Feline Medicine Q&A 10

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A 5-year-old DSH cat is presented which has been depressed, anorexic, and showing upper respiratory tract signs (sneezing, nasal discharge) for the last 2 days. On clinical examination, the cat is pyrexic and has several small lingual ulcers.

Question	Answer		Article
What is the most likely diagnosis?	The acute onset of clinical signs and pyrexia are suggestive of an infectious cause, therefore cat ‘flu’ is the most likely diagnosis.		Link to Article
What are the most likely causal infectious agents?	FHV and FCV are the most likely causal agents. FCV is more frequently associated with tongue ulcers although both viruses can cause all of the signs described in this case.		Link to Article
What treatment is recommended?	Supportive care of the individual cat is a priority and may include: Antibiotic cover for secondary bacterial infections. General nursing care, intravenous fluid therapy, and nutritional support. Steam therapy and/or nebulization. Use of antiviral agents such as interferon has been shown to be helpful in experimental FHV infection and may be of benefit. If the cat is hospitalized, barrier nursing is required in order to reduce the risk of spreading infection to other hospitalized patients.		Link to Article
How can this illness be explained in a fully vaccinated cat?	No vaccine offers 100% protection and potential causes of ‘vaccine failure’ include: Overwhelming challenge. Immunosuppressed individual (due to other disease, e.g. FIV, FeLV, or chemotherapy treatment). The cat was incubating the disease when vaccinated. Many different isolates of FCV exist in the field and the vaccine virus strains used will not provide cross protection for all of these. Clinical signs may not be caused by FCV or FHV infection. The cat was already a carrier of FCV or FHV and shedding of virus was associated with recurrence of clinical signs of disease.		Link to Article