Boston Terrier Research Articles

Brachycephalic airway obstructive syndrome in dogs: 90 cases (1991–2008)

To determine the prevalence of individual anatomic components of brachycephalic airway obstructive syndrome (BAOS), including everted tonsils, and analyze the frequency with which each component occurs with 1 or more other components of BAOS in brachycephalic dogs. Retrospective case series. 90 dogs with BAOS. Medical records were reviewed for signalment, clinical signs at time of admission, historical and physical examination findings, BAOS components found on laryngoscopic examination of the pharynx and larynx, surgical procedures performed, and perioperative complications. English Bulldogs (55/90 [61%]), Pugs (19/90 [21%]), and Boston Terriers (8/90 [9%]) were the most common breeds with BAOS. The most common components of BAOS were elongated soft palate (85/90 [94%]), stenotic nares (69/90 [77%]), everted laryngeal saccules (59/90 [66%]), and everted tonsils (50/90 [56%]). Dogs most commonly had 3 or 4 components of BAOS, with the most common combination being stenotic nares, elongated soft palate, everted laryngeal saccules, and everted tonsils. Dogs with stenotic nares were significantly more likely to have everted laryngeal saccules (50/69 [72%]), and dogs with everted laryngeal saccules were significantly more likely to have everted tonsils (39/59 [66%]). Postoperative surgical complications occurred in 12% (10/83) of dogs that received corrective surgery. No specific BAOS component made dogs more likely to have complications. The prevalence of components of BAOS in brachycephalic dogs of this study differed from that reported previously, especially for everted tonsils. Thorough examination of the pharynx and larynx is necessary for detection of BAOS components.

Novel Use of a Fully-Covered Esophageal Metal Stent in the Treatment of Resistant Anastomotic Stricture Following Gastric Bypass

Purpose: Self-expanding fully covered metal stents have often been used to treat esophageal strictures secondary to malignancy and post-operative anastomotic leaks. In this case, we report the use of such a stent in the successful treatment of a recurrent/resistant post-Roux-en-Y gastric bypass anastomotic stricture. A 41 year-old African American gentleman with morbid obesity underwent a laparoscopic Roux-en-Y gastric bypass and presented in the early post-operative period with complaints of nausea and vomiting. He was diagnosed with a high grade gastro-jejunal anastomotic stricture and underwent through the scope (TTS) balloon dilation but symptoms soon recurred. After a series of failed dilations and a failed surgical stomal revision, the placement of a fully covered esophageal metal stent (Alimaxx® 22x100 mm, Merit Medical Systems, South Jordan, UT) bridging the stricture alleviated all symptoms of obstruction. The stent was attached to the gastric mucosal lining with hemostatic clips to prevent stent migration. Four weeks after stent placement, the stent was successfully removed endoscopically with no complications. The patient has remained symptom free 6 months after successful stent removal and he has continued to lose weight appropriately. Though TTS balloon-dilation has long been accepted as the standard of care for such resistant strictures, this case specifically describes the novel use and possible consequences of the fully covered esophageal stent system when used for resistant stomal strictures. This case report is of specific interest to gastroenterologists and general surgeons who encounter patients in their practice with this serious and common complication of Roux-en-Y gastric bypass.Figure

Proportion of litters of purebred dogs born by caesarean section

To describe the frequency of caesarean sections in a large sample of pedigree dogs in the UK. 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. 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%. These data provide evidence for the need to monitor caesarean rates in certain breeds of dog.

Mutation in HSF4 is associated with hereditary cataract in the Australian Shepherd

Cataracts are a leading cause of blindness in dogs with approximately 100 breeds affected by primary hereditary forms. Despite the large number of breeds affected with hereditary cataracts (HC) little is known about the genetics of the condition, and to date only a single gene, HSF4, has been implicated in the development of the disease in dogs. We previously identified a recessively inherited 1-bp insertion in the transcription factor gene HSF4 resulting in the loss of the open reading frame in Boston terriers and Staffordshire bull terriers. While testing the insertion mutation in other breeds with HC, we identified a 1-bp deletion at the same nucleotide of HSF4 in some Australian Shepherds with cataract. Using DNA samples from almost 400 privately owned Australian Shepherds we have investigated the association between the deletion mutation in HSF4 and cataracts in this breed. We conclude that the mutation is significantly associated with cataracts and that a dog carrying the mutation is approximately 17 times more likely to develop binocular cataracts than dogs that are clear of the mutation. The data also indicate that additional mutations associated with the development of cataracts are likely to be co-segregating in the Australian Shepherd population.

Computed tomography–assisted management of a mandibular dentigerous cyst in a dog with a nasal carcinoma

A 6-year-old neutered male Boston Terrier was examined to determine the cause of sneezing, bilateral nasal discharge, nasal congestion, lethargy, and coughing of 2 months' duration. An undifferentiated nasal carcinoma was diagnosed. During computed tomography (CT) evaluation of response to tomotherapy radiation treatment, a mandibular dentigerous cyst, associated with an unerupted left mandibular first premolar, was monitored for expansion. The dog had a profound response to radiation treatment, and the nasal carcinoma totally resolved. It was determined on the basis of CT that the rate of expansion of the dentigerous cyst was placing the dog at risk for mandibular fracture and loss of vitality to the surrounding teeth. The unerupted left mandibular first premolar and associated dentigerous cyst were surgically removed and submitted for histologic evaluation. Images obtained during sequential CT evaluations performed after radiation treatment of nasal carcinoma should be examined for evidence of the primary neoplasm as well as to detect unrelated lesions of the orofacial region that can compromise the quality of life. Findings of CT evaluations can be used to determine when and how to initiate treatment for dentigerous cysts in regard to the patient's response to radiation treatment.

Solitary Intracerebral Plasmacytoma in a Dog: Microscopic, Immunohistochemical, and Molecular Features

A primary intracerebral plasmacytoma was identified in a 7-year-old spayed female Boston Terrier. Grossly, a well-demarcated, 2 cm in diameter, roughly spherical tumor was in the rostral aspect of the left cerebral hemisphere. Histologically, the neoplasm was composed of sheets of round cells with distinct plasmacytoid features and marked anisocytosis and anisokaryosis. Cells were positive for vimentin, CD18, CD79a, and lambda light-chain, and negative for kappa light chain, cytokeratin, lysozyme, glial fibrillary acidic protein, and S100 protein. Clonally rearranged B-cell antigen receptor genes were detected by PARR (polymerase chain reaction for antigen receptor rearrangements), confirming clonal proliferation of B lymphocytes. Although primary solitary intracerebral plasmacytoma is rare in dogs and other species, it should be included in the differential diagnosis for central nervous system round-cell neoplasms. Clonality testing can be utilized to support the histological diagnosis of this neoplasm type.

Resection of Mast Cell Tumor of the Lip in a Dog

A 10-year-old Boston terrier dog was presented for treatment of a 2-cm mast cell tumor of the left upper lip and nasal planum immediately adjacent to the philtrum and ventral to the nares. CO2 laser was used for resection of the lesion. Wound reconstruction was performed using bilateral labial advancement flaps.

Primary Splenic Torsion in a Boston Terrier

A 7-year-old female Boston terrier was referred to Hokkaido University Veterinary Teaching Hospital with a history of hemoglobinuria and anemia for several days. Abdominal radiographs showed splenomegaly, and ultrasonography revealed a hypoechoic splenic parenchyma with interspersed linear echoes consistent with the ultrasonographic appearance of splenic torsion. Ultrasonography and computed tomography (CT) indicated a C-shaped spleen. Exploratory laparotomy confirmed the diagnosis of splenic torsion. A splenectomy was performed, and the dog recovered well without complications. This is the first report of splenic torsion in Boston terriers, and the usefulness of ultrasonographic and CT findings of the splenic torsion was also confirmed.

Acquired pulmonary artery stenosis in four dogs

4 dogs with acquired pulmonary artery stenosis (PAS) were examined for various clinical signs. One was a mixed-breed dog with congenital valvular PAS that subsequently developed peripheral PAS, one was a Golden Retriever with pulmonary valve fibrosarcoma, one was a Pembroke Welsh Corgi in which the left pulmonary artery had inadvertently been ligated during surgery for correction of patent ductus arteriosus, and one was a Boston Terrier with a heart-base mass compressing the pulmonary arteries. All 4 dogs were evaluated with 2-dimensional and Doppler echocardiography to characterize the nature and severity of the stenoses; other diagnostic tests were also performed. The mixed-breed dog with valvular and peripheral PAS was euthanized, surgical resection of the pulmonic valve mass was performed in the Golden Retriever, corrective surgery was performed on the Pembroke Welsh Corgi with left pulmonary artery ligation, and the Boston Terrier with the heart-base mass was managed medically. Acquired PAS in dogs may manifest as a clinically silent heart murmur, syncope, or right-sided heart failure. The diagnosis is made on the basis of imaging findings, particularly results of 2-dimensional and Doppler echocardiography. Treatment may include surgical, interventional, or medical modalities and is targeted at resolving the inciting cause.

Evaluation of canine heat shock transcription factor 4 (HSF4) as a candidate gene for primary cataracts in the Dachshund and the Entlebucher Mountain dog

Testing of the cataract-causing insertion/deletion mutation in the canine HSF4 gene for its linkage and association with primary cataracts (CAT) in Dachshunds and Entlebucher Mountain dogs. Exon 9 with flanking intronic regions of the canine HSF4 gene was sequenced in 24 Dachshunds and 20 Entlebucher Mountain dogs. The HSF4 cDNA sequence of lens tissue was analyzed in a CAT-unaffected mixed-breed dog and in three CAT-affected dogs of different breeds, including a Wire-haired Dachshund, a Dachshund-mix and a German Shepherd dog. In all dogs investigated here, the previously reported CAT-causing mutation did not exist. We found a single nucleotide polymorphism (SNP) in intron 9, which was neither associated nor linked with the CAT phenotype in the two dog breeds. The CAT phenotype in the two dog breeds investigated here was not caused by the same mutation found to be associated with early-onset CAT in the Staffordshire Bull Terrier and Boston Terrier. The intronic SNP may be useful to test HSF4 for linkage with CAT in further dog breeds.

Evaluation of canine heat‐shock transcription factor 4 as a candidate for primary cataracts in English Cocker Spaniels and wire‐haired Kromfohrlanders

Canine heat-shock transcription factor 4 (HSF4) was evaluated as a candidate for primary cataracts in English Cocker Spaniels (ECS) and wire-haired Kromfohrlanders (KFL). We sequenced exon 9 and its flanking regions of the HSF4 gene in ECS and KFL but were not able to detect a previously reported insertion mutation associated with primary cataracts in Staffordshire Bull Terriers and Boston Terriers. Another single nucleotide polymorphism (LOC489766:g.3243A>G) in intron 9 was identified and included in linkage and association tests together with two flanking microsatellites. Linkage and association tests with primary cataracts in ECS and KFL were not significant. Therefore, we could not verify that the mutation in exon 9 of canine HSF4 gene is causative for primary cataracts in ECS and wire-haired KFL.

Mutation in HSF4 Associated with Early but Not Late-Onset Hereditary Cataract in the Boston Terrier

Primary hereditary cataract (HC) is one of the most common disorders in purebred dogs and is a leading cause of blindness. Boston Terriers suffer from 2 distinct forms of HC which occur at different ages and which are different in their appearance and progression. Early-onset hereditary cataract (EHC) affects dogs within the first few months of life, is always progressive and bilateral, and results in total blindness, whereas late-onset hereditary cataract (LHC) in general affects dogs over the age of 3 and is more variable in its clinical phenotype, age of onset, progression, and the degree to which vision is impaired. A mutation in HSF4 has recently been reported in a small number of Boston Terriers affected with EHC. In this study, we analyzed 22 additional Boston Terriers affected with early-onset cataract to confirm that the HSF4 mutation is causative for this form of cataract in this breed. In addition, we analyzed 40 Boston Terriers that were either clinically clear or affected with LHC for the presence or absence of the HSF4 mutation. By also sequencing HSF4 in dogs affected with LHC, we conclude that HSF4 is not associated with the development of the late-onset form of cataract and that the 2 forms of cataract in this breed are therefore genetically discrete conditions.

Surgical correction of brachycephalic syndrome in dogs: 62 cases (1991–2004)

To assess results of surgical correction of brachycephalic syndrome (including stenotic nares, elongated soft palate, and everted laryngeal saccules) in dogs and determine whether dogs with hypoplastic trachea have a less favorable long-term outcome. Retrospective case series. 62 dogs with brachycephalic syndrome. Medical records from 1991 to 2004 were reviewed for information regarding signalment, clinical signs, diagnosis, surgery, and long-term outcome. Surgical outcome was rated by owners as excellent, good, fair, or poor. Common abnormalities, treatments, and long-term outcomes among the 62 dogs were assessed. Predominantly affected breeds included English Bulldog, Pug, and Boston Terrier. Elongated soft palate was the most common abnormality (54/62 [87.1%] dogs); the most common combination of abnormalities was elongated soft palate, stenotic nares, and everted saccules (16/62 [25.8%] dogs). The English Bulldog was the most common breed for all abnormalities, including elongated soft palate (27/54 [50%] dogs), stenotic nares (14/36 [38.9%] dogs), everted saccules (20/36 [55.6%] dogs), hypoplastic trachea (7/13 [53.9%] dogs), and laryngeal collapse (2/5 [40%]). No dogs had everted saccules alone. Outcome did not differ between dogs under-going staphylectomy by use of laser or scissor resection. Follow-up information was obtained for 34 dogs; 16 (47.1%) had an excellent outcome, and 16 (47.1%) had a good outcome. Overall treatment success rate was 94.2%, and overall mortality rate was 3.2%. Surgical treatment of brachycephalic syndrome in dogs appeared to be associated with a favorable long-term outcome, regardless of age, breed, specific diagnoses, or number and combinations of diagnoses.

メトトレキサートの投与が奏効した炎症性腸疾患が疑われた犬の1例

A five-year-old male Boston terrier was presented to the hospital with chronic diarrhea. Various medical and endoscopic examinations suggested that the case was an inflammatory bowel disease. Immunosuppressive therapy based on prednisolone was effective in stopping the clinical symptoms. But the symptoms relapsed after the prednisolone dose was reduced. Subsequently, treatment with prednisolone and cyclosporine was performed, but improved efficacy was not observed. When the concomitant drug was changed to methotrexate (intramuscular) from cyclosporine, a gradual decrease in the prednisolone dose was possible without a relapse in the symptoms. A favorable prognosis was achieved also with oral administration of methotrexate.

Evaluation of risk factors for development of secondary glaucoma in dogs: 156 cases (1999–2004)

To determine the immediately antecedent cause of secondary glaucoma and the prevalence of secondary glaucoma with anterior uveitis or lens dislocation in dogs. Retrospective case series. 156 dogs with secondary glaucoma. Cause of glaucoma was determined from records. Breed, age, sex, and neuter status of all dogs with secondary glaucoma were compared with the general hospital population. The prevalence of secondary glaucoma in dogs with a primary diagnosis of lens dislocation or anterior uveitis during the same period was determined. Secondary glaucoma was diagnosed in 156 of 2,257 (6.9%) dogs examined because of ophthalmic disease and was bilateral in 33 (21.2%) of those dogs. In 31 (94%) bilaterally affected dogs, the antecedent cause was the same in both eyes. Common causes of secondary glaucoma were non-surgical anterior uveitis (44.9%), anterior uveitis associated with prior phacoemulsification (15.8%), and lens dislocation (15.2%). Parson Russell Terriers, Poodles, Boston Terriers, Cocker Spaniels, Rhodesian Ridgebacks, and Australian Cattle Dogs had diagnoses of secondary glaucoma more often than expected, compared with the reference population. Age, sex, neuter status, and laterality were not associated with secondary glaucoma. The prevalence of secondary glaucoma in dogs with lens dislocation or uveitis was 15% or 17%, respectively. Glaucoma develops secondary to many intraocular diseases, particularly uveitis and lens dislocation. Diagnosis of these diseases should prompt frequent monitoring of intraocular pressure, regardless of signalment.

Identification of mutations in HSF4 in dogs of three different breeds with hereditary cataracts

Cataracts are a leading cause of blindness in both dogs and humans. Mutations in several genes have been associated with inherited forms of human cataract, but no mutations have been identified as the cause of any form of canine inherited cataract. We have used a candidate gene approach to investigate 20 genes, known to be associated with cataract in humans, for their potential association with the development of hereditary cataract (HC) in dogs. We have identified mutations in the HSF4 gene in Staffordshire Bull Terriers, Boston Terriers and Australian Shepherds affected by HC. Interestingly, different mutations in this single gene may be causing a recessive form of cataract in Staffordshire Bull Terriers and Boston Terriers and a dominant cataract in Australian Shepherds. Identification of the mutations that cause HC in these three breeds provides a method of controlling the disease within populations at risk using a simple diagnostic test, and also establishes cataract in these breeds as models for their human counterparts.

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

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. 172 dogs (290 eyes) that underwent phacoemulsification surgery for cataract removal. 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). 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. 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.

Atresia Ani in the Dog: A Retrospective Study

Congenital anomalies of the rectum and anus are rare in dogs. The most frequently reported anomaly is atresia ani. Four types of atresia ani have been reported, including congenital anal stenosis (Type I); imperforate anus alone (Type II) or combined with more cranial termination of the rectum as a blind pouch (Type III); and discontinuity of the proximal rectum with normal anal and terminal rectal development (Type IV). An increased incidence was found in females and in several breeds, including miniature or toy poodles and Boston terriers. Surgical repair is the treatment of choice, but postoperative complications can occur, including fecal incontinence and colonic atony secondary to prolonged preoperative distension.

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.

Outcomes of Dogs Presented for Cataract Evaluation: A Retrospective Study

Two hundred and forty-four dogs were evaluated for cataracts at the University of Tennessee from January 2001 to December 2002. Fifty-four canine breeds were affected. Odds ratios for cataracts were significantly higher for six purebred dogs (including the cocker spaniel, miniature schnauzer, toy poodle, Boston terrier, miniature poodle, and bichon frise) compared with mixed-breed dogs. One hundred fifty-nine dogs did not have cataract surgery. The most common reason for dogs not having surgery was retinal degeneration (n=66).