A retrospective study on the prevalence of primary cataracts in two pedigrees from the German population of English Cocker Spaniels

Objective  Two pedigrees from the German English Cocker Spaniel population are presented to illustrate the familial occurrence of primary cataract (CAT) in single- and multicolored English Cocker Spaniels. The aim was to characterize similarities and differences in the prevalence and formation of CAT in these separately bred color variants of English Cocker Spaniels.
Materials  The study was based on the veterinary records for presumed inherited eye diseases of 1232 English Cocker Spaniels which were provided by the German panel of the European Eye Scheme for diagnosis of inherited eye diseases in animals (DOK, < http://www.dok-vet.de >). Data included information on 615 single-colored and 617 multicolored English Cocker Spaniels.
Results  CAT was diagnosed in 92 (14.96%) of the single-colored and 34 (5.51%) of the multicolored English Cocker Spaniels. The pedigree of the single-colored English Cocker Spaniels included 40 ophthalmologically examined dogs with 18 unaffected and 22 affected dogs. The pedigree of the multicolored English Cocker Spaniels contained 16 ophthalmologically examined dogs with 11 unaffected and five affected dogs.
Conclusions  In both color variants of the English Cocker Spaniels different forms of primary CAT with respect to location within the lens occurred among close relatives. Appearance of CAT was very heterogeneous without obvious sex differences. The sample pedigrees do not support the assumption of familial segregation of specific forms of primary CAT in English Cocker Spaniels.     

Analysis of systematic and genetic effects on the prevalence of different types of primary lens opacifications in the wild-boar-colored wirehaired Dachshund

The aims of this study were to analyze the influence of systematic environmental effects on the prevalence of primary non-congenital cataract (CAT), fibreglass cataract in the nucleus (FCN), and prominent suture lines (PSL) and to estimate the heritabilities of these eye diseases in the wild-boar-colored wirehaired Dachshunds (WWD) bred in the German Dachshund Club 1888 e.V. (DTK). Data included 2,430 WWD born between 1995 and 2003 that were examined between 1996 and 2005 by veterinary ophthalmologists. CAT was diagnosed in 3.83% of the 2,430 dogs, FCN in 3.74%, and PSL in 2.76%. Sex, size, inbreeding coefficient, the age of the dog at examination, experience of the veterinary ophthalmologist and the additive genetic effect of the animal were considered in the multivariate linear model. The age of the dog at examination had a significant influence on the prevalence of FCN. The degree of experience of the veterinary ophthalmologist significantly influenced the prevalence of FCN and PSL. Using a transformation into the Dempster-Lerner threshold model, heritability estimates (h(DL)2) for WWD were h(DL)2 = 0.39 +/- 0.13 for CAT, h(DL)2 = 0.36 +/- 0.11 for FCN and h(DL)2 = 0.49 +/- 0.12 for PSL. Positive genetic correlations (r(g)) were found between CAT and FCN (r(g) = 0.58 +/- 0.21), between PSL and FCN (r(g) = 0.83 +/- 0.23), and between CAT and PSL (r(g) = 0.79 +/- 0.06). The eye diseases investigated here in the Dachshund were found to be genetically influenced and positively correlated traits.     

Three hundred and three dogs with cataracts seen in Rio de Janeiro, Brazil

Objective  To describe the most common canine breeds affected with cataracts in Rio de Janeiro.
Animals  Three hundred and three dogs were included in this retrospective study. Animal ages ranged from 6 months to 14.8 years.
Material and methods  All records of dogs seen by the Ophthalmology Service of Policlínica Veterinária Botafogo between January 2005 and June 2008 were reviewed. Animals with cataracts were separated, and breed and age were evaluated.
Results  Most of the dogs presented with cataracts were Toy Poodles with a mean age of 8.2 years, followed by Cocker Spaniels and Bichon Frises. The percentage of Toy Poodles affected with cataracts was 13.8% while 33.3% of Bichon Frise was diagnosed with cataracts.
Conclusions  Toy Poodles are a popular breed in Rio de Janeiro. Without regulations on breeding, the prevalence of cataracts may increase rapidly. Furthermore, due to the relatively late onset of cataract formation in the Toy Poodle (mean 8.2 years of age), affected animals may have produced several litters of puppies. This study emphasizes the importance of screening for the presence of inherited ocular abnormalities such as cataracts prior to breeding.     

Clinical description and mode of inheritance of idiopathic epilepsy in English springer spaniels

OBJECTIVE: To determine clinical characteristics and mode of inheritance of idiopathic epilepsy (IE) in English Springer Spaniels. DESIGN: Original study. ANIMALS: 45 dogs with IE and 74 siblings and their respective parents. PROCEDURE: IE was diagnosed on the basis of age at the time of seizure onset and results of laboratory testing and neurologic examinations. Simple segregation analysis was performed with the Davie method. RESULTS: Median age at the onset of seizures was 3 years; however, 9 (20%) dogs were between 5 and 6 years old at the time of the onset of seizures. Twenty-one dogs (47%) had generalized seizures, and 24 (53%) had focal onset seizures. Results of segregation analysis were consistent with partially penetrant autosomal recessive or polygenic inheritance. Simulated linkage indicated that there was a 58% chance of obtaining suggestive linkage with the available pedigrees. CONCLUSIONS AND CLINICAL RELEVANCE: Results of the present study suggest that in English Springer Spaniels, IE segregates in a manner that is consistent with partially penetrant autosomal recessive inheritance (ie, a single major locus with modifying genes) or polygenic inheritance. Given enough families with accurate phenotypic information and available DNA, it should be possible to use genetic linkage analysis to identify chromosomal segments containing the causative gene or genes.     

Characterization of chronic pancreatitis in English Cocker Spaniels

Background: Chronic pancreatitis (CP) is common in dogs. The cause is unknown. In humans, different causes of pancreatitis have histologically distinct appearances. The histopathologic lesions in English Cocker Spaniels (ECS) with CP were noted to be histologically different than those of other breeds with CP. Hypothesis: CP in ECS is distinct from CP in other breeds and is characterized by a duct destruction similar to what is observed in autoimmune CP of humans. Animals: Eight ECS and 9 other breeds with histologically confirmed CP recruited over an 8‐year period and 50 postmortem control dogs with CP. Methods: Clinical, clinicopathological, and ultrasonographic findings were recorded. Histological sections were compared with a normal dog and 59 dogs of other breeds with CP. Immunohistochemistry using anti‐CD3, anti‐CD79a, and anti‐cytokeratin antibodies was used to evaluate distribution and type of lymphocytic inflammation and appearance of pancreatic ducts. Results: Four male and 4 female ECS presented at a mean age of 7.2 years. Clinical signs were similar in ECS and other breeds. The pancreas was enlarged and hypoechoic in 4 ECS and 2 controls. Histopathology was characterized by interlobular and periductular fibrosis and inflammation in ECS compared with intralobular disease in most other breeds. Immunohistochemistry identified prominent anti‐CD3⁺ lymphocytic infiltrates around venules and ducts and a marked absence of interlobular ducts in ECS compared with mixed T‐cell infiltration and ductular hyperplasia in most other breeds with CP. Conclusions and Clinical Importance: CP in ECS is distinct from CP in other breeds and is notably duct destructive.     

Pulverulent nuclear cataract in the Norwegian buhund

Pulverulent cataracts were diagnosed in 52 of 102 Norwegian buhunds, with both sexes being equally affected. All the dogs were otherwise considered clinically healthy. Initial lens changes were visible from six and a half weeks of age as small dots parallel to the suture lines behind the nucleus. Gradually, the opacities along the suture lines became more opaque until, by the age of four to five and a half years, they had progressed to involve the fetal nucleus which then resembled a ball of candy floss. The outer part, the adult nucleus, usually remained clear, and the cortex was not involved. The ages of the dogs in the present study ranged from three and a half weeks to 12 years at first examination. An outcross of an affected bitch to a mixed-breed dog resulted in three puppies, of which two were affected. The retinas could be evaluated in all the examined dogs, and revealed no abnormalities except for one case of focal retinopathy. In addition to the pulverulent cataracts, 10 cases of cortical cataracts were diagnosed, three of which also had pulverulent cataracts. Based on the pedigrees, an autosomal dominant mode of inheritance with a high degree of penetrance is suggested for pulverulent cataract.     

Congenital hereditary cataract in Cocker Spaniels

Cases of congenital cataract in red Cocker Spaniels are reported. The investigation comprised clinical, histological and genetic studies. The common feature was bilateral, congenital, partial cataract of non-progressive nature.
Typically the cataract was localized subcapsularly at the anterior pole of the lens. In some cases it was of a more diffuse extent. In a few cases the cataract co-existed with persisting pupillary membrane, microphthalmia, hypotonia and rotatory nystagmus. Histopathological examination of affected eyes confirmed the clinical findings.
The disease appears to be of hereditary nature. The genetic studies on the condition in this breed of dogs showed that the mode of inheritance is presumably complex.     

National survey of owner-directed aggression in English Springer Spaniels

OBJECTIVE: To determine prevalence of owner-directed aggression and identify associated environmental and genetic factors in English Springer Spaniels. DESIGN: Prevalence survey. ANIMALS: 1,053 adult English Springer Spaniels. PROCEDURE: A mail survey was sent to 2,400 randomly selected owners of adult American Kennel Club-registered English Springer Spaniels. Dogs with a history of aggression to family members and familiar humans were compared with dogs without such a history. RESULTS: 1,053 questionnaires (56.1% of the 1,877 delivered) were completed. A history of owner-directed growling or more intense aggression was reported in 510 (48.4%) dogs. Two hundred seventy-seven (26.3%) dogs had bitten a human in the past; 65.2% of bites were directed at familiar (owner or nonowner) adults and children. Variables associated with owner-directed aggression included sex of dog (male), neuter status (neutered, regardless of sex), show or bench lines, age > 4 years, aggression to unfamiliar adults and children, acquisition from a hobby breeder, less responsiveness to obedience cues, and a specific kennel and 1 popular sire from that kennel in a 4-generation pedigree. CONCLUSIONS AND CLINICAL RELEVANCE: Owner-directed aggression in adult English Springer Spaniels was associated with a number of environmental, sex-related, and inherited factors. To reduce the risk of aggression, prospective owners might seek a female, hunting-type English Springer Spaniel from an experienced breeder. However, because risk factors are broad and varied, there are limitations to the extent to which behavior can be predicted and further study is needed of the inheritance of aggression in this breed.     

Breed variations in histopathologic features of chronic severe otitis externa in dogs: 80 cases (1995-2001)

OBJECTIVE: To compare pathologic changes of the horizontal ear canal associated with chronic severe otitis externa between Cocker Spaniels and dogs of other breeds. DESIGN: Retrospective study. ANIMALS: 80 dogs with severe otitis externa that required total ear canal ablation with lateral bulla osteotomy. PROCEDURE: Medical records were reviewed for breed, sex, and age at time of surgery. Histologic specimens from the horizontal ear canal were evaluated by a single examiner for overall tissue response pattern and scored for sebaceous gland hyperplasia, ceruminous gland hyperplasia, ceruminous gland ectasia, fibrosis, pigment-laden macrophages, and osseous metaplasia. RESULTS: 48 of 80 (60%) dogs were Cocker Spaniels. Thirty-five of 48 (72.9%) Cocker Spaniels had a predominately ceruminous tissue response pattern; only 9 of 32 (28.1 %) dogs of other breeds had the same pattern. Other breeds most commonly had a pattern dominated by fibrosis (n = 13 [40.6%]); fibrosis was the predominant pattern in only 4 of 48 (8.3%) Cocker Spaniels. Discriminant analysis and K-means clustering of 4 histopathologic criteria correctly classified 75% of the dogs as Cocker Spaniels or all other breeds. CONCLUSIONS AND CLINICAL RELEVANCE: Cocker Spaniels are at increased risk for chronic severe otitis externa requiring total ear canal ablation with lateral bulla osteotomy, indicating that earlier and more aggressive management of the primary otitis externa and secondary inflammation is warranted in this breed. Cocker Spaniels with chronic severe otitis externa have distinct differences in pathologic characteristics of the horizontal ear canal, compared with other breeds.     

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.     

Long-term complications after phacoemulsification for cataract removal in dogs: 172 cases (1995-2002)

OBJECTIVE: To determine common postoperative complications and risk factors for development of postoperative glaucoma or failure to preserve vision after phacoemulsification for cataract removal in dogs. Design-Retrospective case series. ANIMALS: 172 dogs (290 eyes) that underwent phacoemulsification surgery for cataract removal. PROCEDURE: Medical records were reviewed for postoperative complications; prevalence rates for each complication were calculated for follow-up periods of 3 months, > 3 to 6 months, > 6 months to 1 year, > 1 to 2 years, > 2 to 3 years, > 3 to 4 years, and > 4 years. Odds ratios for breed, age, sex, cataract hypermaturity, lens-induced uveitis, and diabetes mellitus were determined with respect to glaucoma and failure (ie, blindness, enucleation, or evisceration). RESULTS: The most common complication was mild posterior capsule opacification. Retinal detachment was uncommon (1% to 2%) for all time periods. Prevalence of glaucoma increased with time, although it remained < 10% until after the 1-year follow-up period. Boston Terriers, Cocker Spaniels, Cocker Spaniel-Poodle crosses, and Shih Tzus had increased risk of developing glaucoma. Eyes with hypermature cataracts were more likely to develop glaucoma. Prevalence of failure increased with time, although it remained < 10% until after the 3-year follow-up period. Cocker Spaniel-Poodle cross and Shih Tzus were more likely to have failure. CONCLUSIONS AND CLINICAL RELEVANCE: Evaluation of breed and cataract hypermaturity may aid in the selection of patients. The increasing prevalence of postoperative complications with time indicated that longterm monitoring is warranted.     

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.     

Genomic screening for fucosidosis in English Springer Spaniels.

OBJECTIVE: To develop a robust molecular genetic test for alpha-L-fucosidosis in English Springer Spaniels and to screen dogs from the United Kingdom and United States for the mutant allele. ANIMALS: 35 English-bred English Springer Spaniels, 60 American-bred English Springer Spaniels, and 1 affected dog and its parents from a family of English Springer Spaniels in Colorado. PROCEDURE: Polymerase chain reaction analysis was used to amplify the mutated region in the gene encoding alpha-L-fucosidase. High guanine-cytosine (GC) content of the region required use of an amplification buffer with high pH. Mutant and normal alleles were separated by polyacrylamide gel electrophoresis. Molecular genetic test results were compared with enzyme data. RESULTS: A 262-bp PCR product was amplified from normal dogs and compared with a 248-bp product from affected dogs. Carriers had 1 copy of each allele, distinguishable by the 14-bp size difference. Two carriers among the English-bred dogs were identified by use of enzyme and genomic DNA analyses. The molecular defect in dogs from Colorado was proven to be the same as that in British and Australian dogs. None of the other 60 American-bred dogs carried the mutant allele. CONCLUSIONS AND CLINICAL RELEVANCE:A PCR method that can be used to identify dogs affected with or carriers of the autosomal recessive disease fucosidosis was established. Amplification was achieved within a GC-rich region, using a method that may be useful in overcoming amplification problems in GC-rich areas within other genes. Using this test, fucosidosis can be controlled and ultimately eradicated from the English Springer Spaniel population.     

COMPARISON OF CLOSURE TIMES FOR CRANIAL BASE SYNCHONDROSES IN MESATICEPHALIC,BRACHYCEPHALIC, AND CAVALIER KING CHARLES SPANIEL DOGS

Premature closure of cranial base synchondroses has been proposed as the mechanism for brachycephaly in dogs and caudal occipital malformation syndrome (COMS) in Cavalier King Charles Spaniels. The purpose of this retrospective study was to compare times of closure for cranial base synchondroses in mesaticephalic, brachycephalic, and Cavalier King Charles Spaniel dogs. Cranial magnetic resonance imaging studies were retrieved for client‐owned dogs less than 18 months of age. Breed, age, skull conformation, and the open or closed state of cranial base synchondroses were independently recorded by two observers. For dogs with a unanimous observer agreement, regression analysis was used to test effects of age and gender on the open or closed status of synchondroses and differences between groups. A total of 174 dogs were included in MRI interpretations and 165 dogs were included in the regression analysis. Statistically significant differences in closure time of the spheno‐occipital synchondrosis were identified between brachycephalic and mesaticephalic dogs (P = 0.016), Cavalier King Charles Spaniels and mesaticephalic dogs (P < 0.0001), and Cavalier King Charles Spaniels and brachycephalic dogs (P = 0.014). Findings from the current study supported the theory that morphological changes leading to the skull phenotype of the Cavalier King Charles Spaniels could be due to an earlier closure of the spheno‐occipital synchondrosis.     

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.     

Genetic analysis of presumed inherited eye diseases in Tibetan Terriers

We analysed the systematic environmental influences and the additive genetic variation for the presumed inherited eye diseases (PIED), membrana pupillaris persistens, distichiasis, primary lens luxation, non-congenital cataract, and progressive retinal atrophy, in Tibetan Terriers. Data were obtained from the International Kennel Club for Tibetan dog breeds in Germany. PIED were recorded in the years 1987 to 2001 by standardised protocols of the Dortmunder Kreis, the association for diagnosis of inherited eye diseases in animals (DOK). The material included 849 Tibetan Terriers from 596 litters in 203 different kennels. The multivariate linear animal model using residual maximum likelihood methods regarded the fixed effects of sex, birth year, experience of the veterinary ophthalmologist, litter size, percentage of examined dogs per litter, inbreeding coefficient, and age at examination. The common environment of the litter and the additive genetic effect of the animal were taken into account as randomly distributed effects. The heritability estimates for PIED in Tibetan Terriers were h2=0.17+/-0.04 (membrana pupillaris persistens), h2=0.04+/-0.03 (distichiasis), h2=0.13+/-0.04 (primary lens luxation), h2=0.13+/-0.04 (non-congenital cataract), and h2=0.49+/-0.08 (progressive retinal atrophy). The additive genetic correlation between non-congenital cataract and progressive retinal atrophy was highly positive rg=0.76+/-0.11, while that between membrana pupillaris persistens and progressive retinal atrophy rg=-0.43+/-0.14 was highly negative. The number of examinations performed by the veterinary ophthalmologists was associated with higher heritabilities for non-congenital cataract and progressive retinal atrophy. We concluded from our analysis that all investigated PIED in Tibetan Terriers are genetically influenced.     

Breed risk of pyometra in insured dogs in Sweden

An animal insurance database containing data on over 200,000 dogs was used to study the occurrence of pyometra with respect to breed and age during 1995 and 1996 in Swedish bitches <10 years of age. A total of 1,803 females in 1995 and 1,754 females in 1996 had claims submitted because of pyometra. Thirty breeds with at least 800 bitches insured each year were studied using univariate and multivariate methods. The crude 12-month risk of pyometra for females <10 years of age was 2.0% (95% confidence interval = 1.9-2.1%) in 1995 and 1.9% (1.8-2.0%) in 1996. The occurrence of pyometra differed with age, breed, and geographic location. The risk of developing pyometra was increased (identified using multivariate models) in rough Collies, Rottweilers, Cavalier King Charles Spaniels, Golden Retrievers, Bernese Mountain Dogs, and English Cocker Spaniels compared with baseline (all other breeds, including mixed breed dogs). Breeds with a low risk of developing the disease were Drevers, German Shepherd Dogs, Miniature Dachshunds, Dachshunds (normal size), and Swedish Hounds. Survival rates indicate that on average 23-24% of the bitches in the databases will have experienced pyometra by 10 years of age. In the studied breeds, this proportion ranged between 10 and 54%. Pyometra is a clinically relevant problem in intact bitches, and differences related to breed and age should be taken into account in studies of this disease.     

A cardiomyopathy in the English Cocker Spaniel: a clinico-pathological investigation

This report describes some of the characteristics of a cardiomyopathy in English Cocker Spaniels. Forty-nine dogs from a kennel with a history of a cardiomyopathy were assessed clinically, electrocardiographically and radiographically. Angiography, haemodynamic and post-mortem examinations were carried out on selected dogs. On electrocardiographic (ECG) and radiographic criteria the dogs were classified into five groups. Twenty-six dogs (Group 1) were normal. Seven dogs (Group 2) showed ECG changes compatible with left or biventricular hypertrophy in the absence of radiographic abnormality. This was interpreted as concentric hypertrophy. Seven dogs (Group 3) showed ECG and radiographic evidence of cardiac hypertrophy with five of the seven exhibiting enlargement of both chambers. The changes were considered to be compatible with eccentric hypertrophy. Post-mortem findings in dogs with ECG characteristics of Groups 2 and 3 have shown concentric hypertrophy in three cases and eccentric hypertrophy in one case. Six dogs (Group 4) had right axis deviations. Three dogs (Group 5) showed left axis deviations. It is suggested that a cardiomyopathy exists in English Cocker Spaniels initially developing as a concentric hypertrophy and progressing to eccentric hypertrophy. At present the aetiology is unknown.