Successful Clindamycin Therapy of an Infected Subcutaneous Permanent Pacing Lead in a Dog after a Failed Course with Potentiated Amoxicillin and Enrofloxacin

SIMPLE SUMMARY: An inappropriately slow heart rate can lead to exercise intolerance, collapsing episodes, sudden death and congestive heart failure. Pacemaker implantation is often the only effective therapy to treat these cardiac rhythm disturbances. Unfortunately, pacemaker implantation can have various complications, among others bacterial infection. The best way to clear the infection is to remove the pacemaker, and treat the patient with antibiotics for several weeks before the pacemaker can be re-implanted. Though pacemaker-removal can control the infection, the clinical signs of the slow heart rate will recur and remain uncontrolled. The present case describes a 13.5-year-old dog that got a surgical site infection after pacemaker implantation. Though the first course of antibiotics resolved the clinical signs, the infection recurred. To identify the causative bacteria, the swelling under the skin caused by the bacterial infection was punctured under ultrasound-guidance to gain a sample for laboratory testing. Based on a number of considerations, another antibiotic was chosen, which successfully cleared the infection without the need of pacemaker removal. After completion of this 4-week long antibiotic course, the dog remained free of infection and free from the previously noted clinical signs thanks to the appropriately functioning pacemaker. ABSTRACT: Though permanent pacemaker implantation is the only effective therapy for certain bradyarrhythmias in dogs, it is not without risks. Bacterial infection of the device is one of the most common complications. Human guidelines recommend besides systemic antibiotics, surgical explantation of the pacing lead and pulse generator in case of device-infection. This report describes a 13.5-year-old dog that received a transvenous endocardial permanent pacemaker because of syncopal episodes resulting from paroxysmal third-degree atrio-ventricular block. Five days after an uneventful surgery, a painful swelling appeared around the subcutaneous part of the lead where this was inserted into the jugular vein. A 4-week course of amoxicillin and clavulanic acid combined with enrofloxacin failed to clear the infection on long-term. Ultrasound-guided puncture of the abscess was performed to gain a sample for bacterial culture and antibiogram. Oral clindamycin of 4 weeks’ duration successfully resolved the infection with Staphylococcus aureus without having to explant the device. Repeated ultrasonographic examinations and fine-needle aspiration biopsies were used to evaluate for persistent local inflammation, guiding the length of the antibiotic therapy. Though the described approach has traditionally been ill-advised because of the risk of introducing bacteria and damaging the pacemaker lead, it was successful in our case.