Prevalence of canine enteric coronavirus in a cross-sectional survey of dogs presenting at veterinary practices

Abstract

In order to determine the prevalence of canine enteric coronavirus (CECoV) in the general dog population, faecal samples were obtained in a cross-sectional study of 249 dogs presenting for any reason at veterinary practices randomly selected from across the UK. Demographic and clinical data was obtained for each of the samples, including signalment, number of dogs in the household, reason for visiting the practice, and any recent history of diarrhoea. The samples were tested by RT-PCR for the presence of both type I and type II CECoV. Seven samples were positive (three from dogs in the same household), a prevalence of 2.8% (95% confidence intervals 1.1-5.7). Phylogenetic analysis of partial M gene sequences revealed that all seven positive samples grouped with type I CECoV, the first report of this virus in the UK. None of the positive dogs presented for gastrointestinal disease. Interestingly five of the positive dogs from three separate households were aged over 6 years, suggesting that older dogs may play an important role in the persistence of CECoV in such populations.

Fig. 1

Map of the United Kingdom. Squares show approximate locations of participating practices. Black squares indicate practices which submitted positive samples; grey squares indicate all other participating practices. Rooted neighbour-joining tree of the seven partial M gene sequences generated in this study and published reference canine, feline and human coronaviruses (outgroup). 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%. Key: HCoV NL63 accession DQ445912, FCoV C1Je accession DQ848678; FCoV 1146 accession DQ010921; FCoV DF-2 accession DQ286389; CECoV BGF10 accession AY342160; CECoV 259/01 accession AF502583; CECoV 23/03 accession AY548235; CECoV INSAVC accession D13096. Samples from this study are coded CECoV x–y, where x is the internally designated practice number, and y the individual dog reference.

Fig. 2

Histogram to show age distribution of dogs sampled in a cross-sectional study of 249 dogs from 20 UK veterinary practices. Data missing from one dog, therefore total number of dogs included is 248.

Fig. 3

Histogram to show distribution of most common breeds of dog sampled in a cross-sectional study of 249 dogs from 20 UK veterinary practices. 202 dogs are included; breed was not specified for 47 dogs. Breeds with less than 4 dogs sampled are grouped under ‘other breeds’.

Fig. 4

Bar chart to show the reasons for visit cited by study participants. This data was available for 228 dogs. *Routine includes weight check, claw clip, flea/worm treatment and social reasons for visiting the surgery. ^#Sick dog included a broad range of diagnoses such as pyometra, false pregnancy, and convulsions. Conditions classified as ‘misc’ (miscellaneous) were those where the health status of the dog was impossible to determine, e.g. ‘operation’ which could refer to an elective or emergency surgery.

Fig. 5

Histogram to show the length of time between collection of each faecal sample and receipt at the laboratory. Data was available for 233/249 samples submitted.

Fig. 6

Faeces spiked with CECoV-C54 were kept at room temperature for a number of days and then underwent RT-PCR using the protocol described. It can be seen that even after 7 days a faint band was visible at the −3 dilution, suggesting a loss in titre of less than 10-fold.