A survey of cataracts in golden and labrador retrievers

Two thousand two hundred and fifty-one golden and 1399 labrador retrievers were examined for certification under the BVA/Kennel Club eye examination scheme. Cataracts were diagnosed in 7.4 per cent of golden retrievers and 6.6 per cent of labrador retrievers; of these 4.7 per cent and 5.5 per cent, respectively, were of the posterior polar subcapsular (PPS) type and considered to be hereditary. Additional cases were examined as referrals. The PPS cataracts, essentially bilateral and always located at the confluence of the suture lines, were most commonly encountered in young dogs but could arise at any age. Over half of the cases re-examined after periods ranging from 12 to 34 months showed no or only slight progression but evidence was obtained for the occasional transformation of a PPS cataract into a total cataract. The hypothesis of dominant inheritance, probable from the pedigree data, received further support from instances of cataracts in retriever crosses. A perinuclear form of cataract, for which there was limited evidence for inheritance, was encountered almost exclusively in the golden retriever.     

Characterization and prevalence of cataracts in Labrador Retrievers in The Netherlands

OBJECTIVE: To assess the prevalence and distribution of types of cataract, investigate the effects of selective breeding on cataract development, and identify the relationship between posterior polar cataract and other types of cortical cataracts in Labrador Retrievers in The Netherlands. ANIMALS: 9,017 Labrador Retrievers. PROCEDURES: Records of 18,283 ophthalmic examinations performed by veterinary ophthalmologists from 1977 through 2005 were reviewed. There were 522 dogs affected by hereditary cataracts in 1 or both eyes without progressive retinal atrophy (PRA) and 166 PRA-affected dogs with cataracts. These cataracts were divided into 3 groups: posterior polar (triangular) cataract, extensive immature and mature cataract, and a miscellaneous group. Dogs with PRA were analyzed separately. RESULTS: From 1980 through 2000, the prevalence of hereditary cataracts was stable at 8%. The prevalence of cataracts in offspring of cataract-affected dogs was significantly increased, compared with the prevalence in offspring of nonaffected dogs. The distribution of types of cataract was significantly different between dogs with primary cataracts and PRA-affected dogs. Dogs with posterior polar (triangular) cataracts produced affected offspring with the same distribution of types of cataracts as the entire population of primary cataract-affected dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Cataract development in the Labrador Retriever population in The Netherlands appears to be a predominantly genetic disorder. Posterior polar (triangular) cataracts appear to be related to other types of hereditary cataract. Although there is no conclusive evidence, it seems valid to continue exclusion of all Labrador Retrievers affected by any type of primary cataract from breeding.     

Inheritance of cataract in the Bichon Frise

OBJECTIVE: To determine the mode of inheritance of cataract formation in the Bichon Frise. MATERIALS: Thirty-six closely related Bichon Frise dogs in a pedigree of 61 dogs were examined using slit-lamp biomicroscopy and indirect ophthalmoscopy over a period of 10 years. RESULTS: Of the 61 related dogs, 36 were examined repeatedly. Twelve cataractous dogs were diagnosed (three males and nine females). Cataractous dogs resulted from matings between unaffected parents, and when one parent was cataractous and the other parent was unaffected. Age at onset of cataract formation ranged from 18 to 160 months. Available information suggests that the cataracts are inherited as an autosomal recessive trait. CONCLUSION: Cataracts appear inherited in the Bichon Frise as an autosomal recessive trait. Additional cataract x cataract matings are necessary to confirm the autosomal recessive heredity.     

Survey of ophthalmic abnormalities in the labradoodle in the UK

One-hundred and seventy-five labradoodles underwent slit-lamp biomicroscopy and direct and indirect ophthalmoscopy between January 2008 and December 2009. These examinations were performed at shows by the first author. In addition, labradoodle eye certificates from the 2008 and 2009 British Veterinary Association/Kennel Club/International Sheep Dog Society (BVA/KC/ISDS) Eye Scheme were analysed (n=260). The results of the examinations were reviewed, and all ophthalmic abnormalities were recorded. The prevalence of any abnormality was compared with that reported by the Eye Scheme and the KC during 2009 for the labrador retriever, miniature, toy and standard poodles. Multifocal retinal dysplasia (MRD) was identified in 20 labradoodles (4.6 per cent), and cataracts were identified in 16 labradoodles (3.7 per cent). The prevalence of MRD in labradoodles was significantly greater than in labrador retrievers (P<0.0001). There was no difference in the prevalence of cataract between labradoodles and labrador retrievers (P=0.4866). The results of this study suggest that MRD is a relatively common finding in the labradoodle population in the UK. Given such an apparent high prevalence of MRD, routine screening for hereditary eye disease before breeding is advised for this increasingly popular new crossbreed.     

Familial cataracts and concurrent ocular anomalies in chow chows.

A closely inbred line of Chow Chows affected with congenital cataracts was studied. Sixteen dogs were examined including 1 adult male, 2 adult females, and 13 pups. Twelve of the pups were from 6 different litters, out of 6 different bitches, all sired by 1 adult male. The exact relationship of the thirteenth pup was undetermined. Clinical evaluation included slit-lamp biomicroscopy, biomicroscopic photography, and indirect ophthalmoscopy. Clinical appearance of the cataracts was variable, ranging from incipient nuclear or capsular lesions to advanced cortical opacity. The lens nucleus was most consistently affected, with variable involvement of the lens cortex. Concurrent ocular anomalies of some eyes included wandering nystagmus, entropion, microphthalmia, persistent pupillary membrane remnants, and multifocal retinal folds. A correlation was not apparent between the character or severity of the cataracts and the finding of the other anomalies. Histologic examination of 12 lenses revealed posterior displacement of the lens nucleus, retained lens epithelial cell nuclei in the nuclear and cortical lens, anterior capsular irregularity and duplication, anterior lens epithelial duplication, and posterior subcapsular migration of epithelium. The high incidence of cataract in this family of Chow Chows suggested an inherited defect, although the inheritance pattern was undetermined.     

Ocular complications of persistent hyperplastic primary vitreous in three dogs

Persistent hyperplastic primary vitreous (PHPV) syndrome associated with either severe ocular complications or multiple ocular lesions was diagnosed in three young dogs, a Samoyed, a Spanish Pachon, and a mixed breed dog. Due to opacification of the anterior ocular structures, B-mode and color-flow Doppler ultrasonography were performed to aid diagnosis. The Samoyed presented with unilateral hyphema; the Spanish Pachon presented with unilateral secondary glaucoma associated with uveitis and hyphema OD and leucocoria OU; and the mixed breed presented with bilateral leucocoria. B-mode ultrasonography of the Samoyed revealed a subcapsular cataract and a hyperechoic tubular structure attached from the optic disk to the posterior lens capsule. In the Spanish Pachon B-mode ultrasonography of the right eye indicated microphakia, cataract formation, and a retrolental mass with a thin hyperechoic strand stretching from the optic disk to the posterior lens; and for the right eye cataract formation, PHPV, retinal detachment, and vitreous hemorrhage. In the mixed breed dog, B-mode ultrasonography of both eyes indicated microphthalmia, retrolental mass, and hyperechoic lenses. By color-flow Doppler imaging, blood flow was present in the retrolental mass of the right eye suggesting a persistent hyaloid artery.     

Collie eye anomaly in the rough collie in Sweden: genetic transmission and influence on offspring vitality

Between 1989 and 1997, 8204 rough collies were examined for collie eye anomaly (CEA) at up to 10 weeks of age. All dogs were positively identified and the results were registered under the Swedish Kennel Club genetic health programme. A significant decrease in litter size occurred if one of two affected parents had coloboma (3.8 pups) compared with litters from two chorioretinal dysplasia- (CRD-) affected collies (5.2 pups) or litters by two normal collies (5.0 pups), indicating an influence of the coloboma genotype on offspring vitality. The prevalence of CRD in pups from normal x normal matings and CRD x CRD matings was significantly different from that expected under simple autosomal recessive inheritance (43 per cent versus 25 per cent and 85 per cent versus 100 per cent). The results are compatible with polygenic inheritance but not with simple autosomal recessive inheritance. CRD prevalence in offspring of CRD x coloboma matings was significantly lower than in pups of CRD x CRD matings, reflecting effects of the coloboma genotype on vitality. These results have important implications for breeding programmes and the genetic control of CEA.     

Idiopathic asymptomatic thrombocytopenia in Cavalier King Charles Spaniels is an autosomal recessive trait

Cavalier King Charles Spaniels (CKCS) often have idiopathic asymptomatic thrombocytopenia. In affected dogs, the thrombocytes often are large, and it has been speculated that the condition could be an inherited macrothrombocytopenia. The aim of this study was to examine the inheritance of idiopathic, asymptomatic thrombocytopenia in CKCS. Sixteen families (both parents and > or = 3 offspring) of privately owned CKCS were included. There were 105 clinically healthy dogs (50 from Denmark and 55 from Sweden): 81 offspring and 26 parents (2 dogs had both roles). Because autoanalyzers have difficulty counting large platelets, the platelets were counted manually, with a counting chamber. Platelet counts were not influenced by age, gender, or heart murmur status. Thrombocytopenia (< or = 100,000 platelets/microL) was found in 46% of the parents. The pedigrees indicated that thrombocytopenia segregated as an autosomal recessive trait and that 100,000 platelets/microL was appropriate as a lower limit of normal. Affected offspring were found in all families, showing that all of the included parents were at least carriers. Therefore, the expected segregation ratios (which were in good accordance with the observed ones) were 1:0, 1:1, and 1:3 for the 3 crosses: affected x affected, normal x affected, and normal x normal. Within a given cross, the mean parental platelet count had no influence on the platelet counts of the offspring. We conclude that idiopathic, asymptomatic thrombocytopenia in CKCS is inherited in an autosomal recessive manner. The condition most likely constitutes an inherited macrothrombocytopenia in dogs.     

Immunohistochemical analysis of lens epithelial-derived membranes following cataract extraction in the dog

The objective of the study was to characterize the morphologic and immunohistochemical features of lens epithelial-derived proliferative membranes from the anterior segment of canine globes. These features were correlated with those previously identified for diseases resulting from lens epithelial cell (LEC) proliferation including posterior capsular opacification, traumatic subcapsular cataract, and subcapsular plaques associated with hypermature cataracts. Sixteen canine globes were removed as a result of glaucoma or other complications following cataract extraction. Light microscopic and immunohistochemical analysis was performed on sections from formalin-fixed, paraffin-embedded globes. The tissues were stained with a variety of antibodies for cellular markers for LECs, growth factors or other cellular constituents relevant to cellular metaplasia and proliferation. The membranes were composed of monolayers or multilayers of spindle-shaped cells on the external surfaces of the anterior and posterior lens capsule, ciliary processes, iris leaflets, and iridocorneal angle, and they could be seen extending from an obvious monolayer of LEC within the capsular sac. Variably, scattered pigment cells, presumably of uveal origin, were concurrently present. Cellular components of the membranes stained positive for vimentin, transforming growth factor-beta, basic fibroblast growth factor, and smooth muscle actin. An amorphous eosinophilic extracellular matrix consisting predominately of collagen was associated with the membranes. Proliferative anterior segment membranes following cataract surgery were morphologically and immunohistochemically similar to cellular and matrix components of posterior capsular opacification and capsular plaques seen with hypermature cataracts, both of which result from metaplasia and proliferation of LEC. The presence of these LEC-derived membranes in association with secondary glaucoma suggests that exuberant proliferation of LEC outside the confines of the lens capsular sac may cause pathologic alterations in the eye following cataract surgery in the dog.     

Cataracts in the Bichon Frise

Purpose To determine the clinical characteristics of possible inherited cataract in the Bichon Frise breed. These characteristics include the relative frequency, gender effects, site of first cataract formation, age of onset, relationship of age to cataract maturity, and other concurrent pre‐ and postoperative ophthalmic diseases. Methods Four different populations of Bichon Frise were examined. They included: (1) referred patients of the University of Florida (VMTH; 1990–2000); (2) patients from other universities and large institutions (VMDB; 1970–2000); (3) patients from the Canine Eye Registry Foundation (CERF; 1970–2000); and (4) special patients recruited from eye clinics and ACVO specialty practices (1995–2001). Blood samples were obtained from many patients for future DNA analyzes. Statistical comparisons between groups were by general linear and anova analyzes, and P < 0.05 was considered significant. Results The four populations of cataractous and total Bichon Frise dogs included: (1) UF‐VMTH: 57 cataractous dogs; (2) VMDB: 406 dogs (28%) with cataracts; total dogs ? 1407; (3) CERF: 505 cataractous dogs (6%); total dogs ? 8222; and (4) ACVO: 223 cataractous dogs (57%); total dogs ? 391. In each population group, gender did not affect cataract distribution. Dogs between 2 and 8 years of age were most frequently affected, and initial cataract involvement affected equally the anterior and posterior cortices. Immature cataracts occurred more often in younger dogs, and hypermature cataracts were more frequently diagnosed in older dogs. Dogs with early cataracts were encountered more frequently in the CERF population. Pre‐ and postoperative retinal detachments (RD) were not infrequently diagnosed in the UF‐VMTH and VMDB groups. RD in the UF‐VMTH and VMDB groups occurred in 33% and 13% of the patients, respectively. Conclusions Cataracts were first encountered in CERF and VMDB data between 1975 and 1979 and have increased since this time. As expected, both similarities and differences between the four different populations of Bichon Frise were encountered. Both sexes of dogs are equally affected. The anterior and posterior cortical areas of the lens were first involved and dogs 2–8 years of age are most frequently affected. Cataracts affected younger dogs in the CERF group and older cataractous dogs in the other populations. Cataract formation appears to be inherited in the Bichon Frise dog. The frequency of pre‐ and postoperative retinal detachments present higher risks for cataract surgery in this breed.     

Inherited retinal dysplasia and persistent hyperplastic primary vitreous in Miniature Schnauzer dogs

The objectives of this study were to define the clinical syndrome of retinal dysplasia and persistent primary vitreous in Miniature Schnauzer dogs and determine the etiology. We examined 106 Miniature Schnauzers using a biomicroscope and indirect ophthalmoscope. The anterior and posterior segments of affected dogs were photographed. Four enucleated eyes were examined using routine light microscopy and scanning electron microscopy. A pedigree was constructed and related dogs were test-bred to define the mode of inheritance of this syndrome. Congenital retinal dysplasia was confirmed in 24 of 106 related Miniature Schnauzer dogs. Physical and postmortem examinations revealed that congenital abnormalities were limited to the eyes. Biomicroscopic, indirect ophthalmoscopic, and neuro-ophthalmic examinations confirmed that some of these dogs were blind secondary to bilateral retinal dysplasia and detachment (nonattachment) (n = 13), and the remainder had generalized retinal dysplasia (n = 11). Fifteen of these dogs were also diagnosed with unilateral (n = 9) or bilateral (n = 6) persistent hyperplastic primary vitreous. Nutritional, infectious, or toxic etiologies were not evident on physical, postmortem, light microscopic, or transmitting and scanning electron microscopic examination of four affected Miniature Schnauzers. We examined the pedigree and determined that an autosomal recessive mode of inheritance was most likely. Three test-bred litters including those from affected parents, carrier and affected parents, and carrier parents confirmed this mode of inheritance. This study confirms that retinal dysplasia and persistent hyperplastic primary vitreous is a congenital abnormality that is inherited as an autosomal recessive condition in Miniature Schnauzers.     

Hereditary eye dieseas in the Entlebucher Mountaindog in Switzerland: a retrospective study from 1999 to 2009

The aim of this study was to analyze the prevalence and the incidence of hereditary cataract and progressive retinal atrophy (PRA) in the Entlebucher Mountaindog (EMD) and to evaluate possible changes over time. In addition, the influence of selective breeding programs and DNA-testing for PRA was also investigated. Data of eye certifications for hereditary eye diseases was used. Between 1999 and 2009 a total of 798 ocular examinations were carried out in 285 EMD. 20.4 % had cataracts and 69 % of these were of the posterior polar type. PRA was diagnosed in 6.3 % of the dogs. Cataracts were diagnosed at 5.24 ± 2.71 years (mean ± standard error), while PRA was diagnosed at 4.93 ± 1.32 years of age. The incidence of PRA and cataract showed a decreasing trend (p-value > 0.2) without being significant.     

Cataract in the West Highland White Terrier

Cataracts were found in 49 of 97 interrelated West Highland White Terriers. Thirty-four dogs exhibited a ‘y’ suture cataract, mainly affecting the tips of the posterior ‘y’ suture line, while 12 dogs had complete cataracts. An autosomal recessive inheritance is surmised.     

Complex segregation analysis of deafness in Dalmatians

OBJECTIVE: To use pedigree analysis to evaluate the feasibility of a major locus model for deafness in Dalmatians. ANIMALS: 605 purebred Dalmatians from 42 families. PROCEDURE: Hearing loss was evaluated through the brainstem auditory-evoked response. Dogs were classified into mutually exclusive categories: normal hearing, unilaterally deaf, or bilaterally deaf. Information was collected on sex, coat color, presence or absence of a color patch at birth, and eye color. Statistical analyses were performed by use of regressive logistic models designed for complex segregation analysis. Genetic correlations among eye color, deafness, and color patch were estimated. RESULTS: Prevalence of hearing loss was 11% for dogs classified as unilaterally deaf and 5% for dogs that were bilaterally deaf. Complex segregation analysis detected statistical evidence of a single allele with an expected frequency of 0.21 that had an effect on the prevalence of deafness. Results of analyses suggested that this locus cannot completely explain the inheritance and incidence of deafness in Dalmatians. Genetic correlation estimates among deafness, eye color, and color patch revealed strong interrelationships among these characteristics. CONCLUSIONS AND CLINICAL RELEVANCE: To reduce the incidence of hearing loss in Dalmatians, unilaterally deaf, blue-eyed dogs should not be considered as potential parents.     

Inheritance of histiocytosis in Bernese mountain dogs

One hundred and twenty-seven cases of histiocytosis in Bernese mountain dogs (BMD) were evaluated to determine if the tumour is inherited. Family data ruled out autosomal recessive, autosomal dominant and sex-linked modes of inheritance. The trait was determined to be inherited with a polygenic mode of inheritance. The salient points permitting this conclusion are: pedigrees developed from independently selected propositi link up allowing the tracing of all cases through several generations; multiple cases occur in the same litter; multiple cases have been produced by given dams and sires; there is a higher frequency of the disease among offspring of affected parents when compared to offspring of normal parents that produced histiocytosis and all offspring in the general population of BMDs; the fact that histiocytosis is common in BMDs and rare in eight other breeds and accounts for 25·4 per cent of the 500 tumours studied in this breed. The heritability of this trait was calculated to be 0·298.     

Development of glaucoma after cataract surgery in dogs: 220 cases (1987-1998)

OBJECTIVE: To examine postoperative ocular hypertension (POH) and other variables as predictors of the risk of developing glaucoma after cataract surgery in dogs. DESIGN: Retrospective study. ANIMALS: 220 dogs that had cataract surgery. PROCEDURE: Medical records of 220 dogs (346 eyes) that had extracapsular cataract removal or phacoemulsification of cataracts were reviewed. With respect to glaucoma development, 8 variables were analyzed, which included development of POH, breed, sex, age at time of surgery, eye (right vs left), phacoemulsification time, intraocular lens (IOL) placement (yes or no), and stage of cataract development. Eyes developed glaucoma within 6 or 12 months of surgery or did not have signs of glaucoma at least 6 or 12 months after cataract surgery. RESULTS: Of 346 eyes, 58 (16.8%) developed glaucoma after surgery. At 6 months, 32 of 206 (15.5%) eyes examined had glaucoma; at 12 months, 44 of 153 (28.8%) eyes examined had glaucoma. Median follow-up time was 5.8 months (range, 0.1 to 48 months). Mixed-breed dogs were at a significantly lower risk for glaucoma, compared with other breeds. Eyes with IOL placement were at a significantly lower risk for glaucoma, compared with eyes without IOL placement. Eyes with hypermature cataracts were at a significantly higher risk for glaucoma, compared with eyes with mature or immature cataracts. CONCLUSIONS AND CLINICAL RELEVANCE: Multiple factors appear to contribute to the onset of glaucoma in dogs after cataract surgery. Complications prohibiting IOL placement during cataract surgery may lead to a high risk of glaucoma development.     

Thyroid Function and Infertility in the Dog: A Survey in Five Breeds

In our study, a clinical and reproductive examination was undertaken in 204 dogs of five different breeds. Thyroxine and thyroid-stimulating hormone plasma concentrations were assayed in order to assess the real incidence of hypothyroidism associated with reproductive disease. Among these animals, only two breeds were affected by hypothyroidism (4.5% of the Dogue de Bordeaux and 2.4% of the Leonbergers). Moreover, these animals did not suffer from any reproductive disease. Our study showed also that 70% of the male Dogue de Bordeaux were hypothyroxinemic compared with Great Danes, English Mastiff and Leonbergers whose male population was 100% normothyroidic. We found the same tendency in bitches. In our data, there was no difference in thyroxin plasma concentrations between normo- and hypofertile dogs, but our results were not statistically significant.     

The effect of a topical antioxidant formulation including N-acetyl carnosine on canine cataract: a preliminary study

OBJECTIVE: To determine the efficacy of a topical antioxidant formulation including N-acetyl carnosine in the treatment of canine cataract in a preliminary nonplacebo, controlled, unmasked study. ANIMALS STUDIED: Thirty dogs of varying breeds and ages with a spectrum of lens opacities ranging from nuclear sclerosis to total mature cataract. METHODS: Dogs were treated three times daily with topical 2% N-acetyl carnosine in a buffered vehicle containing the antioxidants glutathione, cysteine ascorbate, L-taurine and riboflavin (Ocluvet, Practivet, Phoenix, AZ, USA). Dogs were examined prior to treatment and at 2, 4 and 8 weeks during treatment, by direct and indirect ophthalmoscopy and slit-lamp biomicroscopy after pharmacologic pupil dilation. Photographic documentation of lens opacity was achieved by retroillumination photography, with three photographs taken at each examination time-point. A lens opacification index (LOI), determined by integration of the grayscale level of each pixel across the image, was evaluated by computerized image analysis of digitized images. Alteration in mean LOI was determined for each animal, having normalized the initial LOI. RESULTS: Fifty-eight eyes of 30 dogs were evaluated, 22 with mature cataract, 13 with immature cataract, 9 with cataract associated with other intraocular disease such as uveitis and 14 with nuclear sclerosis alone. One dog was unilaterally anophthalmic after previous enucleation and one had a phthytic eye after previous uveitis-induced glaucoma. Image analysis showed a reduction in mean LOI in all cataract groups (mean resolution in opacity of 2.3 +/- 0.33% for all cataracts), although this was only statistically significant in those eyes with immature cataract (mean resolution of opacity 4.5 +/- 0.33%) or nuclear sclerosis (mean decrease in opacity 5 +/- 0.37%). Reduction in lens opacity was seen in eyes with mature cataract (0.5 +/- 0.4%) and in miscellaneous cataract associated with intraocular inflammation (1.3 +/- 0.4%), but these changes were not statistically significant. Owner evaluation of visual capability, however, suggested improvement in vision in 80% of cases by the end of the study. CONCLUSIONS: This study demonstrates some marginal reduction in lens opacification in a substantial number of cases of canine cataract with the use of a topical nutritional antioxidant formulation including N-acetyl carnosine. Lens opacification was improved with treatment in eyes with immature cataract or nuclear sclerosis while in eyes with mature cataract or cataract with associated intraocular inflammatory pathology less reduction was seen.     

Histologic and immunohistochemical characterization of lens capsular plaques in dogs with cataracts

OBJECTIVE: To determine histologic and immunohistochemical characteristics of the multifocal adherent plaques that commonly develop on the internal surfaces of the anterior and posterior lens capsules in dogs with cataracts. SAMPLE POPULATION: 31 anterior and 4 posterior capsular specimens collected during lens extraction surgery in dogs with cataracts. PROCEDURE: Specimens were evaluated, using light and transmission electron microscopy. Immunohistochemical techniques were used to localize cytokeratin, vimentin, alpha-smooth muscle-specific actin, fibronectin, tenascin, and transforming growth factor-beta (TGF-beta) within plaques. RESULTS: Histologically, plaques comprised elongated spindle-shaped cells that formed a placoid mass. Cells were embedded in an extracellular matrix containing collagen fibrils, often with duplicated or split basement membranes. Immunohistochemically, normal lens epithelial cells and cells within plaques stained for vimentin. Most cells and some areas of the extracellular matrix within plaques stained for TGF-beta and alpha-smooth muscle-specific actin. Fibronectin and tenascin were also detected in the extracellular matrix. CONCLUSIONS AND CLINICAL RELEVANCE: Canine lens capsular plaques are histologically and immunohistochemically similar to posterior capsule opacification and subcapsular cataracts in humans, which suggests that the canine condition, like the human conditions, is associated with fibrous metaplasia of lens epithelial cells. Transforming growth factor-beta may play a role in the genesis of capsular plaques. Because severity of plaques was correlated with stage of cataract development, earlier surgical removal of cataracts may be useful to avoid complications associated with plaque formation.     

Relationship of the degree of goniodysgenesis and other ocular measurements to glaucoma in Great Danes

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.