a A hip result is a two‐letter breed code followed by the evaluation number, a subjective code for the hip conformation (E = excellent; G = good; F = fair), and the age of the dog in months when the hips were evaluated.
b An elbow result is a two‐letter breed code followed by EL that indicates the number is associated with elbows, the evaluation number, an abbreviation of the sex of the dog (M = male; F = female), and the age of the dog in months when the elbows were evaluated.
c An eye result is a two‐letter breed code followed by either the abbreviation EYE that indicates the number is associated with eyes or just the evaluation number.
d A thyroid result is a two‐letter breed code followed by TH that indicates the number is associated with thyroid, the evaluation number, and the age of the dog in months when the thyroid was evaluated.
Dogs are the companion species with the greatest number of health screens available; these screens range from phenotypic tests such as hip conformation, eye, cardiac, or metabolic hormonal profiles to direct genetic mutation tests (see 3.11 Integrating Genotypic and Phenotypic Testing). Depending upon the registry, any and all health information may be collected and reported along with descriptive statistics such as sex, breed, age, etc. Alternatively, a select subset of screening tests that meet particular criteria may be recorded along with the descriptors. An example of the latter is the OFA Canine Health Information Center health registry, the largest repository of canine health information in the US, which covers purebred dog breeds as well as mixed‐breed dogs and some other species. The health screening data recorded and published by the OFA are limited to phenotypic results obtained through examinations and testing by professional veterinarians with the appropriate board certifications and DNA‐based results from validated genetic tests (Table 3.7.3).
Table 3.7.3 Genetic test screenings recorded in the OFA Canine Health Information Center health registry
Source: Data from www.ofa.org.
| Phenotypic genetic tests | Mutation tests |
|---|---|
| Hip dysplasia | Adult‐onset neuropathy |
| Elbow dysplasia | Adult paroxysmal dyskinesia |
| Cardiac disease | Basenji progressive retinal atrophy |
| Congenital deafness | Canine multiple system degeneration |
| Serum bile acid | Degenerative encephalopathy |
| Eye disease | Degenerative myelopathy |
| Legg–Calvé–Perthes | Dilated cardiomyopathy |
| Patellar luxation | Fanconi’s syndrome |
| Sebaceous adenitis | Gangliosidosis |
| Spine | Juvenile laryngeal paralysis and polyneuropathy |
| Shoulder osteochondrosis | Neonatal cerebellar ataxia |
| Thyroid | Neuronal ceroid lipofuscinosis |
| Tracheal hypoplasia | Neonatal encephalopathy with seizures |
| Dentition | Pyruvate dehydrogenase phosphate deficiency |
| Kidney | Primary lens luxation |
| RCD4 progressive retinal atrophy | |
| Spinocerebellar ataxia | |
| Spongiform leukoencephalomyelopathy |
In contrast, some individual dog breed clubs maintain their own health databases managed by dedicated club members. These breed‐specific health registries usually catalogue health conditions more typically observed within that breed as well as collecting information on a multiplicity of medical conditions. The information gathered and recorded often includes anecdotal descriptions of health issues. Although professional diagnoses are the most valuable for reliable use in decision making, sometimes aggregate anecdotal information reveals an emerging health issue.
Health screening results for cats can also be deposited with the OFA, although participation has been limited. The reduced data may be due to fewer health screens being typically employed by cat owners or that the health registration for cats is more decentralized and maintained within breed clubs. A similar breed‐specific approach is seen for equine health registries. Additionally, some registries are specific for a particular condition within a specific breed, such as the International Epilepsy Register for Belgian Shepherds. Registries targeting a single condition or those more anecdotal in nature are much less valuable to the veterinary and research community than the registries that are more comprehensive and centralized with health screenings validated by professionals.
3.7.5 Research Organizations
In general, research into the inheritance and genetic basis of health
