Pet Rat Owners Research Articles

Developing guidelines for pet rat housing through expert consultation.

Pet care guidelines play an important role in ensuring that owners are well informed about good husbandry practices, allowing them to provide the best care for their animals. However, the development of such guidelines is difficult when there is little appropriate empirical evidence on which to base guidelines, as in the case of pet rats. The consultation of multiple experts can help to surmount this challenge. We developed a set of guidelines for pet rat housing by consulting with a group of experts, including veterinarians, veterinary nurses, animal welfare scientists and experienced pet rat owners. The consultation involved two rounds of online surveys (n=13) and one online discussion (n=8). The resulting guidelines cover a broad range of features within pet rat housing, including injury prevention, details of suitable refuges and substrates, and suitable cage sizing. The guidelines may evolve as more information about pet rats comes to light but may nonetheless provide a useful starting point for any future guidelines. At present, these guidelines may not only be useful for pet rat owners and those advising pet rat owners, such as veterinarians, but may also be useful in the design of housing, including for laboratory rodents.

Thinking outside the lab: Can studies of pet rats inform pet and laboratory rat welfare?

Surveys provide a low-cost means to obtain large amounts of data that are ideal for conducting exploratory research, and they are becoming an increasingly valuable tool in a veterinary context. We investigated whether surveys of pet rat owners might provide useful data that could pave the way for more targeted empirical studies of pet and laboratory rat welfare. To achieve this, we used an online survey, distributed via social media, in which we asked pet rat owners questions about the housing, handling, and behaviour of their pet rats, from which we obtained 677 fully-completed surveys. We conducted both qualitative and quantitative analyses of these data, examining the reported frequency of the behaviours and using general linear models to investigate how these reported frequencies varied according to age, sex, total number of rats owned, human-interaction (a variable which summarised data relating to questions about human interaction), total number of enrichment types (a variable which summarised data relating to the provision of enrichment), and predator exposure (a variable which summarised data about the ownership of predator species). The study firstly identified well-established and intuitive findings that supported the validity of this approach, including age-dependent changes in behaviour. The study also identified behaviours that are commonly performed by pet rats, many of which are restricted by standard laboratory cages and may be restricted in poorer pet rat housing. This includes the first scientific report of ‘boggling’ in rats. Additionally, by assessing which behaviours varied according to predator exposure (which is likely to be aversive to rats), the study identified potentially novel, spontaneous behavioural indicators of rat welfare. Specifically, the reported frequency of each of the following behaviours was significantly reduced by greater exposure to predator species: digging (LRT=7.264, FDR-adjusted p-value=0.032), bounding (LRT=8.990, FDR-adjusted p-value=0.015), pinning (LRT=9.242, FDR-adjusted p-value=0.015), and bruxing (LRT=17.780, FDR-adjusted p-value<0.001). We conclude that survey data obtained from pet rat owners may provide useful and fruitful information that can inform both pet and laboratory rat welfare.

Pet rat welfare in the United Kingdom: The good, the bad and the ugly.

To date, despite the substantial literature investigating how rats prefer to be kept in captivity, no research has been conducted to assess the housing, husbandry and health of pet rats. To better understand the United Kingdom's pet rat population and the welfare issues they face, we conducted an online survey of pet rat owners. The survey included questions about the owner and their opinions about pet rats, and about their rats' health, husbandry and housing. The results, from 677 complete responses, highlighted areas of rat care that were "good", "bad" and "ugly" (i.e. likely to be highly detrimental to welfare). The good was that many rats were provided with a social companion and enrichment; the bad was that we could not be certain whether rats had a sufficiently nutritious diet or sufficient opportunities to explore or adequate nesting substrate; and the ugly included cases of exposure of rats to predator species within the home and a generally high prevalence of disease. We conclude that there is much cause for concern about the welfare of pet rats in the United Kingdom.

Seoul Virus Infection and Spread in United States Home-Based Ratteries: Rat and Human Testing Results From a Multistate Outbreak Investigation.

During 2017, a multistate outbreak investigation occurred after the confirmation of Seoul virus (SEOV) infections in people and pet rats. A total of 147 humans and 897 rats were tested. In addition to immunoglobulin (Ig)G and IgM serology and traditional reverse-transcription polymerase chain reaction (RT-PCR), novel quantitative RT-PCR primers/probe were developed, and whole genome sequencing was performed. Seventeen people had SEOV IgM, indicating recent infection; 7 reported symptoms and 3 were hospitalized. All patients recovered. Thirty-one facilities in 11 US states had SEOV infection, and among those with ≥10 rats tested, rat IgG prevalence ranged 2%-70% and SEOV RT-PCR positivity ranged 0%-70%. Human laboratory-confirmed cases were significantly associated with rat IgG positivity and RT-PCR positivity (P = .03 and P = .006, respectively). Genomic sequencing identified >99.5% homology between SEOV sequences in this outbreak, and these were >99% identical to SEOV associated with previous pet rat infections in England, the Netherlands, and France. Frequent trade of rats between home-based ratteries contributed to transmission of SEOV between facilities. Pet rat owners, breeders, and the healthcare and public health community should be aware and take steps to prevent SEOV transmission in pet rats and to humans. Biosecurity measures and diagnostic testing can prevent further infections.

Outbreak of Seoul Virus Among Rats and Rat Owners - United States and Canada, 2017.

In December 2016, the Wisconsin Department of Health Services (WDHS) notified CDC of a patient hospitalized with fever, leukopenia, elevated transaminases, and proteinuria. The patient owned and operated an in-home rattery, or rat-breeding facility, with approximately 100 Norway rats, primarily bred as pets. A family member developed similar symptoms 4 weeks later, but was not hospitalized. Because both patients were known to have rodent contact, they were tested for hantavirus infections. In January 2017, CDC confirmed recent, acute Seoul virus infection in both patients. An investigation was conducted to identify additional human and rat infections and prevent further transmission. Ultimately, the investigation identified 31 facilities in 11 states with human and/or rat Seoul virus infections; six facilities also reported exchanging rats with Canadian ratteries. Testing of serum samples from 183 persons in the United States and Canada identified 24 (13.1%) with Seoul virus antibodies; three (12.5%) were hospitalized and no deaths occurred. This investigation, including cases described in a previously published report from Tennessee (1), identified the first known transmission of Seoul virus from pet rats to humans in the United States and Canada. Pet rat owners should practice safe rodent handling to prevent Seoul virus infection (2).

Outbreak of Seoul virus among rats and rat owners - United States and Canada, 2017.

​: Seoul virus, a type of hantavirus, is carried by Norway rats. Humans become infected through contact with virus shed in rat urine or droppings, or inhalation of virus particles in dust from contaminated bedding. Infected rats do not develop disease, but humans can experience symptoms ranging from mild influenza-like illness to severe disease with kidney failure and death. Although infections have been previously reported in humans after contact with wild rats, Seoul virus infections had not been reported in pet rats in the United States or Canada. ​: This report describes the first known outbreak of Seoul virus infections in humans from contact with pet rats in the United States and Canada. This investigation identified 31 United States facilities with human and/or rat Seoul virus infections in 11 states, including six that exchanged rats with Canadian ratteries. Seventeen persons had recent infection with Seoul virus, eight became ill, and three were hospitalized and recovered. ​: Human hantavirus infections are reportable to state or local health departments in the United States. Clinicians should consider Seoul virus infection in patients with a history of rat contact and compatible symptoms. Pet rat owners and breeders should also be aware of Seoul virus and should practice good hand hygiene and safe rodent handling to prevent infection.

Pets, Purity and Pollution: Why Conventional Models of Disease Transmission Do Not Work for Pet Rat Owners.

In the United Kingdom, following the emergence of Seoul hantavirus in pet rat owners in 2012, public health authorities tried to communicate the risk of this zoonotic disease, but had limited success. To explore this lack of engagement with health advice, we conducted in-depth, semi-structured interviews with pet rat owners and analysed them using a grounded theory approach. The findings from these interviews suggest that rat owners construct their pets as different from wild rats, and by elevating the rat to the status of a pet, the powerful associations that rats have with dirt and disease are removed. Removing the rat from the contaminated outside world moves their pet rat from being ‘out of place’ to ‘in place’. A concept of ‘bounded purity’ keeps the rat protected within the home, allowing owners to interact with their pet, safe in the knowledge that it is clean and disease-free. Additionally, owners constructed a ‘hierarchy of purity’ for their pets, and it is on this structure of disease and risk that owners base their behaviour, not conventional biomedical models of disease.

High prevalence of Seoul hantavirus in a breeding colony of pet rats.

As part of further investigations into three linked haemorrhagic fever with renal syndrome (HFRS) cases in Wales and England, 21 rats from a breeding colony in Cherwell, and three rats from a household in Cheltenham were screened for hantavirus. Hantavirus RNA was detected in either the lungs and/or kidney of 17/21 (81%) of the Cherwell rats tested, higher than previously detected by blood testing alone (7/21, 33%), and in the kidneys of all three Cheltenham rats. The partial L gene sequences obtained from 10 of the Cherwell rats and the three Cheltenham rats were identical to each other and the previously reported UK Cherwell strain. Seoul hantavirus (SEOV) RNA was detected in the heart, kidney, lung, salivary gland and spleen (but not in the liver) of an individual rat from the Cherwell colony suspected of being the source of SEOV. Serum from 20/20 of the Cherwell rats and two associated HFRS cases had high levels of SEOV-specific antibodies (by virus neutralisation). The high prevalence of SEOV in both sites and the moderately severe disease in the pet rat owners suggest that SEOV in pet rats poses a greater public health risk than previously considered.

Cowpox Virus Infection in Pet Rat Owners—Not Always Immediately Recognized: Human to Human Transmission of Poxviruses Have Been Observed Previously

I read the article by Becker et al, on cowpox infections in owners of pet rats (1), with great interest as I was involved with cowpox through my work from 1970 to 1974. The authors write that human to human transmission has not been observed so far. However, according to my own experiences, human to human transmission should be classed at least as possible. Thirty seven years ago I worked in the state vaccination institute in Dusseldorf. A 35 year old woman had received a visit from an 11 month old child. She had held the child in her arms and petted and stroked it. She was not aware that the child had been vaccinated against smallpox 4 weeks previously. Three days later, the woman developed pea sized efflorescences on her left cheek and her right and left upper arms. These remained in place for 6 days; she consulted a doctor who suspected smallpox and referred her to the university dermatology hospital in M. Specimens were taken and sent to the vaccination institute in Dusseldorf for investigation. Smallpox viruses were found on electron microscopy in two specimens—a clear case of human to human transmission. The then director of the state vaccination institute, Dr Richter, and I reported extensively about the case in the journal Offentliches Gesundheits-Wesen [public health] (2).

Cowpox Virus Infection in Pet Rat Owners—Not Always Immediately Recognized: In reply

Cowpox Virus Infection in Pet Rat Owners—Not Always Immediately Recognized: In reply

Cowpox Virus Infection in Pet Rat Owners—Not Always Immediately Recognized: Human to Human Transmission Is Possible in Orthopoxviruses

I wish to congratulate the authors for their clear and well structured case reports and their detailed photographs. This publication will enable more rapid diagnosis of further cases (1). In the meantime, Campe et al have published an article in Emerging Infectious Diseases about the transmission of cowpox from rats to humans in the Munich area (2). Human to human transmission has been described for orthopoxviruses. In 2007, Zafar et al reported nosocomial infections with buffalopox viruses in burns wards in Karachi, Pakistan; a class of virus that also belongs to the genus orthopoxvirus (3). Zafar et al observed buffalopox for 5 months in 2004–5 in 19 patients from 5 burn units. A health care worker developed an infection on a finger. In all cases, the causative strain was confirmed and typed with support from the Special Pathogens Unit at the National Institute for Communicable Diseases (NICD), Sandringham, South Africa, and the Health Protection Agency (HPA)’s Centre for Emergency Preparedness and Response in Porton Down, Salisbury, United Kingdom. The authors recommend that patients should be warned about the risk of smear (contact) infections, as it happened at least in patient No 4 (lesions on abdominal skin and eye). Identification of cowpoxviruses in the biopsy specimen from a pulmonary focus proves that pneumonia in patient 6 was caused by the virus.