Table. Distribution of lesions and influenza virus antigen expression in experimentally infected red foxes*.

Route of inoculation, fox no.	Lesions				Influenza virus antigen
	Lungs	Heart	Brain		Lungs	Heart	Brain
Intratracheal inoculation
1	+++	–	+		–	–	–
2	+++	+	++		++	+	+++
3	++	–	–		–	–	–
Fed infected bird carcasses
5	+	–	–		–	–	–
6	–	–	–		–	–	–
7	+	–	–		–	–	–

*Foxes were infected either intratracheally with highly pathogenic avian influenza (HPAI) virus (H5N1) or by being fed chicks infected with HPAI virus (H5N1); they were examined at 7 days postinoculation. Respiratory lesions, extrarespiratory lesions, or influenza virus antigen expression were not observed in negative-control foxes. –, absence of lesions (no cells expressing the influenza virus antigen); +, mild and focal or multifocal lesions (few cells expressing the influenza virus antigen); ++, moderate and multifocal lesions (moderate number of cells expressing the influenza virus antigen); +++, severe and extensive lesions (numerous cells expressing the influenza virus antigen).