Transvenous extraction of an abandoned endocardial pacemaker lead in a dog

A 6-year-old male castrated labrador retriever presented with endocardial pacemaker infection following migration and subsequent repositioning of the pulse generator. An epicardial lead and pulse generator were surgically implanted and the endocardial lead could not be removed with manual traction. The endocardial lead was severed, anchored, and abandoned at the thoracic inlet. The patient presented 4 months later with endocardial lead migration, bacteremia, and suspected glomerulonephritis. The endocardial pacemaker lead was transvenously extracted using a mechanical dilator sheath and locking stylet. This report of transvenous pacemaker lead extraction in a dog addresses the challenges and describes recent advances in extraction devices.     

Cranial vena caval syndrome secondary to transvenous pacemaker implantation in two dogs

Superior vena caval syndrome is a rare, but reported complication of transvenous pacemaker implantation in humans. This syndrome can occur secondary to fibrotic and/or thrombotic obstruction of venous blood flow into the right atrium. The therapeutic approach depends on the suspicion of the presence of an active thrombus and may include antithrombotics, angioplasty and/or surgical venoplasty. We describe two dogs that developed severe pleural effusion secondary to stricture formation in the cranial vena cava 4 years after dual chamber transvenous pacemaker implantation. The stenosis was most likely due to fibrosis secondary to the transvenous pacemaker leads. Balloon angioplasty of the lesion resulted in resolution of the pleural effusion in both patients. Balloon angioplasty appears to be a viable therapeutic approach in dogs with cranial vena caval syndrome caused by focal stenotic lesions.     

Survival time with pacemaker implantation for dogs diagnosed with persistent atrial standstill

Objectives

To evaluate survival time in dogs with persistent atrial standstill after pacemaker implantation and to compare the survival times for cardiac-related vs. non-cardiac deaths. Secondary objectives were to evaluate the effects of breed and the presence of congestive heart failure (CHF) at the time of diagnosis on survival time.

Follow-up of troponin I concentration in dogs with atrioventricular block and dual-chamber pacing in a case-matched study

Background

Increased cardiac troponin I (cTnI) concentration has been reported in dogs with atrioventricular (AV) block before and shortly following pacemaker implantation. The role of AV dyssynchrony, age, or concurrent cardiac disease on cTnI concentration remains unknown.

Treatment of canine leproid granuloma syndrome: preliminary findings in seven dogs

OBJECTIVE: To determine effective treatment strategies for patients with refractory canine leproid granuloma syndrome. DESIGN: Multi-institutional retrospective/prospective case series using client-owned dogs. PROCEDURE: Seven dogs (four Boxers, one Dobermann, one Bullmastiff and one Bullmastiff cross-bred; ages 3 to 11 years) with leproid granulomas were treated successfully using a variety of treatment regimens. These cases were recruited because: lesions were either widely distributed over the dog; progressive, despite routine therapy, or were associated with particularly disfiguring lesions. The treatment regimen evolved during the course of the clinical study. RESULTS: Combination therapy using rifampicin (5 to 15 mg/kg p.o., every 24 h) and clarithromycin (8 to 24 mg/kg p.o. daily; dose divided every 8 or every 12 h) was used most frequently and proved to be effective and free from side effects. Total daily doses of clarithromycin in excess of 14 mg/kg were considered optimal and long treatment courses, in the order of 1 to 3 months, were used. Combination therapy using rifampicin (25 mg/kg; that is, higher than the recommended dose) and clofazimine was effective in one case, but resulted in hepatotoxicity. A topical formulation of clofazimine in petroleum jelly was used as an adjunct to oral rifampicin and doxycycline in another patient treated successfully. CONCLUSION: Based on our evolving clinical experience, a combination of rifampicin (10 to 15 mg/kg p.o., every 24 h) and clarithromycin (15 to 25 mg/kg p.o. total daily dose; given divided every 8 to 12 h) is currently recommended for treating severe or refractory cases of canine leproid granuloma syndrome. Treatment should be continued (typically for 4 to 8 weeks) until lesions are substantially reduced in size and ideally until lesions have resolved completely. A topical formulation, containing clofazimine in petroleum jelly may be used as an adjunct to systemic drug therapy. Further work is required to determine the most cost effective treatment regimen for this condition.     

犬细小病毒病防控技术研究进展

感染犬细小病毒会导致典型的急性胃肠炎症状,包括呕吐、发热、白细胞显著减少和出血性腹泻等,常与犬瘟热、犬冠状病毒等混合感染。尽管相关疫苗进行了广泛接种,但其仍然是导致犬死亡的主要原因,幼犬死亡率常大于70 %。本文将介绍目前诊断CPV-2的主要方法及近年来取得的进展,并提供最新关于CPV-2疫苗类型和接种方案的信息,同时分析免疫失败的原因,对其防控技术进展进行综合描述。     

Atrial-based pacing for sinus node dysfunction in dogs: initial results

Background

An important consideration for the treatment of sick sinus syndrome (SSS) lies in the function of the atrioventricular (AV) node because most patients with SSS retain the ability to conduct atrial impulses.

Hypothesis/Objectives

This retrospective study examined the feasibility of atrial pacing (AAI) in dogs with sinus node dysfunction (SND).

Animals

Sixteen dogs with SND and AAI pacing were identified.

Methods

Retrospective review of medical records.

Results

Follow‐up time ranged from 45 to 1,227 days (mean: 292 days). Only 1 dog developed AV block 3 days postoperatively. Complete lead dislodgment occurred in 3/16 dogs 1, 19, and 27 days postoperatively. Lead perforation into the pericardial space occurred in 2/16 dogs. Rising thresholds for pacing with possible lead microdislodgment or fibrosis were suspected in another 3/16 dogs 57, 192, and 1,016 days after implantation. None of these dogs had complete loss of capture but all required higher thresholds for pacing.

Conclusions and Clinical Importance

Based on this small group of dogs, clinically important AV block does not appear to occur in the long‐term for dogs with SND. Risks of lead perforation, complete dislodgment, and rising thresholds for pacing, possibly because of microdislodgment, may be related to the initial skill level of the operator or the leads that were used. Use of leads with reduced torque at the lead tip, higher flexibility, increased lead‐tip surface of contact with the endocardium or, more likely, use of alternate locations for pacing in the small right atrium of dogs with SND may decrease the frequency of these complications.     

Efficacy of maropitant in the prevention of delayed vomiting associated with administration of doxorubicin to dogs

Background: Vomiting, nausea, inappetence, and diarrhea are common delayed adverse effects of doxorubicin. Maropitant, a neurokinin‐1 receptor antagonist, is known to prevent acute vomiting in dogs receiving cisplatin. Objective: To evaluate the efficacy of maropitant in preventing delayed vomiting after administration of doxorubicin to dogs. Animals: Fifty‐nine dogs with cancer. Methods: This randomized, double‐blind, placebo‐controlled study used a cross‐over design. Dogs were randomized into 1 of 2 treatment groups. Group A received maropitant after the 1st doxorubicin, and placebo after the 2nd. Group B received placebo first, and maropitant second. Maropitant (2 mg/kg) or placebo tablets were administered PO for 5 days after doxorubicin treatment. Owners completed visual analog scales based on Veterinary Cooperative Oncology Group‐Common Terminology Criteria for Adverse Events to grade their pet's clinical signs during the week after administration of doxorubicin. Statistical differences in gastrointestinal toxicosis and myelosuppression between maropitant and placebo treatments were evaluated. Results: Significantly fewer dogs had vomiting (P= .001) or diarrhea (P= .041), and the severity of vomiting (P < .001) and diarrhea (P= .024) was less the week after doxorubicin when receiving maropitant compared with placebo. No differences were found between maropitant and placebo for other gastrointestinal and bone marrow toxicoses. Conclusions and Clinical Importance: Maropitant is effective in preventing delayed vomiting induced by doxorubicin. Its prophylactic use might improve quality of life and decrease the need for dose reductions in certain dogs.     

仔猪咬尾症的原因及其防治方法

仔猪咬尾症是仔猪常见的异食癖,常由于营养机能紊乱及饲养管理不当导致的该应激反应发生。常见于仔猪12~14周龄,在每年1-3月份及8-12月份发病率较高,母仔猪较公仔猪发病率高。其特征症状是咬尾仔猪的行动敏捷,被咬仔猪一阵尖叫挣扎,猪尾断节,鲜血淋漓。轻者猪尾被咬掉半截,重者全部被咬掉。被咬仔猪,因失血而发生贫血,生长发育受阻,个别仔猪因失血过多而死亡。如果没有及时处理并采取治疗措施,会导致伤口发生感染,引发局部发炎和组织脓肿、坏死,使肉质下降、减产。文章通过分析仔猪咬尾症的症状、发病原因,并根据病因提出应对的防治措施。阐释仔猪咬尾症在养殖生产过程中的危害及在现代化养殖中如何科学合理地避免因咬尾造成的经济损失。     

沈阳市某犬场附红细胞体感染的防治

2010年5月,沈阳市某规模化犬场出现以腹泻、发热、贫血、黄疸和阴道出血等症状的病例.笔者根据实验室诊断结果,结合病犬发病情况和临床症状诊断为犬附红细胞体感染,并对感染病倒进行治疗,对犬场进行综合防控,使疫情得到有效控制.本文对该病的诊断、治疗与预防进行了详细的阐述,并得出一定的体会,以供同行参考.     

A "down under" lesion on the muzzle of a dog

A 10-year-old, castrated, male Labrador Retriever was presented to a local veterinary practice for investigation of a firm, deeply pigmented, alopecic, subcutaneous mass (8 mm in diameter) on the left side of the muzzle. A fine-needle aspirate of the mass was submitted for cytologic evaluation to the University of Florida. Microscopically, the preparation contained a predominant population of histiocytes that contained variable numbers of intracytoplasmic, negative-staining, filamentous structures consistent with Mycobacterium sp. A presumptive diagnosis of canine leproid granuloma syndrome was based on the cytologic findings and location of the lesion. Acid-fast staining revealed bright pink, acid-fast organisms within the histiocytic cells, supporting the diagnosis. The bacteria were not detected in histopathologic sections or by a polymerase chain reaction (PCR) test 1 week later, however, possibly because of spontaneous remission. Canine leproid granuloma syndrome is a common disease in Australia, but is uncommon in dogs in North America. It is caused by a novel, unnamed Mycobacterium species and usually affects the skin and subcutaneous tissues of the head and ears. A diagnosis usually can be made in Wright's-Giemsa and acid-fast-stained cytologic specimens; however, definitive diagnosis requires PCR testing at a specialized laboratory.     

Practices and outcome of artificial cardiac pacing in 154 dogs

Artificial pacing (AP) is a treatment for symptomatic bradyarrhythmias unresponsive to medical therapy. This retrospective study was designed to define the practices and outcome of AP in dogs at 7 referral institutions participating in the Companion Animal Pacemaker Registry and Repository (CANPACERS). The indications, implantation techniques, complications, long-term outcome, and owner satisfaction were examined. One hundred fifty-four dogs were identified as undergoing AP from January 1, 1991, to January 1, 1996. Third-degree atrioventricular (AV) block (n = 91; 59%) and sinus node dysfunction (n = 45; 29%) were the most common indications for AP Transvenous endocardial AP systems were implanted in 136 dogs (88%), and epicardial systems were implanted in 18 (12%). Complications associated with AP were reported in 84 dogs (55%). Major complications occurred in 51 dogs (33%), including dislodgement of the pacing lead (n = 15; 10%), generator failure (n = 10; 6%), cardiac arrest during implantation (n = 9; 6%), and infection (n = 7; 5%). Minor complications occurred in 47 dogs (31%), including seroma formation (n = 18; 12%), muscle twitch (n = 17; 11%), and inconsequential arrhythmias (n = 15; 10%). Fourteen dogs (9%) experienced both major and minor complications. Survival analysis revealed 1-, 2-, and 3-year survival rates of 70, 57, and 45%, respectively. Age and presence of preexisting congestive heart failure (CHF) had a negative effect on survival (P = .001). Sixty percent of dogs with preexisting CHF died within 1 year of implantation, whereas 25% of dogs without heart failure died during the same period. Owners rated their satisfaction with the procedure as high in 80% of the dogs.     

犬细小病毒和犬冠状病毒双重PCR方法的建立及应用

根据GenBank中犬细小病毒(CPV)和犬冠状病毒(CCV)基因序列各设计了一对引物,经试验条件的优化,建立了检测CPV的PCR方法和CCV的RT-PCR方法,扩增目的片段大小分别为337 bp和852 bp.在此基础上建立了检测CPV和CCV双重PCR方法.该双重PCR方法能特异的扩增CPV和CCV,且分别扩增出1...     

Efficacy of enalapril for prevention of congestive heart failure in dogs with myxomatous valve disease and asymptomatic mitral regurgitation

We evaluated the long-term effect of early angiotensin-converting enzyme (ACE) inhibition (enalapril maleate) as monotherapy to postpone or prevent congestive heart failure (CHF) in asymptomatic dogs with mitral regurgitation (MR) attributable to myxomatous valvular disease (MVD) in a prospective, randomized, double-blinded, placebo-controlled multicenter trial involving 14 centers in Scandinavia. Two hundred twenty-nine Cavalier King Charles (CKC) Spaniels with MR attributable to MVD but no signs of CHF were randomly allocated to treatment with enalapril 0.25-0.5 mg daily (n = 116) or to placebo groups (n = 113). Each dog was evaluated by physical examination, electrocardiography, and thoracic radiography at entry and every 12 months (+/-30 days). The number of dogs developing heart failure was similar in the treatment and placebo groups (n = 50 [43%] and n = 48 [42%], respectively; P = .99). The estimated means, adjusted for censored observations, for the period from initiation of therapy to heart failure were 1,150 +/- 50 days for dogs in the treatment group and 1,130 +/- 50 days for dogs in the placebo group (P = .85). When absence or presence of cardiomegaly at the entrance of the trial was considered, there were still no differences between the treatment and placebo groups (P = .98 and .51, respectively). Multivariate analysis showed that enalapril had no significant effect on the time from initiation of therapy to heart failure (P = .86). Long-term treatment with enalapril in asymptomatic dogs with MVD and MR did not delay the onset of heart failure regardless of whether or not cardiomegaly was present at initiation of the study.     

犬瘟热病毒和犬腺病毒2型双重PCR方法的建立及应用

根据犬瘟热病毒(canine distemper virus,CDV)和犬腺病毒2型(Canineadenovirus type2,CAV-2)GeneBank登陆的基因序列各设计一对引物,经试验条件优化,建立了检测CAV-2的PCR方法和CDV的RT-PCR方法,CAV-2可扩增1108bp片段、CDV可扩增560bp的目的片段,特异性试验表明建立的方法只能特异扩增CAV-2和CDV,不能扩增犬细小病毒、犬冠状病毒、犬副流感病毒、犬钩端螺旋体和犬黄胆出血群、狂犬病病毒。敏感性试验表明,所建立的双重PCR方法可以扩增4.63ng总核酸量。在上述试验基础上继续优化条件建立了能同时检测CAV-2和CDV两种病毒的双重PCR检测方法,并用该方法检测来自辽宁、吉林等15家动物医院134份鼻液和眼眵样品,与商品化试纸条检测结果相比,本方法更加敏感和方便。研究结果表明,本实验建立的方法敏感、特异,适用于动物犬瘟热病毒和犬腺病毒2型的快速检测和鉴别诊断。     

Superficial necrolytic dermatitis in 11 dogs with a history of phenobarbital administration (1995-2002)

The clinical records of 11 dogs with histologically confirmed superficial necrolytic dermatitis (SND) and a history of phenobarbital (PB) administration (SND/PB) were evaluated retrospectively (1995-2002). Historical, clinical, clinicopathologic, ultrasonographic, and pathologic findings were compared with those in dogs with SND without prior PB exposure (SND/No PB; n = 9) and with those dogs with PB-associated hepatotoxicity without skin disease (PB/hepatotoxicity). Dogs in the SND/PB group accounted for 44% of all histologically confirmed cases of SND that were evaluated at The Ohio State University Veterinary Teaching Hospital between 1995 and 2002. Median age of dogs in the SND/PB group was 10 years, and median duration of PB therapy was 6 years. Mean alanine aminotransferase (ALT) activity was 239 U/L, and median duration of abnormally high ALT activity was 6.25 months before SND diagnosis. Plasma amino acid concentrations measured in 1 dog were severely decreased. Ultrasonographic findings of hypoechoic nodules with hyperechoic borders corresponded to pathologic findings of nodular areas of normal hepatic tissue surrounded by zones of collapsed parenchyma with vacuolated hepatocytes. Clinical, clinicopathologic, ultrasonographic, and pathologic features of SND/PB and SND/No PB were similar. PB-associated cirrhosis and overt hepatic failure were not features of SND/PB. Different pathogenic mechanisms might induce SND in dogs. Chronic administration of PB requires further examination as a potential risk factor for the development of SND.     

Influence of chemotherapy for lymphoma in canine parvovirus DNA distribution and specific humoral immunity

In man, the combination of cancer and its treatment increases patients’ susceptibility to opportunistic infections, due to immune system impairment. In veterinary medicine little information is available concerning this issue. In order to evaluate if a similar dysfunction is induced in small animals undergoing chemotherapy, we assessed the complete blood count, leukocytic, plasma and fecal canine parvovirus (CPV) viral load, and anti-CPV protective antibody titers, in dogs with lymphoma treated with CHOP (cyclophosphamide, doxorubicin, vincristine and prednisolone) protocol, before and during chemotherapy.There was no evidence of decreased immune response, either at admission or after two chemotherapy cycles, indicating that the previously established immunity against CPV was not significantly impaired, supporting the idea that immunosuppression as a result of hematopoietic neoplasms and their treatment in dogs requires further investigation and conclusions cannot be extrapolated from human literature.     

Incidence of canine dysautonomia in Missouri,USA, between January 1996 and December 2000

A cross-sectional survey of 217 veterinary facilities in Missouri, USA, was conducted to gather information about the occurrence of canine dysautonomia between January 1996 and December 2000. The state was divided into seven geographic regions for sampling, and 40 veterinary facilities from each region were selected randomly by computer-generated numbers to receive the questionnaire. Veterinarians from 74% (95% CI: 69, 79) of clinics in the state that saw canine patients were aware of dysautonomia prior to receiving the survey, and 43 respondents from five of the seven sampled regions stated that dysautonomia had been diagnosed in their practices during the study period. Respondents had diagnosed 182 cases of dysautonomia, leading to an estimated statewide total of 609 (95% CI: 272, 946) cases over the 5 years. Regional incidence estimates ranged from 0 to 1.91 cases per 10,000 dog years at risk. Case-fatality risk was 92%.