Lapis ISSN 2398-2969

Obesity

Contributor(s): Anna Meredith, Glen Cousquer, Virginia Garner-Richardson, Sarah Pellett

Introduction

  • Obesity can be defined as a disease in which excessive body fat has accumulated to the point where the health of the animal is, or may be, adversely affected.
  • Obesity must be considered a welfare concern with both short and long-term repercussions, and eventually, reduced life expectancy (PDSA Animal Wellbeing (PAW) report, 2017).
  • Cause: many pet rabbits are fed an inappropriate diet and have insufficient opportunity to exercise; this imbalance can lead to weight gain and obesity.
  • Diagnosis: obesity can be diagnosed when an animal is 20% above the recommended weight for its size and build.
  • Weight gain occurs when the energy intake exceeds the energy expenditure, resulting in the deposition of fat in various sites around the body.
  • The metabolizable energy (ME) requirement for a rabbit is calculated in the same way as for a dog or cat:
    • ME (kcal/day) = 100 x W(exp0.75).
    • Where 100 is the adult maintenance coefficient, and is the weight of the animal in kg:
      • Growth would be a multiple of 1.9-2.1 from this value.
  • Similarly, gestation a multiple of 1.35-2 as pregnancy progresses and lactation a multiple of 3.
  • Treatment: owner education, weight loss program.

Print off the Owner factsheets Feeding your rabbit, Obesity in your rabbit and Rabbits need exercise to give to your clients.

Geographic incidence

  • Worldwide.
  • In the UK, 28-30% of pet rabbits are believed to be obese, although scientific publications are required to establish the prevalence.

Clinical problems associated with obesity

  • Obesity is linked to hepatic lipidosis, kidney degeneration and the development of heart disease (associated with arteriosclerosis).
  • Obese overfed rabbits are more likely to suffer from chronic soft stools ('sticky bottom syndrome') Sticky bottom syndrome. This can be caused in two ways:
    • They produce more cecotrophs Feces: cecotrophs than they need, and they may be physically unable to practice cecotrophy.
    • They may produce normal amounts of cecotrophs but prefer to eat the food given to them or are satiated and refuse to eat the cecotrophs.
  • On a low fiber diet, cecotrophs may be much softer than normal and the rabbit is unable to eat them efficiently, leading to accumulation of soft cecotrophs around the perineum.
  • Sticky bottom syndrome Sticky bottom syndrome leads to an increased risk of blowfly myiasis (fly strike) Fly strike Fly strike 01Fly strike 02.
  • Obese rabbits may be more prone to the development of spondylosis.
  • Obese rabbits are generally inactive, which is a contributory factor in the development of osteoporosis, and these rabbits are more susceptible to spinal fractures and dislocations Spinal injury. Inactivity may also increase the likelihood of heart disease.
  • Pododermatitis Ulcerative pododermatitis (Bumble foot) Pododermatitis: sore hocks 01 Pododermatitis: sore hocks 02, urine scalding and moist dermatitis of skin folds, eg dewlap, are more common in obese rabbits (but other factors may be involved such as unhygienic conditions, inappropriate hutch flooring, etc).
  • Show rabbits that are bought as pets generally gain more weight than their breed average, and subsequently their metal identification ring may become too tight and damage the leg Wound: necrosis - identification ring.

Care should be taken in using reference weights as they are simply averages for a specific (often unspecified) population and may not apply to any given individual. They can, however, serve as a working guideline or starting point whilst remembering that the patient is always an individual and should be treated as such.

The maximum bodyweight (kg) of adult rabbits depending on the breed are given below. The data is provided by The British Rabbit Council, 2016. Information must be interpreted with caution based on body condition score, clinical examination and body weight.

For reference weights of other breeds, find the specific information for that breed by keyword, index or directory search.

Predisposing factors

  • Domestication.​
  • Ready access to food.
  • A diet too rich and high in fat can lead to significant increase in bodyweight, an increase in skinfold thickness and physiological and biochemical changes such as an increase in the resting heart rate and increase in blood glucose and increase in cholesterol levels.
  • Inappropriate diet.
  • Snacks.
  • Limited opportunities to exercise.
  • Arthritis and other conditions that limit exercise.

Diagnosis

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Treatment

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Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Stapleton N (2014) The chubby bunny: a closer look at obesity in the pet rabbit. Vet Nurse 5 (6), 312-319 VetMedResource.
  • Sweet H, Pearson A J, Watson P J et al (2013) Novel zoometric index for assessing body composition in adult rabbits. Vet Rec 173 (15), 369 PubMed.
  • Courcier E A, Mellor D J, Pendlebury E et al (2012) Preliminary investigation to establish prevalence and risk factors for being overweight in pet rabbits in Great Britain. Vet Rec 171 (8), 197 PubMed.
  • Meredith A (2012) Is obesity a problem in pet rabbits? Vet Rec 171 (8), 192-193 PubMed.
  • German A (2010) Obesity in companion animals. In Pract 32 (2), 42-50 VetMedResource.
  • Dhungel S, Sinha R, Sinha M et al (2009) High fat diet induces obesity in British Angora rabbit: a model for experimental obesity. Indian J Physiol Pharmaco 53 (1), 55-60 PubMed.
  • Mitsuguchi U, Ito T & Ohwada K (2008) Pathologic findings in rabbit models of hereditary hypertriglyceridemia and hereditary postprandial hypertriglyceridemia. Comp Med 58 (5), 465-480 PubMed.
  • Zhang X J, Chinkes D L, Aarsland A et al (2008) Lipid metabolism in diet-induced obese rabbits is similar to that of obese humans. J Nutr​ 138 (3), 515-518 PubMed.
  • Carroll J F, Summers R L, Dzielak D J (1999) Diastolic compliance is reduced in obese rabbits. Hypertension 33 (3), 811-815 PubMed.
  • Carroll J F, Dwyer T M, Grady A W et al (1996) Hypertension, cardiac hypertrophy and neurohumoral activity in a new animal model of obesity. Am J Physiol 271 (1 Pt 2), H373-378 PubMed.
  • Hillyer E V (1994) Pet rabbits. Vet Clin North Am Small Anim Pract 24 (1), 25-65 PubMed.

Other sources of information

  • Chitty J (2018) Obesity Issues in Pet Rabbits. In: Veterinary Times. Available at www.vettimes.co.uk.
  • Benato L (2017) Tackling Pet Rabbit Obesity: Prevalence and Risk Factors. In: Veterinary Times. Available at www.vettimes.co.uk
  • PDSA Animal Wellbeing (PAW) Report (2017). Available at www.pdsa.org.uk
  • Mancinelli E (2016) Taking a Bite into Rabbit Diet Research. In: Veterinary Times. Available at www.vettimes.co.uk. 
  • PFMA (2014) Pet Obesity: Five Years on, Pet Food Manufacturers’ Association. Available at www.pfma.org.uk. 
  • Richardson J & Keeble E (2014) Physical Examination and Clinical Techniques. In: BSAVA Rabbit Medicine. Eds: Keeble A & Lord B. BSAVA, UK. pp 80-107.
  • Prebble J (2014) Nutrition and Feeding. In: BSAVA Rabbit Medicine. Eds: Keeble A & Lord B. BSAVA, UK. pp 27-35.
  • Varga M (2013) Textbook of Rabbit Medicine. 2nd edn. Elsevier Health Science. pp 385. 
  • F.E.D.I.A.F. (2013) Nutritional Guidelines for Feeding Pet Rabbits. Available at www.fediaf.org.
  • Campbell-Ward M & Meredith A (2010) Rabbits. In: BSAVA Manual of Exotic Pets. 5th edn. Eds: Meredith A & Johnson-Delaney C. BSAVA, UK. pp 76-102. 
  • Reusch B (2010) Why do I need to body condition score my rabbit? In: Rabbiting On. Available at www.rabbitwelfare.co.uk. 
  • PFMA (2009) Pet Obesity: The Reality in 2009, Pet Food Manufacturers’ Association. Available at www.pfma.org.uk
  • Bonanno A et al (2008) Body Condition Score and Related Reproductive Reponses in Rabbit Does. In: Proc 9th World Rabbit Congress. pp 297-301.
  • Bonanno A et al (2005) Assessment of a method for evaluating the body condition of Lactating Rabbit Does: Preilminary Results. In: Proc 16th ASPA Congress(Suppl 2), pp 560.
  • Brooks D L (2004) Nutrition and Gastrointestinal Physiology. In: Ferrets, Rabbits and Rodents Clinical Medicine and Surgery. 2nd edn. Eds: Quesenberry K E & Carpenter J W. pp 155-160.
  • Sandford J C (1996) The Domestic Rabbit. Blackwell Science Ltd, Oxford.
  • Tobin G (1996) Small Pets, Food types Nutrient Requirements and Nutritional Disorders. In: Manual of companion animal nutrition and feeding. Eds: Kelly N & Wills J.
  • PFMA (online) Rabbit Size-O-Meter. Available at: www.pfma.org.uk (pdf download)


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