Domestic Rats Research Articles

Detection of Mycoplasma sp using next-generation DNA sequencing is common on nasal swabs from both healthy and unhealthy pet rabbits (Oryctolagus cuniculus).

Upper respiratory infections are a frequent problem in pet rabbits and rodents, and Mycoplasma pulmonis is 1 of the most common causes of respiratory infections in pet rats. M pulmonis was detected in 1967 in laboratory rabbits via culture of the nares and oropharynx, but overall, Mycoplasma is not commonly identified in the upper airway of rabbits. The objective of this study was to compare the prevalence of Mycoplasma sp detection via next-generation DNA sequencing on nasal swabs obtained from healthy and unhealthy rabbits. The results of nasal swabs from both healthy and unhealthy rabbits submitted for next-generation DNA sequencing from January 2022 to February 2023 were reviewed. Data gathered included signalment, whether or not Mycoplasma sp was detected, and the cell count and relative predominance of Mycoplasma sp compared to other organisms. 91 rabbits met the inclusion criteria, of which 49 were healthy and 42 were unhealthy. Overall, 52 of 91 (57.1%) rabbits were positive and 39 of 91 (42.8%) were negative for Mycoplasma sp. Mycoplasma positivity was significantly (P < .001) more common in healthy rabbits (37/49 [75.5%]) compared to unhealthy rabbits (15/42 [35.7%]). The fact that Mycoplasma positivity was common in both groups of rabbits, and particularly common in rabbits without upper respiratory signs, suggests that Mycoplasma may be normal nasal flora in rabbits. Further research is needed to determine whether Mycoplasma could function as an opportunistic pathogen in rabbits.

Exploring pet rat care: A comprehensive survey of husbandry, health, behavior, and the associations between caretaker attitudes, attachment, and husbandry practices

Pet rats are still understudied in terms of animal welfare and human-animal interaction research. An extensive online survey targeting German-speaking rat caretakers was conducted (n = 978). One of the study's goals was to investigate husbandry practices, health indicators, rat behaviors that suggest either good or compromised welfare, as well as elements of the human-animal relationship, including interactions between humans and animals, caretaker attitudes, and attachment. The second aim was to explore the associations between caretaker attitudes and attachment, and caretaker behavior, encompassing routine health checks, interactions between humans and animals, as well as the activities and enrichment provided to rats. In some instances, welfare issues were identified: insufficient space (evident in 10.6% of rats), provision of unhealthy snacks (14.6%). The vast majority of rats enjoyed a variety of enrichment objects, e.g., huts/houses (98.4%), nesting material (92.7%), hammocks (91.7%), and tunnels/tubes (83.7%). The average amount of space and time provided for roaming in case of no permanent roaming possibility (13.9 m2 and 2.5 h per day) was positive in terms of welfare. About 79.0% of rats did not suffer from a disease diagnosed by a veterinarian. Repetitive behaviors, which may represent stereotypies, were uncommon (plucking out own fur and cage bar chewing occurred “never” in 99.1% and 81.5%). Indicators of good welfare (e.g., self-grooming, rearing, eye-boggling) were observed several times/day in 89.6%, 46.7%, and 11.6% respectively. Caretakers who formed strong bonds with their rats tended to express positive general attitudes (such as finding rats ‘‘lovable’’ and ‘‘fun’’), while showing little agreement with statements reflecting negative attitudes (like considering rats ‘‘dirty’’). About 84.4% reported stroking their rat, 94.9% reported talking to it, and 70.9% mentioned hand-feeding their rat several times per day. Caretaker attitudes and attachment and human-animal interactions and caretaker behaviors correlated weakly but consistently (P < 0.01): respondents who felt more comfortable during positive interactions, stroked, hand-fed their rats, offered rat-friendly enrichment and performed health checks more often. In contrast, higher agreement to rats being ‘‘dirty’’ related to less frequent health checks and less frequent positive human-animal interactions. The identified relationships between caretaker attitudes and behaviors can help design interventions to promote caretaker behavior that is beneficial for rat welfare.

Identification of Aichivirus in a Pet Rat (Rattus norvegicus) in Italy

We investigated the occurrence of eight potential zoonotic viruses in 91 exotic companion mammals from pet shops in southern Italy via real-time PCR and end-point PCR. The animals were screened for aichivirus, sapovirus, astrovirus, hepatitis A, noroviruses (GI and GII), rotavirus, circovirus, and SARS-CoV-2. Among the nine species of exotic pets studied, only one rat tested positive for aichivirus. The high sequence similarity to a murine kobuvirus-1 strain previously identified in China suggests that the virus may have been introduced into Italy through the importation of animals from Asia. Since exotic companion mammals live in close contact with humans, continuous sanitary monitoring is crucial to prevent the spread of new pathogens among domestic animals and humans. Further investigations on detecting and typing zoonotic viruses are needed to identify emerging and re-emerging viruses to safeguard public health.

Prognostic value of biohybrid screening results for assessing cancer risk using the example of lung cancer

Introduction. One of the leading places in the structure of socially significant diseases in the Russian Federation is occupied by malignant neoplasms, among which cancer of the trachea, bronchi and lung occupies the first place in terms of prevalence. Screening for lung cancer is not carried out at the federal level in Russia; recommended screening measures include questionnaires to identify risk factors for the development of the disease (including occupational) and the formation of dispensary observation groups. The study aims to assess the prognostic value of a new method of biohybrid screening of lung cancer by exhaled air. Materials and methods. Scientists conducted a study at the National Medical Research Center of Oncology of the Ministry of Health, Russian Federation, with the participation of 24 conditionally healthy volunteers and 5 patients diagnosed with lung cancer in the early stages of the disease. The design of the study is simultaneous (on-line) with blinding; experts estimated the risk of systematic errors at 10 points on the QUADAS scale. The authors examined exhaled air samples on a gas analyzer (biohybrid detector) of the BGS-APK 02SZZ model, in which the sensor were animals — gray domesticated rats (Rattus norvegicus) with microelectrode matrices implanted into the olfactory bulb, and which were in the internal (ventilated) space of the analyzer in a state of drug anesthesia. The conclusion about the presence or absence of a risk of lung cancer was formed by an artificial neural network of the analyzer, at the input of which bioelectric signals from each microelectrode were received, which were preprocessed using a system for recording the focal activity of the olfactory analyzer. The specialists confirmed the presence or absence of a risk of lung cancer by a reference method, according to computed tomography of the chest in accordance with the Lung Imaging Reporting and Data System (LungRADS™). Results. During the study, experts determined the effectiveness indicators of the method of biohybrid lung cancer screening by exhaled air: sensitivity (64%), specificity (87%), prognosticality of negative and positive conclusions about the presence/absence of disease risk (82% and 72%, respectively). Conclusion. The safety, efficiency and throughput of the investigated method, together with the reproducibility of the analyzer's conclusions, meet the criteria of practicability to ensure the first (population-based) stage of lung cancer screening.

Enteric parasites Cyclospora cayetanensis and Cryptosporidium hominis in domestic and wildlife animals in Ghana

BackgroundEnteric parasitic infections remain a major public health problem globally. Cryptosporidium spp., Cyclospora spp. and Giardia spp. are parasites that cause diarrhea in the general populations of both developed and developing countries. Information from molecular genetic studies on the speciation of these parasites and on the role of animals as vectors in disease transmission is lacking in Ghana. This study therefore investigated these diarrhea-causing parasites in humans, domestic rats and wildlife animals in Ghana using molecular tools.MethodsFecal samples were collected from asymptomatic school children aged 9–12 years living around the Shai Hills Resource Reserve (tourist site), from wildlife (zebras, kobs, baboons, ostriches, bush rats and bush bucks) at the same site, from warthogs at the Mole National Park (tourist site) and from rats at the Madina Market (a popular vegetable market in Accra, Ghana. The 18S rRNA gene (18S rRNA) and 60-kDa glycoprotein gene (gp60) for Cryptosporidium spp., the glutamate dehydrogenase gene (gdh) for Giardia spp. and the 18S rDNA for Cyclospora spp. were analyzed in all samples by PCR and Sanger sequencing as markers of speciation and genetic diversity.ResultsThe parasite species identified in the fecal samples collected from humans and animals included the Cryptosporidium species C. hominis, C. muris, C. parvum, C. tyzzeri, C. meleagridis and C. andersoni; the Cyclopora species C. cayetanensis; and the Gardia species, G. lamblia and G. muris. For Cryptosporidium, the presence of the gp60 gene confirmed the finding of C. parvum (41%, 35/85 samples) and C. hominis (29%, 27/85 samples) in animal samples. Cyclospora cayetanensis was found in animal samples for the first time in Ghana. Only one human sample (5%, 1/20) but the majority of animal samples (58%, 51/88) had all three parasite species in the samples tested.ConclusionsBased on these results of fecal sample testing for parasites, we conclude that animals and human share species of the three genera (Cryptosporidium, Cyclospora, Giardia), with the parasitic species mostly found in animals also found in human samples, and vice-versa. The presence of enteric parasites as mixed infections in asymptomatic humans and animal species indicates that they are reservoirs of infections. This is the first study to report the presence of C. cayetanensis and C. hominis in animals from Ghana. Our findings highlight the need for a detailed description of these parasites using high-throughput genetic tools to further understand these parasites and the neglected tropical diseases they cause in Ghana where such information is scanty.Graphical

МОРФОЛОГИЧЕСКАЯ ХАРАКТЕРИСТИКА ПРЕПУЦИАЛЬНЫХ И КЛИТОРАЛЬНЫХ ЖЕЛЕЗ У ДЕКОРАТИВНЫХ КРЫС

The aim of the study is to investigate the structural features of the preputial glands of males and clitoral glands of females in clinically healthy adult sexually mature pet rats. The object of the study is pet rats kept by private owners in the city of Krasnoyarsk and the Krasnoyarsk Region, which died from various disea¬ses not associated with pathologies of the studied glands. The material of the study was the clitoral and preputial glands collected from the corpses of dead animals during pathological examination. The material from 13 females weighing from 248 to 567 g and 11 males weighing from 229 to 720 g was studied. The age of the animals ranged from 12 to 36 months. The preputial and clitoral glands are paired organs of external secretion, located in the thickness of the subcutaneous fat, and are well developed in animals of both sexes. Their absolute weight significantly differs between rats of different sexes and is (0.22 ± 0.02) g in males and (0.14 ± 0.01) g in females (P ≤ 0.01). The relative mass of the glands in animals of both sexes is (0.4 ± 0.01) % of the body mass. It has been established that the preputial glands in males and the clitoral glands in females of pet rats have a comparable histological structure. According to the type of secretion, they are holocrine, according to the characteristics of the excretory ducts, they are branched, and according to the shape of the terminal sections, they are alveolar. They produce a pasty secretion, which has a color from yellowish to light brown, contains a large amount of lipids and has a pungent odor.

Reassessment of the conservation status of Crocidura fingui, a shrew endemic to Príncipe Island, Gulf of Guinea

AbstractThe Fingui white-toothed shrew Crocidura fingui, categorized as Data Deficient on the IUCN Red List, is endemic to Príncipe Island, Central Africa. It is currently known from &lt; 10 sites and its ecology and any threats are largely unknown. We review its distribution and ecology, and any potential threats, based on camera-trap data, field observations and previously published and unpublished sightings. Crocidura fingui appears to have an island-wide distribution and to use a range of ecosystems, from native forests to urban areas. It is largely nocturnal and exhibits considerable spatiotemporal overlap with introduced mammals such as the African civet Civettictis civetta, domestic cat Felis catus and rats Rattus spp. The species has an area of occupancy &lt; 500 km2 and is known from fewer than five locations, and its population is inferred to be affected by several introduced mammals. We recommend that it is recategorized as Endangered on the IUCN Red List.

The Rat Thoracic Ultrasound protocol: scanning technique and normal findings.

Respiratory diseases (especially pneumonia) are very common disorders in pet rats. The suspected diagnosis is mostly based on the clinical signs, thoracic auscultation, and thoracic radiography. However, auscultation is insensitive in determining the severity of the disease, and radiographs are often unremarkable. Non-cardiac thoracic ultrasonography is increasingly used in veterinary medicine; however, it has not been described in detail in rats. Thoracic ultrasonic examination was conducted on 400 client-owned conscious pet rats. The rats were examined in the period from June 2023 to August 2023 in two veterinary clinics. Due to the small size of the animal, different anatomical considerations, and different evaluation protocols, as well as to meet the optimal outcome of detailed thoracic ultrasound, a standard methodological protocol was developed, and the name RATTUS (Rat Thoracic Ultrasound) was proposed. Typical signs of normal RATTUS were described (bat sign, lung sliding, A-lines, abdominal curtain sign, ski jump sign, lung pulse, seashore sign in M-mode, and bamboo sign). The new evaluation of lung inflation symmetry by substernal access was also described. The methodical approach presented and the normal findings description are proposed to be used for a standard/routine thoracic ultrasound examination in pet rats.

The quantitative evaluation of cardiac structures and major thoracic vessels dimensions by means of lateral contrast radiography in Wistar albino rats (Rattus norvegicus)

The aim of this study was to define reference values for vertebral heart score (VHS) and modified left atrium (LA)-VHS, cardiac structures, and major thoracic vessels measurements and ratios obtained from thoracic contrast radiography Wistar albino rats. VHS, modified LA-VHS, left (LV) and right (RV) ventricles, interventricular septum (IVS), aorta (Ao), caudal vena cava (CaVC), and fourth thoracic vertebrae (v) length (T4) were measured from left lateral thoracic contrast radiographs of 50 young, healthy adult male Wistar albino rats. LV/T4, RV/T4, IVS/T4, Ao/T4, CaVC/T4, and CaVC/ Ao ratios were calculated from these values. Measurements were performed by two observers unaware of the signalment data for interobserver repeatability analysis. Median values and references ranges were 8.2v (7.4-9.1) for VHS, 1.2 (1.0-1.5) for modified LA-VHS, 7.8 mm (6.2-9.1) for LV, 3.4 mm (2.8-4.5) for RV, 2.1 mm (1.8-3.0) for IVS, 2.1 mm (1.8-2.8) for Ao, 2.2 mm (1.7-3.0) for CaVC, 4 mm (3.5-4.5) for T4, 2 (1.5-2.3) for LV/T4, 0.85 (0.68-1.22) for RV/T4, 0.52 (0.42-0.83) for IVS/T4, 0.53 (0.42-0.75) for Ao/T4, 0.55 (0.45-0.7) for CaVC/T4 and 1.05 (0.74-1.1.37) for CaVC/Ao. Further studies are now needed to determine whether measurement values obtained from contrast radiography in rats are useful in the diagnosis of cardiomyopathy and heart failure. The radiographic measurement values presented in this study can be used as a reference baseline for both pet and laboratory rats.

Hantavirus Disease Cluster Caused by Seoul Virus, Germany.

A cluster of 3 persons in Germany experienced hantavirus disease with renal insufficiency. Reverse transcription PCR-based genotyping revealed infection by Seoul hantavirus transmitted from pet rats. Seoul virus could be responsible for disease clusters in Europe, and infected pet rats should be considered a health threat.

RATTUS (Rat Thoracic Ultrasound): diagnosis of pneumothorax in pet rats.

Rat thoracic ultrasound (RATTUS) is a non-invasive, easy-to-perform method for the evaluation of the pleural space and lungs in pet rats. The aim of the article is to present species-specific differences in the sonographic diagnosis of pneumothorax (PTX) in pet rats. In total, 158 client-owned pet rats were examined during the period from July 2023 to January 2024. PTX was diagnosed in 20 of the examined rats (13.25%, the age of the animals ranged from 2 months to 32 months (19.08 ± 6.93 months; mean ± SD) and their body weight ranged from 97 g to 885 g (461.27 ± 138.97 g; mean ± SD). Radiographic confirmation of PTX was performed in all these 20 rats, in the control group radiography was used to confirm that PTX was not present. The lung point and the barcode sign was found in 7/20 animals with sensitivity of 33.3% (95% CI, 0.16-0.59) and specificity of 100% (95% CI, 0.97-1.0). The abnormal curtain sign was found in 19/20 of animals with the sensitivity of 95% (95% CI, 0.73-0.99.7) and the specificity of 89% (95% CI, 0.82-0.93). The abnormalities in the substernal access were in 17/20 of animals with the sensitivity of 85% (95% CI, 0.61-0.96) and the specificity of 71% (95% CI, 0.62-0.78). In conclusion, RATTUS is a non-invasive method for the diagnosis of PTX in rats. Lung point and barcode sign are specific but not easily diagnosed signs. The curtain sign in RATTUS is not specific for PTX, as there are e.g. geriatric rats (rats older than 1,5 years) in which the abnormal curtain sign is visible without the presence of PTX. The presence of moderate to severe PTX can be assessed by the substernal approach based on the presence of cardiac displacement toward the collapsed lung lobe, and on evaluation of the lung inflation symmetry. This sign is not specific for PTX but in conjunction with other ultrasonic signs described makes the RATTUS a feasible tool for PTX diagnosis in rats.

In silico prediction of interaction between Nipah virus attachment glycoprotein and host cell receptors Ephrin-B2 and Ephrin-B3 in domestic and peridomestic mammals

Nipah virus (NiV) is a lethal bat-borne zoonotic virus that causes mild to acute respiratory distress and neurological manifestations in humans with a high mortality rate. NiV transmission to humans occurs via consumption of bat-contaminated fruit and date palm sap (DPS), or through direct contact with infected individuals and livestock. Since NiV outbreaks were first reported in pigs from Malaysia and Singapore, non-neutralizing antibodies against NiV attachment Glycoprotein (G) have also been detected in a few domestic mammals. NiV infection is initiated after NiV G binds to the host cell receptors Ephrin-B2 and Ephrin-B3. In this study, we assessed the degree of NiV host tropism in domestic and peridomestic mammals commonly found in Bangladesh that may be crucial in the transmission of NiV by serving as intermediate hosts. We carried out a protein-protein docking analysis of NiV G complexes (n = 52) with Ephrin-B2 and B3 of 13 domestic and peridomestic species using bioinformatics tools. Protein models were generated by homology modelling and the structures were validated for model quality. The different protein-protein complexes in this study were stable, and their binding affinity (ΔG) scores ranged between −8.0 to −19.1 kcal/mol. NiV Bangladesh (NiV-B) strain displayed stronger binding to Ephrin receptors, especially with Ephrin-B3 than the NiV Malaysia (NiV-M) strain, correlating with the observed higher pathogenicity of NiV-B strains. From the docking result, we found that Ephrin receptors of domestic rat (R. norvegicus) had a higher binding affinity for NiV G, suggesting greater susceptibility to NiV infections compared to other study species. Investigations for NiV exposure to domestic/peridomestic animals will help us knowing more the possible role of rats and other animals as intermediate hosts of NiV and would improve future NiV outbreak control and prevention in humans and domestic animals.

Sonography of the pituitary gland in pet rats.

Pituitary gland (PG) tumors are common in rats over the age of 2. CT and MRI can be difficult to apply in this species, whereas ultrasound is more feasible and useful. To our knowledge, there are no studies on PG ultrasound in rats. The aim of this prospective, analytical study was to evaluate the reliability of ultrasound in identifying PG, to define the ultrasound dimension of the gland in a group of rats with no evidence of pituitary diseases, and to examine its correlations with age, sex, and weight. After localizing the PG with an MRI study on one rat, the gland was identified in 21 rats by ultrasound by two sonographers using a ventral neck approach and a transversal scan with a linear probe. The gland appears as a hypoechoic oval structure with a thin hyperechoic margin. The rats (15 male and 6 female) ranged from 4 to 18 months in age (median 6 months) and from 270 to 640g in weight (median 370g). The median pituitary width was 3.96mm (interquartile range 25-75%: 6-4.5mm), and the median height was 1.48mm (interquartile range 25-75%: 1.3-1.67mm). There was no statistically significant correlation between PG size and rat weight, gender, or age. We believe that these ultrasound measurements could be useful for the diagnosis of pituitary disease, irrespective of whether neurological symptoms are present. We report a clinical case of a rat with a pituitary mass detected by ultrasound and CT.

Diagnosis of intracranial neoplasia by transcranial ultrasound in two pet rats (Rattus norvegicus)

AbstractThis article describes the use of transcranial ultrasound for confirmation of intracranial neoplasia in two pet rats. The diagnosis was confirmed by means of a contrast‐enhanced computed tomography scan in one case, and postmortem examination and histopathology in the other. Pituitary adenoma is a common condition in rats and, until now, advanced diagnostic imaging, such as computed tomography or magnetic resonance imaging, was required to support a presumptive diagnosis of an intracranial mass based on anamnesis and clinical signs. Despite some limitations of image quality, ultrasound provided images of diagnostic quality in both cases in this study. Compared to computed tomography or magnetic resonance imaging, transcranial ultrasound is a less expensive, less time consuming and more readily available diagnostic imaging technique that can be valuable to aid diagnosis of intracranial tumours in pet rats.

Antimicrobial susceptibility patterns and molecular phylogenetics of Proteus mirabilis isolated from domestic rats: An environmental driver to antimicrobial resistance in public health in Arusha Tanzania

Proteus mirabilis (P. mirabilis) is a bacterial pathogen contributing to opportunistic infections, nosocomial outbreaks, and mostly hematogenous ascending urinary tract infections. It has repeatedly been found in rats. Due to rat-human interaction, rats are likely responsible for spreading these bacteria and their antimicrobial-resistant. This study was performed to genetically characterize and assess antimicrobial susceptibility patterns of P. mirabilis isolated from rats cohabiting with humans in Arusha municipality, Tanzania. A total of 139 rats were trapped from March to May 2021 and identified at the species level using morphological and morphometric features. Deep-intestinal swabs were obtained and pre-enriched in buffered peptone water. P. mirabilis was isolated by conventional culture and biochemical methods and confirmed by 16S rRNA polymerase chain reaction and sequencing. Phylogenetics was used to assess the similarities of the isolates. Antimicrobial susceptibility test was done by disk diffusion method using seven antibiotics, including tetracycline, ciprofloxacin, gentamicin, cefotaxime, trimethoprim-sulfamethoxazole, azithromycin, and ampicillin. Resistance genes blaTEM, tetA, tetB, mphA, blaSHV, blaCTX-M, sul1, and sul2 were traced in each isolate using PCR. Mixed rat species, Rattus rattus (55.4%), Mus musculus (15.8%), and Mastomys natalensis (28.8%), were captured. P. mirabilis was isolated from four (2.9%) Rattus rattus samples. By PCR and sequencing, all were confirmed as P. mirabilis and 100% similar to strains from GenBank. Three isolates showed multidrug resistance (MDR) against trimethoprim-sulfamethoxazole, azithromycin, and ampicillin, while all isolates were resistant to azithromycin and ampicillin, and susceptible to ciprofloxacin, gentamicin, and cefotaxime. Three were resistance to trimethoprim-sulfamethoxazole and intermediate to tetracycline. PCR analysis detected tetA, blaTEM, sul1, and sul2 resistance genes. Constructed phylogenetic tree showed that all isolates from this study were closely related to isolates from Tunisia. The study has discovered the first P. mirabilis isolates from rats in Tanzania with antimicrobial resistance traits that could be of public health concern.

Between Deserts and Jungles: The Emergence and Circulation of Sylvatic Plague (1920-1950)

ABSTRACT I trace the development of the concept of sylvatic plague – the first sylvatic disease – examining its invention by Ricardo Jorge to describe a global phenomenon of plague reservoirs among wild rodents, and its circulation. The concept implied a space where plague was enzootic, and relied on a division between inhabited and uninhabited spaces and between domestic rats and wild rodents. Some of the characteristics of this space varied, but it always referred to places imagined as empty of humans and rats. In 1927, it designated ambiguously deserts, in 1935, uninhabited regions in general, and in Brazil, it referred to the jungle.

Pet Rats as the Likely Reservoir for Human Seoul Orthohantavirus Infection.

Seoul orthohantavirus (SEOV) is a rat-associated zoonotic pathogen with an almost worldwide distribution. In 2019, the first autochthonous human case of SEOV-induced hemorrhagic fever with renal syndrome was reported in Germany, and a pet rat was identified as the source of the zoonotic infection. To further investigate the SEOV reservoir, additional rats from the patient and another owner, all of which were purchased from the same vendor, were tested. SEOV RNA and anti-SEOV antibodies were found in both of the patient's rats and in two of the three rats belonging to the other owner. The complete coding sequences of the small (S), medium (M), and large (L) segments obtained from one rat per owner exhibited a high sequence similarity to SEOV strains of breeder rat or human origin from the Netherlands, France, the USA, and Great Britain. Serological screening of 490 rats from breeding facilities and 563 wild rats from Germany (2007-2020) as well as 594 wild rats from the Netherlands (2013-2021) revealed 1 and 6 seropositive individuals, respectively. However, SEOV RNA was not detected in any of these animals. Increased surveillance of pet, breeder, and wild rats is needed to identify the origin of the SEOV strain in Europe and to develop measures to prevent transmission to the human population.

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.

JEPM (July 2022) - Abstracts

Reproductive tract disease is not commonly reported in pet rats. Prevalence, disease identification, outcome and treatment of reproductive tract diseases in pet rats has not been reported.Records from all female rats presented to Oklahoma State University Veterinary Teaching Hospital from 2012-2020 were manually reviewed. Animals undergoing ovariohysterectomy (OVH) and/or ovariectomy (OE) were eligible for inclusion in the study.Of 42 female pet rats, 7 rats (16.6%) underwent routine OHE/OE and 3 rats (7.1%) underwent non-elective (emergent) OHE for treatment of reproductive disease, including dystocia, vaginal prolapse and hemorrhagic endometritis. Of the non-elective OHE procedures, one of the three rats survived surgery and the other two died. Postmortem examinations demonstrated respiratory disease in the non-survivors. All the rats that presented for elective OHE/OE survived to discharge.Reproductive disease in female rats is relatively frequent and herein we described a condition previously unreported in pet rats (vaginal prolapse). This report adds to the body of evidence that supports elective reproductive surgery for pet rats.

Auricular cutaneous T‐cell lymphoma, subtype mycosis fungoides and otitis externa/media in a domestic rat (Rattus norvegicus forma domestica)

AbstractAn adult female, entire domestic rat (Rattus norvegicus forma domestica) presented with swollen auricles and incoordination. The rat was diagnosed with bilateral otitis externa. Radiographs of the skull revealed bilateral otitis externa/media. Bacterial culture of a swap from the external ear canals identified large numbers of Pasteurella pneumotropica as well as fewer Streptococcus merionis, Bacteroides fragilis and Fusobacterium spp. Microscopic examination of a deep skin scraping and a core needle biopsy of the pinnae diagnosed lymphoma. The animal was euthanased after being treated unsuccessfully symptomatically for 10 days. Postmortem examination revealed a cutaneous T‐cell lymphoma, mycosis fungoides, associated with bilateral otitis externa/media and metastases into several lymph nodes, thymus and lungs. Cutaneous T‐cell lymphoma has not been reported in pet rats to date. Lymphoma should be considered as a differential diagnosis in rats presented with swelling of the pinnae.