The diagnosis and differential diagnosis of cataract in the dog

Cataract is a common eye condition in the dog, classified in several ways and with a varied aetiology. The clinical appearance of hereditary cataract is described in the Boston Terrier, Miniature Schnauzer, Staffordshire Bull Terrier, Cavalier King Charles Spaniel, Golden Retriever, Labrador Retriever, Large Munsterlander, English Cocker Spaniel, American Cocker Spaniel, Afghan Hound, Welsh Springer Spaniel, German Shepherd Dog, Standard Poodle. Cataracts secondary to other eye diseases, both hereditary and non-hereditary, and to systemic conditions are also discussed, as well as the differential diagnosis of cataract.     

Retinal dysplasia in dogs--a review

Retinal dysplasia is a developmental aberration of the neuroretina characterized by formation of retinal tubules, malformation rosettes and folding of the retina. Retinal dysplasia has been reported in Bedlington Terrier, Sealyham Terrier, Beagle, Labrador Retriever, English Cocker Spaniel, American Cocker Spaniel, English Springer Spaniel, Yorkshire Terrier and Rottweiler. A hereditary basis for retinal dysplasia has been proved or suggested for all breeds exhibiting retinal dysplasia except Beagle and Rottweiler. Ophthalmoscopically retinal dysplasia is characterized by vermiform streaks often radiating from the optic disc. The reflectivity of the tapetum is often altered in these areas. Accompanying retinal detachment or cataractous changes in the lens may be seen. Extensive retinal dysplasia and retinal detachment or cataract may result in visual impairment or blindness. Eyes exhibiting retinal dysplasia may be classified according to the number of layers from the retinal structure that are represented in the rosettes. Three-layer rosette. Two-layer rosette. Single-layer rosette. Primitive unilayer rosette. The etiology of retinal dysplasia includes viral disorders, irradiation, X-radiation, intrauterine trauma and heritable factors.     

Opinions of veterinarians regarding aggression in different breeds of dogs

Aggression in 108 dog breeds and six crosses was ranked by 185 members of the Companion Animal Society of the New Zealand Veterinary Association. The Rottweiler and German Shepherd were categorised as extremely aggressive and the Akita, Basengi, Chihuahua (long-coated and short-coated), Chow Chow, Cocker Spaniel, Shar pei and Welsh Corgi (Cardigan and Pembroke) were classified as very aggressive. A chi-squared test of data from the twenty most popular breeds showed that significant differences were perceived between the breeds. Cocker Spaniels, Pembroke Welsh Corgis, German Shepherds and Rottweilers were more aggressive than Staffordshire Bull Terriers, Border Collies and Doberman Pinchers, which were more aggressive than Cavalier King Charles Spaniels, Bichon Frise, English Springer Spaniels, German Shorthaired Pointers, Weimaraners, Labrador Retrievers, Golden Retrievers, Newfoundlands, Dalmatians, Boxers, Bulldogs, Bull Mastiffs and Rough Collies.     

Neutrophil function in dogs with congenital ciliary dyskinesia.

In vitro neutrophil function was assessed in two English Springer Spaniel dogs, two Bichon Frise dogs, and one Chow Chow dog with congenital ciliary dyskinesia; three clinically normal English Springer Spaniel dogs that were presumed heterozygous for congenital ciliary dyskinesia; and five control dogs. Chemotaxis and random migration in affected and heterozygous dogs were found to be comparable to those of control dogs. Increased (P less than or equal to 0.05) neutrophil adhesion, antibody dependent cell-mediated cytotoxicity, iodination of proteins, and oxygen radical production in neutrophils from affected dogs were probably the result of chronic bacterial infection in vivo. Bacterial ingestion by neutrophils from the three heterozygous English Springer Spaniel dogs was significantly increased compared to control dogs but was not different from affected English Springer Spaniel dogs, suggesting a breed-related phenomenon. Significant decreases in neutrophil function were not seen in any of the dogs with congenital ciliary dyskinesia, indicating that a defective microtubular system is not shared by respiratory cilia and neutrophils and that defective neutrophil function does not contribute to respiratory infection.     

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.     

Hereditary cataract in the dog

Hereditary cataract in the dog is described as it occurs in the Boston Terrier, the Staffordshire Bull Terrier, the Miniature Schnauzer, the Golden Retriever, the Labrador Retriever, the American Cocker Spaniel, the Afghan Hound, and the Old English Sheepdog. The mode of inheritance in each breed is also discussed and includes both dominant and recessive patterns.     

Neurolymphomatosis in a dog with B-cell lymphoma

Lymphoma in the left femoral nerve of a 10-year-old English Cocker Spaniel caused complete paralysis of the affected limb. Neoplastic cells were immunopositive for CD79a and Pax5 and negative for CD3. Neoplastic cells were in multiple lymph nodes and one kidney but spared bone marrow. The clinical and histologic features in this case resemble those of the rare human condition of neurolymphomatosis.     

A gonioscopic study of the iridocorneal angle in the English and American breeds of Cocker Spaniel and the Basset Hound

Closure of the iridocorneal angle is the cause of a primary form of glaucoma which occurs in certain breeds of dog, but the precise mechanism involved in that closure is not completely understood. However, narrowness of the angle is considered to be the important predisposing factor, and in gonioscopic survey work the author has demonstrated that angle narrowness occurs with some frequency in the English Cocker Spaniel and Basset Hound breeds.     

Congenital orbital cysts of neural tissue in two dogs

A 3-month-old English Cocker Spaniel and a 6-month-old miniature poodle presented with clinical signs related to an abnormal right eye since birth. In both dogs, the right globe could not be identified and was replaced by a fluctuant intraorbital mass covered by a vascularized mucous membrane. Ultrasonography demonstrated that both masses were cystic structures markedly larger in size than the normal contralateral globes. In both cases, surgical excision revealed a multilobular cyst filling the whole orbital cavity. Histopathologic examination and immunostaining for glial fibrillary acid protein and S100 protein supported a diagnosis of neural cysts associated with ocular dysplasia. The definitive diagnosis was congenital cystic eye and microphthalmos with cyst for the Cocker Spaniel and miniature poodle, respectively. Karyotype was normal in both dogs. Congenital cystic eye and microphthalmos with cyst result from defects in early embryonic life that arise following formation of the optic vesicle and prior to closure of the optic fissure. To the authors' knowledge neither has been reported in the canine species. They should be considered in the differential diagnosis of orbital cysts in dogs.     

Transient hypoparathyroidism following successful treatment of hypercalcaemia of malignancy in a dog

A 4-year-old, entire female, English Cocker Spaniel was presented for treatment of lymphosarcoma and secondary hypercalcaemia. After induction chemotherapy the dog became severely hypocalcaemic and showed signs of weakness, muscle fasciculation and facial pruritus. Hormone analysis confirmed inadequate production of parathyroid hormone. Although hypocalcaemia has been previously reported as a component of tumour lysis syndrome, it has not been associated with transient parathyroid hormone deficiency.     

Interference of an algal nutritional supplement with a urinary metabolic screening test for glycosaminoglycans in a dog suspected to have a storage disease

The finding of excess urinary glycosaminoglycans (GAG) is the first step in the laboratory diagnosis of mucopolysaccharidosis (MPS). Urinary screening tests are based upon the binding of GAG to dimethylmethylene blue. Alternatively, paper spot tests using toluidine blue are used in human and veterinary laboratory medicine. Positive samples undergo GAG isolation for subsequent characterization. Here, we describe a 3‐year‐old English Cocker Spaniel with a positive urinary GAG test, but without other clinical signs of MPS. Urine samples were strongly positive with the dimethylmethylene blue test, and isolated GAG subjected to electrophoresis on cellulose acetate revealed a band co‐migrating with dermatan sulfate. However, the isolated GAG were resistant to digestion with chondroitinase ABC, suggesting that the band did not represent dermatan sulfate. This was confirmed by mobility of the isolated GAG different from dermatan sulfate on agarose gel electrophoresis. MPS types VI and VII were excluded by enzyme assay. To test the hypothesis of a nutritional source, a healthy control dog was fed the same dog food as the index case. His urine showed a comparable abnormal GAG screening test and electrophoretic pattern. In addition, the analysis of an algal supplement present in the administered dog food showed a similar electrophoretic GAG pattern. The Cocker Spaniel was not available for further testing after withdrawal of the supplement. Algae contain highly sulfated fucans and galactans, and it appears that commercial dog food containing such algal, and possibly other, supplements can give rise to false‐positive urinary MPS screening tests.     

Nonspherocytic haemolytic anaemia due to phosphofructokinase deficiency in an English Springer Spaniel

A five-year-old female English Springer Spaniel was evaluated for chronic episodic anaemia, pigmenturia and icterus. There was increased erythrocyte pyruvate kinase activity, increased in vitro erythrocyte alkaline fragility, decreased erythrocyte 2,3-diphosphoglycerate activity and severely decreased erythrocyte phosphofructokinase activity. The clinical features and haematological values were identical with erythrocyte phosphofructokinase deficiency and resulting nonspherocytic haemolytic anaemia recently described in this breed.     

Prevalence of the breed-related glaucomas in pure-bred dogs in North America

Objective To determine the prevalence of the breed‐related glaucomas in pure‐bred dogs presented to the veterinary medical teaching hospitals in North America that participate in the Veterinary Medical Data Base (VMDB). Materials and methods In this retrospective study, age of first diagnosis, breed, and gender data for all breeds of dogs were collected from the VMDB with the clinical diagnosis of primary glaucoma (glaucoma‐NOS) at 5–10 year intervals from 1964 to 2002. The prevalence for each breed (affected dogs compared to all dogs of each breed), any changes over the 38 years, and any gender differences for these glaucomas were determined. Results The prevalence of the primary breed‐related glaucomas has gradually increased from 0.29% (1964–1973); 0.46% (1974–1983); 0.76% (1984–1993); to 0.89% (1994–2002). Breeds that consistently featured among the highest 10 for glaucoma prevalence from four different periods (1964 to 2002) included American Cocker Spaniel, Basset Hound, Wire Fox Terrier, and Boston Terrier. During the last observation period (1994–2002), 22 different breeds had 1% or higher prevalence of the glaucomas. The highest prevalence of glaucomas in 1994–2002 by breed included: American Cocker Spaniel (5.52%); Basset Hound (5.44%); Chow Chow (4.70%); Shar‐Pei (4.40%); Boston Terrier (2.88%); Wire Fox Terrier (2.28%); Norwegian ElkHound (1.98%); Siberian Husky (1.88%); Cairn Terrier (1.82%); and Miniature Poodle (1.68%). A predominance of females with glaucoma occurred in the American Cocker Spaniel, Basset Hound, Cairn Terrier, Chow Chow, English Cocker Spaniel, Samoyed, and perhaps the Siberian Husky, and a predominance of males in the Australian Cattle dog and St Bernard. Age affected the time for first presentation of the glaucomas in the pure‐bred dog. In the majority of breeds the glaucomas were presented for initial diagnosis in dogs between 4 and 10 years of age. Conclusion Breed‐related glaucomas in pure‐bred dogs are frequently presented to the veterinary medical teaching hospitals in North America. The prevalence of the breed‐related glaucomas in the dog appears similar to humans, and in some breeds exceeds that in humans. In many breeds the high prevalence of the glaucomas suggests a genetic basis.     

Pectinate ligament dysplasia and narrowing of the iridocorneal angle associated with glaucoma in the English Springer Spaniel

Objective The aim of the study was to evaluate if tonometry and gonioscopy could serve as predictors of later glaucoma development in the English Springer Spaniel, a breed prone to developing primary glaucoma. Animals studied Gonioscopy was performed on 279 English Springer Spaniel dogs, 119 males and 160 females, with clinically normal eyes. In addition, 14 dogs, five males and nine females were examined for glaucoma. Results A positive relation between pectinate ligament dysplasia (PLD) and narrowing of the relative width of the ciliary cleft (RWOCC) and also between PLD, RWOCC and age was demonstrated. The prevalence of PLD was 25.5%, which is higher than in other breeds reported. A positive association was demonstrated between PLD and glaucoma, as well as between narrowing of the RWOCC and glaucoma. Glaucoma was not observed in dogs with normal appearance of the iridocorneal angle. English Springer Spaniels related to dogs with glaucoma show more narrowing of the RWOCC and more PLD than unrelated dogs. Conclusion This study demonstrates the positive association between PLD and glaucoma, between narrowing of the iridocorneal angle and glaucoma and the effect of age on the iridocorneal angle. Mating of dogs with normal iridocorneal angles appears to reduce the presence and degree of abnormal appearance of the iridocorneal angle in the offspring. However, breeding only dogs with normal iridocorneal angles without consideration of their relationship to dogs with glaucoma is not a guarantee for preventing glaucoma in the offspring.     

Inherited lysosomal storage disease in an English springer spaniel.

Alpha-L-fucosidosis was diagnosed in a 17-month-old English Springer Spaniel with a history of slow development and progressive visual impairment. Lymphocytes and mononuclear cells with vacuolated cytoplasm were seen in a blood smear and in CSF, respectively. A severe deficiency of alpha-L-fucosidase activities in plasma and leukocytes was determined. Histologic examination revealed vacuolation of neurons, macrophages, and epithelial cells in most organ tissues. Canine fucosidosis is a progressive and fatal lysosomal storage disease in English Springer Spaniels. Affected dogs develop a neurologic disorder characterized by progressive motor and mental deterioration. Visual impairment is an unusual primary sign in a dog with alpha-L-fucosidosis.     

Malignant thymoma with widespread metastases in a dog: case report and brief literature review

A malignant thymoma of epithelial type with metastases to the liver, spleen and bone marrow in a 16 year old female Cocker Spaniel dog is described. Lesions were considered to be incidental findings at necropsy.     

Dilated cardiomyopathy in an American Cocker Spaniel with taurine deficiency

An American Cocker Spaniel with low plasma taurine concentration (< 2 nmol/mL) was presented with dyspnoea associated with pulmonary oedema and a left ventricular shortening fraction of 9%. Emergency therapy with furosemide, dobutamine, nitroglycerine and oxygen supplementation led to a good response. Chronic therapy was started with enalapril, furosemide, digoxin and taurine. Improvement in all echocardiographic indices were noted over a 22 week follow-up, most notably an increase in left ventricular shorteningfraction to 20%, a decrease of E-point septal separation from 14 mm to 7 mm and marked left ventricular remodelling. This degree of improvement in myocardial function may represent a direct link between dilated cardiomyopathy in the American Cocker Spaniel andplasma taurine deficiency. Alternatively, this response may reflect a breed-related cardiomyopathy with a natural history and therapeutic response not commonly seen in the morecommon large breed cardiomyopathy presentations.     

Acupuncture treatment for idiopathic Horner's syndrome in a dog

A one-year-old female English Cocker Spaniel dog with idiopathic Horner''s Syndrome is described. The specific clinical signs in this specimen were miosis, ptosis, enophthalmos, and prolapsed nictitans for 2 days following sudden onset. According to history taking, ophthalmic, neurological, and radiological examination, the patient was diagnosed with idiopathic Horner''s syndrome. Manual acupuncture treatment was applied to the dog on local points two times in 2 days. The local acupoints were ST-4 (Di Chang) and GB-1 (Tong Zi Liao). The day after the initial acupuncture treatment, clinical signs related to idiopathic Horner''s syndrome had almost disappeared. The day after the second treatment, specific clinical signs were completely absent. During this period, the dog did not receive any orthodox treatment. Thus, it is suggested that manual acupuncture might be an effective therapy for idiopathic Horner''s syndrome.     

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.