Lapis ISSN 2398-2969

Trichobezoars (hairballs)

Synonym(s): Hairballs, wool block

Contributor(s): Hannah Orr, Glen Cousquer, Virginia Garner-Richardson, Sarah Pellett


  • A mat of ingested hair combined with inspissated food, is an abnormal finding and is often a result of gastrointestinal stasis and hypomotility, or outflow obstruction.
  • Often located in the stomach but can be found within the intestines.
  • A trichobezoar (ball of felted hair) takes on two forms: it is either a significant-sized ball of stomach contents and fur located in the pylorus and is found in rabbits with GI stasis. Alternatively, it is a small hard pellet of compacted felted hair that causes an intestinal obstruction.
  • Historically, rabbits were thought to suffer from a hair impaction of the stomach, however, hair in the stomach is a normal finding in healthy rabbits.
  • Cause: 'hairballs' are no longer thought to be a primary condition, but rather the result of gastric hypomotility and gastric stasis Gastric dilation and stasis. As such, the terms "hairball" and "trichobezoars" should be viewed as findings secondary to gastric stasis in the rabbit.
  • Factors that predispose the rabbit to gastric stasis will increase the risk of secondary 'hairball' formation. These include low-fiber diets, lack of exercise, reduced water intake, anorexia and concurrent disease. Rabbits that are molting or that groom a companion that is molting may demonstrate a seasonal increase in the amount of hair ingested.
  • It is normal for a rabbit to ingest some hair. If the rabbit is on a high fiber diet and has normal gastrointestinal motility, the hair will pass through the digestive system with the ingesta without causing any problems Feces: compressed fecal hair pellets 01.
  • If peristalsis is reduced, or stops, then fluid is drawn out of the gastrointestinal tract and the ingesta and hair pack together to form a 'hairball' Trichobezoar.
  • If a rabbit is fed a high-fiber diet there is no greater incidence of 'hairballs' in long-coated breeds.
  • Rabbits of <7 months of age are unlikely to suffer from 'hairballs', as they do not develop a full hair coat until this time.
  • House rabbits can ingest other fibers such as wool and carpet which can lead to similar impactions.
  • Signs: anorexia, lethargy, reluctance to move, painful, weight loss, inactivity, failure to groom, small/scant fecal pellets, abdominal distension.
  • Diagnosis: clinical examination, radiography.
  • Treatment: analgesia, fluid therapy, medical, diet changes, surgery.
  • Prognosis: poor to good, depending on underlying causes.

Print-off the Owner Factsheet on Hairballs to give to your clients

Presenting signs

  • Gradual to sudden onset of anorexia.
  • Fecal pellets scant and small.
  • Bruxism.
  • Hunched posture.
  • Depression.
  • Weakness.
  • Abdominal distension.

Acute presentation

  • Abdominal distension.
  • Weakness.
  • Bruxism.
  • Hunched posture.
  • Lateral recumbency.
  • Sudden death.

Age predisposition

  • Can occur at any age.
  • More commonly seen in middle to older rabbits on inappropriate diets.

Sex predisposition

  • No sex predilection.

Breed predisposition

  • No breed predilection.
  • Pellets of fur may be more common during molting and in long-haired rabbits, however, they also occur in short-haired breeds such as Rex rabbits Rex


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Further Reading


Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Summa N M & Brandao J (2017) Evidence based advances in rabbit medicine. Vet Clin Exot Anim 20 (3), 749-771 PubMed.
  • Benato L, Hastie P, O'Shaughnessy P et al (2014) Effects of probiotic Enterococcus faecium and Saccharomyces cerevisiae on the faecal microflora of pet rabbits. J Small Anim Pract 55 (9), 442-446 PubMed.
  • Huynh M, Vilmouth S, Gonzalez M S, Calvo Carrasco D, Di Girolamo N & Forbes N A (2014) Retrospective cohort study of gastrointestinal stasis in pet rabbits. Vet Rec 175 (9), 225 PubMed.
  • Ritzman T K (2014) Diagnosis and clinical management of gastrointestinal conditions in exotic companion mammals (rabbits, guinea pigs and chinchillas). Vet Clin Exot Anim 17 (2), 179-194 PubMed.
  • Harcourt-Brown F M & Harcourt-Brown S F (2012) Clinical value of blood glucose measurement in pet rabbits. Vet Rec 170 (26), 674 PubMed.
  • Lord B (2012) Companion animal practice: gastrointestinal disease in rabbits 1. Gastric disease. In Pract 34 (2), 90-96 VetMedResource.
  • Lichtenberger M & Lennox A (2010) Updates and advanced therapies for gastrointestinal stasis in rabbits. Vet Clin North Am Exot Anim Pract 13 (3), 525-541 PubMed.
  • Harcourt-Brown F M (2007) Gastric dilation and intestinal obstruction in 76 rabbits. Vet Rec 161 (12), 409-414 PubMed.
  • Harcourt-Brown F M (2007) Management of acute gastric dilation in rabbits. J Exot Pet Med 16 (3), 168-174 VetMedResource.
  • Mondal D, Risa M K S, Sharma S R & Al E (2006) Prevalence of trichobezoards in Angora rabbits in sub-temperate Himalayan conditions. World Rabbit Sci 14, 33–38
  • Rees Davies R & Rees Davies J A E (2003) Rabbit gastrointestinal physiology. Vet Clin Exot Anim (1), 139-153 PubMed.
  • Hillyer E V (1994) Pet rabbits. Vet Clin North Am Small Anim Pract 24 (1), 25-65 PubMed.
  • Fekete S (1989) Recent findings and future perspectives of digestive physiology in rabbits - a review. Acta Vet Hung 37 (3), 265-279 PubMed.
  • Letter (1988) Hairball problem in rabbits. Can Vet J 29 (7), 553-554 PubMed.
  • Leary S L, Manning P J, Anderson L C (1984) Experimental and naturally occurring gastric foreign bodies in laboratory rabbits. Lab Anim Sci 34 (1), 58-61 PubMed.
  • Gillett N A, Brooks D L & Tillman P C (1983) Medical and surgical management of gastric obstruction from a hairball in the rabbit. JAVMA 183 (11), 1176-1178 PubMed.
  • Rambow V J, Fox J G (1981) What's your diagnosis? Trichobezoar. JAVMA 179 (6), 600, 602 PubMed.
  • Lee K J, Johnson W D, Lang C M (1978) Acute peritonitis in the rabbit (Oryctolagus cuniculus) resulting from a gastric trichobezoar. Lab Anim Sci 28 (2), 202-204 PubMed.
  • Sebesteny A (1977) Acute obstruction of the duodenum of a rabbit following the apparently successful treatment of a hairball. Lab Anim 11 (2), 135 PubMed.
  • Williams C S (1975) Letter. Outbreak of gastric trichobezoars in New Zealand white rabbits. Lab Anim Sci 25 (1), 114 PubMed.
  • Wagner J L, Hackel D B, Samsell A G (1974) Spontaneous deaths in rabbits resulting from gastric trichobezoars. Lab Anim Sci 24 (5), 826-830 PubMed.

Other sources of information

  • Delaney M A, Treutling P M & Rothenburger J L (2018) Lagomorpha. In: Pathology of Wildlife and Zoo Animals. Eds: Terio K A, McAloose D & St Leger J. Elsevier, UK. pp 481-497.
  • Harcourt-Brown F (2014) Digestive System Disease. In: BSAVA Manual of Rabbit Medicine. Eds: Meredith A & Lord B. BSAVA, UK. pp 168-190.
  • Prebble J (2014) Nutrition and Feeding. In: BSAVA Manual of Rabbit Medicine. Eds: Meredith A & Lord B. BSAVA, UK. pp 27-35.
  • Harcourt-Brown F (2013) Gastric Dilation and Intestinal Obstruction. In: BSAVA Manual of Rabbit Surgery, Dentistry and Imaging. Eds: Harcourt-Brown F & Chitty J. BSAVA, UK. pp 172-189.
  • Benato L, Hastie P, Shaw D, Murray J & Meredith A (2012) The Semi-Quantitative Effect of Probiotic Enterococcus faecium NCIMB 30183 and Saccharomyces cerevisiae NCYC Sc47 on the Faecal Microflora of Healthy Adult Rabbits (Oryctolagus cuniculus) using Real Rime PCR. In: Proc BSAVA Congress. pp 460.
  • Oglesbee B (2011) Trichobezoars. In: Blackwell’s Five-Minute Veterinary Consult: Small Mammal. 2nd edn. Ed: Oglesbee B L. Wiley-Blackwell, UK. pp 524-527.
  • Richardson V C (2000) Rabbits, Health, Husbandry and Diseases. Blackwell Science, UK.
  • Brown S A (1998) Rabbit Gastrointestinal Physiology and Disease. In: Proc BSAVA Conference.