Proportion of litters of purebred dogs born by caesarean section

Objectives : To describe the frequency of caesarean sections in a large sample of pedigree dogs in the UK. Methods : Data on the numbers of litters born in the previous 10 years were available from a cross-sectional study of dogs belonging to breed club members (2004 Kennel Club/BSAVA Scientific Committee Purebred Dog Health Survey). In this survey 151 breeds were represented with data for households that had reported on at least 10 litters (range 10–14,15): this represented 13,141 bitches which had whelped 22,005 litters. The frequency of caesarean sections was estimated as the percentage of litters that were reported to be born by caesarean section (caesarean rates) and are reported by breed. The dogs were categorised into brachycephalic, mesocephalic and dolicocephalic breeds. Results : The 10 breeds with the highest caesarean rates were the Boston terrier, bulldog, French bulldog, mastiff, Scottish terrier, miniature bull terrier, German wirehaired pointer, Clumber spaniel, Pekingese and Dandie Dinmont terrier. In the Boston terrier, bulldog and French bulldog, the rate was > 80%. Clinical Significance : These data provide evidence for the need to monitor caesarean rates in certain breeds of dog.     

Norwich terriers possess a greater vertebral heart scale than the canine reference value

Previous studies have demonstrated evidence that normal reference ranges for radiographic vertebral heart scale values can vary among dog breeds. The purpose of this retrospective, observational study was to determine whether the normal vertebral heart scale values published by Buchanan and Bücheler for lateral radiographs are applicable to the Norwich terrier. Secondary objectives were to determine if clinical signs of respiratory disease, age, sex, weight, body condition score, recumbency, or thoracic depth‐to‐width ratio had any influence on vertebral heart scale measurements in this breed. The electronic medical record systems of two universities were reviewed and Norwich terriers were included in the study if they had orthogonal thoracic radiographs performed and no historical or radiographic evidence of cardiopulmonary disease. A vertebral heart scale was calculated for each patient. Sixty‐one client‐owned, Norwich terrier dogs with no clinical signs of cardiovascular disease were evaluated. The vertebral heart scale for Norwich terriers without evidence of cardiac disease (10.6 ± 0.6) was found to be significantly greater than the canine reference value of 9.7 ± 0.5 initially established by Buchanan and Bücheler. No significant correlation was found between clinical signs of respiratory disease, sex, age, thoracic depth‐to‐width ratio or lateral recumbency, and vertebral heart scale. Norwich terriers with a body condition score ≥6 had a significantly higher vertebral heart scale than those with a body condition score ≤5. Breed‐specific ranges and body condition scores need to be considered when interpreting vertebral heart scale values for Norwich terriers.     

Breed, age and gender distribution of dogs with chronic hepatitis in the United Kingdom

Standardised histological criteria are now available for the diagnosis of canine chronic hepatitis (CH). CH is common in dogs, but no studies have reported breed, age and gender distributions in the United Kingdom (UK). The objective of this study was to determine which breeds had an increased risk for developing CH in the UK and to report the age and gender distribution for those breeds. The databases of six veterinary histopathology laboratories were searched for cases with a histological diagnosis of CH according to standardised criteria. The breed, age and gender of dogs was recorded and compared to a control population to calculate the odds ratio and 95% confidence intervals for developing CH. A total of 551 cases of CH were identified, consisting of 61 breeds. Nineteen breeds were represented by five or more cases. Breeds with an increased risk for developing CH included the American cocker spaniel, Cairn terrier, Dalmatian, Dobermann pinscher, English cocker spaniel, English springer spaniel, Great Dane, Labrador retriever and Samoyed. The median age at diagnosis for all breeds with CH was 8 years (range 7 months to 16 years). Dalmatians, Dobermann pinschers and English springer spaniels with CH were significantly younger than Cairn terriers, English cocker spaniels and Labrador retrievers with CH. Females were over-represented when all cases were examined together. In conclusion, several breeds in the UK have an increased risk of CH, some of which have not been previously reported.     

Determination of inheritance of single congenital portosystemic shunts in Yorkshire terriers

A hereditary basis for congenital portosystemic shunts (PSS) in Yorkshire terriers was explored through record and pedigree analysis and a breeding trial. The odds ratio for PSS in Yorkshire terriers was 35.9 times greater than for all other breeds combined. Wright's coefficient of inbreeding was approximately twice as high for Yorkshire terriers with PSS as compared to normal members of the breed (P=0.09). No common ancestors were found that were significant to the PSS group. Two affected Yorkshire terriers were bred and produced two normal puppies. Congenital PSS appears to be hereditary in Yorkshire terriers; however, the mechanism of inheritance has yet to be elucidated.     

Esophageal dysmotility in young dogs

BACKGROUND: Abnormal esophageal motility can exist without megaesophagus, although its prevalence in dogs is unknown and its cause has not been elucidated. HYPOTHESIS: Esophageal dysmotility without overt megaesophagus exists in both symptomatic and asymptomatic young dogs, and motility can improve with age. ANIMALS: Dogs examined at the Department of Veterinary Medicine, University of Cambridge for regurgitation, but without evidence of megaesophagus on radiographs, and a further group of asymptomatic dogs. METHODS: Dogs underwent an initial and a repeat videofluoroscopic swallowing study. Images were reviewed and 5 criteria of esophageal motility evaluated. RESULTS: Eight affected dogs were identified (median age 9 months), and terrier dogs predominated (6 terriers of 3 breeds). Esophageal motility was reduced either globally (n = 3) or segmentally (n = 5). Repeat examination at a median of 3 months revealed that regurgitation had reduced or resolved in the majority of terrier dogs, and 4 of 6 cases demonstrated an improvement in esophageal motility. Videofluoroscopic evaluation of young (median age 11 months) asymptomatic dogs of various breeds (n = 22) revealed evidence of esophageal dysmotility in 4 of 5 control terrier dogs. Repeat evaluation demonstrated an improvement in esophageal motility in 3 dogs. CONCLUSION AND CLINICAL IMPORTANCE: Esophageal dysmotility without overt megaesophagus occurs in young terrier dogs, and affected animals can be symptomatic or asymptomatic. Further, an improvement in esophageal motility occurs with time in some dogs, and might represent a syndrome of delayed esophageal maturation.     

Breed, sex and age distribution in dogs with chronic liver disease: a demographic study

Breed, sex and age distribution were studied in dogs with histopathologically diagnosed chronic (active or progressive) hepatitis and liver cirrhosis in Sweden. The study was based on clinical and histopathological records obtained during three years from a histopathological laboratory and during six years from an animal hospital. Some breeds were significantly (P<0–001) over-represented: American and English cocker spaniels, labrador retrievers and West Highland white terriers. In both spaniel breeds the males were most frequent whereas in the labrador retriever, the females were over represented. In the West Highland white terrier there was no sex difference. The average age at presentation was approximately five years in spaniels and West Highland white terriers and seven years in labrador retrievers. The high incidence of chronic liver disease and liver cirrhosis in certain breeds indicate that hereditary factors may be of importance in the development of chronic hepatitis and liver cirrhosis.     

A KCNJ10 mutation previously identified in the Russell group of terriers also occurs in Smooth-Haired Fox Terriers with hereditary ataxia and in related breeds

Background

Hereditary ataxias with similar phenotypes were reported in the Smooth-Haired Fox Terrier, the Jack Russell Terrier and the Parson Russell Terrier. However, segregation analyses showed differing inheritance modes in these breeds. Recently, molecular genetic studies on the Russell group of terriers found independent mutations in KCNJ10 and CAPN1, each associated with a specific clinical subtype of inherited ataxia. The aim of this study was to clarify whether or not Smooth-Haired Fox Terriers with hereditary ataxia and dogs of other related breeds harbor either of the same mutations. A sub goal was to update the results of KCNJ10 genotyping in Russell group terriers.

Findings

Three Smooth-Haired Fox Terriers with hereditary ataxia and two Toy Fox Terriers with a similar phenotype were all homozygous for the KCNJ10 mutation. The same mutation was also found in a heterozygous state in clinically unaffected Tenterfield Terriers (n = 5) and, in agreement with previous studies, in Jack Russell Terriers, Parson Russell Terriers, and Russell Terriers.

Conclusions

A KCNJ10 mutation, previously associated with an autosomal recessive spinocerebellar ataxia in Jack Russell Terriers, Parson Russell Terriers, and Russell Terriers segregates in at least three more breeds descended from British hunting terriers. Ataxic members of two of these breeds, the Smooth-Haired Fox Terrier and the Toy Fox Terrier, were homozygous for the mutation, strengthening the likelihood that this genetic defect is indeed the causative mutation for the disease known as “hereditary ataxia” in Fox Terriers and “spinocerebellar ataxia with myokymia, seizures or both” in the Russell group of terriers.     

Is breed-specific legislation justified? Study of the results of the temperament test of Lower Saxony

Beginning in July 2000 legislation in Lower Saxony restricted the keeping of bull terriers, American Staffordshire terriers, pit bull terriers, and 11 other breeds. Exemption was possible after attending an especially developed test. The tests analyzed for breed predisposition for excessively aggressive signaling or aggressive behavior in inappropriate situations, differences in behavior between breeds, and factors differentiating biting from nonbiting dogs.The test results of 415 dogs were analyzed. The test consisted of a veterinary examination; a learning test; situations of dog-human, dog-environment, and dog-dog contact; and obedience. Escalation in aggressive behavior was scored using a scale of 1-7. No aggressive behavior (1 on the scale) was shown by 38.07% of the dogs, 61.69% showed aggressive behavior scored as 2 to 5 on the scale, and 0.24% bit without previous threatening signals (6 on the scale).Concerning a score of 1 on the scale, pairwise comparison (chi-square test) showed significant differences between bull terriers and American Staffordshire terriers (P = 0.004), pit bull terriers (P = 0.01), Doberman pinschers (P = 0.003), and rottweilers (P = 0.009). Concerning scores of 2 to 7 on the scale,, no significant differences were found.Ninety-five percent of the animals reacted appropriately in the test situation. Five percent displayed excessive aggressive signaling or aggressive behavior in inappropriate situations. These displays were associated with unusual movements and the dogs' apparent apprehension. Correlation between test results and owners jerking on the leash or misinterpreting their dogs' behavior and dogs trying to elude physical manipulation was found. No significant difference in behavior between breeds was detected.The results show no indication of dangerousness in specific breeds. Justification for specific breed lists in the legislation was not shown.     

Breed predisposition to congenital alacrima in dogs

Objective  To evaluate the clinical characteristics and breed predisposition of congenital alacrima in dogs.
Animals studied  Dogs with congenital keratoconjunctivitis sicca.
Procedures  A search of the medical records of the University of Tennessee Veterinary Teaching Hospital from 1974–2005 and the University of California–Davis Veterinary Teaching Hospital from 1986–2006 for dogs under 1 year of age with a diagnosis of keratoconjunctivitis sicca (KCS) was performed. These cases were further reviewed for dogs with a Schirmer's tear test I of ≤ 5 mm/min before 6 months of age, with no known causes for KCS, which did not respond to appropriate KCS therapy; these cases were considered to have congenital alacrima. These breeds were compared to all other breeds using the Fisher's exact test with correction for multiple comparisons.
Results  Congenital alacrima was identified in 19 dogs representing 11 breeds and mixed breeds. Yorkshire Terriers and Bedlington Terriers were statistically overrepresented compared to reference populations ( P  < 0.01 and P  = 0.04, respectively).
Conclusions  Yorkshire terriers are significantly at risk for congenital alacrima compared to other breeds. The significance of the increase in congenital alacrima in Bedlington Terriers in this study may not be clinically relevant and may be due to the small total number of dogs of this breed that presented to the both hospitals. Based on the poor response to therapy in humans with congenital alacrima, it may be prudent to offer guarded prognoses for KCS in juvenile Yorkshire terriers.     

Incidence of and risk factors for atopic dermatitis in a Swedish population of insured dogs

The incidence of atopic dermatitis was estimated to be 1.7 cases per 1000 dog-years at risk in a population of insured Swedish dogs whose insurance claims for the period 1995 to 2002 were examined. Several factors were found to increase the risk of having a recorded claim, including living in a city or in central or southern Sweden, being born in the autumn, and belonging to a high-risk breed. Bull terriers had the highest risk, with 21 cases per 1000 dog-years at risk, and several other breeds including boxers and West Highland white terriers also had an above average risk. There was no difference in the incidence between the sexes. There was a slight increase in the incidence during the period. In a subset of the data that consisted only of dogs from 15 high-risk breeds, the overall survival appeared to be lower for the dogs that had had an insurance claim for the disease.     

Estimated frequency of the canine hyperuricosuria mutation in different dog breeds

Background: Hyperuricosuria is a condition that predisposes dogs to urate urolithiasis. A mutation that causes canine hyperuricosuria was previously identified in 3 unrelated dog breeds. The occurrence of the mutation in additional breeds was not determined. Hypothesis/Objectives: Identify additional breeds that have the hyperuricosuria mutation and estimate the mutant allele frequency in those breeds. Animals: Three thousand five hundred and thirty dogs from 127 different breeds were screened for the hyperuricosuria mutation. Methods: DNA samples were genotyped by pyrosequencing and allele‐specific polymerase chain reaction methods. Results: Mutant allele frequencies that range from 0.001 to 0.15 were identified in the American Staffordshire Terrier, Australian Shepherd, German Shepherd Dog, Giant Schnauzer, Parson (Jack) Russell Terrier, Labrador Retriever, Large Munsterlander, Pomeranian, South African Boerboel, and Weimaraner breeds. Conclusions and Clinical Importance: The hyperuricosuria mutation has been identified in several unrelated dog breeds. The mutant allele frequencies vary among breeds and can be used to determine an appropriate breeding plan for each breed. A DNA test is available and may be used by breeders to decrease the mutant allele frequency in breeds that carry the mutation. In addition, veterinarians may use the test as a diagnostic tool to identify the cause of urate urolithiasis.     

Prevalence and features of canine atopic dermatitis in Hungary

Medical records of 600 dogs diagnosed with atopic dermatitis were reviewed and evaluated with reference to history, geographical distribution, breed predilection, clinical signs and positive reactions to allergens as determined by intradermal skin testing (IDT) manufactured by Artuvetrin Laboratories. In 66.6% of dogs, the age of onset of atopic dermatitis was between 4 months and 3 years. Dogs living in the garden suburb of Budapest were more sensitive to house dust mites, fleas and moulds, and dogs from the western part of Hungary were more sensitive to weeds than to other allergens (p < 0.01). Positive reactions were most common to Dermatophagoides farinae followed by human dander. The breed distribution found in the present study was consistent with that reported in the literature, except for the breeds Hungarian Vizsla, Pumi, French bulldog, Doberman Pinscher and Bobtail which were over-represented among atopic dogs compared to the breed distribution of the general dog population of a large city in Hungary. Breeds with verified adverse reaction to food were Cocker spaniels, French bulldogs, Bullmastiffs, Bull terriers, St. Bernards, Tervurens, West Highland White terriers and American Staffordshire terriers (p < 0.05). The clinical signs of atopic dermatitis and their occurrence are in accordance with the data described in the literature.     

Copper storage disease with intravascular haemolysis in a Bedlington terrier

A 5-year-old male Bedlington terrier was found to have haemoglobinuria from intravascular haemolysis. The owners reported also recent vomiting, occasional diarrhoea, reduced activity and increased drinking and urination. A diagnosis of inherited copper storage disease, as previously described in this breed, was established by demonstrating characteristic light and electron microscopic changes and copper content of 7, 717 micrograms/g in biopsied liver. Treatment by chelation with d-penicillamine and a low copper diet was instituted and the dog remains well 10 months later. Intravascular haemolysis is rare in dogs and an uncommon finding in Bedlington terriers with copper storage disease.     

Demodex injai infestation and dorsal greasy skin and hair in eight wirehaired fox terrier dogs

Demodex injai mites were detected on trichoscopic examinations and/or deep skin scrapings in eight wirehaired fox terrier dogs with dorsal greasy skin and hair. Histological examination performed in five dogs revealed marked sebaceous gland hyperplasia with lympho-plasmacytic periadnexal dermatitis in all of them. One mite section was observed in one patient. Seven dogs were parasitologically cured after 2 to 7 months of oral ivermectin treatment. Greasy skin and hair resolved in four dogs, was partially reduced in two dogs and persisted in the remaining dog. Skin biopsies were repeated after parasitological cure in two dogs and revealed the persistence of sebaceous gland hyperplasia with mild lympho-plasmacytic periadnexal dermatitis and no parasites. Based on the findings in this case series, the terrier dog breed might be at increased risk for the development of D. injai mite infestation associated with dorsal greasy skin and hair, and microscopically with sebaceous gland hyperplasia. Persistence of sebaceous gland hyperplasia after parasitological cure in some patients suggested that this histological finding may not always be resulting from Demodex infestation. Moreover, low numbers of adult mites and variable clinical responses to acaricidal therapy suggested a contributory rather than a major role of D. injai in this skin condition. Dermatopathological diagnosis of sebaceous gland hyperplasia, particularly in case of dorsal trunk specimens from terrier dog breeds, warrants the search for D. injai mites on trichoscopic examinations and/or deep skin scrapings.     

Use of breed-specific ranges for the vertebral heart scale as an aid to the radiographic diagnosis of cardiac disease in dogs.

The vertebral heart scale was measured on right lateral recumbent thoracic radiographs of 320 dogs of six popular breeds, including for each breed at least 20 dogs with no clinical signs of cardiovascular or respiratory disease and at least 19 dogs with cardiac or respiratory disease. There were significant differences between the mean values of the scale for the different breeds; the normal boxer dogs had a significantly higher mean value than the normal dogs of all the other breeds, and the labrador retrievers had a significantly higher mean value than all the other breeds except the boxer and the cavalier King Charles spaniel. For all the breeds except the boxer, there was a trend for dogs with cardiac disease (but not respiratory disease) to have higher mean values on the scale than normal dogs of the same breed; however, at the optimal value of the scale for distinguishing between dogs of each breed with and without cardiac disease, the sensitivity and specificity were relatively low, in the range 58 to 83 per cent. The scale was most accurate for the diagnosis of cardiac disease in the Yorkshire terrier and the cavalier King Charles spaniel, breeds affected by predominantly dilative forms of cardiac disease. In contrast, it was very inaccurate in the boxer, a breed that has a higher incidence of cardiac diseases associated with concentric hypertrophy.     

Idiopathic generalized sebaceous gland hyperplasia of the Border terrier: a morphometric study

Skin biopsies from five Border terriers with histologically confirmed idiopathic, generalized sebaceous gland hyperplasia (Group A) were compared morphometrically to those from four unaffected Border terriers (Group B) and the unaffected dogs to biopsies from four other terrier breeds (Group C). Dogs in Group A had significantly higher numbers of sebaceous gland lobules per hair follicle than those in Group B (P = 0.020) but there was no significant difference between Groups B and C. The total sebaceous gland lobular area per hair follicle was significantly higher in dogs in Group A than Group B (P = 0.020) but there were no differences between Groups B and C. There were no significant differences in the size of the individual sebaceous gland lobules. There were no significant differences in the total number of basal or mature sebocytes between Groups A and B but significantly lower numbers of both cell types were seen in Group C compared to Group B. There were significantly more basal sebaceous cells undergoing mitosis in dogs in Group A than Group B (P = 0.017) but no significant difference between Groups B and C. These results indicate that the physical signs of sebaceous gland hyperplasia are caused by an increase in the number of sebaceous gland lobules and total lobular area. Border terriers may be genetically predisposed to the development of idiopathic generalized sebaceous gland hyperplasia compared with other dog breeds but also to sebaceous gland hyperplasia secondary to other dermatopathies.     

Selecting pet dogs on the basis of cluster analysis of breed behavior profiles and gender

Using a computer-generated data base of rankings of 56 breeds of dogs on 13 behavioral traits, a factor analysis was performed to determine the extent to which a few general underlying behavioral tendencies are manifested in specific characteristics. Three factors, referred to as reactivity, aggression, and trainability, accounted for 81% of the variance in the 13 behavioral traits. Subsequently, a cluster analysis was performed to generate 7 clusters of dog breeds on the basis of similarity in scores for each of the 3 main factors. The clusters reflected to some degree the conventional groupings of dogs into working, sporting, hound, and terrier breeds. A quantitative analysis of the ranking of male dogs vs female dogs for the 13 characteristics revealed that males differed from females on 10 traits. It was concluded that these gender and cluster profiles will allow people to select a breed or gender of dog that is most likely to match the emotional and physical needs of the person who will provide a home for the pet.     

Breed associations of canine ectopic ureter: a study of 217 female cases

Ectopic ureter has been diagnosed in 228 dogs collectively at 15 North American university veterinary medical teaching hospitals over a 17 year reporting period. The female-to-male ratio was 217:11. Among female dogs, six breeds (Siberian husky, Newfoundland, bulldog. West Highland white terrier, fox terrier, and miniature and toy poodle), representing more than half of the total cases, were identified with significantly greater frequency of diagnosis than expected by their representation in the overall hospital population. The strength of association in certain purebred dogs, plus the significant deficit in mongrel dogs supports the likelihood that familial genetics are responsible for a substantial amount of the occurrence of this defect.     

Characteristics of 234 dog bite incidents in Ireland during 2004 and 2005

Information was obtained by telephone interview from 100 dog owners whose dog had bitten a person, and from 134 victims of bites by a dog not owned by the victim. Three-quarters of the victims were female and aged from 21 to 60 years. The majority of the dogs were owned, male, two to six years old, over 10 kg in bodyweight and belonged to the popular breeds: collies, cocker/springer spaniels, terrier breeds, Jack Russell terriers, German shepherd dogs, golden retrievers and crossbreeds. The numbers of bites by the different breeds indicated that those that inflicted the most bites were the popular breeds rather than the breeds with any greater propensity to bite. Most attacks were rapid single bites and in 50 per cent of the cases, neither the owner nor the victim was able to identify any signal of the dog's intention to bite. Overall, 21 per cent of the incidents were rated as 'serious' and 2 per cent as 'life threatening'. One fifth of the dogs were euthanased as a result of the incident. Half the incidents required professional medical assistance for the victim. Almost half the incidents took place while the victim was walking or passing close to the dog's territory, or while the victim was interacting with the dog at home.