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how does a parrot's digestive system work?

How Does A Parrot’s Digestive System Work?

Last Updated on: 6th July 2023, 07:14 pm

Parrots have a unique digestive tract. They don’t chew their food like mammals because they lack teeth, relying on their digestive system to do the work.

All organs within the digestive tract are small, compact, and lightweight, enabling parrots to remain in the air for hours, even while digesting food.

Parrots’ digestive systems are adapted to pulverize food to move it through the gut. The crop is a muscular pouch that enables parrots to store food for later consumption.

Parrots risk starvation if they don’t get sufficient food, so they have fast-moving digestive systems.

How Do Parrots Digest Food?

Parrots have an efficient way of digesting their food that utilizes several organs. As parrots eat foods that are hard to digest, like seeds and nuts, the digestive process is well adapted to cope.

The digestive system gleans the most from the food a parrot finds in the shortest possible time. This is key to survival from starvation and predators who attack when a parrot is preoccupied with eating.

The parrots’ digestive system process and the organs that are involved are the following:

Mouth and Tongue

Once a parrot has the food in its mouth, the tongue pushes it into the digestive tract. The tongue sometimes holds worms, grubs, and other insects in place.

Parrots can’t chew their food, so they drop food into the throat. The pharynx is located between the mouth and esophagus, enabling parrots to swallow food.


The esophagus (situated on the right of the neck) is what food moves down toward the parrot’s stomach. The extension of the neck also aids swallowing.


The crop is a muscular pouch in the parrot’s neck, just above the top of the sternum.

Parrots eat when they find food because they don’t know when their next meal will come. Food can’t be digested as fast as it’s consumed, so the crop allows parrots to store the surplus.

parrot digestive problems


Once the food moves from the crop, it enters the proventriculus (glandular stomach).

Parrots have a two-chambered stomach. The proventriculus is a rod-shaped organ located between the esophagus and the gizzard.

The food is softened and broken down by gastric acid, mucus, and digestive fluids.


The gizzard is the second chamber of the stomach, located toward the rear of the parrot.

It consists of muscles and a thick wall that grind food into smaller pieces. Parrots sometimes swallow sand and grit while eating, which some birds (not parrots) use to pulverize food.

Tough pieces of food move between the proventriculus and gizzard to break it down more efficiently.

Small Intestine

Once the food is broken down, it moves into the small intestine.

At this point, the liver and pancreas absorb the nutrients, and the waste products are passed through to the next stages of the digestive process. The small intestine is divided into 3 parts:


The duodenum is the first part of the small intestine, located between the stomach and jejunum. It breaks down partially digested food using enzymes and begins absorbing nutrients.

It produces hormones and receives secretions from the liver and pancreas. These fluids neutralize the acidity of chyme traveling from the stomach to prevent digestive problems and damage to the gut lining.


The jejunum is the middle part of the small intestine and is nestled between the duodenum and the ileum, comprising 40% of the small intestine.

With the assistance of pancreatic enzymes and bile produced in the liver, the stomach contents move through the duodenum and enter the jejunum.

It absorbs nutrients, which enter the bloodstream for distribution to the organs.


The ileum is the final section of the small intestines. It weighs 20-50% less than the jejunum, enabling a parrot to stay in the air while flying. It accounts for 60% of the small intestine length.

Some fat, protein, and starch absorption occurs in the ileum, but it’s mainly a water, vitamin B12, and mineral absorption site.

Large Intestine

Leftover material travels through the large intestine, primarily to reabsorb water. The large intestine’s role during the digestive process is mostly redundant compared to a mammal’s large intestine.


The rectum is a short tube that connects the intestines to the cloaca. It’s at the end of the intestine and has no other function than allowing undigested food to pass into the cloaca.


The cloaca is a reproductive organ and storage facility for feces and urine.

Waste accumulates here before being excreted from the body. When the parrot is ready to release waste, it’s expelled through a sphincter at the base of the cloaca.

Common Parrot Digestive Problems

The most common parrot digestive problems include:

Avian Gastric Yeast

Avian gastric yeast is caused by a fungus (Macrorhabdus sp) that can affect a parrot’s crop, proventriculus, and ventriculus. It’s common in lovebirds, cockatiels, and budgies.

As described by the MSD Veterinary Manual, avian gastric yeast colonizes the digestive tract of birds. Parrots with weak immune systems are most affected.

The symptoms of avian gastric yeast include:

  • Chronic weight loss.
  • Regurgitation.
  • Lethargy.
  • Diarrhea.
  • Undigested seeds or pellets in the feces.

A vet will examine the parrot’s droppings under a microscope. If organisms are present in the parrot’s waste, avian gastric yeast can be treated with Amphotericin B.

The death rate in affected parrots is 10-80%, with stronger yeast strains more likely to be fatal. If a parrot recovers, relapses are likely, so close monitoring is required for the rest of the parrot’s life.

Parrots can shed the organisms in their droppings. Therefore, the parrot’s poop (and old food) must be removed from the cage to prevent infection from re-entering the body.

The infection can be transmitted between parrots. If you own more than one parrot, avoid spreading the infection by quarantining the bird to stop the spread.

Candidiasis (Thrush)

Thrush is a common environmental fungus caused by Candida albicans yeast, usually found in small amounts in the parrot’s digestive tract. The symptoms of thrush include:

Thrush is more common in young, unweaned parrots on antibiotics because they have undeveloped immune systems and are more susceptible to illnesses.

Adult parrots with malnutrition or on antibiotics are prone to thrush. Thrush can spread from adult to juvenile parrots or through a contaminated environment. Candidiasis affects a parrot’s:

  • Crop.
  • Stomach.
  • Intestines.
  • Skin.
  • Respiratory tract.
  • Central nervous system.

A vet will recommend a reduced feeding program to empty the crop and antifungals, like nystatin or fluconazole. To prevent candida from growing in the parrot’s environment:

Proventricular Dilatation Disease (PDD)

Also known as macaw wasting disease, this condition affects the nerves of the digestive tract.

It stretches the stomach and prevents the normal function of the muscles required for digestion. The damaged nervous system stops nutrients from being absorbed and digested.

Proventricular dilatation disease is caused by an avian-bornavirus that occurs after exposure to the feces of infected birds, usually when sharing a cage. The signs of PDD include the following:

  • An initial increase in appetite.
  • Chronic weight loss.
  • Undigested food in the feces.
  • Smelly stools.
  • Regurgitation.
  • Convulsions.
  • Head tremors.
  • Weakness.
  • Incoordination.
  • Blindness.
  • Difficulty perching.
  • Leg paralysis.

Proventricular dilatation disease is uncommon, but it can be fatal. It’s incurable, but it can be controlled with palliative care. The only way to prevent transmission is to isolate the stricken parrot.

Its cage must be disinfected to remove traces of the infection, and ventilation can reduce transmission rates. The infection doesn’t survive for long, so good hygiene can prevent the spread of the disease.

Easily digestible foods and anti-inflammatory medication can be beneficial.

Pacheco’s Disease

The psittacine herpes virus causes Pacheco’s disease. It leads to viral inflammation of the liver, commonly affecting Amazon parrots, conures, hawk-headed parrots, and macaws. The symptoms include:

  • Lethargy.
  • Diarrhea.
  • Ruffled feathers.
  • Sinusitis.
  • Anorexia.
  • Conjunctivitis (red eye).
  • Neck, wings, and leg tremors.
  • Discolored urine and feces.

The disease is contagious and transmitted through contaminated feces and nasal discharge. It can also spread through contact with sick birds and contaminated food and water.

Pacheco’s disease can manifest as pink, cauliflower-like growths called papillomas. Papillomas grow in the mouth and digestive tracts, causing wheezing, open-mouthed breathing, and difficulty swallowing. 

Papillomas that grow in the digestive tract can cause vomiting and loss of appetite. They sometimes protrude from a parrot’s vent and can be seen when the parrot strains while defecating.

Surgical removal of papilloma is required. However, growths may recur, so palliative treatment is usually needed. Pacheco’s disease kills birds, so vaccinate the parrot to protect against the disease.

Gastrointestinal Parasites

Intestinal parasites are common in parrots, including the following:


Giardiasis (bird giardia) is when microscopic single-celled parasites called protozoa attach themselves to the intestines of parrots.

They’re common in cockatiels and budgerigars but affect most species. Adult parrots are often carriers; transmission occurs when through infected water or consuming contaminated feces.

The symptoms of giardiasis include the following:

  • Diarrhea.
  • Malnutrition.
  • Inability to absorb nutrients.
  • Itching, which causes the parrot to pull or dig at its feathers.
  • Abnormally large droppings.
  • Thinness.
  • Poor feathers.
  • Excessive crying.

Oral medications, like metronidazole and ronidazole, are used to treat giardiasis.

how parrots feed and digest food


Trichomoniasis (frounce or canker) is a protozoan infection that causes whiteish-yellow lesions on the mouth and throat lining, crop, and esophagus.

While the lesions aren’t always visible, infected parrots display signs of increased salivation and regurgitation. It’s transmitted through direct contact or contaminated food and water.

Treatment involves taking antibiotics, like metronidazole, twice daily for 5-7 days.


There are many types of roundworms, all of which reside in a parrot’s digestive tract.

Roundworm is transmitted when a parrot eats roundworm eggs (larvae). Affected parrots show signs of weakness and emaciation, which can lead to death if roundworms block the intestines.

Vets will examine the feces for parasitic eggs, prescribing Ivermectin, fenbendazole, or piperazine. If roundworms obstruct the intestines, surgery may be required to remove them.


Tapeworms are uncommon in captive parrot species, except cockatoos and African greys.

Parrots become infected by eating food contaminated with tapeworm eggs. Once they reach the bowels, the tapeworms grow a ribbon-like body with eggs that enter the digestive tract.

The eggs exit the body through the parrot’s droppings, and insects consume the eggs. In turn, the insects are eaten by parrots, continuing the cycle. The symptoms of tapeworms include:

  • Weight loss.
  • Quietness.
  • Loose droppings.
  • Nutritional deficiencies.
  • Change in appearance.
  • Loss of appetite.

A vet will administer praziquantel or epsiprantel for tapeworms. Also, the cage will need deep cleaning.

Why Is My Parrot Regurgitating?

When a parrot regurgitates, it’s more of a spitting than a vomiting action. The parrot will shake its head from side to side before expelling undigested or partially digested food.

Regurgitation is usually a behavioral trait around bonded birds. However, it can happen with bonded humans, especially if the bird doesn’t have a same-species mate.

It happens when parrots respond to stimulation. This could be during a game, which causes the bird to become over-excited. Parrots may also regurgitate after being petted in areas reserved for mates.

Parrots regurgitate food for birds they’re bonded with and their young. Therefore, if a parrot regurgitates on you, they mistakenly see you as a mate and provide for you.

The purpose of a parrot’s digestive tract is to absorb nutrients from food. If the digestive process encounters problems, the parrot risks becoming malnourished.

Avoid feeding the parrot junk food, like bread, French fries, and other human food scraps. Also, clean the parrot’s feeder to remove spoiled, wet, or moldy seeds and pellets.