Genetically distant American Canine distemper virus lineages have recently caused epizootics with somewhat different characteristics in raccoons living around a large suburban zoo in the USA

Table 1 Histologic lesions of CDV-infected raccoons.

Raccoon	Sex	M/Y^a	Site^b	Presentation	Encephalitis^f	Pneumonia^h	Other findings	EMCV^k
98-2645	F	8/98	FP^c	Euthanized	++; Demyelination; axonal loss; few IB^g	+++; Chronic; no IB	Lymphoid depletion (LNⁱ); IB – other sites	-
98-2646	M	8/98	ZG^d	Dead	-	++; Sub-acute to chronic; no IB	IB – other sites^j	-
98-2654	M	10/98	ZG	Euthanized	Rare axonal loss	++	Ocular discharge; CDV in footpad ("Hardpad" disease); lymphoid depletion (LN and spleen)	-
98-2655	F	10/98	ZG	Dead	++; IB common	None	Lymphoid depletion (LN and spleen); IB – other sites	-
98-2666	F	12/98	ZG	Euthanized	++; Axonal loss; rare neuronal IB	++; Chronic; no IB	Lymphoid depletion (LN and spleen); IB – other sites	-
00-2601	M	1/00	ZG	Euthanized	++; Rare neuronal IB; severe axonal loss	None	IB – other sites	-
01-2641	M	5/01	OFP^e	Euthanized	+; IB; syncytia in hippocampus	+++ with syncytia; IB	Lymphoid depletion (LN and spleen); IB – other sites	+ brain, LN, spleen)
01-2663	F	6/01	ZG	Euthanized	None	+++ with syncytia; IB	Lymphoid depletion (LN and spleen); IB – other sites	-
01-2676	F	7/01	ZG	Euthanized	+; Axonal loss; neuronal necrosis; IB; syncytia in hippocampus	+++; IB	Lymphoid depletion (LN); IB – other sites	-
01-2689	F	8/01	ZG	Euthanized	+; IB	++ with syncytia; IB	Lymphoid depletion (LN and spleen); IB – other sites; rhinitis; purulent conjunctivitis	-
01-2690	M	8/01	ZG	Euthanized	Rare neuronal necrosis; IB	None	Lymphoid depletion (LN); IB – other sites	+ (spleen)

^aM/Y; Month and year animal examined by necropsy and specimens frozen.
^bSite; Location where animal was trapped or found dead.
^cFP; Forest preserve at border of zoo.
^dZG; Zoo grounds.
^eOFP; Off-site forest preserve
^fEncephalitis: -, none; +, mild; ++, moderate.
^gIB; Characteristic intracytoplasmic or intranuclear inclusion bodies formed by Canine distemper virus.
^hPneumonia: +, mild; ++, moderate; +++, severe.
ⁱLN; Lymph node.
^JIB – other sites: Inclusion bodies in other epithelial sites.
^kEMCV, Encephalomyocarditis virus.

ISSN: 1743-422X