SYMPTOM
Intermittent vomiting
Episodes of vomiting that occur irregularly over days or weeks rather than as a single acute event.
Gastrointestinal
Intermittent vomiting may originate from conditions affecting the stomach or intestines directly. Chronic gastritis, inflammatory bowel disease, gastric motility disorders, and food sensitivities can all produce episodic vomiting that occurs irregularly rather than in a constant pattern. The intermittent nature often reflects the fluctuating activity of the underlying gastrointestinal condition, with episodes triggered by specific foods, stress, or seemingly random factors. The character of the vomitus — whether it contains food, bile, mucus, or is simply fluid — may vary between episodes and can provide context about the timing relative to meals and the level of the gastrointestinal tract involved.
Metabolic or Systemic
Conditions affecting organs outside the gastrointestinal tract can produce vomiting through their effects on the chemoreceptor trigger zone or through the accumulation of metabolic waste products that stimulate nausea. Kidney disease, liver disease, pancreatitis, and electrolyte imbalances can all produce intermittent vomiting as one component of a broader clinical picture. The vomiting in these metabolic causes may not show an obvious relationship to feeding and can occur at seemingly random intervals.
Dietary
Food intolerances, sudden dietary changes, consumption of inappropriate items, or sensitivity to specific ingredients can produce intermittent vomiting that correlates — though not always obviously — with dietary factors. The intermittent pattern may reflect inconsistent exposure to the triggering food or ingredient, variation in portion sizes, or the animal's intermittent access to non-food items. Rapid eating, competitive feeding situations, and eating immediately before vigorous activity can also produce episodic vomiting without underlying disease.
Endocrine
Hormonal conditions such as hyperthyroidism in cats and hypoadrenocorticism in dogs can produce intermittent vomiting as part of their clinical presentation. Hyperthyroid cats may vomit intermittently due to increased gastric acid secretion and altered motility. Hypoadrenocorticism can produce episodic gastrointestinal signs including vomiting that may wax and wane with fluctuations in cortisol levels, sometimes following a pattern of periodic crises interspersed with periods of relative normality.
Foreign Body or Obstruction
Partial gastrointestinal obstructions — from foreign bodies, masses, or intussusceptions that intermittently block the passage of intestinal contents — can produce a pattern of episodic vomiting that occurs when the obstruction temporarily worsens and resolves when it shifts. Linear foreign bodies such as string or ribbon can produce intermittent vomiting as the intestine bunches around the material. The intermittent nature of the vomiting in partial obstruction can delay recognition, as the animal may appear normal between episodes.
Why timing matters
Early observation
Occasional vomiting is not uncommon in companion animals, and isolated episodes may represent nothing more than dietary indiscretion, hairballs in cats, or mild gastric irritation. The significance lies in the pattern — when occasional vomiting becomes a recurring feature rather than a rare event. Early in the development of a pattern, noting the frequency, timing relative to meals, character of the vomitus, and the animal's behaviour before and after episodes can help establish whether a meaningful trend is emerging. A useful threshold for concern is when vomiting occurs with a regularity or frequency that differs from the individual animal's established baseline.
Later presentation
As intermittent vomiting persists over weeks to months, its cumulative effects may become apparent even if individual episodes seem mild. Weight loss, reduced muscle condition, subtle dehydration, and declining coat quality may develop gradually. The animal may develop food aversions or altered eating patterns as it associates certain foods or feeding contexts with nausea. Chronic intermittent vomiting can also produce changes in the oesophageal and gastric mucosa from repeated exposure to stomach acid. The pattern itself may evolve, with episodes becoming more frequent, more severe, or changing in character over time.
The trajectory of intermittent vomiting depends heavily on its underlying cause. Dietary causes may remain stable or resolve with dietary modification. Inflammatory bowel disease may show gradual worsening or may fluctuate with periods of relative quiescence. Metabolic causes tend to worsen as the underlying organ dysfunction progresses. Partial obstructions may produce an escalating pattern as the obstruction becomes more complete. Understanding whether the episodes are becoming more frequent, more severe, or are associated with declining overall condition can help distinguish a stable, benign pattern from an evolving pathological process.
Conditions commonly associated
Addisons Disease in Dogs
Chronic Kidney Disease in Cats
Chronic Kidney Disease in Dogs
Food Allergy in Dogs
Food allergy can cause intermittent vomiting as the immune-mediated inflammatory response affects the gastrointestinal mucosa. Vomiting may occur alongside skin signs or as a relatively isolated gastrointestinal manifestation of the dietary hypersensitivity.
Gastroenteritis in Dogs
Intermittent vomiting is one of the hallmark presentations of gastroenteritis, often appearing suddenly alongside other gastrointestinal signs.
Vestibular Disease in Dogs
Vomiting frequently accompanies acute vestibular episodes due to the close link between the vestibular system and the centres that regulate motion sickness and nausea.
Constipation and Megacolon in Cats
Vomiting may accompany significant constipation and megacolon through vagal-mediated reflexes triggered by colonic distension, and through generalised nausea associated with faecal retention and toxin absorption.
Hepatic Lipidosis in Cats
Intermittent vomiting may occur with hepatic lipidosis as the overwhelmed liver struggles to process metabolic byproducts effectively.
Triaditis in Cats
Cats with triaditis often experience episodic vomiting that may wax and wane with disease activity.
Gastroenteritis in Cats
Episodes of vomiting are a cardinal feature of gastroenteritis, with frequency and timing providing diagnostic clues.
Foreign Body Ingestion
Partial obstructions or objects in the stomach may cause intermittent vomiting that comes and goes, sometimes over several days before a clear pattern emerges.
Giardiasis
Some animals with giardiasis may experience occasional vomiting alongside the more typical intestinal signs.
Mast Cell Tumours
Gastric ulceration from histamine effects may cause vomiting episodes.
Constipation and Megacolon
Vomiting may occur secondary to abdominal distension and discomfort from constipation.
Hepatic Lipidosis
Nausea and vomiting commonly accompany liver dysfunction in hepatic lipidosis.
Urethral Obstruction
Vomiting develops as uraemia (waste accumulation) progresses due to inability to eliminate waste products.
Vestibular Disease
Motion sickness from vestibular disturbance commonly causes nausea and vomiting.
Canine Parvovirus
Severe vomiting develops early in parvovirus infection and contributes to rapid dehydration.
Leptospirosis
Vomiting results from toxin accumulation due to kidney and liver damage.
Gallbladder Mucocele
Vomiting may occur with gallbladder disease, often intermittently and without obvious pattern.
Alabama Rot (CRGV)
Kidney dysfunction causes nausea and vomiting due to uraemic toxin accumulation.
When to explore further
Vomiting that occurs with increasing frequency over weeks, progressing from occasional episodes to multiple times per week, may suggest a worsening underlying process rather than a stable, self-limiting condition.
When intermittent vomiting is accompanied by progressive weight loss, the combination suggests that the vomiting is either preventing adequate nutritional intake or is a manifestation of a systemic condition that is also affecting the body's ability to maintain weight.
Vomiting that consistently contains bile — a yellow-green fluid typically seen when the stomach is empty — particularly in the early morning hours, may suggest a specific pattern of gastric motility or biliary reflux that differs from food-related vomiting.
When intermittent vomiting occurs alongside other gastrointestinal changes such as altered stool consistency, increased flatulence, abdominal discomfort, or changes in appetite, the combination may point toward a gastrointestinal process affecting multiple levels of the digestive tract.
Vomiting that produces undigested food hours after eating, or that contains food eaten the previous day, may suggest impaired gastric motility or a gastric outflow obstruction that is preventing normal emptying of stomach contents into the small intestine.
Keeping a vomiting diary that records the date, time, relationship to meals, character of the vomitus, and the animal's behaviour before and after each episode can reveal patterns that are not apparent from memory alone. Noting whether particular foods, feeding schedules, or activities seem to correlate with episodes can help identify potential triggers. Monitoring the animal's weight on a regular basis — ideally weekly — provides objective data about whether the intermittent vomiting is affecting nutritional status, as gradual weight loss may not be apparent from visual assessment alone.
Last reviewed: 24 April 2026 · Dr Alastair Greenway MRCVS