Presenting problem: Regurgitation in Birds

Regurgitation versus vomiting

The terms “regurgitation” and “vomiting” are often used interchangeably in the avian patient. Regurgitation is the passive expulsion of contents from the esophagus or crop (Fig 1). Vomiting is the expulsion of ingesta from the proventriculus, ventriculus, or intestines. It is not always possible to make a distinction in the clinical patient between regurgitation and vomiting although doing so can be helpful in reaching a definitive diagnosis.

Key points of urgent care

Persistent regurgitation can lead to electrolyte disturbances, dehydration, weight loss, aspiration pneumonia, and possibly even death. Therefore a bird with a history of chronic regurgitation should always be hospitalized. Even reports of just one or two regurgitations must be taken very seriously as the bird may be critically ill and its clinical condition could deteriorate rapidly.
Supportive care is critical:

• Supplemental heat
• Fluid therapy
• Nutritional support

Nutritional management of the regurgitating bird can be tricky. Although large macaw-sized birds may be fasted for several hours if need be, the small body size and high metabolic rate of many avian patients means that veterinarians do not always have the luxury of giving “nil per os”. Instead small amounts of liquid formulas are fed frequently.

Case management

Signalment

Your patient’s sex, age, and species may provide helpful clues to the underlying cause of regurgitation. For instance, many husbandry-related conditions are important in young, growing birds. See our Basic Information Sheets on the macaw, cockatoo, Amazon parrot, African grey parrot, conure, cockatiel, parakeet, canary, finch, lory and lorikeet, and lovebird for a brief list of medical conditions common in each group.

 

History

Obtain a complete, detailed history (Box 1). If the patient is critically ill or dyspneic, transfer the bird to an incubator and provide supplemental oxygen as needed, while the history is obtained.

Box 1. Questions for the owner of a regurgitating bird should include:

Medical history Duration of illness, progression of signs. Current drug therapy? Any change in the droppings? Previous medical problems? Any change in the bird’s environment or daily routine? Environmental history Caging? Time out cage? Supervision? Toxin exposure? Dietary history When did the bird last eat or drink? What items are actually consumed? Vitamin/mineral supplementation? Water source? Reproductive behavior or broodiness Has the bird been regurgitating to a favorite owner, toy, or cage mate?

See LafeberVet Forms and Questionnaires for our collection of comprehensive history forms.

 

Physical examination

Perform a complete physical examination (Box 2), whenever possible, including a body weight in grams and evaluation of the patient’s body condition. Perform an abbreviated exam when the patient’s clinical condition is not strong enough to handle more than brief restraint. In some instances, observation may suggest the patient is not strong enough to tolerate any evaluation at the moment. Instead the patient should be placed in a warm incubator in a dark, quiet environment.

Box 2. Examination of the bird with a history of regurgitation

Visual	Food material on the feathers behind the nares and on top of the head.
Oropharynx	Choanal slit, mucous membrane color
Crop or ingluvies	Gently palpate the walls of the crop for thickness or irregularities. Is the lumen distended with food or fluid? In tiny patients, the interior may be transilluminated.
Sternum	Palpate the pectoral musculature and keel to evaluate body condition of the adult bird.
Coelomic palpation.	Gently place a thumb and forefinger on either side of the coelom. Coelomic palpation is a relatively insensitive test in the bird due to the short distance between the sternum and pubis, however eggs, masses, fluid, and/or organomegaly may sometimes be detected.
Vent	Check the external sphincter of the cloaca for evidence of erythema, edema, trauma, discharge, pasted feces—or an egg!
Droppings	Carefully evaluate the droppings.

Differential diagnoses

The causes of regurgitation can be pathologic or physiologic. Stress or fear associated with travel, excessive handling, and excitement can cause regurgitation. Regurgitation may also be an expression of sexual behavior. For instance, a bird may regurgitate to a mirror, or a favorite toy, or a favorite person. Regurgitation may also be associated with broodiness or incubatory behavior. Pathologic causes of regurgitation range from substandard care to gastrointestinal disease to systemic illness.

Husbandry-related problems such as cold formula lead to delayed emptying of the crop or crop stasis (Box 3), which in turn leads to regurgitation in juvenile birds, particularly neonates.

Box 3. Husbandry-related causes of regurgitation in young birds

Cold environmental temperature Cold formula Overfeeding formula Improper consistency of formula Crop burn Other trauma to the crop (i.e. aggressive use of a feeding tube)

Diseases of the crop are common in companion parrots. Problems such as candidiasis and foreign body ingestion are particularly common in young, growing birds. Local infections of the crop or ingluvitis are unusual in adult parrots, and an underlying cause should always be identified.

 

Box 4. Crop-related causes of regurgitation

Infection or ingluvitis: candidiasis, bacterial, trichomoniasis Foreign body or ingluviolith Mass lesion (neoplasia, papillomatosis) Extraluminal compression (goiter, granuloma, neoplasia) Esophageal stricture

Disease of the lower gastrointestinal tract can cause a constellation of clinical problems including crop stasis, regurgitation, and vomiting (Box 5).

 

Box 5. Problems anywhere along the gastrointestinal tract can cause regurgitation

Dietary indiscretion or ingestion of spoiled food Ingestion of toxic plants or chemical irritants Heavy metal toxicosis Crop-related disease Esophageal strictures Infection, foreign body, neoplasia, or impaction of the proventriculus, ventriculus, or intestinal tract including gram-negative bacterial infection, avian gastric yeast, avian bornavirus (proventricular dilitation disease), candidiasis Gastritis, gastric ulcer, koilin degeneration Intestinal intussusception or volvulus

Finally, anything that causes the gastrointestinal tract to slow can result in regurgitation (Box 6). Therefore regurgitation in the bird may simply be a manifestation of generalized ileus secondary to systemic disease.

Box 6. Generalized ileus may cause regurgitation

D	Degenerative
A	Anomalous
M	Metabolic	Dehydration Electrolyte imbalances (i.e. hypokalemia) Liver disease Renal disease Pancreatitis Diabetes mellitus
N	Neoplasia
	Nutritional	Vitamin E/selenium deficiency
I	Infectious	Sepsis or viremia Psittacosis Aspergillosis Avian bornavirus infection Avian polyomavirus, etc., etc., etc.
	Inflammation	Peritonitis
T	Traumatic
	Toxic	Heavy metal toxicity (Lead, zinc) Organophosphates Antibiotics (sulfa drugs, doxycycline)

Diagnostics

Clearly there is a long list of differential diagnoses for regurgitation in the bird. Signalment, detailed history, and careful physical examination can provide important clues to narrow the differential diagnosis list, and diagnostic testing can help to narrow the field further.

1. Test for crop-related disease:
   • Collect samples from the crop via cotton swabs and/or crop wash.
   • Perform wet mount cytology, gram stains, and/or modified Wright’s staining on these samples.
   • Perform culture/sensitivity when abnormal cytology is seen.

   For simple cases, particularly in juvenile birds, crop cytology may sufficient to obtain an accurate diagnosis and treatment plan.

2. Collect a minimum database:
   • Complete blood count
   • Chemistry panel
   • Protein electrophoresis
   • Survey whole body radiographs (Empty the crop before taking x-rays).

If diagnosis remains inconclusive, consider referring the patient to a specialist additional tests that may be performed by an avian veterinarian depending on the clues gathered may include:

• Blood lead and zinc levels
• Serum bile acids
• Serology &/or PCR testing: Chlamydophila psittaci, avian polyoma virus, aspergillosis, psittacine beak and feather disease, avian bornavirus, etc.
• Urinalysis
• Contrast radiography
• Alternate imaging such as ultrasound or fluoroscopy
• Endoscopy

Therapy

Pro-kinetic agents such as metoclopramide and cisapride may also prove helpful. Although cisapride has been removed from the US market for use in human patients due to reports of serious cardiac arrhythmias, generic versions may still be obtained from some compounding pharmacies. Prescribe antibiotics if aspiration is suspected, or if the underlying cause of regurgitation is believed to be bacterial.

If the patient’s clinical status does not improve, consider referral to an avian specialist.

Conclusion

Regurgitation is a non-specific clinical sign, and it is not pathognomonic for any specific problem. Regurgitation can be associated with disease limited to the crop, or it can be the mere “tip of the iceberg”. Regurgitation can indicate a problem anywhere along the gastrointestinal tract or it may occur secondary to crop stasis caused by systemic illness.

References