Background: Chronic rhinitis (CR) is a common and frustrating syndrome in cats, with few broadly effective treatments. At present, little is known regarding nasal immune responses in cats and how they may be altered in animals with CR.
Objectives: To help elucidate the pathogenesis of CR in cats, we collected deep nasal swabs and performed full RNA sequencing on collected cells and compared the nasal transcriptomes of healthy cats and cats with CR. Animals and Study
Design: Prospective study design, which included 5 healthy cats (no clinical signs) and 3 cats with CR that were evaluated by rhinoscopy and CT imaging to rule out nasal cancer and fungal infection.
Methods: Deep nasal swabs were collected under general anesthesia from study animals, with care to avoid nasal bleeding. RNA extracted from nasal swab cells was subjected to full sequencing, using an Illumina platform (Novogene). Sequence files were analyzed using Partek Flow software, including identification of differentially expressed genes and pathway analysis.
Results: Transcriptome comparisons revealed 450 significantly upregulated genes in cats with CR and 106 significantly downregulated genes compared to healthy cats. Pathway analysis revealed significant upregulation of pathways associated with innate immunity, including TNF, IFN-g, IFN-a and IL-6 signaling in cats with CR. Conclusions and Clinical Importance: Nasal transcriptome analysis in cats with CR revealed significant upregulation of innate immune pathways associated with responses to viral infections, including interferon pathways. These findings are distinctly different from those of dogs with CR and suggest a possible underlying viral etiology in cats.
