Dogslife: a web-based longitudinal study of Labrador Retriever health in the UK

Abstract

Background: Dogslife is the first large-scale internet-based longitudinal study of canine health. The study has been designed to examine how environmental and genetic factors influence the health and development of a birth cohort of UK-based pedigree Labrador Retrievers.

Results: In the first 12 months of the study 1,407 Kennel Club (KC) registered eligible dogs were recruited, at a mean age of 119 days of age (SD 69 days, range 3 days - 504 days). Recruitment rates varied depending upon the study team's ability to contact owners. Where owners authorised the provision of contact details 8.4% of dogs were recruited compared to 1.3% where no direct contact was possible. The proportion of dogs recruited was higher for owners who transferred the registration of their puppy from the breeder to themselves with the KC, and for owners who were sent an e-mail or postcard requesting participation in the project. Compliance with monthly updates was highly variable. For the 280 dogs that were aged 400 days or more on the 30th June 2011, we estimated between 39% and 45% of owners were still actively involved in the project. Initial evaluation suggests that the cohort is representative of the general population of the KC registered Labrador Retrievers eligible to enrol with the project. Clinical signs of illnesses were reported in 44.3% of Labrador Retrievers registered with Dogslife (median age of first illness 138 days), although only 44.1% of these resulted in a veterinary presentation (median age 316 days).

Conclusions: The web-based platform has enabled the recruitment of a representative population of KC registered Labrador Retrievers, providing the first large-scale longitudinal population-based study of dog health. The use of multiple different methods (e-mail, post and telephone) of contact with dog owners was essential to maximise recruitment and retention of the cohort.

Figure 1

Description of the study population and recruitment method. All KC registered Labrador Retriever dogs born on or after 1^st January 2010 were eligible to join the project. The project launched on 1^st July 2010 and “actively targeted” dogs whose registration was transferred on or after this date.

Figure 2

Workflow description of recruitment into the Dogslife cohort. The breeder registers a litter of puppies with the Kennel Club (KC) (1). A flyer advertising the project is included with the registration documentation provided by the KC (2). The puppy owner transfers registration of the puppy (3), and receives a flyer advertising the project with the transfer of registration documentation sent by the KC (4). The Dogslife database receives the KC number (KC No.) and date of birth (DOB) of all new puppy registrations (1) and transfers of registration (3). Puppy owners not registering with Dogslife are contacted by e-mail (5) and / or postcard (6) to encourage participation. The puppy owner joins the project and registers their puppy using the KC No. and DOB, which is checked by the Dogslife database (7).

Figure 3

A profile of the data entry windows where participants were considered “active” for dogs aged 400 days or older on 30^th June 2011. The number of dogs with a complete data entry is listed with the total number of dogs eligible for a data entry in the window in brackets.

Figure 4

Profiles of the timescale between recruitment and active intervention. The cumulative proportion of dogs registered (red line), dogs actively targeted (Labrador Retrievers whose registration has been transferred with the Kennel Club (KC), green line) and visits to the website (http://www.dogslife.ac.uk, blue line) are presented over the first year of the project. The number of website visits on the first day of the project (1^st July 2010) was high, hence the cumulative proportion on this date appears to be greater than 0. The KC registration transfers also started in advance of 1^st July 2010. The e-mail and postcard reminders are initiated 7 and 14 days after the transfer of registration.

Figure 5

Pattern of recruitment by different methods. After 1^st July 2010 all transfers of registration were sent a flyer advertising the project with their transfer documentation. ¹The number of people contacted by e-mail includes those who were subsequently contacted by postcard when they did not join the project. ²The number of people contacted by mail excludes those who were also previously contacted by postcard. ³No contact by e-mail or post includes 528 dogs with e-mail and postal addresses, but who had not been sent the contact by 30^th June 2011 as the timeline for contact (7 and 14 days after transfer of KC registration respectively) had not elapsed.

Figure 6

Proportion of eligible dogs recruited by different methods with 95% confidence intervals. *dogs with transfer of registration on or after 1^st July 2010.

Figure 7

Profiles of the timescale between recruitment and active intervention. The profile of the number of responses to the postcard shows that the majority had previously received, but not responded to, an e-mail requesting participation in the project.

Figure 8

A profile of the timescale between completed data entries in the cohort.

Figure 9

The geographic distribution of the proportions of eligible participants registering with the Dogslife project. Location was defined by the first two letters of the postcode forwarded from the Kennel Club, and the proportion of eligible dogs registering with the study is highlighted on the right hand scale. The graph scales across 7 standard deviations (<−1SD [0.000-0.003], -1SD – 0SD [0.003-0.041], 0SD-1SD [0.041-0.082], 1SD-2SD [0.082-0.123], 2SD-3SD [0.123-0.164], 3SD-4SD [0.164-0.205], 4SD-5SD [0.205-0.246], 5SD-6SD [0.246-0.287], 6SD-7SD [0.287-0.3327]), 7SD-8SD [0.327-0.368]).

Figure 10

Survival analysis of the time to first owner-reported illness with 95% confidence intervals.

Figure 11

Survival analysis of the time to first non-routine veterinary presentation (B) with 95% confidence intervals.