Feline Upper Respiratory Disease (FURD) is a complex disease characterized by, but not limited to, conjunctivitis, rhinitis, and tracheitis. Several pathogens encompass this disease including Feline Rhinotracheitis Virus (FHV), Feline Calicivirus (FCV), Chlamydophila felis (C. felis) , Bordatella bronchiseptica (B. bronchiseptica) , and Mycoplasma felis (M. felis) . This disease process significantly effects cats in group housing situations such as animal shelters and is a leading cause of morbidity and mortality in these cats. Previous research has investigated the epidemiology of pathogens and risk factors in several geographical areas, the development of molecular diagnostic tools for the detection of pathogens, and the detection of previously unreported pathogens in this complex. This thesis encompasses three papers meant to address the objectives of atypical Mycoplasma detection in cats with and without FURD, validation of a field deployable molecular device for pathogen detection, and an overall epidemiologic evaluation of the unique Midwestern geographical area.
The first paper investigated the hypothesis that Mycoplasma species occur in the cat at higher levels of diversity than previously appreciated utilizing the unique molecular based Pan –Myco SYBR qPCR assay for the detection of the Mycoplasma genus and may be contributing to FURD. Overall, 15 Mycoplasma species were detected including: M. gateae/canadense/arginini cluster, M. canis, M. hyorhinis, M. alkalescens, M. cynos, M. faucium, M. dispar, M. buccale, M. spumans, M. hominis, M. bovis, M. bovoculi, M. maculosum/leopharyngis cluster, 2 new unknown species, and Acholeplasma laidlawii. Twelve of these Mycoplasma species were previously unreported in cats and several of these species are potential zoonotic pathogens.
The second paper implemented a 5 stage pipeline for development and validation of field deployable assays utilizing the Insulated Isothermal Polymerase Chain Reaction (iiPCR) on the candidate field deployable device, POCKITTM for the detection of FURD including FHV, FCV, C. felis, M. felis, and B. bronchiseptica. Thirty of both positive and negative clinical samples and surrogate samples were randomized, blinded, and tested side-by-side on both platforms for each pathogen. Limits of detection were biologically relevant, were equal to or less than 10 infectious units, and demonstrated near equivalency with clinical samples for all pathogen targets. Exclusivity testing demonstrated the iiPCR to be pathogen and target specific. Sensitivity and specificity for clinical samples ranged from 80%–97% and 93–100% respectively. Kappa values ranging from 0.80–0.93 demonstrated strong agreement. Results demonstrate exceptional performance of the iiPCR reagents for detection of feline respiratory pathogens in clinical samples. This study demonstrates the effectiveness of the iiPCR for detection of feline pathogens and the use of the stages 1 through 3 of the pipeline for validation of field deployable reagents.
The final paper assessed detection of FURD pathogens in ocular, nasal, and oro-pharyngeal samples from cats in a specific unique geographical region and evaluated their association with disease in a cross-sectional study. There were 71 cats with respiratory disease and 119 cats without disease were enrolled in this study. Prevalence of FHV, FCV, C. felis, Bordetella species, M. felis, M. gateae cluster, and other Mycoplasma species in the total study population was 49%, 19.5%, 3.2%, 23.7%, 40%, 24.7%, and 15.3% respectively. Multivariate modeling showed that detection of Bordetella species (odds ratio (OR) = 3.143), FCV (OR = 2.830), and housing cats in shelters for 2 to 6 months (OR = 0.146) were all significantly related to FURD severity. Age of cats and detection of C. felis were confounding factors for relationship between Bordetella species and respiratory disease.
Taken in total, this research illustrates the necessity for continued research in the field of FURD. The discovery of previously unreported pathogens in felines, the application of new and emerging detection platforms for triage of disease outbreak, and the continued exploration of pathogen association and risk factors all contribute to the management of this disease in shelters. The impacts and translation of this research will help to prevent the high morbidity and mortality in shelter cat populations.