1. Introduction
Australia has an owned dog and cat population of approximately 4.8 million and 3.9 million, respectively [
1]. However, it is likely that the total population of dogs and cats is higher, as un-owned animals/strays, and those in registered or independent shelters or pounds would also contribute to the total population. In addition, the ownership of an animal may be transferred through sale or other trade, and animals in a shelter or pound can be rehomed. This results in a complex network of animals transferred between the owned and un-owned populations, and between different owners. Animals leave the care of their owners through being lost, surrenders to a shelter or pound, being abandoned, being given away or being sold. Worldwide, there have been attempts to measure the un-owned population of dogs and cats in shelters [
2,
3], but there is a lack of research into the dogs and cats that are transferred between owners and between owned and un-owned populations in other ways.
Much of what we know about the flow of animals from the owned and un-owned populations comes from rescue shelters and pounds. Larger rescue organizations collect data on numbers of surrendered dogs and cats each year. There were 55,570 cats admitted to Royal Society for the Prevention of Cruelty to Animals (RSPCA) shelters around Australia in 2015/16, with numbers rising in the last few years. In contrast, there were 45,256 dogs admitted to RSPCA shelters in the same year and numbers are declining [
4]. However, the RSPCA represents only a portion of the surrendered population. The total number of both stray and surrendered dogs in Australia in 2012/13 from shelters and local municipal facilities, has been estimated at 211,655 dogs admitted, with 101,037 of these reclaimed [
2]. There is no data available estimating the total numbers of stray and surrendered cats in Australia, although it is likely to be even higher. The incidence of unowned dogs and cats is a worldwide problem, with an estimated 129,743 dogs and 131,070 cats entering UK shelters in 2009 [
3], and a study from South Korea reporting over 10,000 abandoned dogs in Seoul [
5]. In the US, it was estimated that 4.4% of dog-owning and 3.8% of cat-owning households had relinquished a pet to a shelter in the previous year [
6].
The relinquishment of pets represents a significant cost to society in a number of ways. In Australia in 2004, there was an estimated
$AUS180 million spent annually by animal welfare agencies [
7], while in the United Kingdom expenditure by animal welfare organizations was approximately £340 million in 2010 [
8]. Local governments in Australia in 2004 spent
$AUS83 million on animal management [
7]; in the UK in 2011 the comparable figure was £57.5 million [
9]. While local government costs include dog registrations and dealing with dog attacks, a large portion of these figures would be expected to arise from stray and relinquished animals.
As well as the economic costs there are also emotional costs as people may be forced to relinquish their pets due to external influences, such as a relationship breakdown or inability to find rental accommodation that will allow a pet [
10,
11]. There are also emotional costs experienced by staff involved in euthanizing large numbers of pets at shelters, with shelter workers struggling with the moral dilemma of their job, often resulting in mental health problems and high staff turnover [
12,
13,
14]. Finally, un-owned dogs and cats are at an increased risk of impaired welfare using both physical and psychological measures of welfare [
15,
16], as well as the emergence of diseases, demonstrated by an outbreak of virulent systemic feline calicivirus in cats [
17], and of
Streptococcus equi pneumonia in dogs [
18].
If we are to design evidence-based strategies to reduce the numbers of dogs and cats relinquished, as well as protect the welfare of pets in which relinquishment cannot be avoided, we need to know more about the population of dogs and cats involved. Some shelters survey owners who are relinquishing pets to determine their reasons for relinquishment [
19,
20], and also collect demographic data on the age, sex and breed of the relinquished animal [
4,
19,
20]. While this information is not perfect (for example, owners may not be truthful about the behavior of their pet if they think it will negatively impact the likelihood of that pet finding a new home), it has been helpful in designing interventions. For instance, knowing that sometimes pets are relinquished because owners cannot find rental accommodation that allows pets has resulted in real changes, with the Australian state of Victoria recently announcing modifications to rental agreements to make it easier for people to rent with pets [
21].
Pets are given away or sold through advertisements in newspapers, bulletin boards and using the internet. In Australia, Gumtree [
22] has the highest volume of online ads for dogs and cats, followed by Trading Post [
23]. Breeders of purebred dogs also advertise on DogzOnline [
24], although this site represents a smaller number of animals compared to Gumtree and Trading Post. Other forms of social media, such as Facebook
®, also advertise pets for sale or to find new homes. These online sites advertise both puppies and kittens being sold by a breeder, and animals being relinquished.
There has been limited research into online trading of dogs and cats. In a US study, dog breeders who advertised puppies on the internet were less knowledgeable about health issues specific to their breed/s and less likely to screen their animals for heritable diseases compared to dog breeders who did not advertise their puppies on a puppy internet site [
25]. To our knowledge, no published studies have focused on pets being relinquished online. The aims of the present study were to: (1) estimate the total numbers and prices of dogs and cats relinquished online on Gumtree; (2) analyze the breed and Australian State/Territory of origin of dogs and cats relinquished on Gumtree and compare with animals presented to PetRescue [
26] (an online charity advertising pets from a shelter or rescue organization in Australia) and the RSPCA; and (3) interview a sample of pet owners relinquishing their pets on Gumtree to determine their reasons for relinquishment and why they chose to advertise their pet online.
4. Discussion
The current study provides evidence about the numbers and types of dogs and cats relinquished on one popular website Gumtree in Australia, filling an important gap in knowledge. It indicates that thousands of dogs and cats are being relinquished on Gumtree per year. Information collected on their breed and age profiles allows comparison with other relinquished populations on PetRescue and published RSPCA and surrender data [
2,
4]. Although there are similarities between the populations, such as the most common dog breeds on Gumtree, PetRescue and in published figures, there also appear to be differences suggesting pets relinquished on Gumtree represent a subpopulation of relinquished animals.
By extrapolation, the total number of dogs and cats relinquished via Gumtree ads was approximately 30,000 and 16,000, respectively. Recent estimates have indicated that 211,655 dogs were admitted to shelters and municipal facilities in Australia in 2012/13 [
2]. Some of the dogs being offered on Gumtree may eventually be relinquished to a shelter or end up at a municipal pound if a new owner is not found. The estimated Gumtree ads represent a significant proportion (~14%) of the total number of dogs admitted to shelters and municipal facilities per year. This proportion would be even higher if one considered other online websites (e.g., DogzOnline, TradingPost), as well as Facebook
®, and other private or closed websites advertising pets. The diverse and diffuse nature of online ads, as well as the fact some are closed websites, makes it impossible to estimate the total numbers of pets advertised online. If it is also considered that less than half of shelter relinquishments are owner surrenders (19% in dogs to Queensland RSPCA shelters in 2014 and 32% of cats between 2006 and 2009 in Queensland RSPCA shelters; [
19,
29]) then the online ads would represent an even higher proportion of owner surrenders.
There is a complex flow of dogs and cats between the owned and un-owned populations. The data presented from the Gumtree ads, from Pet Rescue (representing larger and smaller shelters and pounds) and from published data from the RSPCA, illustrate the complexity of movements of surrendered dogs and cats within and between Australian States/Territories. The human population for each State/Territory was used for comparison; if one assumes that a similar percentage of people in each State/Territory own a dog or cat, the human population is a proxy for the dog and cat population. If one then assumes that a similar proportion of dog and cat owners in each State/Territory relinquish their dogs or cats each year, the proportions should be similar. In fact, they were not, and this may be because these two assumptions are not true, and that people in different States/Territories are more or less likely to own a dog/cat and to then relinquish it. In general, Queensland had an overrepresentation of the surrendered population of dogs and cats on Gumtree, PetRescue and the RSPCA compared to their human population, while Victoria tended to have an underrepresentation of relinquished dogs and cats compared to their population. An additional confounder is that RSPCA data is dependent on the numbers and sizes of shelters in each State/Territory, and the PetRescue data depends on the market penetration of shelters/pounds using their website from each region. Internet access and hence access to Gumtree may be more uniform between States. To fully understand the flow of owned and un-owned dogs and cats within and between regions of Australia will require further research.
Although there were similar total numbers of ads for dogs and cats on Gumtree, there were fewer new ads posted in the follow-up datasets for cats versus dogs. This suggests the turnover of cat ads on Gumtree is longer than for dogs. Of the dog and cat owners that were interviewed, a higher proportion of dog owners had already successfully rehomed their pets versus the cat owners, at the time of interview. Of the two cat owners who had multiple responses for relinquishment, and had been able to successfully rehome their pets, both were purebred cats. However, the very small number of responses from owners relinquishing their pets on Gumtree means that this data is not likely to be representative of the entire population of relinquishing owners.
There are many risks involved with online trade in pets for both prospective owners and animals, but as yet online sales of dogs and cats remain unregulated around the world. In some countries voluntary standards for online sales of pets have been developed, with the Pet Advertising Advisory Group in the UK, the Irish Pet Advertising Advisory Group and the BelgPAAG (Belgian Pet Advertising Advisory Group) was recently launched in Belgium [
30]. The EU Dog & Cat Alliance released a report into the cost of online sales in the EU recently [
31]. The main findings were that online ads are now the most common way for people to purchase a pet, that there are no regulations around Europe that cover this trade, and the many risks involved. These include sale of unweaned animals and animals in poor health. There are up to 269,620 dogs and 67,847 cats estimated as being advertised online in the European Union on any given day [
31]. A report issued by the Better Business Bureau (BBB)
® International Investigations Initiative presents evidence on how online pet sellers scam pet buyers in the US [
32]. The BBB ScamTracker contained 907 reports on pet scams at the time the report was published, which was 12.5% of all online purchase fraud complaints. Many of the scams do not involve a real animal, for example, an ad for a free dog or cat that urgently needs a new home may be posted. Once a person responds to the advertisement, costs relating to transportation and care of the animal are requested. The report includes information from other countries, with 337 pet complaints to the Australian Competition and Consumer Commission in the first six months of 2017, and 377 complaints involving animals to the Canadian Antifraud Centre in 2016, with estimated losses of
$222,000 [
32].
In addition to the risks relating to online sales of dogs and cats outlined above, there are other risks relating specifically to dog and cat relinquishment. If an aggressive dog is relinquished to a reputable shelter, the dog’s behavior will be assessed and the risk to new owners evaluated. Although behavioral assessments performed in shelters are unreliable [
33], prospective owners can be educated on the behavior of the dog and triggers of aggression prior to adoption, and post-adoption support provided if behavioral problems arise. In addition, good shelters have access to trainers and behaviorists who can implement programs to improve the behavior of an animal. In some of the ads it was possible to read between the lines and see that aggression was likely to have been a problem (e.g., “Urgent rehoming needed for Jack Russell cross, male, 10 years. Beautiful dog, very friendly but best suited to a kid free home.”) but there is nothing to prevent owners advertising and selling pets with a behavioral problem without providing any warning or information to the new owner.
As well as the risk to new owners, there are also risks to the animals themselves. While not perfect, shelters do question prospective new owners on their ability to look after a pet and may not allow somebody to adopt a pet if they believe it will not be well cared for. Again, there is no obligation when dogs and cats are traded online for this to occur. As people may have ready access to the internet at any time of the day, and with the posting of cute photos, impulse buying may also be a significant problem. The wording of some of the ads indicated an impulse purchase, for example: “6-month-old Shar Pei puppy we brought him off Gumtree two weeks ago and he's the best puppy ever but unfortunately I have no time for him as I have three babies. He has had all he's (sic) needle are up to date. Looking for a good home with someone who has plenty of time for him”. An additional risk associated with the Gumtree ads was that a large proportion were free, or a minimal cost. It has been suggested that animals obtained at no or a low cost are at an increased risk of future relinquishment [
34], perpetuating the problem. However, a later study suggested that the attachment of people to cats did not differ between free- and fee-based cat adoptions [
35]. Further research will be needed to assess whether free animals adopted online are more or less at risk of being re-relinquished.
There is also an additional risk associated with offering dogs and cats free, or very low cost. One of the interview respondents discussed how they had been taking home dogs advertised on Gumtree free in order to find them a new home. This respondent felt that otherwise, people involved in dog fighting would take them (they had rehomed approximately 80 animals in the past year). To our knowledge, there is no evidence of trade and use of dogs in dog fighting, although it should be considered as a possibility. There were a number of ads describing dogs suitable for pig hunting, which is illegal in some States of Australia [
36]. In fact, the Bull Arab, which is not a recognized breed by the Australian National Kennel Council [
37], is a breed often associated with pig hunting, and a large number of Gumtree ads for Bull Arabs from Queensland (in which pig hunting is legal) were observed. The final risk for dogs and cats advertised free or for low cost online is from animal hoarders. Arluke et al. (2017) describe three types of animal hoarders: the overwhelmed caregiver, rescuer, and exploiter. The rescue hoarder has a missionary zeal to save all animals and actively seeks to acquire animals [
38]. Being exposed to advertisements of animals that need rescuing on Gumtree is likely to trigger a rescue hoarder, who can acquire multiple animals free or at minimal cost.
It is difficult to determine if the population of dogs and cats surrendered on Gumtree overlaps with the animals that are surrendered to the RSPCA or other shelters. Four of the people interviewed who had relinquished dogs on Gumtree stated that they used Gumtree as the local shelters were full, and while this was not given as a reason by any cat owners there was one person who said they used Gumtree because the cat would be ‘put down’ at a shelter. The animals advertised on Gumtree would represent the ‘owner surrender’ dog admissions to a shelter. Only 19% of the 11,967 dogs entering the RSPCA in Queensland in 2014 were owner surrender, with 24% classified as strays admitted by the public, and 34% from municipal councils [
29]. However, some of the strays admitted by the public may represent owned animals, with owners avoiding paying shelter surrender fees, or not wanting people to know they are relinquishing their own pet. The top four breeds processed by RSPCA shelters in Queensland in 2014 were the Staffordshire Bull Terrier (20%), Australian Cattle Dog (8%), Kelpie (7%) and Bull Arab (7%). The top four breeds advertised on Gumtree in the current study were the Staffordshire Bull Terrier (12%), Bull Arab (8%), Kelpie (6%) and Australian Cattle Dog (5%). Thus, the most popular breeds for the RSPCA and Gumtree are similar, and also to the dogs offered on PetRescue which represent both larger and smaller shelters. Despite similarities in the breeds, the proportions of pure and cross-breed dogs differ widely, with 92% of the dogs admitted to the RSPCA in Queensland in 2014 being cross-bred, while only 46% of dogs from Queensland advertised on Gumtree cross-bred. The median price of purebred dogs was significantly higher in the Gumtree ads than for cross-bred dogs.
There is an important difference in relinquishing online versus giving up a dog or cat at a shelter. At a shelter, owners may have to pay a fee to relinquish their pets, whereas on an online site, they can request a sum of money. However, based on the definition of relinquishment being used in this study (“Voluntarily cease to keep or claim; give up”) the owners are voluntarily giving up their dog or cat. Indeed, if a dog or cat has been purchased originally for a large sum of money, offering the pet online may allow the owners to make up for some of this loss. The general use of the term relinquishment describes an animal taken to a shelter. When devising the criteria to determine if a dog or cat was being relinquished, we originally planned to have a cap on price for the animals we included in our study. However, when reading the descriptions of the ads, there were ads in which the dog or cat was being traded for over $AUS1000, and yet the wording suggested that the decision of the owner to relinquish their pet had been difficult. Thus, it was not possible to use a cut-off price and say that all pets below that price were relinquished and above that price were not.
One reason provided by respondents for the use of Gumtree for relinquishing their pets was that they could speak to the new owners and see where their pet would live before agreeing to give their pet a new home. One of the owners had even run trials of their dog with the prospective new owners and had two failed trials before having success with the third. Follow-up and control on the re-homing of their pet is something that cannot be provided in a traditional shelter, where the animal is left and no further information on where, and even if it has been rehomed, is provided. A novel dog adoption program has been suggested in the US which involves placing dogs into foster homes, with the foster carer tasked with finding the dog a new home [
39]. There are obvious issues with protection of privacy and the possibility of the new owners being harassed by the previous owner (or vice versa), but this feedback is important for shelters to consider. To accommodate owners who want to know where their pet goes and that it is being well looked after, innovative programs should be considered.
An important limitation of the current study was the limited number of relinquished owners who responded. Of those who did respond, all would be classified as responsible pet owners who were in positions in which they had no real choice but to relinquish their pet, and who were doing their best to find a good home. One of the respondents had rescued the animal previously from an ad on Gumtree and believed that the owner was going to kill the animal if a new owner was not found quickly (an unavoidable change in this persons’ living arrangements outside of their control meant that they needed to relinquish the pet). It is likely the population of people relinquishing their pets on Gumtree are mixed, with some doing everything they can to find a good home, and others not caring where their pet goes as long as they can dispose of it. Further research with responses from a larger range of respondents would be difficult, as people who do not care for their pet are also unlikely to respond to requests to participate in research. For the owners who were relinquishing their pets, several were obviously upset about the difficult decision they had been forced to make. It was also interesting that some owners felt it necessary to respond to the email to notify us that they were not willing to participate as they found the situation too distressing. This aligns with previous research that concluded that rather than giving their pet up at a shelter thoughtlessly many people struggled with an unavoidable situation and really had no choice [
20].
Research based on the use of big data from web scraping (automated collection of data from web pages) provides both important research data but also ethical questions. Guidelines for internet research have been published [
40], and we believe the current study presents no significant ethical problem using these guidelines. The respondents in the present study who were interviewed provided their informed consent to participate, and no personal details are included that could be used to identify them. However, owners whose data were used to estimate numbers and demographics of the relinquished pets did not consent to this use. Although the data were publically available on Gumtree, it can be argued that people did not consent to other uses of their information. However, risks to these people are minimal in the present study as aggregate data were used that do not permit identification of individuals, and the direct quotes used in the paper are unlikely to be able to be used to identify individuals as the ads are now more than a year old and are taken down from Gumtree once new owners are found, or owners decide not to continue advertising. The benefits of the research in understanding a population of relinquished pets that have hitherto not been studied are also likely to outweigh the minimal risks to the individuals whose data was used.
Another important limitation of the study is that not all information posted by the dog and cat owners is accurate, for example, some owners may not know the true age of their pet or may provide false information on factors such as dog breed. Owners may also provide false reasons for the relinquishment due to social pressure to have others think well of us [
41]. Finally, the extrapolation from the ads posted in February to the total number per year is likely to be inaccurate as numbers of ads will vary from month to month. This is particularly relevant for cats, as they are seasonal breeders.
