Secondary glaucomas in the dog in North America

OBJECTIVE: To determine the prevalence of secondary glaucomas in dogs associated with cataract formation, lens luxation or displacement, cataract surgery, uveitis, hyphema and intraocular neoplasia. METHODS: Information was obtained from the Veterinary Medical Data Base (VMDB) from all veterinary medical teaching hospitals in North America from March 1964 to March 2003. Secondary glaucomas were diagnosed at the same examination or after the primary diagnosis was made, and included those associated with cataract formation, lens luxation, cataract surgery, uveitis of unknown cause, hyphema of unknown cause, and intraocular neoplasia. The data were evaluated by decade, breed, gender and age of presentation. RESULTS: A total of 1 592 831 dogs were presented, and 9695 canine secondary glaucomas. Secondary glaucoma associated with cataract formation represented 81% of all the canine secondary glaucomas. Breeds (n = 7890 dogs) predisposed to secondary glaucoma and cataracts had an overall prevalence of 0.5%, but nearly 20% of all the cataractous dogs developed secondary glaucoma in at least one eye. For the years 1994-2003, these breeds included the American Cocker Spaniel; Boston Terrier; Toy, Miniature and Standard Poodle; English Springer Spaniel; Bichon Frise; and Labrador Retriever. The other forms of secondary glaucoma occurred less frequently, and included those glaucomas with lens luxation or displacement (779 dogs; 12.0%), postcataract surgery (528 dogs; 5.1%), with uveitis from unknown cause (399 dogs; 7.1%), with hyphema from unknown cause (117 dogs; 7.3%), and with intraocular neoplasia (19 dogs; 3.5%). The risk of the secondary glaucomas from 1984 to 2002 was highest after the intracapsular lens extraction (ICLE), less in the extracapsular technique (ECLE), and lowest for the phacoemulsification/phacofragmentation method. CONCLUSION: Prevalence of the canine secondary glaucomas ranges from 0.25% (1964-1973), 0.46% (1974-1983), 0.79% (1984-1993), to 0.80% (1994-2003) and are as frequent as the primary or breed-related glaucomas during these same time periods.     

Effects of risk factors and prophylactic treatment on primary glaucoma in the dog

Seventy dogs from 26 breeds were admitted with primary glaucoma between January 1979 and December 1983. Compared with mixed-breed dogs, 8 breeds were at higher risk (P less than 0.01) of developing glaucoma: Basset Hound, Beagle, Boston Terrier, Cocker Spaniel, Dalmatian, Miniature Poodle, Norwegian Elkhound, and Siberian Husky. Dogs between the ages of 5 and 10 years were at increased risk (P less than 0.001). There was no predisposition for either eye to be affected first (P greater than 0.55). Females were at twice the risk of males (P less than 0.01). Fourteen dogs had bilateral glaucoma. Among 46 dogs for which the number of months that the second eye remained normal was available, 24 were treated prophylactically and 22 were not treated or had treatment stopped. Prophylactic treatment significantly extended the interval between diagnosis in the first eye and development of glaucoma in the second eye for dogs in predisposed breeds (P less than 0.01). Prophylactic treatment did not make a difference when all breeds were considered (P greater than 0.19), nor did gender affect this interval (P greater than 0.37).     

Seasonal incidence of estrus and interestrous interval for bitches of seven breeds

For 7 breeds of bitches (Toy Poodle, Cocker Spaniel, Basset Hound, Boston Terrier, German Shepherd Dog, Pekingese, and Beagle), estrous activity occurred in all seasons. Differences in seasonal incidence of estrus were not statistically significant when compared within the total group or within and between breeds. The German Shepherd Dog breed had the shortest interestrous interval (149 +/- 28.5 days), which was significantly different from that of the other breeds. Means interestrous interval in parous Beagle bitches was not significantly different from that in nonparous Beagle bitches. In Beagle bitches, the mean interval between fertile estrous periods was not significantly different from the mean interval between nonfertile estrous periods.     

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.     

Epidemiology of canine glaucoma presented to University of Zurich from 1995 to 2009. Part 2: secondary glaucoma (217 cases)

Objective To investigate the epidemiology of canine secondary glaucomas in the cases presented to the University of Zurich, Vetsuisse Faculty (UZH) from 1995 to 2009 focusing on possible risk factors for developing secondary glaucoma in this population of dogs. Methods Information was obtained from the computer database of patients examined by members of the UZH Ophthalmology Service, between January 1995 and August 2009. Secondary glaucoma was diagnosed based on the presence of antecedent eye conditions. The data was evaluated for breed, gender, age at presentation, and for antecedent eye conditions known to cause glaucoma including anterior uveitis of unknown cause (AU), lens luxation (LL), intraocular surgery (SX), intraocular neoplasia (IN), unspecified trauma to the globe (T), ocular melanosis (OM), hypermature cataract (PY), hyphema (HY), and six other less frequent conditions. Results A total of 217 dogs were diagnosed with secondary glaucoma from 1995 to 2009. The age of the dogs with secondary glaucoma ranged between 88 days and 19 years (mean 7.7 ± 3.6 years). Data suggested a predisposition for secondary glaucoma in the Cairn Terrier and the Jack Russell Terrier breeds from 2004 to 2009. Common causes of secondary glaucoma from 1995 to 2009 were AU (23.0%), LL (22.6%), SX (13.4%), IN (10.6%), T (8.3%), OM and PY (both 6.9%) and HY (3.23%). Conclusion The report presents the epidemiology of secondary glaucomas presented to UZH from 1995 to 2009. Fourteen risk factors were recorded for secondary glaucoma. This is the first paper documenting OM in the Swiss Cairn Terrier dog population.     

Responses of atopic dogs to regional allergens: 268 cases (1981-1984)

Responses of atopic dogs to intradermal challenge with 60 allergens were determined and compared for 4 regions of the United States Twenty-seven allergens incited significantly higher responses in atopic dogs residing in northern Florida, when compared with dogs in Illinois; responses to 28 allergens were more significant in dogs residing in southern Florida vs Illinois. Only 1 allergen caused more responses in atopic dogs in northern Florida, compared with dogs in southern Florida. Females had a higher tendency to develop clinical signs of atopy. Dogs of the West Highland White Terrier, Cairn Terrier, English Setter, Irish Setter, Dalmatian, Lhasa Apso, Golden Retriever, and Labrador Retriever breeds were found to be predisposed to develop clinical signs of atopy. Dogs of the Poodle, Pug, German Shepherd Dog, Cocker Spaniel, Bulldog, Schnauzer, Doberman Pinscher breeds, of mixed breeding, and of terrier breeds other than the 2 aforementioned were not found to have a higher prevalence, when compared with the general hospital population. Of the atopic dogs evaluated in Florida, 79% had a significant response to flea antigen, compared with only 9% of atopic dogs evaluated in Illinois.     

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.     

Prevalence of primary breed-related cataracts in the dog in North America

The objective of the study was to determine the prevalence of cataracts in dogs presented to veterinary medical teaching hospitals in North America between 1964 and 2003. A retrospective study of all dogs presented with cataracts to veterinary medical teaching hospitals in North America between 1964 and 2003 was conducted to determine cataract prevalence. The different decades, breeds, gender, and age at time of presentation with cataract were compared. The prevalence of dogs presented with cataract varied by decade and ranged from 0.95% (1964-73), 1.88% (1974-83), 2.42% (1994-2003), to 3.5% (1984-93). The total number of dogs presented with cataracts over the 40-year period was 39,229. From 1964 to 2003 the prevalence of cataract formation in this patient population increased by about 255%. Fifty-nine breeds of dogs were affected with cataracts above the baseline prevalence of 1.61% seen in mixed-breed/hybrid dogs. The breeds with the highest cataract prevalence included: Smooth Fox Terrier (11.70%), Havanese (11.57%), Bichon Frise (11.45%), Boston Terrier (11.11%), Miniature Poodle (10.79%), Silky Terrier (10.29%) and Toy Poodle (10.21%). The breeds with the largest number of cataractous dogs during the entire four decades were the Boston Terrier (11.11%), Miniature Poodle (10.79%), American Cocker Spaniel (8.77%), Standard Poodle (7.00%), and Miniature Schnauzer (4.98%). Gender ratios of cataractous dogs seemed to affect limited breeds. Age of presentation with cataract diagnosis varied among several breeds. In the mixed-breed/hybrid baseline population, cataract formation appeared to be age related with a higher frequency of cataract formation in dogs after 4-7 years. Cataract formation is one of the most prevalent eye diseases in the dog population, and in about 60 breeds of dogs the prevalence of cataract exceeds that of the baseline mixed-breed/hybrid group. The prevalence of cataract is also influenced by age in most purebred dogs and affects 16.80% of the 7-15+-year-old mixed-breed/hybrid dog population. Total and age-related cataract prevalence in dogs seems very similar to that in man.     

Spontaneous cataract resorption and lens-induced uveitis in the dog.

Spontaneous cataract resorption and the associated lens-induced uveitis occur primarily in young dogs, especially the Afghan Hound, American Cocker Spaniel, Boston Terrier, Miniature and Toy Poodle, and Miniature Schnauzer. The resorption process, if extensive, will restore vision without surgical intervention, but medical control of the lens-induced uveitis by use of mydriatics and, infrequently, topical and systemic corticosteroids is essential. The main potential complications, severe medically nonresponsive uveitis and glaucoma, necessitate immediate cataract extraction.     

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.     

Lens-induced uveitis in dogs: 151 cases (1985-1990).

During a 5-year period, phacolytic uveitis was diagnosed in 202 eyes of 151 dogs admitted to the veterinary teaching hospital. The diagnosis of phacolytic uveitis was based on the finding of a cataractous lens and anterior uveitis, unassociated with other identifiable causes of uveal inflammation. The most commonly affected breeds were the Toy and Miniature Poodle (35%) and the American Cocker Spaniel (19%). The mean age was 7.0 years for all breeds, 5.1 years for the Cocker Spaniel, and 9.0 years for the Poodle breeds. Evidence of cataract resorption was visible in 72% of the eyes. Fifty-one dogs were affected bilaterally and 100 dogs unilaterally. The mean interval between recognition of the cataract and the onset of lens-induced uveitis (LIU) was 17 months; mean times of 25 and 11 months were seen in the Poodle breeds and American Cocker Spaniel, respectively. The mean age of dogs requiring greater than 1 revisit before the inflammation had subsided was 5.5 years. Complications, referable to the uveitis, were seen in 14% of eyes, the most important of which were glaucoma (16 eyes) and phthisis bulbi (9 eyes). Lens extraction surgery was done on 50 LIU-affected eyes, and on 35 normal eyes in LIU-affected animals. The 2- and 6-month success rates for LIU-affected eyes were 78 and 39%, respectively, and for normal eyes in LIU-affected animals were 85 and 71%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)     

Corneal dystrophy in the dog and cat

Two types of epithelial dystrophy have been described in dogs, one each in the Boxer and Shetland Sheepdog breeds, both of which can be associated with corneal erosions. Medical therapy is recommended when erosions or tear film abnormalities are present. Stromal dystrophies documented in dogs appear to be a primary lipid deposition in various layers of the stroma, depending on the breed. Stromal dystrophies seldom lead to loss of vision, but vision loss has been observed in middle aged Airedale Terriers and aged Siberian Huskies. Treatment is usually unnecessary. The dog demonstrates two types of endothelial dystrophy, one of which (posterior polymorphous dystrophy in the American Cocker Spaniel) does not lead to corneal edema. Endothelial dystrophy observed in the Boston Terrier, Chihuahua, and other breeds is associated with progressive corneal edema, which can lead to bullous keratopathy and corneal erosions. Stromal and endothelial dystrophies, both of which are associated with rapid progression of corneal edema, occur rarely in the cat. Treatment of dystrophies with progressive corneal edema is symptomatic and palliative.     

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.     

Prevalence of serum thyroid hormone autoantibodies in dogs with clinical signs of hypothyroidism

OBJECTIVE: To determine prevalence of thyroid hormone autoantibodies (THAA) in serum of dogs with clinical signs of hypothyroidism. DESIGN: Cohort study. SAMPLE POPULATION: 287,948 serum samples from dogs with clinical signs consistent with hypothyroidism. PROCEDURE: Serum THAA were detected by use of a radiometric assay. Correlation and chi2 analyses were used to determine whether prevalence varied with breed, age, sex, or body weight. Only breeds for which > or = 50 samples had been submitted were used for analysis of breed prevalence. RESULTS: Thyroid hormone autoantibodies were detected in 18,135 (6.3%) samples. The 10 breeds with the highest prevalence of THAA were the Pointer, English Setter, English Pointer, Skye Terrier, German Wirehaired Pointer, Old English Sheepdog, Boxer, Maltese, Kuvasz, and Petit Basset Griffon Vendeen. Prevalence was significantly correlated with body weight and was highest in dogs between 2 and 4 years old. Females were significantly more likely to have THAA than were males. CONCLUSIONS AND CLINICAL RELEVANCE: Thyroid hormone autoantibodies may falsely increase measured triiodothyronine (T3) and thyroxine (T4) concentrations in dogs; results suggest that T3 concentration may be falsely increased in approximately 57 of 1,000 dogs with hypothyroidism and that T4 concentration may be falsely increased in approximately 17 of 1,000 dogs with hypothyroidism. Results also suggested that dogs of certain breeds were significantly more or less likely to have THAA than were dogs in general.     

Incidence and risk factors of heat-related illness in dogs from New South Wales,Australia (1997–2017)

Heat Related Illness (HRI) in dogs is expected to increase as heatwaves surge due to global warming. The most severe form of HRI, heat stroke, is potentially fatal in dogs. The current study investigated the incidence and risk factors for HRI in dogs in NSW, Australia, from 1997 to 2017. We identified 119 HRI cases during this period, with a fatality rate of 23%. Dog breeds at elevated risk of HRI were Australian Stumpy Tail Cattle Dog, British Bulldog, French Bulldog, Maremma Sheepdog, Italian Greyhound, Chow Chow, Airedale Terrier, Pug, Samoyed, English Springer Spaniel, Labrador Retriever, Golden Retriever, Cavalier King Charles Spaniel, Border Collie, Staffordshire Bull Terrier, and pooled non-Australian National Kennel Council breeds (which included the American and Australian Bulldog) when compared with cross breeds (i.e., the reference variable). As expected, HRI cases were more likely in December and January, during the Australian summer and during hotter years (e.g., 2016). There were no differences in the risk of HRI between males and females nor between desexed or un-desexed dogs; but older dogs were at increased risk of HRI. These findings underscore the need for data collection that will enable the incidence of HRI in dogs to be monitored and to better understand canine risk factors particularly as temperatures will continue to rise due to global warming. The risk of mortality from HRI underpins the need for education programs focussed on prevention and early identification of HRI so that owners present affected dogs to their veterinarian as promptly as possible.     

Prevalence of Deafness in Dogs Heterozygous or Homozygous for the Merle Allele

Background: Deafness in dogs is frequently associated with the pigment genes piebald and merle. Little is known about the prevalence of deafness in dogs carrying the merle allele.
Objective: To determine the prevalence of deafness in dogs heterozygous and homozygous for the merle allele of the mouse Silver pigment locus homolog (SILV) gene.
Animals: One hundred and fifty-three privately owned merle dogs of different breeds and both sexes.
Methods: Hearing was tested by brainstem auditory-evoked response and classified as bilaterally hearing, unilaterally deaf, or bilaterally deaf. DNA from buccal cells was genotyped as either heterozygous or homozygous for the merle allele. Deafness association tests among merle genotype, eye color, and sex were performed by the χ² test.
Results: Deafness prevalence in merles overall was 4.6% unilaterally deaf and 4.6% bilaterally deaf. There was a significant association between hearing status and heterozygous versus homozygous merle genotype. For single merles ( Mm ), 2.7% were unilaterally deaf and 0.9% were bilaterally deaf. For double merles ( MM ), 10% were unilaterally deaf and 15% were bilaterally deaf. There was no significant association with eye color or sex.
Conclusions: Deafness prevalence in merle dogs was greater than that in some dog breeds homozygous for the piebald gene, such as the English Cocker Spaniel, but comparable to, or lower than, that in the Dalmatian and white Bull Terrier. Dogs homozygous for the merle allele were significantly more likely to be deaf than heterozygotes.     

Resistance and immunity of dogs against Babesia canis in an endemic area

Canine babesiosis is increasing in incidence and prevalence in some areas in France and is now a major problem for dogs. Sex and age do not have any influence on the animals' susceptibility to the disease. Some breeds are more resistant (Beagle, Fox terrier, Porcelain, Teckel, mongrel dogs) and others are more susceptible (Spaniel, Cocker, Griffon, Yorkshire terrier, Doberman, Pekinese); however, none of them is completely resistant. Dogs which live in endemic areas can synthesize antibodies against Babesia canis, sometimes at high levels, without any sign of disease.     

Inherited phosphofructokinase deficiency in an American cocker spaniel.

A 3-year-old female American Cocker Spaniel with a chronic hemolytic disorder and hemolytic crises was found to have M-type phosphofructokinase deficiency. This inherited erythroenzymopathy and myopathy is commonly diagnosed in English Springer Spaniels, but the family study of this Cocker Spaniel, although supporting an autosomal recessive mode of inheritance, did not reveal any English Springer Spaniel ancestors. Molecular genetic studies did, however, identify the same mutation in this dog as we previously reported in the English Springer Spaniel breed, suggesting that this mutation originated prior to the separation of these 2 breeds.     

Association of breed with the diagnosis of congenital portosystemic shunts in dogs: 2,400 cases (1980-2002)

OBJECTIVE: To determine the annual and overall proportion of diagnoses of congenital portosystemic shunts (CPSS) in dogs and identify breeds at increased risk for CPSS. DESIGN: Retrospective study. ANIMALS: 2,400 dogs with CPSS from veterinary teaching hospitals that reported to the Veterinary Medical Database (VMDB) from January 1, 1980 to February 28, 2002. PROCEDURE: The proportion of diagnoses of CPSS was calculated for all dogs and each breed recorded in the VMDB annually and for the 22.2-year period. Odds ratios and adjusted confidence intervals were calculated for breeds with at least 100 accessions by comparing odds of each breed with a diagnosis of CPSS with that of mixed-breed dogs. RESULTS: Congenital portosystemic shunts were reported in 0.18% of all dogs and 0.05% of mixed-breed dogs. The proportion of diagnoses of CPSS increased from 5 in 10,000 dogs in 1980 to 5 in 1,000 dogs in 2001. Yorkshire Terriers had the greatest total number of diagnoses of CPSS. Thirty-three breeds were significantly more likely to have a diagnosis of CPSS, compared with mixed-breed dogs. The greatest proportions of diagnoses were found in Havanese (3.2%), Yorkshire Terriers (2.9%), Maltese (1.6%), Dandie Dinmont Terriers (1.6%), and Pugs (1.3%). CONCLUSIONS AND CLINICAL RELEVANCE: Certain breeds appear to be at increased risk for CPSS, compared with mixed-breed dogs. The increased odds ratios among specific breeds support the hypothesis of a genetic predisposition for CPSS. Clients and veterinarians should consider appropriate diagnostic tests for dogs with clinical signs and those used for breeding from breeds with increased risk of CPSS.     

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.