Efficacy of azithromycin for the treatment of feline chlamydophilosis

Abstract

The current recommended treatment for feline chlamydophilosis involves daily oral administration of antimicrobials to all cats within an affected group for a prolonged period of time (4-6 weeks). Not surprisingly, owner compliance can be poor resulting in apparent treatment failure. Recent anecdotal evidence, supported by its efficacy in the treatment of Chlamydia trachomatis infection in humans, has suggested that azithromycin may offer an alternative by allowing less frequent dosing for a shorter duration. A clinical trial was designed to evaluate the efficacy of azithromycin for the treatment of chlamydia (Chlamydophila felis) infection in cats. Whilst azithromycin, given at 10-15 mg/kg daily for 3 days and then twice weekly, provided a similar, rapid resolution of clinical signs and negative isolation scores as doxycycline, C felis was re-isolated in four out of the five cats treated. Furthermore, even daily administration of azithromycin to chronically infected cats was ineffective in clearing infection. The azithromycin protocols used here were therefore found to be unsuccessful in eliminating the carriage of this strain of C felis.

Use of Quantitative Real-Time PCR To Monitor the Response of Chlamydophila felis Infection to Doxycycline Treatment

“…The time course of infection, clinical signs, and response to treatment in this study were similar to those seen in previous studies (8,10,11,14). The C. felis isolate used in this study was the same as that used in a 2003 study by Owen et al (8).…”

“…On day 0, each cat was infected by bilateral inoculation of 3 ϫ 10 3 infectious units of a field isolate of C. felis onto the conjunctiva, as previously described (8).…”

“…Doxycycline is currently regarded as the treatment of choice for C. felis infection. Previous controlled studies have demonstrated that other systemic and topical treatments are less efficacious at eliminating infection (8,10,11). A requirement for prolonged courses (4 to 6 weeks) of doxycycline to eliminate the organism has been advocated, as has the idea that all in-contact cats should be treated (3).…”

“…In previous treatment studies, C. felis isolation and conventional PCR techniques have been used to monitor the response of infection to treatment (8,10,11,12,14). PCR has been shown to be more sensitive than isolation techniques (7,12), and real-time PCR has further advantages as it facilitates quantification of the organism (5).…”

An Immunohistochemical and Polymerase Chain Reaction Evaluation of Feline Plasmacytic Pododermatitis

“…Anaplasma phagocytophilum, some Mycobacteria spp., Mycoplasma spp., Chlamydophila felis, and Bartonella spp. 5,7,9,22,24,28,30 The purpose of this study was to evaluate biopsy specimens of feline plasmacytic pododermatitis for possible infectious organisms.…”