Buchanan, James W

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  • Publication
    Persistent Left Cranial Vena Cava in Dogs: Angiocardiography, Significance, and Coexisting Anomalies
    (1963) Buchanan, James W
    Persistent left cranial venae were observed in angiocardiograms of 3 dogs at the University of Pennsylvania Veterinary Hospital. Although this vessel seldom has clinical significance, it is hoped this report will spare others the confusion caused by the first case in this series. These 3 dogs and 5 out of 7 others had significant cardiovascular anomalies in addition to persistent left cranial venae cavae.
  • Publication
    Aortic Embolism in Cats: Prevalence, Surgical Treatment and Electrocardiography
    (1966-10-29) Buchanan, James W; Baker, Gordan J; Hill, John D
    Aortic embolism (caudal arterial thromboembolism) was diagnosed over a four-year-period in 14 out of 2,000 cats in a hospital clinic population (7/1,000). Including 35 cases reported in the literature, the average age of 50 cats with aortic embolism was 6-8 years (range one to 16 years). Of these, 37 were males and 13 were females. Endocarditis with thrombosis was the most frequently observed cause of aortic embolism, although aortic arteriosclerosis was reported in one cat. The clinical and pathological features of aortic embolism in five cats are described in this report. In electrocardiograms of four of these, arrhythmias or conduction disturbances were recorded. Intact emboli in the aorta and external iliac arteries were removed by abdominal aortic embolectomy in two cats within hours after the onset of posterior paralysis. Death resulted in one case from cardiac complications and in the other by euthanasia at the later date because of probably recurrent aortic embolism. In the other three cases, multiple sections of the aorta with the embolus in situ were examined, but no microscopic changes in the aortic wall were noted. Surgical removal of an aortic embolus is technically and economically feasible and is considered the treatment of choice when treatment is requested within hours after the onset of clinical signs. Although embolectomy can yield a good immediate result; the long range justification for such therapy requires further evaluation, since recurrent embolization may develop.
  • Publication
    Changing Breed Predispositions in Canine Heart Disease
    (1993-12-01) Buchanan, James W
    Breed predispositions for some types of congenital heart disease were recognized 30 years ago and led to breeding experiments that confirmed the genetic transmission of specific congenital heart defects in most instances. As a result, certain breeds were associated with certain diseases, and this became a legitimate consideration in the differential diagnosis of some abnormalities in the absence of more definite diagnostic studies. As an example, a significant systolic murmur in a young Newfoundland dog means sub-aortic stenosis (SAS) until proven otherwise. The diagnosis of SAS is usually confirmed by Doppler echocardiography or angiocardiography. Although cardiologists take breed into consideration, they still rely on proper examination and appropriate diagnostic procedures; however, practitioners are comes pressed to give opinions on the likelihood of particular diagnoses and prognoses without benefit of a full work-up. In this setting, knowledge of new and changing breed predispositions can be helpful. In recent years, some defects and new breeds have been found to be overrepresented in cardiology clinics across the country. All practitioners need to be alert in order to recognize new breed predispositions and counsel breeders accordingly. Of particular note is the rising frequency of SAS in Golden Retriever and Rottweiler dogs. The purpose of this presentation is to describe changing breed predispositions that have been observed in recent years and share the results of a recent tabulation of data at our institution as well as 1987- 1989 data in the national Veterinary Medical Data Base (VMDB) at Purdue University.
  • Publication
    Clinico-Pathologic Conference: Chronic Nephritis in a Bull
    (1961-10-15) Marshak, Robert; Buchanan, James W; Sauer, R. M
  • Publication
  • Publication
    Mineralization of Short Term Pericardial Cardiac Patch Grafts
    (1984-01-27) Buchanan, James W; Frasca, P.; Soriano, R. Z; Dunn, J. M; Marmon, L.; Buchanan, Sarah A.; Melbin, J.; Chang, S. H; Golub, E. E; Shapiro, I. M
    Glutaraldehyde fixed patch grafts of bovine pericardium were implanted in myocardial windows in young (3-4 months old) sheep. The samples were retrieved after one to three weeks for study with scanning electron microscopy (SEM) and energy dispersive x-ray microanalysis (EDX). A layer of porous material (pseudoneointima, PNI), consisting mostly of a dense mesh of fibers interspersed with blood cells, was noted to form on the blood contacting surface of the graft. Four distinct sets of mineralization were noted in the retrieved grafts: (1) at the blood contacting surface of the PNI; (2) within the PNI at the junction between layers of PNI with differing densities; (#) near the junction of PNI and pericardium (but in the PNI); and (4) within the pericardium. In both the PNI and pericardium the mineral was shown by EDX analysis to contain both calcium and phosphorous indicating the mineral to be a calcium phosphate. Mineralization in the PNI differed from that in the pericardium; in the PNI it was deposited in discrete regions and apparently in association with thrombi while in the pericardium it was distributed diffusely within the collagen matrix, which may influence its formation.
  • Publication
    Infection and Twiddler Syndrome in a Dog With Addison's Disease, Complete Heart Block, and Wandering Artificial Pacemakers
    (1990-02-01) Buchanan, James W; Hill, Richard C
    Third-degree heart block developed in an obese seven-year-old dog with adrenal cortical failure. After three days of extensive medial therapy and use of a temporary transvenous pacemaker, a transthoracic permanent pacemaker was implanted in the usual paracostal location. After two years of normal function, the pulse generator suddenly migrated to a ventral location in the flank and became surrounded by an abscess. Intermittent pacing failure ensued. Medical therapy with antibiotics failed to eliminate infection until the infected pacemaker and site were excised surgically. A new pacemaker was placed on the opposite side and functioned well for two months. Subsequent migration and rotation of the new pacemaker led to spiral twisting of the lead and dislodgment of the corkscrew electrode from the myocardium in a syndrome analogous to Twiddler's syndrome in man. The dog presently is 10 years old and asymptomatic with a nonpaced ventricular rhythm of 60 beats per minute and an usual chest radiograph.
  • Publication
    Tracheal Signs and Associated Vascular Anomalies in Dogs With Persistent Right Aortic Arch
    (2004-07-01) Buchanan, James W
    Medical records of 55 dogs with 1 or more vascular rings around the esophagus and trachea were reviewed to determine the nature and frequency of related vascular anomalies and to determine the reliability of tracheal deviation on radiographs for the diagnosis of persistent right aortic arch (PRAA). Fifty-two (95%) of the 55 dogs had PRAA. Of the 52 dogs with PRAA, 44% had coexisting compressive arterial anomalies: 17 had retroesophageal left subclavian artery and 6 had double aortic arch with atretic left arch. Characteristic tracheal deviation was consistently present in dogs with PRAA. Moderate or marked focal leftward curvature of the trachea near the cranial border of the heart in dorsoventral (DV) or ventrodorsal (VD) radiographs was found in 100% of available radiographs of 27 dogs with PRAA. Moderate or marked focal narrowing of the trachea also was noted in 74% of DV or VD radiographs and 29% of lateral radiographs of the dogs. Tracheal position in 30 of 30 dogs with megaesophagus and 62 of 63 control dogs was midline or rightward in VD or DV radiographs. Histology in a neonatal dog with PRAA revealed evidence of tracheal deviation and compression even before birth. Focal leftward deviation of the trachea near the cranial border of the heart in DV or VD radiographs is a reliable sign of PRAA in young dogs that regurgitate after eating solid food, and contrast esophagrams are not necessary to confirm the diagnosis of vascular ring compression.
  • Publication
    Etiology of Patent Ductus Arteriosus in Dogs
    (2003-03-01) Buchanan, James W; Patterson, Donald F
    Patent ductus arteriosus (PDA) is the most common congenital heart disease in dogs and usually causes heart failure and death unless corrected at a young age. Previous histologic studies in a line of dogs derived from Miniature Poodles with hereditary PDA identified varying degrees of hypoplasia and asymmetry of ductus-specific smooth muscle and the presence of aortalike elastic tissue in the ductus wall sufficient to cause patency. To determine if similar structural abnormalities cause PDA in other dogs, serial-section, 3-dimensional histology of ductal architecture was studied in 8 non-Poodle purebred dogs with PDA with no immediate family history of PDA. Morphologic abnormalities were observed in 7 of 8 dogs with PDA and essentially were the same as those in dogs known to have a hereditary form of PDA. These findings suggest that apparently sporadic PDA in these breeds is caused by a genetic defect in the structure of the ductus arteriosus that is similar or identical to that in the Poodle. The relatives of dogs with PDA, particularly parents, offspring, and siblings, should be screened for evidence of PDA. Dogs with PDA should not be used for breeding, regardless of breed.
  • Publication
    Experimental Studies on Ectopic Atrial Rhythms in Dogs
    (1967-05-01) Moore, E. Neil; Jomain, Serge L; Stuckey, Jackson H; Buchanan, James W; Hoffman, Brian F