The Natural Clinical History of Canine Congenital Subaortic Stenosis

The demographics and natural clinical history of canine congenital subaortic stenosis (SAS) were evaluated by retrospective analysis of 195 confirmed cases (1967 to 1991), 96 of which were untreated and available for follow-up evaluation. Of these, 58 dogs had left ventricular outflow systolic pressure gradients available for assessment of severity. All 195 dogs were used for demographic analysis. Breeds found to be at increased relative risk included the Newfoundland (odds ratio, 88.1; P < .001), Rottweiler (odds ratio, 19.3; P < .001), Boxer (odds ratio, 8.6; P < .001), and Golden Retriever (odds ratio, 5.5; P < .001). Dogs with mild gradients (16 to 35 mm Hg) and those that developed infective endocarditis or left heart failure were diagnosed at older ages than those with moderate (36 to 80 mm Hg) and severe (>80 mm Hg) gradients. Of 96 untreated dogs, 32 (33.3%) had signs of illness varying from fatigue to syncope; 11 dogs (11.3%) developed infective endocarditis or left heart failure. Exercise intolerance or fatigue was reported in 22 dogs, syncope in 11 dogs, and respiratory signs (cough, dyspnea, tachypnea) in 9 dogs. In addition, 21 dogs (21.9%) died suddenly. Sudden death occurred mainly in the first 3 years of life, primarily but not exclusively, in dogs with severe obstructions (gradient, > 80 mm Hg; odds ratio, 16.0; P < .001). Infective endocarditis (6.3%) and left heart failure (7.3%) tended to occur later in life and in dogs with mild to moderate obstructions. Left heart failure was uncommon in the absence of additional congenital defects or infective endocarditis. Dogs with mild obstructions lived longer than other groups and tended to remain asymptomatic. The majority of dogs with severe obstructions died before 3 years of age and had a high prevalence (8 of 15) of sudden death. The prognosis for long-term survival in dogs with untreated mild or moderate SAS is favorable (median survival, 30.5 and 51.1 months, respectively), while the prognosis for dogs with severe SAS is very poor (median survival, 18.9 months).     

Treatment of Congenital Pulmonic Stenosis in Two Dogs by Balloon Valvuloplasty

Balloon valvuloplasty was performed on two dogs with pulmonic valve stenosis. Immediately following balloon valvuloplasty, peak right ventricular systolic pressure declined from 92 to 44 mm Hg in the first dog and from 108 to 46 mm Hg in the second dog. The peak systolic pressure gradient across the pulmonic valve declined from 60 to 12 mm Hg in the first dog and from 84 to 22 mm Hg in the second dog. Hemodynamic improvement was sustained in both dogs at the time of recatheterization 3 months later. Both dogs tolerated the procedure well and there were no serious complications. It was concluded that balloon valvuloplasty offers an alternative to surgery for the treatment of valvular pulmonic stenosis in dogs. The exact indications for and limitations of balloon valvuloplasty must await the results of additional and more long-term studies.     

幼犬急性胃扩张的诊治

幼犬胃扩张是北方犬场幼犬冬季常发的疾病之一,其发病原因为幼犬胃内食物排空停滞,造成胃内容物、分泌物和气体在胃内大量积聚,严重影响幼犬的胃肠吸收以及心肺功能,在严寒时发病率更高,发病突然,病程较快,一般为3～5天,如果诊断不准确,治疗不及时,患幼犬可迅速脱水,呼吸、循环功能迅速衰竭而引起死亡.哈尔滨市某犬场2000年冬季8周龄以下幼犬发生此病,发病率为25%(64/184),死亡率为3.8%,经诊断后及时治疗,很快控制了本病.现将具体临床情况总结如下.     

Closed Transventricular Dilation of Discrete Subvalvular Aortic Stenosis in Dogs

Discrete subvalvular aortic stenosis with peak systolic pressure gradients of more than 60 mm Hg was treated by closed transventricular dilation in six young dogs. Peak systolic pressure gradients were measured by direct catheterization before surgery, immediately after dilation, and 3 months after surgery. Maximum instantaneous pressure gradients were measured by continuous wave Doppler echocardiography before surgery and 6 weeks to 9 months after surgery. All dogs survived the procedure, and two dogs were clinically normal after 9 and 14 months. Two dogs died at week 6 and month 7. One dog was receiving medication for pulmonary edema 15 months after surgery. One dog underwent open resection of the subvalvular ring at month 3, and was clinically normal 6 months after the second procedure. Complications included intraoperative ventricular fibrillation in one dog, and mild postoperative aortic insufficiency in one dog. Closed transventricular dilation resulted in an immediate 83% decrease in the peak systolic pressure gradient from a preoperative mean of 97 +/- 22 mm Hg to a mean of 14 +/- 15 mm Hg. However, systolic pressure gradients measured by direct catheterization at month 3 (77 +/- 26 mm Hg), and by Doppler echocardiography at week 6 to month 9 (85 +/- 32 mm Hg) were not significantly different from preoperative values, which suggested recurrence of the aortic stenosis. Closed transventricular dilation should not be considered a definitive treatment for discrete subvalvular aortic stenosis in dogs, but may be useful in young dogs with critical aortic stenosis as a bridge to more definitive surgery.     

Congenital Abnormalities of the Iris of the Dog

Abstract— An illustrated review is presented of some congenital abnormalities of the iris of the dog. The defects discussed include albinism, heterochromia iridium, anaridia, coloboma, persistant pupillary membranes and corpora nigra.
Résumé— Une revue illustrée est présentée, de quelques anomalies congénitales de l'iris du chien. Less défauts discutés incluent l'albinisme, l'hétérochromie, l'anaridia, colobome, membrane pupillaire persistante et corpora nigra.
Zusammenfassung— Es wird ein illustrierter Überblick über einige kongenitale Abnormalitäten der Regenbogenhaut von Hunden gegeben. Unter anderem werden Defekte wie Albinismus, Heterochromie iridium, anaridia, Kolobom, hartnäckige Pupillenmembranen und corpora nigra besprochen.     

Congenital Esophageal Hiatal Hernia in the Chinese Shar-Pei Dog

Esophageal hiatal hernia was diagnosed in 11 young Chinese Shar-Pei dogs between October 1985 and July 1991. The dogs ranged in age from 2 to 11 months and included 3 females and 8 males. The most common clinical signs were regurgitation, vomiting, and hypersalivation. Physical examination was normal in 6 dogs; abnormal physical examination findings in the other 5 dogs included fever, dehydration, hypersalivation, and pulmonary wheezes and crackles. Laboratory evaluation was significant only for neutrophilia in 5 dogs. A diagnosis of hiatal hernia was made on the basis of survey thoracic radio-graphic and/or barium esophagram findings of displacement of the esophagogastric junction and stomach into the thoracic cavity; the diagnosis was confirmed by surgery in 9 dogs and at necropsy in 2 dogs. Megaesophagus (n = 7), gastroesophageal reflux (n = 4), and esophageal hypomotility (n = 1) were additional findings in some dogs. Aspiration pneumonia was diagnosed in 7 of the dogs. Medical therapies formulated for the therapy of presumed reflux esophagitis generally failed to resolve the clinical signs associated with the hiatal hernia. Hiatal herniae were surgically repaired in 9 of the Shar-Peis by various combinations of diaphragmatic crural apposition, fixation of the esophagus to the diaphragmatic crus (esophagopexy), and left fundic tube gastropexy. Eight of the animals survived surgery, six of which have been asymptomatic since surgery (19 to 36 months). The megaesophagus, esophageal hypomotility, and bronchopneumonia resolved in all of these dogs. (Journal of Veterinary Internal Medicine 1993; 7:210–215. Copyright © 1993 by the American College of Veterinary Internal Medicine.)     

An Open Patch-Graft Technique for Correction of Pulmonic Stenosis in the Dog

An open patch-graft technique for correction of pulmonic stenosis was performed in four dogs. A synthetic patch-graft was presutured to a partial-thickness incision in the right ventricular outflow tract and to the pulmonary artery along its cranial border. The pulmonary artery and right ventricle were incised during venous inflow occlusion, and dysplastic pulmonic valve leaflets were excised. The arteriotomy was closed by suturing the caudal margin of the incision to the patch-graft. The entire procedure was performed during mild hypothermia (30 degrees - 32 degrees C). The mean circulatory arrest time was 5.5 +/- 0.2 minutes. The mean systolic pressure gradient across the pulmonic valve before surgery was 121 +/- 29 mm Hg; after surgery it was 9 +/- 2 mm Hg.     

Use of Auscultation and Doppler Echocardiography in Boxer Puppies to Predict Development of Subaortic or Pulmonary Stenosis

Background: Boxers are predisposed to subaortic and pulmonic stenosis (SAS, PS). Screening of puppies may be useful in estimating the risk of their developing a defect that potentially compromises life expectancy or exercise tolerance.
Hypothesis: Presence of SAS or PS in adult Boxers can be predicted by auscultation and Doppler echocardiography at 9–10 weeks of age.
Animals: Eighty-five Boxer puppies examined at 9–10 weeks of age and at 12 months of age.
Methods: Prospective, longitudinal observational study. Auscultation by stethoscope and continuous wave-Doppler echocardiography for peak velocities ( V _max) in the aorta (Ao) and pulmonary artery (PA).
Results: Intensity of heart murmurs in puppies correlated with V _maxAo and V _maxPA in adults. V _maxAo and V _maxPA in puppies correlated with V _maxAo and V _maxPA in adults, respectively. From puppy to adult, V _maxAo increased and V _maxPA remained unchanged. The negative predictive value for absent or only a soft (≤II/VI) murmur in puppies being associated with V _maxAo and PA ≤ 2.4 m/s as an adult was 90% and ≤3.5 m/s 100%. The negative predictive value of a V _max≤ 2.4 m/s as a puppy still being ≤2.4 m/s as an adult was 94% for Ao and 96% for PA, and of a V _max≤ 3.5 m/s, 99% for Ao and 100% for PA.
Conclusions and Clinical Importance: Even though V _maxAo increases during growth in Boxer puppies, indicating relative narrowing of the aorta, puppies with V _maxAo ≤ 2.4 m/s do not usually progress to clinically have relevant SAS at 12 months of age.     

Congenital Hemolytic Anemia in the Basenji Dog Due to Erythrocyte Pyruvate Kinase Deficiency

Congenital hemolytic anemia in the Basenji dog resembles pyruvate kinase (PK) deficiency in man as it is characterized by an abbreviated erythrocyte life span, an intense reticulocytosis, type II autohemolysis and splenomegaly. Glucose utilization and lactate production were inadequate with respect to the immature cell population. Analysis of enzymes involved in erythrocyte glycolysis revealed a deficiency of pyruvate kinase.     

Testicular Descent in the Dog

The mechanism underlying the process of normal testicular descent in the dog has been examined by a morphological, histological and histochemical analysis of testis and gubernaculum during the period from the 53rd day post coitum (p. c.) until the 40th day post partum (p. p.). Within this period, the testis passes the inguinal canal on the third or fourth day p. p. and reaches its scrotal location on the 35th day p. p. During the entire period the histological composition of the testis (volume percentage of seminiferous tubules, volume percentage of Leydig cells, diameter of seminiferous tubules, number of germ cells) is fairly constant. The △⁵-3β-hydroxysteroid dehydrogenase activity in the Leydig cells before birth suggests a steroid synthesis. Outgrowth and swelling of the gubernaculum occurs until the fifth day p. p. but morphological, histological and histochemical data indicate an onset of gubernacular regression during the last phase of the outgrowth reaction. The migration of the testis from the caudal end of the kidney towards the inguinal canal is associated with the outgrowth of the gubernaculum; during the phase of gubernacular regression, the testis moves from the inguinal canal towards its ultimate location in the scrotal pouch.