A 12-year-old 10-kg (22-lb) spayed female mixed-breed dog was evaluated at the Veterinary Medical Center of the University of Florida because of chronic renal failure. On initial physical examination, a grade 3/6 left apical systolic murmur was ausculted, which had previously been diagnosed by the hospital clinicians as mild mitral regurgitation secondary to chronic degenerative valvular disease. The dog was admitted to the hospital, and crystalloid solutions were administered IV. After 3 days of diuresis, tachycardia was detected on physical examination and an ECG was obtained (Figure 1).
A 14-year-old spayed female Schnauzer was evaluated for syncopal episodes and cough of 3 months’ duration. The owner reported that syncopal episodes occurred during periods of excitement or coughing. The dog had a prior history of degenerative mitral valve disease and congestive heart failure. Current treatments included furosemide (1.5 mg/kg [0.68 mg/lb], PO, q 12 h), spironolactone (1.5 mg/kg, PO, q 12 h), and enalapril (0.6 mg/kg [0.27 mg/lb], PO, q 12 h). A diagnosis of sicksinus syndrome was made by the referring veterinarian following analysis of Holter monitor data collected during a 24-hour period. The Holter monitor data indicated
A 7-year-old spayed female American domestic short-hair cat was evaluated at the Cornell University Hospital for Animals because of a history of sudden onset of recumbency, unresponsiveness, ptyalism, and shallow breathing. On physical examination, mucous membranes were pale and the cat was hypothermic (rectal temperature, 35.7°C [96.2°F]). Indirect systolic blood pressure was undetectable by use of an ultrasonic Doppler flow detector.a Thoracic auscultation revealed a heart rate > 300 beats/min and no abnormal lung sounds bilaterally. Electrocardiography was performed to assess the tachycardia (Figure 1). A venous catheter was placed, and supportive care was initiated, including
A7-year-old castrated male German Shepherd Dog was evaluated at the Veterinary Medical Center of the University of Florida because of coughing, anorexia, and weight loss. Prior history included pacemaker implantation 1 year previously for third-degree atrioventricular (AV) block. At that time, echocardiography revealed volume overload and hyperkinesis of the left ventricle; no other abnormalities were identified echocardiographically. A transvenous, bipolar, dual-chamber VDDa,b (singlelead atrial synchronous and ventricular inhibited) pacing system was implanted in the right ventricular apex (RVA). The owner had not returned the dog for scheduled reevaluation following implantation.
A1-year-old 27.5-kg (60.5-lb) sexually intact male Boxer was evaluated because of right-sided congestive heart failure and exercise intolerance. Current treatments included furosemide (2.98 mg/kg [1.35 mg/lb], PO, q 8 h), benazepril hydrochloride (0.36 mg/kg [0.16 mg/lb], PO, q 12 h), spironolactone (1.1 mg/kg [0.50 mg/lb], PO, q 12 h), and hydrochlorothiazide (0.45 mg/kg [0.20 mg/lb], PO, q 12 h). At the initial referral evaluation, the dog was bright, alert, responsive, and cachexic (body condition score, 2/9). Cardiac auscultation revealed a regularly irregular rhythm with a heart rate of 130 beats/min. There was a grade 5/6 left basilar systolic murmur. The
A 3-year-old sexually intact male mixed-breed dog was referred to the University of Florida for evaluation because of emaciation, recumbency, and dull mentation. The dog had a 1-month history of malnutrition with neglect. Results of clinicopathologic analyses performed by the referring veterinarian had indicated that the dog had anemia, hypoglycemia, hypoproteinemia, hypocalcemia, hyponatremia, and hyperphosphatemia. The initial physical examination (day 1) at the University of Florida revealed that the patient was emaciated (body condition score,1 1/9) with extensive muscle atrophy, weakness, and flea infestation. Mucous membranes were white, and capillary refill was undetectable. On auscultation, the dog had
A 13-year-old 20-kg (44-lb) castrated male English Springer Spaniel was evaluated at the University of Florida Veterinary Medical Center for transvenous pacemaker implantation because of third-degree atrioventricular (AV) block. The AV block was initially diagnosed several months prior to this evaluation, and no treatment had been initiated. One month prior to evaluation, the dog was treated for congestive heart failure, which prompted referral for further treatment and pacemaker implantation. At the time of the evaluation, the dog was receiving furosemide (2 mg/kg [0.91 mg/lb], PO, q 12 h) and enalapril (0.5 mg/kg [0.23 mg/lb], PO, q 12 h). On initial
A 4-year-old 1.4-kg (3.1-lb) male Chihuahua was referred for sudden onset of ataxia and stupor. Physical examination revealed a rectal temperature of 37°C (98.6°F) and a respiratory rate of 32 breaths/min. The dog's heart rate was 60 beats/min, and auscultation revealed a pronounced regularly irregular rhythm, no murmurs, and crackles bilaterally in the dorsal aspects of the lung fields. Tetraparesis was evident, and reflexes in all limbs were diminished; ataxia was detectable during ambulation. Cranial nerve function was intact but a delayed menace response was detected in each eye. Abnormal findings of a CBC included leukocytosis, neutrophilia, a left shift,
Objective—To compare procedure times and major and minor complication rates associated with single-chamber versus dual-chamber pacemaker implantation and with 1-lead, 2-lead, and 3-lead pacemaker implantation in dogs with clinical signs of bradyarrhythmia.
Design—Retrospective case series.
Animals—54 dogs that underwent pacemaker implantation because of clinical signs of bradyarrhythmia.
Procedures—Medical records of dogs that received pacemakers between July 2004 and December 2009 were reviewed for information regarding signalment, diagnosis, pacemaker implantation, pacemaker type, complications, and survival time. Analyses were performed to determine significant differences in anesthesia time, procedure time, and outcome for dogs on the basis of pacing mode and number of pacing leads.
Results—28 of 54 (51.9%) dogs received single-chamber pacemakers and 26 (48.1%) received dual-chamber pacemakers. Mean ± SD procedural time was significantly longer for patients with dual-chamber pacemakers (133.5 ± 51.3 minutes) than for patients with single-chamber pacemakers (94.9 ± 37.0 minutes), and procedure time increased significantly as the number of leads increased (1 lead, 102.3 ± 51.1 minutes; 2 leads, 114.9 ± 24.8 minutes; 3 leads, 158.2 ± 8.5 minutes). Rates of major and minor complications were not significantly different between dogs that received single-chamber pacemakers and those that received dual-chamber pacemakers or among dogs grouped on the basis of the number of pacing leads placed.
Conclusions and Clinical Relevance—Although dual-chamber pacemaker implantation did result in increased procedural and anesthesia times, compared with single-chamber pacemaker implantation, this did not result in a higher complication rate.
OBJECTIVE To compare mitochondrial oxygen consumption rate (OCR) of fibroblasts from Doberman Pinschers with and without dilated cardiomyopathy (DCM) and mutation of the gene for pyruvate dehydrogenase kinase isozyme 4 (PDK4) and to evaluate in vitro whether treatment with adeno-associated virus (AAV) vector (ie, gene therapy) would alter metabolic efficiency.
ANIMALS 10 Doberman Pinschers screened for DCM and PDK4 mutation.
PROCEDURES Fibroblasts were harvested from skin biopsy specimens obtained from Doberman Pinschers, and dogs were classified as without DCM or PDK4 mutation (n = 3) or with occult DCM and heterozygous (4) or homozygous (3) for PDK4 mutation. Fibroblasts were or were not treated with tyrosine mutant AAV type 2 vector containing PDK4 at multiplicities of infection of 1,000. Mitochondrial OCR was measured to evaluate mitochondrial metabolism. The OCR was compared among dog groups and between untreated and treated fibroblasts within groups.
RESULTS Mean ± SD basal OCR of fibroblasts from heterozygous (74 ± 8 pmol of O2/min) and homozygous (58 ± 12 pmol of O2/min) dogs was significantly lower than that for dogs without PDK4 mutation (115 ± 9 pmol of O2/min). After AAV transduction, OCR did not increase significantly in any group (mutation-free group, 121 ± 26 pmol of O2/min; heterozygous group, 88 ± 6 pmol of O2/min; homozygous group, 59 ± 3 pmol of O2/min).
CONCLUSIONS AND CLINICAL RELEVANCE Mitochondrial function was altered in skin fibroblasts of Doberman Pinschers with DCM and PDK4 mutation. Change in mitochondrial function after in vitro gene therapy at the multiplicities of infection used in this study was not significant. (Am J Vet Res 2016;77:156–161)