Mycoplasma felis and equine influenza were detected from a nasal swab in a three year old quarter horse mare submitted for testing using the Animal Health Diagnostic Center Equine Respiratory PCR Panel (ERPLN). The mare had recently traveled to a barrel racing competition and she developed a cough, swollen submandibular lymph nodes, nasal discharge, abnormal respiratory sounds (squeaks/pleural rubs) and lethargy soon after returning home.

Mycoplasma felis has been associated with respiratory disease, typically concurrent with a viral etiology. There have been seven positive M. felis PCR samples out of 306 nasal swab submissions in 2018, which is a 2% prevalence of those horses tested.

Mycoplasma agents are not isolated easily and may be missed in routine aerobic culture unless a selective media is used. A request for mycoplasma culture or PCR must be added to a nasal swab, transtracheal wash or bronchoalveolar lavage. Consider adding this agent to your differential in respiratory cases.