Читать книгу Pet-Specific Care for the Veterinary Team - Группа авторов - Страница 331

In pet‐specific care, there is a focus on prevention and early detection. To accomplish early detection, both genotypic and phenotypic tests are needed. Genotypic tests examine an individual's DNA for mutations (variants) or markers that may be correlated with traits and disease risk. Phenotypic tests measure observable features (e.g., blood test results, heart rhythm, body weight, etc.) and diagnostic judgments are made on that basis, and comparisons with so‐called “normal” reference intervals (ranges).

Genotypic tests on their own have value, but they cannot always predict actual risk of diseases. In addition, genotypic tests are available primarily for conditions transmitted as simple Mendelian traits (e.g., von Willebrand disease, progressive rod‐cone dysplasia, mdr1, etc.), mostly controlled by one set of genes. On the other hand, the most common hereditary conditions encountered in veterinary practice (e.g., atopic dermatitis, hip dysplasia, seizure disorders, etc.) have a more complex pattern of inheritance, often influenced by environmental factors and multiple genes, and confirmed principally through phenotypic testing. Because of this, both genotypic and phenotypic testing are needed as part of most early detection schemes.