Patent ductus arteriosus in the dog: a retrospective study of clinical presentation, diagnostics and comparison of interventional techniques in 102 dogs (2003-2011)

A left-to-right shunting patent ductus arteriosus (PDA) is a common congenital heart defect in dogs. If it is left uncorrected, life expectancy in most cases is decreased due to the development of left-sided congestive heart failure. The aim of this study was to describe the dogs diagnosed with PDA in the Utrecht University Companion Animal Clinic from 2003 to 2011. The medical records of 102 patients were retrieved, and the clinical presentation and outcome of PDA closure by surgical ligation or transarterial catheter occlusion (TCO) were reviewed. In the TCO group, the result of coiling was compared with the placement of an Amplatz Canine Duct Occluder (ACDO). A predisposition to PDA was found in the German Brak, Stabyhoun, and Schapendoes. Dogs treated with surgical ligation were significantly older and heavier than those treated with TCO; within the TCO group, dogs treated with ACDO were significantly older and heavier The initial success rate (complete disappearance of the audible murmur in a patient that survived the procedure) was not significantly different between the different treatment modalities. Major complications were more common with surgical ligation, but the incidence of minor complications was not significantly different. There was no diference in survival between dogs treated with surgical ligation and dogs treated with TCO. This study shows a previously unreported predisposition to PDA in certain breeds. Both surgical ligation and TCO are suitable techniques for PDA closure, although major complications were more common with surgical ligation. ACDO appears to be the method with the least complications and thus can be considered the safest method.     

Repellency and efficacy of a 65% permethrin spot-on formulation for dogs against Aedes aegypti (Diptera: Culicidae) mosquitoes

A topically applied 65% permethrin spot-on (Defend EXspot Treatment for Dogs, Schering-Plough Animal Health) used for flea and tick control on dogs was evaluated for repellency and efficacy against the yellow fever mosquito, Aedes aegypti, a vector of canine filariasis. Six dogs were randomly assigned to receive a single application of 65% permethrin on Day 0 (n=3) or to remain untreated as controls (n=3). Dogs were anesthetized and exposed to 100 unfed, female mosquitoes in screened cages for 2 hours on Days -6, -4, -1, 0, 1, 7, 14, 21, and 28. Mosquito landing rates, engorgement rates, and mortality were determined for each mosquito challenge. Cages were thoroughly cleaned after each mosquito challenge. Treatment of dogs with 65% permethrin reduced the mosquito landing rates by 96.3% 6 hours after treatment and by 82.5% on Day 1. Mosquito mortality, relative to the control group, was 28.2% 6 hours after treatment, ranged from 84.0% to 90.9% through Day 21, and declined to 50.3% 28 days after treatment. Successful feeding by mosquitoes was significantly (P=.05) reduced on Days 1 through 28. The 65% permethrin spot-on treatment killed and repelled significantly (P =.05) more mosquitoes on treated dogs versus untreated dogs for 28 days after treatment.     

Surgical management of left-divisional intrahepatic portosystemic shunts: outcome after partial ligation of, or ameroid ring constrictor placement on, the left hepatic vein in twenty-eight dogs (1995-2005)

OBJECTIVES: To evaluate outcome in dogs with left divisional intrahepatic portosystemic shunts (PSS) treated by partial ligation (PL) or ameroid ring constrictor (ARC) placement on the left hepatic vein. DESIGN: Retrospective study. ANIMALS: Dogs (n=28) with left divisional intrahepatic PSS. METHODS: Retrieved data from medical records of dogs with left divisional intrahepatic PSS that had PL (n=17) or ARC (n=11) were signalment, history, clinical signs, preoperative blood work, portal pressure measurements, ARC size, complications and postoperative technetium scintigraphy. Outcome assessed by owner interview 6 months-10 years after surgery was classified as excellent, good or poor. Differences were tested by exact chi2 test. RESULTS: Major complications occurred in 3 dogs: coagulopathy (1 PL dog died), ascites (1 PL dog survived) and seizures (1 ARC dog died). Eight PL dogs had technetium portal scintigraphy; 1 dog was negative and 7 dogs positive for persistent shunting. Seven ARC dogs had scintigraphy; 4 dogs were negative and 3 positive for persistent shunting. In PL dogs, long-term clinical outcome was excellent (92%) or good (8%) whereas, in ARC dogs it was excellent (20%), good (50%) or poor (30%). This outcome difference between treatment groups was significant (P=.0012). CONCLUSION: Dogs treated by PL had significantly better long-term outcome compared with ARC treated dogs. CLINICAL RELEVANCE: Based on these data, ARC placement on the left hepatic vein in dogs with left-divisional intrahepatic PSS cannot be recommended.     

Clinical outcome of nonnasal chondrosarcoma in dogs: thirty-one cases (1986-2003)

OBJECTIVE: To evaluate metastatic rate and survival times of dogs with chondrosarcoma of nonnasal bony sites treated by wide surgical excision. STUDY DESIGN: Retrospective study. ANIMALS: Dogs (n=31) with chondrosarcoma. METHODS: Medical records were retrospectively reviewed to identify dogs with chondrosarcoma of bone in potentially surgically accessible sites. When complete information was not available in the medical record, owners and referring veterinarians were contacted by telephone to evaluate the course of disease and survival times. When possible, histopathologic diagnosis was confirmed by a single board certified pathologist and tumors were histologically graded. RESULTS: Dogs treated by wide surgical excision (n=18) had a mean survival time of 3097 days and did not reach median survival time. Dogs untreated except for diagnostic biopsy (n =13) had a median survival time of 523 days and a mean survival time of 495 days. Method of treatment and tumor grade predicted survival time (P=.016 and P=.007, respectively). Metastatic rate was 28% for treated dogs and 15% for untreated dogs, with no significant difference between the 2 groups (P=.39). CONCLUSIONS: Wide surgical excision significantly improves survival time for dogs with chondrosarcoma of nonnasal bony sites, but does not affect the likelihood of metastasis. Grade may be prognostic for survival. CLINICAL RELEVANCE: Surgical excision benefits dogs with chondrosarcoma and can result in prolonged survival times. Metastasis still occurs in approximately 1 of 4 dogs even after surgical resection.     

Predictive factors and the effect of phenoxybenzamine on outcome in dogs undergoing adrenalectomy for pheochromocytoma

BACKGROUND: Some studies in dogs undergoing adrenalectomy for pheochromocytoma suggest that anesthetic complications and perioperative mortality are common. In humans, surgical outcome has improved with the use of phenoxybenzamine (PBZ) before adrenalectomy. HYPOTHESIS: Dogs treated with PBZ before adrenalectomy have increased survival compared with untreated dogs. ANIMALS: Forty-eight dogs that underwent adrenalectomy for pheochromocytoma. METHODS: A retrospective medical record review for dogs that underwent adrenalectomy for pheochromocytoma at a veterinary medical teaching hospital over the period from January 1986 through December 2005. RESULTS: Twenty-three of 48 dogs were pretreated with PBZ (median dosage: 0.6 mg/kg PO q12h) for a median duration of 20 days before adrenalectomy. Duration of anesthesia and surgery, percentage of dogs with pheochromocytoma involving the right versus left adrenal gland, size of tumor, and presence of vascular invasion were similar for PBZ-treated and untreated dogs. Thirty-three (69%) of 48 dogs survived adrenalectomy in the perioperative period. PBZ-treated dogs had a significantly (P = .014) decreased mortality rate compared with untreated dogs (13 versus 48%, respectively). Additional significant prognostic factors for improved survival included younger age (P = .028), lack of intraoperative arrhythmias (P = .0075), and decreased surgical time (P = .0089). CONCLUSIONS AND CLINICAL IMPORTANCE: Results from this retrospective study support treatment with PBZ before surgical removal of pheochromocytoma in dogs.     

Epidemiologic factors associated with the anatomic location of intrahepatic portosystemic shunts in dogs

OBJECTIVE: To determine whether breed, sex, country of origin, and age are associated with anatomic location of intrahepatic portosystemic shunts (IHPSS) in dogs. STUDY DESIGN: Multi-institutional retrospective case series. SAMPLE POPULATION: Dogs (n=125) with IHPSS from the veterinary teaching hospitals of the University of Florida (21), Sydney University (44), and the University of California-Davis (60). METHODS: Dogs with surgical/necropsy confirmation of single IHPSS were identified. Data were analyzed using logistic regression for associations between age, breed, sex, and country with the anatomic location of IHPSS. RESULTS: Right (34%), left (34%), and central divisional IHPSS (32%) were prevalent with approximately equal frequency in Australia; in the United States, the prevalence of right (24%) and central divisional (26%) combined was similar to left divisional IHPSS (51%). Country (P=048), sex (P=.016), and Australian cattle dog ([ACD], P=.025) were significantly associated with IHPSS location. Dogs in Australia had 2.5-fold higher odds of having right versus left divisional IHPSS. Males and ACD had 2.8- and 5.6-fold higher odds of having right versus left divisional IHPSS. Australian dogs were significantly older than those in the United States (P<.0001) and ACD were significantly older than other breeds (P=.0067). CONCLUSIONS: Although country of origin, breed, and sex had significant associations with anatomic location of IHPSS, signalment does not appear to be a strong predictor of shunt location when used alone. CLINICAL RELEVANCE: For the common breeds in this report, signalment is only occasionally helpful in predicting likelihood of anatomic division in IHPSS. Australian cattle dogs and male dogs have a statistical association with right (versus left) divisional IHPSS. If advanced imaging techniques are not available, veterinary surgeons should be prepared to locate and address any anatomic configuration of IHPSS in a dog.     

Risk factors for ventral luxation in canine total hip replacement

Objective— To identify risk factors associated with ventral luxation (VL) of canine total hip replacement (THR), and outcome.
Study Design— Retrospective study.
Animals— Dogs (n=602) that had THR (563 cemented, 35 cementless, 4 hybrid).
Methods— Dogs (1999–2004) with VL after THR were compared with dogs with uncomplicated THR. Data included signalment, body weight, diagnosis, implant size, acetabular cup orientation, and femoral displacement ratio (FDR).
Results— VL was diagnosed in 11 (1.8%) dogs after primary THR. Including 2 other dogs that had VL after the study period, 10 (77%) of 13 dogs had VL within 7 days of surgery. Risk factors for VL included Saint Bernard-type dogs ( P =.0001), short neck extension ( P =.0005), and high angle of lateral opening in other breeds ( P =.018). There were trends toward higher risk of VL with lower FDR in Saint Bernardtypes ( P =.060), and with cementless implants ( P =.061). Twelve dogs had revision arthroplasty that was successful in all cementless and 2 cemented VL cases. Five dogs had recurrent VL and a poor outcome.
Conclusion— VL is generally an early complication of THR, with no single common risk factor identified.
Clinical Relevance— Saint Bernard types and short neck extensions are associated with increased risk of VL. Poor cup orientation is a determining factor for VL in some dogs, but a protective orientation of the acetabular cup was not found. Revision is successful in most dogs, but recurrent VL merits a guarded prognosis.     

Repellency and efficacy of 65% permethrin and selamectin spot-on formulations against Ixodes ricinus ticks on dogs

Two topically applied spot-on products used for flea and tick control on dogs, 65% permethrin (Defend EXspot Treatment for Dogs, Schering-Plough Animal Health Corp., Union, NJ) and selamectin (Revolution [United States] or Stronghold [Europe], Pfizer Animal Health, New York, NY), were evaluated for repellency and efficacy against Ixodes ricinus, the primary vector of Lyme disease in Europe. Eighteen dogs were evenly and randomly allocated to the following treatments: 1) 65% permethrin, 2) selamectin, 3) untreated control. Dogs were treated by topical application of the assigned product in accordance with product label directions on Day 0. At 7, 14, 21, 28, and 35 days after treatment, each dog was exposed for 2 hours to 50 unfed, adult ticks in a cage with a carpet that covered approximately 70% of the floor area. After the exposure period, dogs were removed from the cages and live and dead ticks were counted on the dogs and in the cages. The number of live ticks recovered was reduced by 90.3% to 99.5% for dogs treated with 65% permethrin (P <.0001 versus controls and selamectin), compared with 10.9% to 31.1% for dogs treated with selamectin (P >.05 versus controls). The repellency of 65% permethrin was 63.4% to 80.2% against I. ricinus ticks (P <.0001 versus controls, P <.0007 versus selamectin), compared with 0% to 10.9% repellency for selamectin (P >.05 versus controls).     

Evaluation of the success of medical management for presumptive thoracolumbar intervertebral disk herniation in dogs

Objective— To determine the success of medical management of presumptive thoracolumbar disk herniation in dogs and the variables associated with treatment outcome.
Study Design— Retrospective case series.
Animals— Dogs (n=223) with presumptive thoracolumbar disk herniation.
Methods— Medical records from 2 clinics were used to identify affected dogs, and owners were mailed a questionnaire about success of therapy, recurrence of clinical signs, and quality of life (QOL) as interpreted by the owner. Signalment, duration and degree of neurologic dysfunction, and medication administration were determined from medical records.
Results— Eighty-three percent of dogs (185/223) were ambulatory at initial evaluation. Successful treatment was reported for 54.7% of dogs, with 30.9% having recurrence of clinical signs and 14.4% classified as therapeutic failures. From bivariable logistic regression, glucocorticoid administration was negatively associated with success ( P =.008; odds ratio [OR]=.48) and QOL scores ( P =.004; OR=.48). The duration of cage rest was not significantly associated with success or QOL. Nonambulatory dogs were more likely to have lower QOL scores ( P =.01; OR=2.34).
Conclusions— Medical management can lead to an acceptable outcome in many dogs with presumptive thoracolumbar disk herniation. Cage rest duration does not seem to affect outcome and glucocorticoids may negatively impact success and QOL. The conclusions in this report should be interpreted cautiously because of the retrospective data collection and the use of client self-administered questionnaire follow-up.
Clinical Relevance— These results provide an insight into the success of medical management for presumptive thoracolumbar disk herniation in dogs and may allow for refinement of treatment protocols.     

Open peritoneal drainage versus primary closure for the treatment of septic peritonitis in dogs and cats: 42 cases (1993-1999)

OBJECTIVE: To determine survival rates in dogs and cats with septic peritonitis treated with open peritoneal drainage (OPD) versus primary closure (PC) after laparotomy. STUDY DESIGN: Retrospective analysis of medical records from Colorado State University Veterinary Teaching Hospital from 1993 to 1999. SAMPLE POPULATION: Thirty-six dogs and 6 cats with septic peritonitis documented by cytological examination or microbiological culture of abdominal fluid. METHODS: Medical records of dogs and cats with septic peritonitis treated by OPD or PC were reviewed. Age, weight, species, white blood cell (WBC) count, band neutrophil count, platelet count, serum glucose concentration, heart rate, body temperature, duration of hospitalization, and clinical outcome were recorded for each animal. Differences in treatments administered between the OPD and PC groups as well as the underlying cause of septic peritonitis were determined. RESULTS: There was no significant difference in survival between animals in the OPD versus PC groups (P =.26) with an overall survival rate of 71%. White blood cell count, band neutrophil count, platelet count, serum glucose and total bilirubin concentrations, heart rate, age, and weight were not significantly different between groups (P >.05). A significantly greater number of animals in the OPD group received plasma (P =.009), blood (P =.037), and a jejunostomy tube (P =.02) than animals in the PC group. There was a significant difference in the number of days spent in critical care unit with a mean of 6.0 +/- 4.1 days for the OPD group and 3.5 +/- 2.3 days for the PC group (P =.02). CONCLUSIONS: Open peritoneal drainage for the management of septic peritonitis in dogs and cats is an acceptable alternative to PC.     

Evaluation of Risk Factors for Morbidity and Mortality after Pylorectomy and Gastroduodenostomy in Dogs

Objectives— To (1) identify and describe the type and frequency of postoperative complications after pylorectomy and gastroduodenostomy in dogs and (2) identify preoperative and intraoperative risk factors, including the presence of neoplasia, prognostic for patient mortality after surgery. Study Design— Case series. Animals— Dogs (n=24) treated by pylorectomy and gastroduodenostomy. Methods— Medical records (2000–2007) for 2 teaching hospitals of dogs treated that had pylorectomy and gastroduodenostomy were reviewed. Pre‐, intra‐, and postoperative data were obtained from the medical record. Results— Of the 24 dogs, 75% survived 14 days, but 10 (41%) died by 3 months. Overall median survival time (MST) was 578 days. On log‐rank univariate analysis, preoperative weight loss (P=.001) and malignant neoplasia (P=.01) were associated with decreased survival time. Dogs with malignant neoplasia had a MST of 33 days. Common postoperative morbidity included hypoalbuminemia (62.5%) and anemia (58.3%). Conclusions— Pylorectomy with gastroduodenostomy has a good short‐term outcome but long‐term survival time is poor in dogs with malignant neoplasia. Clinical Relevance— Overall, most dogs treated with pylorectomy and gastroduodenostomy survived the postoperative period; however, preoperative weight loss and malignant neoplasia were associated with decreased survival time. Because dogs with malignant neoplasia have markedly shortened survival times, pertinent preoperative, diagnostics steps should be exhausted to identify underlying neoplasia.     

An evaluation of combined immunosuppression with MNA 715 and microemulsified cyclosporine on renal allograft rejection in mismatched mongrel dogs

OBJECTIVE: To evaluate a combination of MNA 715 and microemulsifed cyclosporine for the prevention of renal allograft rejection in mismatched mongrel dogs. STUDY DESIGN: Randomized, experimental study. ANIMALS: Fourteen female mismatched mongrel dogs. METHODS: Heterotopic renal transplantation and bilateral nephrectomy were performed in each dog. Dogs were randomly assigned to receive either MNA 715 and cyclosporine (n = 8) or cyclosporine alone (n = 6). Dogs were killed at 100 days after transplantation or when plasma creatinine exceeded 7 mg/dL. RESULTS: In the cyclosporine and MNA 715 group: 4 dogs survived to 100 days with normal plasma creatinine concentrations; 2 dogs with intestinal intussusceptions were killed at 5 and 8 days, 1 dog with a wound infection and sepsis was killed at 14 days, and 1 dog with a serum creatinine concentration >7 mg/dL was killed at 51 days postoperatively. In the cyclosporine-alone group: 3 dogs with acute rejection were killed at 6 to 9 days and 3 dogs survived to 100 days. In dogs treated with cyclosporine and MNA 715, survival to histologically confirmed acute rejection was significantly longer (P =.044) and the degree of mononuclear cell infiltration was significantly reduced (P =.040), compared with dogs treated with cyclosporine alone. CONCLUSIONS: MNA 715 combined with cyclosporine prolonged allograft survival and reduced the severity of histologic rejection in a clinically relevant renal transplant model. CLINICAL RELEVANCE: An immunosuppressive regimen consisting of MNA715 and microemulsified cyclosporine may be effective in preventing allograft rejection in canine renal transplant patients.     

Pre-procedural femoral vessel ultrasound in dogs with patent ductus arteriosus: diameter,image quality and relationship with arterial catheterization

IntroductionObjectives: Patent ductus arteriosus (PDA) in dogs is often treated via minimally invasive transvascular occlusion using femoral artery access. This study compared ultrasound-derived diameter and image quality of the right femoral artery (RFA) and vein (RFV) in dogs with PDA using a linear ultrasound probe (L-P) and phased-array transthoracic echocardiography probe (TTE-P). The case outcome was assessed.Animals, materials & methodsForty-five client-owned dogs with PDA were prospectively enrolled. Ultrasound-measured RFA and RFV diameters were obtained on images acquired with both probes pre-operatively and compared using Bland–Altman plots. The image quality of RFA and RFV was scored on L-P and TTE-P images.ResultsComparison of RFA and RFV diameter from L-P versus TTE-P images revealed: [Mean difference (limits of agreement): RFA = 0.009 mm (−0.78–0.79 mm), RFV = 0.523 mm (−1.75–2.79 mm)]. Image quality scores were significantly higher for L-P than TTE-P (P < 0.0001). In six small dogs, measurable images were unattainable with TTE-P. Dogs of similar body weight had variable RFA diameters. Twenty-seven dogs had RFA catheterization. In 21/27 dogs, RFA diameter exceeded the external diameter of the introducer used for catheterization, and in 6/27, it was smaller.ConclusionsPre-procedural ultrasound of the RFA in dogs with PDA is useful given variable RFA diameter relative to body weight. Despite poorer image quality, RFA diameters from TTE-P images were very similar to L-P images on average, suggesting TTE-Ps are suitable for pre-procedural planning in most dogs. Vasospasm, hypotension or differences in the location of ultrasound measurement versus catheterization might produce variation in pre-procedural versus intraoperative RFA size.     

Variables associated with outcome in dogs undergoing extrahepatic biliary surgery: 60 cases (1988-2002)

OBJECTIVE: To report clinical findings and define clinical variables associated with outcome in dogs undergoing extrahepatic biliary surgery. STUDY DESIGN: Retrospective study. ANIMALS: Sixty dogs that had extrahepatic biliary tract surgery. RESULTS: Primary diagnoses included necrotizing cholecystitis (36 dogs, 60%), pancreatitis (12 dogs, 20%), neoplasia (5 dogs, 8%), trauma (4 dogs, 7%), and gallbladder rupture from cholelithiasis without necrotizing cholecystitis (3 dogs, 5%). Bile peritonitis occurred in 19 (53%) dogs with necrotizing cholecystitis, 4 dogs with trauma, and 3 dogs with cholelithiasis without evidence of necrotizing cholecystitis. Cholecystectomy (37 dogs, 62%) and cholecystoduodenostomy (14 dogs, 23%) were the 2 most commonly performed procedures. Median hospitalization for survivors was 5 days (range, 1-15 days). There were 43 surviving dogs (72%) and 17 nonsurvivors (28%, 4 died, 13 euthanatized). Presence of septic bile peritonitis (P=.038), elevation in serum creatinine concentration (P=.003), prolonged partial thromboplastin times (PTTs; P=.003), and lower postoperative mean arterial pressures (P=.0001) were significantly associated with mortality. CONCLUSIONS: Extrahepatic biliary surgery is associated with high mortality and a relatively long hospitalization time for survivors. Cholecystectomy and cholecystoduodenostomy were the most common surgical procedures to treat the 4 major biliary problems (necrotizing cholecystitis, pancreatitis, neoplasia, and trauma) observed in this cohort of dogs. The relatively high mortality rate likely reflects the underlying diseases and their effects on the animal (septic bile peritonitis, higher serum creatinine, prolonged PTT, and lower postoperative mean arterial pressure) rather than complications of surgery. CLINICAL RELEVANCE: Septic bile peritonitis, preoperative elevated creatinine concentration, and immediate postoperative hypotension in dogs undergoing extrahepatic biliary tract surgery are associated with a poor clinical outcome. Adequate supportive care and monitoring in the perioperative period is critical to improve survival of dogs with extrahepatic biliary disease.     

Comparison of postoperative pain after ovariohysterectomy by harmonic scalpel-assisted laparoscopy compared with median celiotomy and ligation in dogs

OBJECTIVE: To compare the effects of postoperative pain after ovariohysterectomy by harmonic scalpel-assisted laparoscopy (HALO) and traditional ovariohysterectomy (OVH) in dogs. STUDY DESIGN: A randomized, blinded, prospective study. SAMPLE POPULATION: Sixteen, purpose-bred, intact female, Beagle dogs. METHODS: Dogs were divided into 2 groups: Group 1 (8 dogs), which had OVH by HALO, and Group 2 (8 dogs), which had traditional OVH. Physiologic data, abdominal nociceptive threshold scores, and University of Melbourne pain scores (UMPS) were recorded at 2, 6, 12, 24, 48, and 72 hours after surgery. Blood samples for measurement of plasma cortisol, glucose, and creatine phosphokinase (CPK) concentrations were collected at the time of the incision, and 2, 6, 12, 24, 48, and 72 hours after surgery. RESULTS: No significant surgical complications occurred. The HALO mean surgical time was significantly longer (55.7 minutes) than traditional OVH (31.7 minutes). No significant differences were observed between groups for the pain measures of heart rate, respiratory rate, temperature, CPK, and glucose concentrations. The OVH group had significantly higher mean plasma cortisol levels at hour 2 after surgery than the HALO group (P=.0001). The mean UMPS were significantly higher in OVH than the HALO group at all postoperative times (P=.0001). The mean nociceptive threshold measurements revealed significantly higher tolerated palpation pressures in HALO than OVH at all postoperative times, except hour 72 (P=.0002). CONCLUSIONS: Dogs appeared to be in less pain with HALO than OVH. The harmonic scalpel coagulated ovarian and uterine vessels completely with minimal collateral damage to surrounding tissues. CLINICAL RELEVANCE: HALO is a safe alternative to OVH and offers a minimally invasive and less painful method of surgery.     

Analysis of Factors Affecting Survival in Dogs With Aortic Body Tumors

OBJECTIVE: To evaluate the effect of perioperative and operative variables on survival time in dogs with aortic body tumors. STUDY DESIGN: Retrospective study. SAMPLE POPULATION: Twenty-four client-owned dogs with histologically confirmed aortic body tumor. METHODS: Seventy-eight patient records of dogs seen at the University of Illinois Veterinary Teaching Hospital between 1989 and 1999 with a diagnosis of a heart-base mass were reviewed. Dogs without histologic conformation of an aortic body tumor were excluded. Age; sex; breed; the presence of pleural effusion, pericardial effusion, or abdominal effusion; evidence of cardiac arrhythmias; evidence of distant metastasis; treatment with pericardectomy; treatment with chemotherapy; and time from diagnosis until euthanasia or death were recorded on a spreadsheet. Cox proportional-hazard ratios were used to calculate the relationship of risk variables to survival time. Median survival time was determined using life-table analysis. RESULTS: Twenty-four dogs met the criteria for inclusion in the study. The median age of dogs with aortic body tumors was 9 years. All dogs had a surgical biopsy performed. Fourteen dogs had a pericardectomy at the time of the biopsy procedure. Of all factors analyzed, only treatment with pericardectomy had a significant influence on survival (P =.0029). Dogs that had pericardectomy survived longer (median survival, 730 days; range, 1-1,621 days) compared with dogs that did not have pericardectomy (median survival, 42 days; range, 1-180 days). This finding was independent of the presence or absence of pericardial effusion at the time of surgery. CLINICAL RELEVANCE: Dogs that are diagnosed with aortic body tumors may benefit from a pericardectomy at the time of surgical biopsy.     

Outcome of and postoperative complications in dogs undergoing surgical treatment of laryngeal paralysis: 140 cases (1985-1998).

OBJECTIVE: To compare outcomes of various surgical techniques for treatment of laryngeal paralysis in dogs and determine incidence and risk factors for development of postoperative complications. DESIGN: Retrospective study. ANIMALS: 140 dogs undergoing surgical treatment for laryngeal paralysis at a veterinary teaching hospital between 1985 and 1998. PROCEDURE: Data were analyzed to determine outcome and factors influencing outcome and development of complications. Kaplan-Meier curves were constructed for survival analysis. RESULTS: Postoperative complications were documented in 48 (34.3%) dogs; 20 (14.3%) dogs died of related causes. Aspiration pneumonia was the most common complication (33; 23.6%). Seven dogs died of aspiration pneumonia > 1 year after surgery. Dogs that underwent bilateral arytenoid lateralization were significantly more likely to develop complications and significantly less likely to survive than were dogs that underwent unilateral arytenoid lateralization or partial laryngectomy. Factors that were significantly associated with a higher risk of dying or of developing complications included age, temporary tracheostomy placement, concurrent respiratory tract abnormalities, concurrent esophageal disease, postoperative megaesophagus, concurrent neoplastic disease, and concurrent neurologic disease. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that surgical repair of laryngeal paralysis may be associated with high postoperative complication and mortality rates. Surgical technique and concurrent problems or diseases increased the risk of complications. Dogs appeared to have a life-long risk of developing respiratory tract complications following surgical correction.     

Intercalary bone grafts for joint and limb preservation in 17 dogs with high-grade malignant tumors of the diaphysis

OBJECTIVE: To evaluate postoperative complications, limb function, and tumor control after intercalary resection and reconstruction for preservation of limb and joint function in dogs with high-grade malignant tumors of diaphyseal bone. STUDY DESIGN: Retrospective study. ANIMALS: Seventeen client-owned dogs. METHODS: The bone tumor database and medical records were reviewed (1986-2002) for dogs with diaphyseal tumors treated with intercalary resection and reconstruction with either an allograft or irradiated autograft. Clinical presentation, diagnostic findings, surgical management, and outcome were determined from medical records and telephone interviews with veterinarians and owners. Statistical analyses included chi2 to test associations between intra- and postoperative variables with complications, and Kaplan-Meier survival analysis for disease-free interval, metastasis-free interval (MFI), and median survival time. RESULTS: Intercalary limb-sparing surgery was performed in 17 dogs with diaphyseal tumors: osteosarcoma (OSA) (15), histiocytic sarcoma (1), and solitary metastasis from a pulmonary adenocarcinoma (1). One dog was excluded from further analysis when the spared limb was amputated 4 days postoperatively because of incomplete tumor resection. In 16 dogs, limb function was good to excellent. Complications occurred in 5 dogs (31.3%) and included superficial infection in 2 dogs (12.5%) and implant failure in 4 dogs (25%). All implant failures occurred in the ulna and there was a significant association between implant failure and non-cemented allografts (P=.042). Non-union of 1 or both osteotomies was diagnosed in 10 dogs (83.3%) and, despite lack of clinical signs in all cases, was significantly associated with the use of intracavitary locally released cisplatin (P=.046) and cemented intercalary grafts (P=.046). Local tumor recurrence was diagnosed in 1 dog (6.3%) and metastatic disease in 12 dogs (75.0%), including 10 dogs with OSA. The median MFI was 137 days. The local disease-free and overall limb-salvage rate was 94% and 100%, respectively. Overall median survival time was 393 days and the median survival time for dogs with OSA was 449 days. CONCLUSION: Intercalary limb-sparing surgery results in better postoperative limb function with fewer and less severe complications than historical reports of dogs treated with non-intercalary limb-sparing surgery. CLINICAL RELEVANCE: In dogs with diaphyseal tumors, intercalary limb-sparing surgery preserves normal joint function and results in good to excellent limb use with few complications and good local tumor control.     

Magnetic Resonance Imaging in Dogs with Neurologic Impairment Due to Acute Thoracic and Lumbar Intervertebral Disk Herniation

Background: Magnetic resonance imaging (MRI) is a correlate to physical examination in various myelopathies and a predictor of functional outcome.
Objectives: To describe associations among MRI features, neurological dysfunction before MRI, and functional outcome in dogs with disk herniation.
Animals: One hundred and fifty-nine dogs with acute thoracolumbar disk herniation.
Methods: Retrospective case series. Signalment, initial neurological function as assessed by a modified Frankel score (MFS), and ambulatory outcome at hospital discharge and >3 months (long-term) follow-up were recorded from medical records and telephone interview of owners. Associations were estimated between these parameters and MRI signal and morphometric data.
Results: Dogs with intramedullary T2W hyperintensity had more severe pre-MRI MFS (median 2, range 0–4) and lower ambulatory proportion at long-term follow-up (0.76) than those dogs lacking hyperintensity (median MFS 3, range 0–5; ambulatory proportion, 0.93) ( P =.001 and .013, respectively). Each unit of T2W length ratio was associated with a 1.9 times lower odds of long-term ambulation when adjusted for pre-MRI MFS (95% confidence interval 1.0–3.52, P =.05). Dogs with a compressive length ratio >1.31 (which was the median ratio within this population) had more severe pre-MRI MFS (median 3, range 0–5) compared with those with ratios ≤1.31 (median MFS 3, range 0–4; P =.006).
Conclusions and Clinical Importance: MRI features were associated with initial injury severity in dogs with thoracolumbar disk herniation. Based on results of this study, the T2W length ratio and presence of T2W intramedullary hyperintensity appear to be predictive of long-term ambulatory status.     

Risk factors for tibial tuberosity fracture after tibial plateau leveling osteotomy in dogs

Objective— To evaluate factors that predispose to tibial tuberosity (TT) fracture after tibial plateau leveling osteotomy (TPLO) in dogs.
Study Design— Retrospective study.
Animals— Dogs (n=182) with cranial cruciate ligament (CCL) rupture undergoing 213 TPLO surgeries.
Methods— Medical records and radiographs of 2 groups of dogs that had TPLO surgery (2000–2001, 2004–2005) were evaluated to determine the effect of operative technique and surgeon experience on TT fracture.
Results— TT fracture was diagnosed in 8 dogs (9 TPLO, 4.2% of surgical procedures). Four fractures occurred after unilateral TPLO in 167 dogs (2.4%), 4 fractures occurred after simultaneous bilateral TPLO in 5 dogs (40%), and 1 fracture occurred after staged bilateral TPLO in 36 dogs (2.8%). Simultaneous bilateral TPLO resulted in a 12.4 times higher odds of TT fracture versus unilateral TPLO ( P =.046). The mean absolute thickness of the TT after TPLO was less in dogs sustaining TT fractures (7.2 ± 2.2 mm) than those that did not (10.8 ± 2.7 mm, P <.0001). The odds of fracture decreased by 37% when the absolute TT width postosteotomy increased by 1 mm ( P <.0001). An increase in tibial plateau angle at follow-up versus immediately postoperative was associated with TT fracture ( P =.025). Surgeon experience was not associated with TT fracture.
Conclusion— A combination of surgical decision-making and surgical technique play a role in the occurrence of TT fracture after TPLO. Simultaneous bilateral TPLO was associated with a high percentage of TT fracture.
Clinical Relevance— Careful planning of osteotomy positioning is advised while performing TPLO surgery.