Retrospective analysis of nonradiation complications in dogs undergoing radiation therapy

Dogs receiving radiation can develop complications unrelated to the radiation treatment. No study to date has described these complications in clinical patients undergoing multiple radiation therapy treatments. The purpose of this retrospective case‐control study was to characterize the incidence and type of complications that occur in these dogs. A secondary goal was to evaluate whether patient and treatment characteristics could be identified to predict the risk of these complications. Medical records of 268 dogs receiving at least one radiation treatment at a single institution, between September, 2004 and June, 2007 were reviewed. Age, breed, gender, body weight, tumor type, tumor location, number of treatments, pre‐treatment blood work abnormalities, and whether chemotherapy, glucocorticoids, or nonsteroidal anti‐inflammatory drugs were given were collected. Number, type, and severity of nonradiation complications were recorded. Complications attributed to the tumor or to the radiation were excluded. Statistical analyses were performed to determine whether demographic and clinical characteristics were associated with development of a complication. General anesthesia was used for all treatments. Complications occurred in 101 (37%) cases including diarrhea, vomiting, cough, and loss of appetite, which were typically mild. Seventeen dogs (6%) developed severe complications. Eight dogs (3%) died from their complication. Dogs that developed complications were younger, received more treatments, had leukocytosis, received glucocorticoids, and were less likely to have thrombocytopenia. On multivariate analysis, number of treatments and leukocytosis were significantly associated with complications. Findings indicate that nonradiation complications are common in dogs receiving radiotherapy under general anesthesia. In this population, complications were usually mild or self‐limiting.     

Retrospective evaluation of fixation complications of 49 pelvic osteotomies in 36 dogs

Thirty-six dogs undergoing 49 pelvic osteotomies (POs) stabilised either by manually twisted dynamic compression plates (DCPS; n= 29) or canine pelvic osteotomy plates (CPOPS; n = 20) were retrospectively reviewed. Postoperative radiographs were available for all POs and 36 had additional radiographic follow-up. Pelvic osteotomies with CPOPs were more likely to have three screws placed in the sacrum while DCPs were associated with none, one or two screws in the sacrum. There was no difference in the postoperative sagittal alignment of the acetabular segments for POs with DCPs or CPOPs. Screw loosening was the most common complication (n = 13/36, 36 per cent), usually involving screws in the ilial segment. On follow-up radiographs, medial displacement of the acetabular segment was most frequently associated with screw loosening and plate bending. Medial displacement of the acetabular segment caused apparent pelvic narrowing on radiographs, more pronounced in dogs with bilateral POs, but clinical problems were not reported.     

Retrospective analysis of complications associated with retrobulbar bupivacaine in dogs undergoing enucleation surgery

ObjectiveTo investigate complications associated with, and without, bupivacaine retrobulbar local anesthesia in dogs undergoing unilateral enucleation surgery.Study designRetrospective, observational study.AnimalsA total of 167 dogs underwent unilateral enucleation surgery via a transpalpebral approach.MethodsRecords from 167 dogs that underwent unilateral enucleation surgery that did (RB) or did not (NB) include retrobulbar bupivacaine anesthesia were reviewed, including anesthetic record, daily physical examination records, surgery report, patient discharge report and patient notes within 14 days of the surgery. Specific complications and severity were compared between RB and NB using the Wilcoxon rank-sum test. A ‘complication burden’ (0–5) comprising five prespecified complications was assigned and tested using rank-sum procedures. Statistical significance was set to 0.05.ResultsGroup RB included 97 dogs and group NB 70 dogs. Dogs in NB had a 17.0 percentage points (points) greater risk for a postoperative recovery complication (38.6% versus 21.6%; 95% confidence interval: 3.0–30.6 points; p = 0.017). There was inconclusive evidence that dogs in group RB had a lower risk of requiring perioperative anticholinergic administration (12.4% versus 22.9%; 10.5 points; p = 0.073). Other complications were similar between groups RB and NB with risks that differed by <10 points. The risk of hemorrhage was similar between groups RB (22.7%) and NB (20.0%) with no significant difference in the level of severity (p = 0.664).Conclusions and clinical relevanceIn this retrospective study, the use of retrobulbar bupivacaine for enucleation surgery in dogs was not associated with an increased risk of major or minor complications.     

Retrospective study of congenital heart defects in 151 dogs

The case records of 151 dogs diagnosed with congenital heart disease were revlewed retrospectlvely. The most common defect Was aortic stenosls, accounting for 35 per cent of all cases, followed by pulmonic stenosls (20 per cent), ventricular septal defect (12 per cent), patent ductus arterlosus (11 per cent), mltral valve dysplasla (8 per cent), tricuspld valve dysplasla (7 per cent), endocardlal fibroelastosls (1.9 per cent) and tetralogy of Fallot (04 per cent). Fifty-one breeds were represented, with golden retrievers, German shepherd dogs and boxers predominating. No overall sex predilection was obvious. Seventy-five per cent of the dogs were asymptomatic presentation. The defects most often associated with presenting symptoms, such as dyspnoea, syncope, ascltes, fallure to grow and depression, were mltral valve dysplasla, atrial septal defect, tricuspld valve dysplasla and endocardial flbroelastosls. The latter presented with the most severe signs of heart fallure. In some cases of aortic stenosls and pulmonlc stenosls, where the defect could not be accurately visuallsed with two-dimensional echocardlography, Doppler echocardlographic examination was needed for definltive dlagnosls.     

Retrospective study of bacterial infective arthritis in 31 dogs

OBJECTIVES: To characterise the presenting signs and pathological changes of canine bacterial infective arthritis in 31 dogs, and to document the response to different treatment regimens. Risk factors that may predispose joints to bacterial infective arthritis and influence the success of treatment were also investigated. METHODS: A retrospective review of cases of bacterial infective arthritis that were presented to three university veterinary referral hospitals over a five-year period (January 1997 to January 2002) was performed. RESULTS: The elbow joint (38 per cent) and stifle joint (44 per cent) were most commonly affected. Radiographic changes consistent with pre-existing osteoarthritis were identified in 14 joints, which had no history of previous surgery (articular or periarticular) or penetrating wound. No significant difference (P = 0.78) was identified between the outcome of combined surgical and medical management, and medical management alone. There were trends for poorer outcomes with increased bodyweight of the dog, longer duration of lameness and a higher nucleated cell count of the affected joint fluid at presentation. The overall infection rate for articular surgical procedures at one institution was 1-3 per cent. CLINICAL SIGNIFICANCE: Medical and/or surgical management were usually successful in resolving infection (94 per cent). However, they were frequently unsuccessful in restoring full joint function; this may in part have been due to the nature of the underlying joint     

Retrospective evaluation of notched and fragmented QRS complex in dogs with naturally occurring myxomatous mitral valve disease

Myxomatous mitral valve disease (MMVD) is the most common cardiac disease in dogs. The association of QRS notching (nQRS) or fragmentation (fQRS) with disease severity is currently unknown. The study objective was to assess the prevalence of nQRS and fQRS in dogs with MMVD and its severity according to ACVIM classification and to compare the results with a group of healthy dogs. This retrospective cross-sectional study included 34 healthy control dogs and 155 dogs with spontaneous MMVD (42% of dogs in class B1, 23% in class B2 and 35% in class C). fQRS was defined as nQRS complexes in two contiguous leads in the frontal plane (leads I and aVL) and (II, III or aVF). A one-way ANOVA with Bonferroni post-hoc test was used to assess the differences in continuous data between control and MMVD groups. Of the MMVD group, 58% showed nQRS in at least one lead and 27% presented fQRS. There was no difference between the number of leads with a nQRS and disease severity (p = 0.75) nor did the number of leads with a nQRS correlate with left atrial size (r = 0.48; p = 0.5). The number of dogs with fQRS did not differ among classes of MMVD (p = 0.21). nQRS and fQRS were more prevalent in dogs with MMVD compared to control dogs (p < 0.01). This study did not identify any relationship between the number of leads with a nQRS and disease severity. However, dogs with MMVD had a higher prevalence of nQRS and fQRS compared to control group.     

Retrospective study of tetanus in 20 dogs: 1988-2004

The case records of 20 dogs that were treated for tetanus between 1988 and 2004 were reviewed. Young, large-breed dogs were most commonly affected. Twelve dogs had a likely source of infection identified. All dogs were treated with intravenous antibiotics and supportive care, such as muscle relaxants and sedation for muscle tremors and rigidity. Sixteen dogs received tetanus antitoxin. The mortality rate was 50%. Complete recovery in survivors required approximately 1 month.     

Retrospective study of orthovoltage radiation therapy for nasal tumors in 42 dogs

Megavoltage radiation therapy currently is the standard of care for dogs with nasal tumors. Some studies report that surgery and adjunctive orthovoltage radiation therapy result in longer control of these tumors than does megavoltage radiation therapy alone. This study reports less effective control of nasal tumors in dogs treated with surgery and orthovoltage radiation than previously observed, supporting the superiority of megavoltage radiation therapy for these tumors. In addition, this study suggests 2 new prognostic indicators for dogs with nasal tumors and describes toxicity associated with surgery and orthovoltage therapy. Forty-two dogs with nasal tumors were treated with surgical cytoreduction and 48 Gy orthovoltage radiation therapy administered in twelve 4-Gy fractions. Median survival was 7.4 months. One- and 2-year survival rates were 37% and 17%, respectively. Dogs with facial deformity had shorter survival than those without deformity (P = .005). Dogs with resolution of clinical signs after treatment had longer survival than those with chronic nasal signs (P = .0001). Acute radiation toxicity was moderate to severe for skin and eye and negligible for oral mucosa. Toxicity healed within 1 month after radiation therapy. Late toxicity was mild, but 70% of evaluable dogs experienced persistent ocular signs. Only 39% of dogs achieved a disease-free period.     

Oncolytic reovirus therapy: Pilot study in dogs with spontaneously occurring tumours

Oncolytic virotherapy is a novel treatment involving replication‐competent virus in the elimination of cancer. We have previously reported the oncolytic effects of reovirus in various canine cancer cell lines. This study aims to establish the safety profile of reovirus in dogs with spontaneously occurring tumours and to determine a recommended dosing regimen. Nineteen dogs with various tumours, mostly of advanced stages, were treated with reovirus, ranging from 1.0 × 10⁸ to 5.0 × 10⁹ TCID₅₀ given as intratumour injection (IT) or intravenous infusion (IV) daily for up to 5 consecutive days in 1 or multiple treatment cycles. Adverse events (AEs) were graded according to the Veterinary Cooperative Oncology Group‐ Common Terminology Criteria for Adverse Events (VCOG‐CTCAE) v1.1 guidelines. Viral shedding, neutralizing anti‐reovirus antibody (NARA) production and immunohistochemical (IHC) detection of reovirus protein in the tumours were also assessed. AE was not observed in most dogs and events were limited to Grade I or II fever, vomiting, diarrhoea and inflammation of the injected tumour. No infectious virus was shed and all dogs had elevated NARA levels post‐treatment. Although IHC results were only available in 6 dogs, 4 were detected positive for reovirus protein. In conclusion, reovirus is well‐tolerated and can be given safely to tumour‐bearing dogs according to the dosing regimen used in this study without significant concerns of viral shedding. Reovirus is also potentially effective in various types of canine tumours.     

Retrospective clinical evaluation of ultrasound guided transverse abdominis plane block in dogs undergoing mastectomy

HistoryEleven female dogs of different breeds undergoing unilateral radical (n = 7) or regional abdominal mastectomy (n = 4) received an ultrasound guided transverse abdominis plane block (TAP-block).Physical examinationSubjects showed single or multiple mammary tumours. Serum biochemistry, CBC and electrocardiogram were unremarkable. Eight animals were classified as ASA physical status II and 3 as ASA III.ManagementDogs were premedicated with methadone [0.1 or 0.2 mg kg^?1 intravenously (IV) or intramuscularly respectively] or fentanyl (2.5 μgkg^?1 IV). Anaesthesia was induced with propofol and maintained with isoflurane or sevoflurane. Unilateral ultrasound guided TAP blocks were performed in the caudal and cranial abdomen with bupivacaine 0.25% (0.3 to 0.35 mL kg^?1). Intercostal nerve blocks (T₄ to T₁₁) with bupivacaine 0.25% (0.013 to 0.04 mL kg^?1) completed the blocked area in dogs undergoing radical mastectomy.Follow upThe median (range) of end-expired isoflurane and sevoflurane necessary to maintain anaesthesia was 1.15 (1.07–1.22) and 2.07 (2.05–2.2) vol% respectively. A single administration of fentanyl (2.5 μg kg^?1, IV) was administered to control nociception (defined as an increased heart rate or mean arterial blood pressure above 20% of the pre-incisional value) in four of 11 dogs. All dogs received carprofen (2 mg kg^?1 subcutaneously) at the end of surgery. Post-operative pain, assessed for 120 minutes using the short form of Glasgow Composite Pain Scale (0–24), was always lower than 3. No rescue analgesia (allowed by the protocol) was required in this time.ConclusionTransverse abdominis plane block combined with intercostal nerve blocks may be useful to produce intraoperative anti-nociception and short term post-operative analgesia in dogs undergoing unilateral mastectomy.