current Figure (2019)
All Chows	4.7%
Our dogs (all kept and bought)	5.883%
Current Breeding	5.274%

What do we look for?

We start this process when a puppy is 8 weeks of age and assessing them then, and keeping the best prospects for moving forward with, this regards temperament, make and shape along with the pedigree, I assess to the breed standard rather than one puppy against the other. Once over a year in age all of our Chows will be hip and elbow scored. We used to score our bitches once they’ve had a litter, we now feel as though this scoring needs to be done before. We also regularly take part in the Chow Chow Breed Council (CCBC) Bronze Certificate. I like to have all chows need to be assessed by a vet on an annual basis. This vet check is above and beyond the Bronze certificate of the CCBC, is performed annually with a pass and fail criteria.

Once we know what we are keeping, we will raise them to the best of our ability, assisting them to reach their potential. They are born from scored parents, and will themselves be scored. They will be vet checked annually for permission to be bred with. In my mind this is as much as I can do towards ensuring the health and wellbeing of the next generation.

With this said, I do consider the whole animal. They will only have been kept if they are above a certain standard, if they fail to meet that standard at a year I will not breed with them. If they fail the Vet check I can’t breed with them. If they pass the vet check, are aesthetically pleasing but happen to have a higher hip score they need to be considered still in my opinion. Hips and elbows can skip generations, as I will normally have had the parents scored, and normally a half sibling I have an informed picture. I do not just look at the scores of the dog/ bitch in question but what they are out of and what they are going to. Each mating and all practice is done to try and ensure the puppies being born are healthy because at the end of the day I am doing a mating for me to keep something back myself, to date I have kept over 1/4 of all puppies born.

In short scoring assists me to make a more informed decision on what to keep, what to breed with and how to progress my dogs with an eye for the future.

BVA eye testing

The British Vetenairy Association have two bands/ lists of dog breeds which need to or should take part in the BVA eye test Chows don’t appear on these lists. To find more information regardign these lists please look at https://www.bva.co.uk/Canine-Health-Schemes/Eye-scheme/

Chow Chow Breed Council Bronze health certificate

The British Chow Chow Breed Council created the bronze health certificate which looks as the generic health of a Chow. There are several areas which are reviewed but this is a basic health check that all chows should have completed. more information on this can be found on http://www.chowchowbreedcouncil.com/bronze.htm the information on this page should be updated when more dogs have completed this.