zithromax and Otitis-Externa

Describe lateral ear canal resection and bulla osteotomy with marsupialization (LECARBOM) in rabbits with otitis media (OM), and report outcomes, complications, bacteria cultured from middle ears, and their antimicrobial susceptibility testing (AST) results.. Retrospective clinical case series; single referral hospital.. Forty-two rabbits with naturally occurring OM.. Medical records (2011-2021) of rabbits with CT-confirmed OM undergoing surgery were reviewed for outcomes, complications, bacteria cultured from middle ears, and AST.. Surgery was performed on 48 ears, and outcomes determined 21 days postoperatively. All rabbits survived the procedure. Otitis externa resolved in all lop-eared rabbits. Of 29 ears with OM-associated head tilt, eight (28%) resolved, nine (31%) improved, seven (24%) remained unchanged and five (17%) worsened. Outcome was not associated with head tilt duration nor OM severity. Postoperative complications occurred in 12 (25%) cases, seven of which had wound margin dehiscence that healed by 21 days. The most frequent bacteria isolated were Pasteurella multocida (16%), Bordetella bronchiseptica (14%) and Staphylococcus aureus (14%). Bacteria were sensitive to azithromycin, marbofloxacin or enrofloxacin and resistant to penicillin.. LECARBOM is a well-tolerated surgical procedure to treat OM. It also improved or stabilized 83% of cases with head tilt and resolved all cases with otitis externa.. LECARBOM with administration of an AST-sensitive antibiotic, or azithromycin when no AST is performed, should be effective in rabbits with OM. Postsurgically, it resolves or alleviates most secondary conditions such as otitis externa, head tilt and facial nerve paralysis.

Topics: Animals; Azithromycin; Bacteria; Blister; Ear Canal; Osteotomy; Otitis Externa; Otitis Media; Rabbits; Retrospective Studies

To determine azithromycin concentration in severely inflamed canine external ear canals.. Five dogs of various breeds and ages with severe and chronic otitis externa underwent ear canal reconstruction surgery. A single oral dose of azithromycin at 10 mg/kg was administered 12 to 24 hours prior to surgery. Tissue samples were collected from the excised external ear canals and azithromycin concentration was determined using a liquid chromatography-tandem mass spectrometry method.. Azithromycin concentrations ranging from 11.4 to 107.0 μg/g (mean 59.2 ± 44.6 μg/g, median 50.9 μg/g) were detected in the chronically infected external ear canal tissue 12 to 24 hours after administration.. Little information exists on antibiotic concentrations in pathological tissues of dogs. Macrolides are known to concentrate in skin tissue. In light of the present results, investigation of clinical efficacy of azithromycin in chronic canine otitis externa is warranted.

Topics: Animals; Anti-Bacterial Agents; Azithromycin; Dog Diseases; Dogs; Ear Canal; Otitis Externa

The murine model of cantharidin-induced ear inflammation was profiled in detail for its alignment with the human model and to explore the mechanism of anti-inflammatory activity of the macrolide antibiotics, clarithromycin and azithromycin. Ear swelling in CD1 mice persisted for 7 days, with peak intensity at 16 h after inflammation induction. As in humans, cantharidin (12.5 μg/ear) generated macrophage-inflammatory protein (MIP)-2, monocyte chemoattractant protein (MCP)-1, keratinocyte-derived chemokine (KC), interleukin (IL)-6, IL-1β, and myeloperoxidase (MPO) production, as well as neutrophil accumulation in mouse ear tissue. The tested macrolides, clarithromycin and azithromycin, administered orally (2 × 150 mg/kg) 0.5 h before and 5 h after cantharidin challenge, reduced MIP-2, MCP-1, KC, and MPO concentrations and thereby decreased ear swelling. Our results suggest that cantharidin-induced acute inflammation represents an excellent model for translational research of novel anti-inflammatories.

Topics: Administration, Topical; Animals; Anti-Bacterial Agents; Anti-Inflammatory Agents; Azithromycin; Cantharidin; Clarithromycin; Disease Models, Animal; Dose-Response Relationship, Drug; Ear, External; Edema; Irritants; Male; Mice; Mice, Inbred Strains; Otitis Externa; Translational Research, Biomedical