Objectives—To assess the association between
goniodysgenesis, ocular measurements, and glaucoma
in Great Danes.
Animals—180 Great Danes.
Procedure—Eye examination and measurements
were obtained from 180 Great Danes; for 30 of these
dogs, depth of the anterior chamber, vitreal body
length, and total depth of the globe were also measured.
These data were merged with electronic pedigree
information on 43,371 kennel club registered
Great Danes. Relationships among goniodysgenesis,
ocular measurements, and glaucoma and the heritability
of goniodysgenesis were estimated.
Results—The degree of goniodysgenesis was significantly
and positively associated with the likelihood of
glaucoma. There was a significant association
between the degree of goniodysgenesis in offspring
and parents. The estimated heritability of the degree
of goniodysgenesis was 0.52. The depth of the anterior
chamber of the eye was also a good predictor of
goniodysgenesis (ie, the dog was almost certain to
have glaucoma if the depth was < 3.7 mm). If both
parents had goniodysgenesis < 70%, then with 95%
confidence, the occurrence of glaucoma in the ensuing
offspring would be < 4/1000. This strategy translates
to ensuring that the depth of the anterior chamber
of the eye is > 3.7 mm for both parents.
Conclusions and Clinical Relevance—The strong
and significant correlation among goniodysgenesis,
other eye measurements, and glaucoma and the significant
heritability of goniodysgenesis suggests that
glaucoma may be heritable in Great Danes. If so, glaucoma
can be controlled by breeding only from sires
and dams with a minimum degree of goniodysgenesis.
(Am J Vet Res 2001;62:1493–1499)
Objective—To establish a model for inheritance of
gluten-sensitive enteropathy (GSE) in Irish Setters.
Animals—44 dogs of a 6-generation family of Irish
Setters with GSE and 7 healthy Irish Setters.
Procedure—Phenotype of each dog was determined
after oral administration of gluten in the weaning diet,
using morphometric evaluation of jejunal biopsies (all
generations) and measurement of small intestinal
permeability by use of a lactulose-rhamnose permeation
test (generations 1, 2, and 3). Overall probability
for each of 4 genetic models of inheritance (autosomal
recessive, autosomal dominant, sex-linked recessive,
and sex-linked dominant) accounting for segregation
of partial villus atrophy within the entire family
Results—The autosomal recessive model was most
tenable and was 56,250 times more likely to
account for segregation of partial villus atrophy than
the autosomal dominant model, assuming disease
prevalence of 0.8%. Both sex-linked models were
untenable. These conclusions were robust to the
error attached to estimation of disease prevalence.
High intestinal permeability without morphometric
jejunal abnormalities in 4 of 20 dogs in the 3
youngest generations suggested heterogeneity of
lesions associated with GSE.
Conclusions—Genetic transmission of GSE is under
the control of a single major autosomal recessive
locus. (Am J Vet Res 2000;61:462–468)