Analysis of the 2000 AKC Stud Book for Rhodesian Ridgebacks; Relationship of Breeding Practices to Affiliation with the National Breed Club

by Clayton H. Heathcock

The American Kennel Club "Stud Book" is the basic registry from which all pedigrees are constructed. When a dog or bitch is first registered as the sire or dam of a litter, they are entered in the stud book. The stud book is a public document and can be examined at the AKC offices. The entry includes the following information:

Beginning in January, 2000, the stud book for each breed is available for purchase from the AKC online store. A sample of the first two pages of the January, 2000, stud book for Rhodesian Ridgebacks is attached as an appendix.

This essay reports the results of a study of the Rhodesian Ridgeback entries in the 2000 stud book. During the year, exactly 400 Rhodesian Ridgebacks were entered in the stud book, 154 males and 246 females. It is not possible to tell from the stud book alone how many litters are represented by these entries because some of these dogs and bitches were presumably bred to dogs entered into the stud book at some previous time.[1] However, we can estimate that these new entries represent approximately half of the Ridgeback litters registered in 2000.[2]

For the purpose of evaluating the stud book to discern various trends, the data were transferred to a database that can be sorted in various ways. Additional data was acquired from two other sources, the Orthopedic Foundation for Animals (OFA) online database and the 1999 roster of the Rhodesian Ridgeback Club of the United States (RRCUS). The OFA database was used to determine if a hip registration number has been entered for each of the 400 dogs and bitches whose names appear in the 2000 stud book.[3] The RRCUS roster was used to determine if the listed owner or breeder was a RRCUS member. Data are collected in Tables 1 and 2 and summarized graphically in Figure 1.

The data shows that dogs owned or bred by members of RRCUS, the national breed club, are more likely to have achieved an AKC conformation championship and are more likely to have OFA hip, elbow, and thyroid certifications. Even having some loose connection with the `establishment' has a noticeable effect on breeding practices. One can sort the 236 dogs who were neither owned nor bred by RRCUS members into two groups-those `touched' by the establishment (76 animals) and those with no obvious connection to the establishment (160 animals). For purposes of this analysis, I assigned to the former category any dog who had an AKC championship, whose sire or dam had an AKC championship, or whose sire or dam has a kennel name recognized by me to be that of a RRCUS member. Tables 1 and 2 show that even a loose connection with the `establishment' leads to an increased use of OFA, at least for hip certifications, relative to the group which has no obvious establishment connection.

Table 2 and Figure 2 also show the distribution of hip scores for those animals bred for the first time in 2000. The good news here is that more than 30% of the dogs who had OFA hip scores and were bred for the first time had OFA ratings of "Excellent." This is significantly higher than the breed average of 19.7%. Overall, 6% of the animals bred for the first time in 2000 had hip ratings of "Fair", about equal to the breed average of 6.6%. However, in general, the weaker the `establishment' connection, the more likely it was for dogs with "Fair" ratings to be bred.

The stud book can also be used to determine another breeding practice--the age at first breeding. There is a two-month delay after a litter registration before the dog's name appears in the online stud book. That is, dogs whose names appear in the January, 2000, stud book, were registered in November, 1999. Since the date of birth is given, one can determine the age of the dog (±2 weeks) at the time its name was entered in the stud book.[4] Data are shown in Table 1 and graphically in Figure 3. This data shows that breeders who are not affiliated with the national club are far more likely to breed bitches at a young age.

Analysis of the stud book confirms that there are several relatively large-volume breeders of AKC-registered Rhodesian Ridgebacks who have no obvious connection with the AKC through conformation competition, make little or no use of OFA, and who do not belong to the national breed club. Table 4 presents selected entries from the 2000 AKC Stud Book for Rhodesian Ridgebacks. These 25 entries represent litters produced by 16 females and 9 males who were sired by six breeders using a total of only 7 males. Only one of the 25 had an OFA hip score and 60% were entered in the stud book before their 2nd birthday.

What conclusions can we draw from examination of the 2000 stud book?

* First, we see that the majority of Rhodesian Ridgeback litters do not come from `establishment' breeders. Large-scale `non-establishment' breeders are producing a relatively large fraction of the Rhodesian Ridgeback litters registered in the United States. Many more seem to come from `backyard' breeders.

* Second, we see that affiliation with the `establishment' has a strong influence on three breeding practices: (1) breeding dogs and bitches who have achieved AKC conformation championships, (2) use of OFA to screen for hip dysplasia, and (3) age at first breeding. The stronger this `establishment' link, the greater the effect; dogs belonging to RRCUS members have a higher championship rate, higher OFA rate, and greater average age at first breeding.

* Third, although the RRCUS Code of Ethics has for many years stated that "Only dogs screened and certified clear of hip dysplasia shall be bred," only four in five dogs and bitches bred in 2000 by RRCUS members had an OFA hip certification number as of April 6, 2001.[5] Of course, this 20% of non-OFA certified dogs may have been evaluated by veterinarians not affiliated with OFA, but nevertheless the relatively high percentage of non-OFA certified dogs bred by RRCUS members is surprising.

* Fourth, `establishment' breeders are making extensive use of OFA for certification of elbows--more than 60% of the animals bred for the first time in 2000 were certified clear of elbow dysplasia. Thyroid testing still lags, but the `establishment' group does seem to beginning to use OFA for thyroid certification.

For an example page from the January, 2000, AKC stud book for Rhodesian Ridgebacks, click here (this is a PDF file and you will need Acrobat Reader to view it).

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