Vomiting is the active expulsion of stomach and sometimes duodenal contents and is typically preceded by nausea and retching. Chronic vomiting is a very common clinical sign in cats and can be associated with a wide variety of disorders. There are 4 main pathways that stimulate the vomiting centre:

1.  Peripheral sensory receptors

a.  Intra-abdominal

i.  Stomach, intestines, pancreas, liver, peritoneum, kidneys, bladder

ii.  Visceral afferent fibres in sympathetic and vagal nerves

b.  Heart and large vessels, via vagus nerve

c.  Pharynx, via glossopharyngeal nerve

2.  Stimulation of the chemoreceptor trigger zone

a.  Uremia

b.  Electrolyte imbalances

c.  Bacterial toxins

d.  Drugs

3.  Vestibular input

a.  Inflammatory disorders

b.  Motion sickness, via acoustic nerve

4.  Higher central nervous system centres

a.  Psychogenic, e.g., fear, stress, excitement via catecholamine release

b.  Inflammatory CNS lesions

Therefore, evaluation of the vomiting cat requires consideration of the whole animal and not just the gastrointestinal tract. Some common causes of vomiting in cats include:

1.  Gastrointestinal disease

a.  Infectious disease: bacterial (e.g., Helicobacter, Salmonella), viral

b.  Parasites: Giardia, Ollulanus, ascarids

c.  Obstruction: foreign body, intussusception

d.  Neoplasia: e.g., lymphoma

e.  Inflammation: e.g., gastritis, inflammatory bowel disease

f.  Dietary: food intolerance, food allergy

2.  Non-gastrointestinal disease

a.  Metabolic, systemic: e.g., heartworm, renal disease, hyperthyroidism, diabetic ketoacidosis, urethral obstruction, hepatic disease, pancreatitis, peritonitis

b.  Toxins, drugs: chemotherapy drugs, NSAIDs, antibiotics, plants (e.g., lily), other chemicals/intoxications

c.  Neurological: e.g., vestibular disease

The diagnostic steps for the vomiting cat include the signalment and clinical history, physical examination, initial database (CBC, serum chemistries, urinalysis, fecal examination, FeLV/FIV serology, total T4 [senior cats], radiographs and/or ultrasound); in some patients, advanced testing and biopsy of relevant tissues may also be required. A summary of diagnostic steps is shown in Figure 1.

The signalment and clinical history for vomiting cats must be detailed and complete to determine differential diagnoses and guide diagnostic testing and therapeutics. The following areas should be considered:

1.  Signalment: younger cats are more likely to ingest foreign bodies, older cats are more likely to have systemic disease

2.  Diet: current diet, recent changes, 'table' food, supplements, hunting

3.  Environment: plants, potential foreign bodies, toxins

4.  Duration and frequency: acute (< 7 days) versus chronic, severity

5.  Relationship to eating: > 8 hours after eating implies gastric outlet obstruction or motility disorder; no relationship to eating implies systemic disease

6.  Vomiting process: distinguish vomiting from regurgitation

7.  Vomitus: presence of blood (gastric mucosal damage), bile (reflux from small intestine), parasites (e.g., Ollulanus tricuspis), food (state of digestion), hair

8.  Deworming history

9.  Previous illnesses

10.  Current medications

11.  Other changes: anorexia, polydipsia/polyuria, diarrhea, weight loss, etc. (may imply systemic disorder)

Figure 1. Summary of diagnostic steps for investigation of vomiting in cats.

References

1.  Hall J. Clinical approach to chronic vomiting. In August J, ed. Consultations in Feline Internal Medicine. 3rd ed, Philadelphia, Saunders. 1997.

2.  MacPhail C. Gastrointestinal obstruction. Clin Tech Small Anim Pract 2002;17:178–183.

3.  Mansell J, Willard MD. Biopsy of the gastrointestinal tract. Vet Clin North Am Small Anim Pract 2003;33:1099–1116.

4.  Suchodolski JS, Steiner JM. Laboratory assessment of gastrointestinal function. Clin Tech Small Anim Pract 2003;18:203–210.

5.  Trepanier L. Acute vomiting in cats: Rational treatment selection. J Feline Med Surg 2010;12:225–230.