Food and water intake and selective feeding in rabbits on four feeding regimes

Dental disease in companion rabbits under UK primary veterinary care: Frequency and risk factors

BACKGROUND

Some prior evidence has suggested that lop-eared rabbits and those with brachycephalic skull conformations have a higher dental disease risk. This retrospective cohort study reports the frequency and conformational risk factors for primary-care veterinary diagnosis with dental disease in companion rabbits in the UK.

METHODS

Anonymised VetCompass clinical records were manually reviewed to confirm dental disease cases. Risk factor analysis used multivariable binary logistic regression modelling.

RESULTS

From 161,979 rabbits under primary veterinary care in 2019, the 1-year period prevalence of overall dental disease was 15.36% (95% confidence interval [CI]: 14.78-15.96). The prevalence of dental disease affecting incisors was 3.14% (95% CI: 2.87-3.44), and for cheek teeth it was 13.72% (95% CI: 13.17-14.29). Neither lop-eared conformation nor brachycephalic skull conformation was significantly associated with increased odds of dental disease. Dental disease odds increased as age increased and decreased as bodyweight increased.

LIMITATIONS

This study retrospectively accessed clinical records, so breed names may sometimes be imprecise.

CONCLUSION

The high overall prevalence of dental disease represents a major welfare concern for all companion rabbits, regardless of conformation. This information can be used to encourage regular routine dental assessment of rabbits of all conformations to promote earlier diagnosis, paying particular attention to older rabbits and those with low bodyweight.

Dental Disease in Rabbits (Oryctolagus cuniculus) and Its Risk Factors-A Private Practice Study in the Metropolitan Region of Chile

Rabbits (Oryctolagus cuniculus) have elodont dentition, a characteristic that predisposes them to the development of Acquired Dental Disease (ADD), which is a multifactorial disease. The aim of this study was to assess the risk factors for ADD in domestic pet rabbits. To do this, a retrospective analysis of 1420 rabbits treated at a private practice during 2018-2021 was performed. For this, several variables were retrieved from clinical records, in addition to signology at the time of diagnosis. ADD was found on 25.4% of rabbits, mostly on their cheek teeth. In addition, age (OR = 1.029; 95% CI = 1.023-1.035; p < 0.001) and sex (male) (OR = 1.591; 95% CI = 1.226-2.064; p < 0.001) were found to be significant risk factors for ADD. In contrast, a free lifestyle (OR = 0.565; 95% CI = 0.362-0.882; p = 0.012) and consuming hay in the diet (OR = 0.323; 95% CI = 0.220-0.473; p < 0.001) were protective factors. In conclusion, ADD has a high prevalence and is usually underdiagnosed, highlighting the need for an exhaustive evaluation of patients during the clinical examination. This study improves our knowledge of ADD and its prevention.

Managing the Health of Captive Herds of Exotic Companion Mammals

Common medical problems diagnosed and treated in individual companion exotic mammals are relevant in a herd-health setting. Many of these problems are often associated with poor husbandry and/or inappropriate nutrition. Rabbits, ferrets, chinchillas, and rodents have been domesticated alongside humans and an understanding of their ethology gives veterinarians a base knowledge in making recommendations for animals in their care. This article briefly reviews the ethology and husbandry in such species, but detailed needs are beyond the scope of this article.

Tooth wear, growth and height in rabbits (Oryctolagus cuniculus) fed pelleted or extruded diets with or without added abrasives

Among the different factors thought to affect dental wear, dietary consistency is possibly the least investigated. To understand tooth wear of herbivorous animals consuming different dietary consistencies with different abrasive potential, we fed 14 rabbits (Oryctolagus cuniculus) exclusively with a timothy grassmeal-based diet in either pelleted or extruded form, or the same diets with an addition of 5% fine sand abrasives (mean size 130 µm). First, we offered the rabbits the pelleted and extruded diets as well as the pelleted control and pelleted abrasive diet in a two-stage preference experiment. Then, the rabbits received each diet for 2 weeks in a randomised serial feeding experiment, where each animal served as its own control. Tooth measurements for wear, growth and height were achieved using a manual calliper, endoscopic examination and CT scans. The analysis of the diets as fed showed almost identical mean particle size, but the extruded diet had a lower density (volume/mass) and softer consistency compared to the pelleted one and was favoured by most rabbits. The rabbits selected against the diet with sand during the preference experiment, possibly because it caused more tooth wear, especially on the teeth most exposed to wear along the upper tooth row (upper P4 and M1). The maxillary teeth also showed evidence of an increased chewing laterality by the end of the experiment. The extruded diet led to a significantly lower cheek teeth height than the pelleted diet, potentially due to the higher chewing effort needed for a similar dry matter intake. The results suggest that dietary hardness alone is a poor predictor of dental wear. The regrowth of the teeth matched wear consistently.

Driving evidence-based improvements for the UK's 'Stressed. Lonely. Overweight. Bored. Aggressive. Misunderstood…but loved' companion animals

BACKGROUND

The Five Welfare Needs in UK animal welfare legislation underpin a legal duty of care and are an animal welfare assessment framework. Health and welfare problems arise when these needs are unmet. The veterinary professions work with others to address these problems, but there is no publicly funded U.K. companion animal welfare surveillance to identify priorities, or promote and monitor change.

METHODS

The veterinary charity, the People's Dispensary for Sick Animals (PDSA), together with the market research organisation, YouGov, has undertaken a longitudinal nationwide survey, assessing whether the U.K's pet dogs, cats and rabbits are having their Five Welfare Needs met. Data from nationally representative samples of pet-owning adults, drawn from YouGov's online survey panel, have been used to produce the PDSA Animal Wellbeing (PAW) Report annually since 2011.

RESULTS

Examples are given of how the PAW Report has been used to monitor trends in animal welfare problems, drive collaborative behaviour change campaigns, create evidence-based funding applications and inspire innovation in veterinary practice.

CONCLUSION

The PAW Report has contributed to closing a gap in national companion animal welfare surveillance. When governments rely on non-governmental organisations to assist with animal welfare surveillance, reliable sources such as the PAW Report can inform research, policy and legislation.

Evidence-Based Rabbit Housing and Nutrition

Because most research on rabbit husbandry, welfare, and nutrition was performed on production animals, evidence for best practices in pet rabbits is scarce, and guidelines must be based on transfer of results, deduction, and common sense. Rabbits benefit from being kept with at least one conspecific; from large enclosures and multistory hutches; from drinking water offered ad libitum in open dish drinker systems; and from receiving hay ad libitum, with restricted amounts of fresh grass, herbs, or green leafy vegetables, and a high-fiber complete diet. Offering hay ad libitum bears several advantages and should be considered a matter of course.

Impact of diet on faecal output and caecotroph consumption in rabbits

OBJECTIVES

To assess the impact of four rabbit diets (hay only, extruded diet with hay, muesli with hay and muesli only) on faecal pellet size, faecal output and caecotrophy.

MATERIALS AND METHODS

Thirty-two Dutch rabbits were studied over 17 months. Faecal pellet size and weight were measured in weeks 3, 9, 21 and 43 and faecal output in weeks 10, 22 and 45. Number of uneaten caecotrophs was recorded weekly.

RESULTS

Faecal pellets were consistently smaller and lighter in rabbits fed muesli only, and the size of pellets produced by those fed muesli with hay decreased over the course of the study. Faecal output was greatest in rabbits with the highest hay intake. Uneaten caecotrophs were found in greatest frequency in rabbits fed muesli.

CLINICAL SIGNIFICANCE

Muesli diets have a negative effect on faecal output and caecotroph ingestion and may therefore predispose to digestive disorders. Higher hay intake is associated with greater faecal output and fewer uneaten caecotrophs and may assist in preventing the gastrointestinal stasis.

ExNOTic: Should We Be Keeping Exotic Pets?

There has been a recent trend towards keeping non-traditional companion animals, also known as exotic pets. These pets include parrots, reptiles, amphibians and rabbits, as well as small species of rodent such as degus and guinea pigs. Many of these exotic pet species are not domesticated, and often have special requirements in captivity, which many owners do not have the facilities or knowledge to provide. Keeping animals in settings to which they are poorly adapted is a threat to their welfare. Additionally, owner satisfaction with the animal may be poor due to a misalignment of expectations, which further impacts on welfare, as it may lead to repeated rehoming or neglect. We investigate a range of commonly kept exotic species in terms of their suitability as companion animals from the point of view of animal welfare and owner satisfaction, and make recommendations on the suitability of various species as pets.

Low-residue diet fed to rabbits induces histomorphological and biomechanical remodeling of small intestine

BACKGROUND

The composition of ingested food is important for the gut microbiome and intestinal homeostasis. We have previously demonstrated that the structure and mechanical properties in the small intestine remodel significantly during fasting. However, it is not clear to what extent the intestinal mechanical properties changes when the composition of food is changed. This study aimed to investigate the passive biomechanical properties and intestinal tissue remodeling in rabbits fed a low-residue diet.

METHODS

New Zealand rabbits (control group n=6, intervention group n=7) were studied. Segments from duodenum, jejunum and ileum were excised. The intestinal diameter and length were obtained from digitized images of the segments at preselected luminal pressure levels and at no-load and zero-stress states. Circumferential and longitudinal stresses (force per area) and strains (deformation) were computed from the length, diameter and pressure data referenced to the zero-stress state geometry. Histomorphometric data were also obtained.

KEY RESULTS

The wet weight-per-unit length, wall thickness and wall area decreased in the intervention group (P<.05, P<.01). Histological measurement confirmed that the wall thickness decreased in all three segments, which was primarily due to mucosal thinning (P<.05). The opening angle tended to increase in all segments in the intervention group. Significant difference between the two groups was found for the jejunum (P<.05). Feeding the low-residue diet shifted the circumferential stress-strain curves in the intervention group to the right, indicating intestinal wall softening.

CONCLUSIONS & INFERENCES

Low-residue diet in rabbits for 1 month induces location-dependent histomorphometric and biomechanical remodeling of the intestine.

Intake of different hays with presence of Colchicum autumnale by rabbits

<p>The ingestion of 3 hay types by growing rabbits and the consequences on animal performance were studied in a first part. Two kinds of hay from high nature value grasslands [CFP (<em>Colchico-Festucetum pratensis</em>) and SBR (<em>Senecioni-Brometum racemosi</em>)] differentiated by their botanical composition were compared to a classical agricultural hay (control). The 3 hays, offered <em>ad libitum</em>, were ingested at 30.6, 34.8 and 36.1 g/kg body weight (BW) respectively for SBR, CFP and the control, where the consumption of SBR hay was significantly lower. (P&lt;0.01). The type of hay distributed did not affect the consumption of commercial feed or growth (44 g/kg BW and 36 g/d, respectively). The effect of meadow saffron concentration (<em>Colchicum autumnale</em>) in CFP hay was tested at 3 doses (absence, 2.75 and 15% of the distributed hay mass) with respect to their effect on ingestion and animal health. Again, no effect of the presence of meadow saffron (MeS) in the hay on these parameters was observed, even at the highest dose. However, during this second part, rabbits preferred to consume meadow saffron instead of the rest of the distributed hay (hardly any MeS was refused by rabbits at the representative dose, whereas 12% of the rest of the hay was refused, and 3.4 and 20% respectively at the maximal dose). The intake of the toxic alkaloid colchicine corresponded to 30 to 44% of the median lethal doses (LD₅₀) at the representative and maximal doses respectively. The real exposure of the rabbits was probably lower, as the absorption of ingested colchicine is reported to be around 50% of the LD₅₀ values which are established after an intravenous injection. Nevertheless, the absence of any effect should be interpreted with caution. The colchicine content of MeS varied greatly depending on the time of harvest and the parts of the plant taken into consideration. A late harvest (mid-June or later) would ensure (very) low concentrations of colchicine in the aerial parts of MeS. The presence of cloves on this plant should be completely avoided, due to the very high concentration of colchicine in the seeds. Moreover, long term exposure of the animals to this toxic plant may increase the risk of adverse effects. The study shows that hay distribution can aid digestion without altering the animal’s performance. Moreover, the valorisation of hay from high nature value grasslands would not only add real value to the commercialisation of rabbit meat by commercial breeders, but also to pet owners on the condition that hay quality would be guaranteed.</p>

Clinical Application of Cone-Beam Computed Tomography of the Rabbit Head: Part 1 - Normal Dentition

Domestic rabbits (Oryctolagus cuniculus) are increasingly popular as household pets; therefore, veterinarians need to be familiar with the most common diseases afflicting rabbits including dental diseases. Diagnostic approaches for dental disease include gross oral examination, endoscopic oral examination, skull radiography, and computed tomography (CT). CT overcomes many limitations of standard radiography by permitting cross-sectional images of the rabbit head in multiple planes without superimposition of anatomic structures. Cone-beam CT (CBCT) is an oral and maxillofacial imaging modality that produces high-resolution images. The objective of this study was to describe and compare the normal anatomic features of the dentition and surrounding maxillofacial structures in healthy rabbits on CBCT and conventional CT. Ten New Zealand white rabbit cadaver heads were scanned using CBCT and conventional CT. Images were evaluated using Anatomage Invivo 5 software. The maxillofacial anatomy was labeled on CBCT images, and the mean lengths and widths of the teeth were determined. The visibility of relevant dental and anatomic features (pulp cavity, germinal center, tooth outline, periodontal ligament) were scored and compared between conventional CT and CBCT. The thinnest teeth were the maxillary second incisor teeth at 1.29 ± 0.26 mm and the maxillary third molar teeth at 1.04 ± 0.10 mm. In general, it was found that CBCT was superior to conventional CT when imaging the dentition. Importantly, the periodontal ligament was significantly (P < 0.01) more visible on CBCT than on conventional CT. Ability to see the periodontal ligament with such detail may allow earlier detection and treatment of periodontal disease in rabbits. This study is the first of its kind and shows the feasibility and yield of CBCT when evaluating the maxillofacial features and dentition in rabbits.

Appropriate handling of pet rabbits: a literature review

Many rabbits show fear behaviours when lifted off the ground. Estimates from owner surveys suggest that around 60% of pet rabbits struggle when lifted and fear-related aggression is common. This article integrates information from both laboratory and pet rabbit studies to formulate a list of recommendations for appropriate handling of rabbits. Reduction of the frequency of the stressor can be achieved by educating owners on alternative management practices to reduce the need to carry their rabbits. However, in some situations, it is unavoidable that a rabbit is lifted. Amelioration of the stress in these instances can be achieved by a 2 pronged strategy. First, the population of rabbits can be made more resilient to infrequent stressors by selectively breeding for confident rabbits and by better socialisation of unweaned kits, and, where possible, training of individual animals to permit handling. Secondly, any unavoidable lifting can be made less stressful by educating veterinary staff in appropriate methods of holding rabbits during both consultations and inpatient care. Better understanding of appropriate interactions with rabbits will improve welfare.

The current state of welfare, housing and husbandry of the English pet rabbit population

BACKGROUND

The welfare of pet rabbits is an area of growing interest in Europe and the UK. This study analyses questionnaire results from a diverse population of 1254 rabbit owners from three different geographical areas in England with the aim of providing an accurate representation of how pet rabbits are currently housed and cared for and key aspects of their health and welfare.

RESULTS

Rabbits were kept in a variety of different housing types, the most common being a traditional hutch/cage (59%). Although the majority had additional exercise areas, access was often unpredictable, or ill-timed, which may compromise welfare. Only 41.9% of owners kept their rabbit with conspecifics, limiting their ability to engage in social behaviour. Of those rabbits housed with a companion, although many were reported to be amicable and to engage in positive interactions, over a quarter were reported to fight at least occasionally (25.3%), whilst 22.7% guarded resources and 27.1% avoided one another. Whilst low levels of some of these behaviours may be a normal part of social interaction, the relatively high levels reported here suggest that not all cohabiting pairs of rabbits are compatible, which is potentially a significant welfare issue.Although the vast majority of owners fed hay for over 10% this was less than daily. Pelleted foods were very popular (71.4% at least daily) compared to commercial muesli mixes (32.6%). As in previous studies, dental problems were commonly reported (12.2% of rabbits); however, so were eye problems (12.9%), digestive problems (11.5%) and parasites (11.3%). A large proportion of rabbits (58%) were thought to be fearful of loud noises, and 61% were not reported as calm when handled by their owner, which may be a significant concern for this species.

CONCLUSION

This study has confirmed and expanded on previous findings: many pet rabbits were found to be in good health, had compatible companions and were provided with enriched living areas. However, it also found numerous welfare issues that affect large numbers of pet rabbits. We suggest further studies are required exploring the accuracy of owner reports (which possibly under-report many problems) and prioritising the issues raised here.

Bodyweight and body condition score in rabbits on four different feeding regimes

OBJECTIVES

The aim of this study was to assess the effects of four diet regimes (extruded diet with ad lib hay, muesli with ad lib hay, ad lib hay only, ad lib muesli only) on bodyweight and body condition score in rabbits.

METHODS

Thirty-two Dutch rabbits were studied over 9 months. Bodyweight and body condition score were recorded weekly.

RESULTS

All groups gained weight with age, but relative to the ad lib hay only group (mean, 1 · 77 ± 0 · 13 kg), after 9 months rabbits in the ad lib muesli only group were 146% heavier (2 · 59 ± 0 · 32 kg); extruded diet with ad lib hay group 125% heavier (2 · 21 ± 0 · 10 kg); and muesli with ad lib hay group 123% heavier (2 · 18 ± 0 · 13 kg). Median body condition score of the ad lib muesli only group was obese (4 · 5) and was higher than that in both the extruded diet with ad lib hay and muesli with ad lib hay (median = 3 · 5) groups (P < 0 · 001). Both the extruded diet with ad lib hay and muesli with ad lib hay groups had above-ideal body condition score despite having bodyweights within the breed standard range. The ad lib hay only group had a median body condition score of 3 (ideal). There was an overall positive correlation between body condition score and weight (qs = 0 · 814, P < 0 · 001).

CLINICAL SIGNIFICANCE

The feeding of muesli without hay should be avoided, to prevent obesity.

Tooth length and incisal wear and growth in guinea pigs (Cavia porcellus) fed diets of different abrasiveness

Dental diseases are among the most important reasons for presenting guinea pigs (Cavia porcellus) and other rodents to veterinary clinics, but the aetiopathology of this disease complex is unclear. Clinicians tend to believe that the ever-growing teeth of rabbits and rodents have a constant growth that needs to be worn down by the mastication of an appropriate diet. In this study, we tested the effect of four different pelleted diets of increasing abrasiveness [due to both internal (phytoliths) and external abrasives (sand)] or whole grass hay fed for 2 weeks each in random order to 16 guinea pigs on incisor growth and wear, and tooth length of incisors and cheek teeth. There was a positive correlation between wear and growth of incisors. Tooth lengths depended both on internal and external abrasives, but only upper incisors were additionally affected by the feeding of whole hay. Diet effects were most prominent in anterior cheek teeth, in particular M1 and m1. Cheek tooth angle did not become shallower with decreasing diet abrasiveness, suggesting that a lack of dietary abrasiveness does not cause the typical 'bridge formation' of anterior cheek teeth frequently observed in guinea pigs. The findings suggest that other factors than diet abrasiveness, such as mineral imbalances and in particular hereditary malocclusion, are more likely causes for dental problems observed in this species.