Relevance Rating: There is some evidence or research available for these breeds
Relevance Rating: The test is unknown, there is no evidence (i.e. research) available, or it has not been evaluated yet. These tests may or may not be meaningful in this breed
Ichthyosis is considered rare and appears to be breed specific, sometimes known as "fish scale" disease. It can resemble many other skin conditions such as allergies, dermatitis, and localized reactions. Most often present at birth, and can be painful. Symptoms include: thickened pads of his paws, irritated, flaking skin, may not itch or scab, also can cause thickened skin with scaly and greasy patches and flakes. This can cause water loss, as skin is unable to maintain moisture.
"The gross phenotype was manifest as a disheveled pelage shortly after birth, generalized scaling, and adherent brown scale with erythema of the abdominal skin (Mauldin et al. 2015)...Affected dogs exhibited diffuse laminated to compact orthokeratotic hyperkeratosis with hypergranulosis and mild acanthosis. The epidermis had a prominent granular layer, and multifocal granular layer keratinocytes displayed a perinuclear clear space. Malassezia could be found within the corneal layer in at least one sample in approximately 60% of cases. The yeast were typically present without an inflammatory response. Ultrastructurally, the epidermis showed discontinuous lipid bilayers, unprocessed lipid within corneocytes, and abnormal lamellar bodies (Mauldin et al. 2015)...As reported by Casal et al. (2017), "Obligate carriers were confirmed to be heterozygous for this variant, and 150 clinically non-affected dogs of other breeds were homozygous for the wild-type gene. Among 800 American bulldogs tested, 34% of clinically healthy dogs were discovered to be heterozygous for the defective allele." [From OMIA]
2017 Casal, M.L., Wang, P., Mauldin, E.A., Lin, G., Henthorn, P.S. : A Defect in NIPAL4 Is Associated with Autosomal Recessive Congenital Ichthyosis in American Bulldogs. PLoS One 12:e0170708, 2017. Pubmed reference: 28122049. DOI: 10.1371/journal.pone.0170708.
2019 Briand, A., Cochet-Faivre, N., Reyes-Gomez, E., Jaraud-Darnault, A., Tiret, L., Chevallier, L. : NIPAL4 deletion identified in an American Bully with autosomal recessive congenital ichthyosis and response to topical therapy. Vet Med Sci :, 2019. Pubmed reference: 30741495. DOI: 10.1002/vms3.149.