# Detection of Felis catus Gammaherpesvirus 1 in Domestic Cat Saliva: Prevalence, Risk Factors, and Attempted Virus Isolation

## TL;DR

This study found that FcaGHV1 is commonly shed in cat saliva, with feral cats showing higher virus levels, and it provides new insights into the virus's prevalence and shedding patterns.

## Contribution

The first detection of FcaGHV1 in Canadian cats and evidence of chronic shedding in saliva, with higher viral loads in feral cats.

## Key findings

- FcaGHV1 DNA was detected in 19.8% of cat saliva samples with variable viral loads.
- Chronic shedding of FcaGHV1 was observed in some cats over a two-month period.
- Feral cats had significantly higher FcaGHV1 DNA loads compared to non-feral cats.

## Abstract

Felis catus gammaherpesvirus 1 (FcaGHV1) infects domestic cats worldwide, yet it has not been successfully propagated in cell culture, and little is known about how it is shed and transmitted. To investigate the salivary shedding of FcaGHV1, we quantified FcaGHV1 DNA in feline saliva by qPCR. For FcaGHV1-positive saliva, we sequenced a portion of the viral glycoprotein B (gB) gene and attempted to isolate the infectious virus by passage in several felid and non-felid cell lines. We detected FcaGHV1 DNA in 45/227 (19.8%) saliva samples with variable viral DNA loads from less than 100 to greater than 3 million copies/mL (median 4884 copies/mL). Multiple saliva samples collected from an infected cat over a two-month period were consistently positive, indicating that chronic shedding can occur for at least two months. Cat age, sex, and health status were not associated with shedding prevalence or viral DNA load in saliva. Feral status was also not associated with shedding prevalence. However, feral cats had significantly higher FcaGHV1 DNA load than non-feral cats. Sequencing of FcaGHV1 gB showed low sequence diversity and >99.5% nucleotide identity to the worldwide consensus FcaGHV1 gB sequence. We did not detect virus replication during the passage of FcaGHV1-positive saliva in cell culture, as indicated by consistently negative qPCR on cell lysate and supernatant. To our knowledge, these data show for the first time that cats in Canada are infected with FcaGHV1. The data further suggest that shedding of FcaGHV1 in saliva is common, can occur chronically over an extended period of time, and may occur at higher levels in feral compared to non-feral cats.