The Rhodesian Ridgeback Club of the United States Rhodesian Ridgeback Club of the United States

HEALTH & GENETICS RESOURCES

Deciphering OFA Numbers

by Caroline Cox

I wonder how many of you, like me, anxiously open your OFA results, glance at the grading and either breathe a huge sigh of relief (or shed a few tears into the coffee cup). Then we file the piece of paper away and only look at it again if we plan on breeding our dog. Once in a while we may look at the certificate and wonder, in passing, what all the letters and numbers mean, but we don’t really think too much about it.

Well, it turns out that those letters and numbers have real significance, and the OFA website in fact has a section called OFA Number Key that details each code for each database. For example, the first two letters in the number for Hip Dysplasia are the code for the breed; in the case of the Ridgeback, it is RR. The next three numbers are a numerical identifier given to each animal evaluated as normal within the breed. The next letter is the OFA evaluation–E = Excellent, G = Good and F = Fair (curiously, there doesn’t seem to be a letter for Borderline, Mild, Moderate and Severe – all failing grades). The next two numbers are the age in months at which the test was done. Then comes the sex, and finally, letters indicating the animal has some form of permanent identification. So you can obtain at a glance quite a lot of information on, in this case, a dog’s hip X-ray. 

OFA runs a database for Hip Dysplasia, Elbow Dysplasia, Cardiac, Thyroid, Deafness, Patellar Luxation, Sebaceous Adenitis, Legg-Calve-Perthes and DNA.

The following table (source: www.offa.org/numberkey.html) lists the codes for each database:

 

Code

Explanation

HIP DYSPLASIA

(E.g.: RR-100E24M-PI)

RR (Rhodesian Ridgeback)

Breed code

100

Numerical identification given to each dog evaluated as normal within the breed

E

OFA phenotypic evaluation

E= Excellent

G = Good

F = Fair

24

Age in months when X-ray was done

M (Male); F (Female)

Sex of the dog

PI

Indicates that the animal has been permanently identified by tattoo or microchip

NOPI

Indicates that the animal lacks permanent identification

ELBOW DYSPLASIA

(E.g., RR-EL100F24-PI)

RR (Rhodesian Ridgeback)

Breed

EL

OFA elbow dysplasia database

100

Numerical identification given to each animal evaluated as normal with the breed

M (Male); F (Female)

Sex

24

Age in months when X-rays were taken

PI

Indicates permanently identified by tattoo or microchip

NOPI

Indicates no permanent identification

CARDIAC

(E.g.: RR-CA100/12M/C-PI)

RR (Rhodesian Ridgeback)

Breed

CA

OFA cardiac database

100

Numerical identification given to each animal evaluated as normal within the breed

12

Age in months when testing was done

M (Male); F (Female)

Sex

C

Suffix indicating the area of specialty of the attending veterinarian:

P = General Practitioner

S = Specialist

C = Board Certified Cardiologist

PI

Indicates permanently identified by tattoo or microchip

NOPI

Indicates no permanent identification

THYROID

(E.g.: RR-TH100/24M-PI)

RR (Rhodesian Ridgeback)

Breed

TH       

OFA database for thyroid

100      

 

Numerical identification given to each animal evaluated as normal within the breed

24                                

           

Age in months when testing was done

M (Male); F (Female)      

Sex

PI        

Indicates permanently identified by tattoo or microchip

NOPI   

Indicates no permanent identification

DEAFNESS

(Eg.: RR-BR100/12M-PI)

RR (Rhodesian Ridgeback)

Breed

BR

OFA database for Deafness (BR - BAER Test)

100

Numerical identification given to each animal evaluated as normal within the breed

12

Age in months when test was done

M (Male); F (Female)      

Sex

PI

Indicates permanently identified by tattoo or microchip

NOPI

Indicates no permanent identification

PATELLAR LUXATION
(Eg.: PO-PA100/18M/S-PI)

PO (Poodle)

Breed

PA

OFA database for Patellar Luxation

100

Numerical identification given to each animal evaluated as normal within the breed

18

Age in months at which testing was done

M (Male; F (Female)

Sex

S

Suffix indicating the area of specialty of the attending veterinarian:

P = General Practitioner

S = Specialist

C = Board Certified Surgeon

PI

Indicates that the animal has been permanently identified

NOPI

Indicates no permanent identification

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