Fig. 3.

Neighbour-joining tree of partial (a) M gene (ORF 3a), and (b) S gene (ORF 7b) sequences generated in this study and published reference canine and feline coronaviruses. All branch lengths are proportional to distances established using the Jukes–Cantor method. Bootstraps are expressed as percentages, and only included where greater than 75%. Each sample is identified by a combination of unique dog identification number and the date of sampling. Reference strains CECoV 23/03 (AY548235), CECoV 1-71 (AY664662) and FcoVC1Je (DQ848678); additionally CECoV C54 (Tennant et al., 1991), RS 2006 (sequence from a sample collected at R1 in 2006) and AJ (a diagnostic sample received in 2009) are included in the trees. Accession numbers for sequences obtained in this study JX035812–JX035862. ^∗ Samples from dogs 16 and 71, whose titres are shown in Fig. 1. The potential transmission event referred to in the text is indicated.