Test Detail
Long coat/short coat and ivermectin sensitivity (MDR-1) — German Shepherd and Czechoslovakian Wolfdog
General · Dog
Panel aimed at the German Shepherd and the Czechoslovakian Wolfdog that combines tests of the FGF5 gene for the coat-length phenotype (long coat/short coat) with the MDR-1 defect test (hypersensitivity to ivermectin and other drugs that are P-glycoprotein substrates). The first block reports the genetic status for coat length; the second, the clear/carrier/affected status for the MDR-1 defect. The panel is not strictly a disease test for the long coat (it is a phenotypic trait), but it includes the pharmacological risk of MDR-1, which requires lifelong therapeutic caution.
Incidence
Applicable breeds: German Shepherd and Czechoslovakian Wolfdog. The MDR-1 defect is well documented in the German Shepherd (OMIA:001402-9615); in the Czechoslovakian Wolfdog it is not recorded in OMIA and published figures are scarce (limited data).
Breeder management
- Genotype breeding animals before mating
- For the long coat: report the genotype to the breeder according to the breed standard being pursued (long or short coat); it is not a disease and no cross is discouraged from a health standpoint
- For MDR-1: avoid mating two mutated homozygotes (the whole litter would be sensitive to ivermectin and other P-gp drugs); heterozygotes may be mated with clear animals
- After a confirmed clinical case of toxicity, do not repeat the parental mating and communicate the status to the buyer
- For the long coat: report the genotype to the breeder according to the breed standard being pursued (long or short coat); it is not a disease and no cross is discouraged from a health standpoint
- For MDR-1: avoid mating two mutated homozygotes (the whole litter would be sensitive to ivermectin and other P-gp drugs); heterozygotes may be mated with clear animals
- After a confirmed clinical case of toxicity, do not repeat the parental mating and communicate the status to the buyer
Specialist notes
MDR-1 sensitivity makes it necessary to review the list of contraindicated drugs (ivermectin at antiparasitic doses, loperamide, several chemotherapeutic agents) before any treatment. The long-coat phenotype can be inferred visually, but the genotype helps predict long-coated litters from short-coated carrier parents. Verify which FGF5 variants each laboratory includes.
References
1. Mealey KL, Bentjen SA, Gay JM, Cantor GH. 2001. Ivermectin sensitivity in collies is associated with a deletion mutation of the mdr1 gene (Pharmacogenetics) (PMID 11692082).
2. Housley DJE, Venta PJ. 2006. The long and the short of it: evidence that FGF5 is a major determinant of canine 'hair'-itability (Anim Genet) (PMID 16879338).
3. Cadieu E, Neff MW, Quignon P, et al. 2009. Coat variation in the domestic dog is governed by variants in three genes (Science) (PMID 19713490).
4. OMIA:001402-9615 (Multidrug resistance 1, ABCB1-related) y OMIA:000439-9615 (Hair, long; FGF5).
2. Housley DJE, Venta PJ. 2006. The long and the short of it: evidence that FGF5 is a major determinant of canine 'hair'-itability (Anim Genet) (PMID 16879338).
3. Cadieu E, Neff MW, Quignon P, et al. 2009. Coat variation in the domestic dog is governed by variants in three genes (Science) (PMID 19713490).
4. OMIA:001402-9615 (Multidrug resistance 1, ABCB1-related) y OMIA:000439-9615 (Hair, long; FGF5).