Last Updated on January 29, 2024 by Carrie Stephens
Sour crop (called crop stasis) is observed in hand-reared chicks due to unsuitable feeding techniques. Adult parrots can also develop sour crop due to bacterial and viral infections.
A parrot with crop stasis shouldn’t eat for 24 to 48 hours (under vet advisement) until intestinal tract motility is restored. This should be combined with fluid therapy to avoid dehydration.
Emptying the crop, antibiotics, crop washes, and manual blockage removal may be required.
Causes of Sour Crop in Parrots
There are many causes of sour crop, including problems with the digestive tract, toxicities, and metabolic diseases. The most likely explanations include:
The acidity changes when food stays in the crop for too long, disrupting the natural balance.
In particular, Candida, a fungal species, overpopulates and proliferates into large white plaques, impairing the crop’s ability to function correctly.
Candida grows into the esophagus and mouth when the infection worsens, causing visibly white patches.
The crop slows down when there’s too much Candida in the body, leaving leftover food fermenting inside. This creates a foul smell, hence the name “sour crop.”
Bacteria come from other parrots, contaminated food and water bowls, or foods left in the cage for too long, especially foods that spoil quickly.
Sometimes, bacteria in the intestinal tract overpopulate and weaken the immune system. It’s a bigger problem if the parrot is stressed because the body is more susceptible to health conditions.
Also, the inappropriate use of antibiotics can lead to bacterial overgrowth.
Roundworms and tapeworms can be a problem. Similarly, protozoan parasites, like trichomonas, are responsible for sour crop in smaller birds, such as budgerigars and cockatiels.
According to Science Direct, the parasites colonize the crop, preventing it from functioning and impairing its ability to empty itself of food.
A foreign body inside the tract can impact the crop. This affects the proventriculus (glandular stomach) in severe cases, where gastric acid softens and breaks down food. Obstructions include:
Always cut food into bite-sized pieces and throw away broken toys.
If the formula is too hot, cold, or thick, it’ll affect the crop’s ability to empty itself. This will cause the food to ferment, leading to secondary bacterial and yeast infections.
Insufficient fluids cause parrots to dehydrate, and fluid is pulled from the intestinal tract, resulting in obstruction due to thickened, dry food.
MSD Vet Manual recommends a temperature for hatchlings of 92-94°F. Owners mustn’t allow this to drop as chicks can’t independently regulate their body temperature.
Several viral diseases cause crop stasis, including:
- Proventricular dilation disease.
- Herpes virus.
While all symptoms vary based on the virus, they cause food movement to slow down. Each virus does this differently, but the outcome remains the same.
Heavy metal toxicity from lead or zinc is common, affecting their gastrointestinal tract.
Powder-coated cages and zinc-based water and food bowls commonly cause heavy metal toxicity. Some birds develop crop stasis and neurological symptoms.
Goiters often occur in budgies with iodine deficiencies or fed an all-seed diet.
It causes the thyroid glands (located on either side of the crop) to enlarge, blocking the crop’s outflow and causing the trapped food to ferment.
Metabolic diseases inhibit the crop and disrupt the digestive and intestinal tract. Diseases include:
- Liver disease.
- Diabetes mellitus.
- Renal disease.
In these cases, sour crop is a symptom of these diseases.
Signs of Sour Crop in Parrots
The symptoms of sour crop manifest after the condition develops. The signs include:
Like a water-filled balloon, a healthy, full crop feels soft and mushy.
Once impacted, it’ll become hard and swollen, a condition called crop overdistention. The crop should empty itself by the morning. If it hasn’t emptied, a crop infection is the likely explanation.
You may hear gurgling from the gases produced by exerting gentle pressure on the crop.
Crop stasis is called ‘sour crop’ because infected crops emit a foul odor due to bacteria, yeast, and fermenting food. As the food rots, it releases gasses that leave through the mouth.
Owners recognize the smell of sour crop as unpleasant-smelling breath is most commonly due to a crop infection disrupting the body’s balance of bacteria.
Regurgitation And Vomiting
Regurgitation allows parrots to clear their crop, usually in the morning. However, frequent or chronic regurgitation signifies something is amiss.
Depending on the severity of the condition, the parrot might regurgitate clear liquid or undigested food. It may also vomit if it has crop stasis. When vomiting, a parrot will:
- Appear visibly stressed.
- Uncontrollably expel its stomach contents.
- Produce partially or mostly digested food.
At this point, the parrot needs veterinary care.
Undigested Food in Droppings
Undigested food in parrot droppings indicates the digestive tract isn’t functioning.
It usually signifies an infection, which is correlated to sour crop. In addition to undigested food, parrots with crop stasis develop diarrhea and foul-smelling stools. The number of droppings can also decrease.
A parrot won’t eat anything else until the stuck food is removed as the crop is full. Where burns or lacerations are the cause, it’s likely too uncomfortable to eat.
As a result, the parrot won’t gain or lose weight. In hatchlings, this can quickly be fatal.
Parrots with sour crop become dehydrated, and their skin color changes from a healthy pink to a much brighter red, depending on the severity. The skin will also lose elasticity.
According to Avian Medicine, parrots with sour crop become listless as the disease progresses because they aren’t eating food. The body must draw on its energy reserves to function.
The feeding response in parrots with sour crop varies from normal to absent. While feeding chicks their formula, they may refuse it.
How Sour Crop Is Diagnosed
Usually, the fullness and foul smell make it easy to tell if a parrot has sour crop.
Also known as a crop lavage or crop infusion, a crop wash is among the best ways to diagnose sour crop. During the procedure, the vet injects water into the crop through a feeding tube.
A direct microscopic examination is sometimes sufficient to diagnose sour crop. If not, the vet will swab the crop, take an x-ray, or perform a biopsy. They may also take a blood profile.
Other testing methods include the following:
- Physical examination.
- A sampling of the feces to test for infection and inflammation.
- Serum biochemistry panel.
- Barium contrast study to detect the slowing of intestinal motility, foreign objects, and tumors.
- Infectious disease testing.
Treatment for Sour Crop in Parrots
Treatments vary based on the cause and severity but include:
Adding more food to a crop that can’t be emptied will exacerbate the problem.
The nutritional content will not benefit a parrot because the body cannot utilize it. A parrot can survive without food for 1-4 days, with smaller birds succumbing sooner.
Once the parrot’s intestinal tract motility normalizes, feed it easy-to-digest foods.
Parrots with crop stasis are often dehydrated. To provide fluids, vets use the following:
- Intravenous catheter.
- An interosseous catheter into the bone marrow.
- Subcutaneously (under the skin).
The method used depends on the severity of the parrot’s dehydration.
Hold the parrot with its head facing down and get as close to the bottom of the crop as possible. Gently massage it. Be careful not to push it up because the parrot may aspirate the food into the trachea.
Use a cotton pad or Q-tip to remove formula or liquid exiting the mouth.
A crop wash is the only way to remove fermenting food in severe cases.
A vet will place a catheter into the mouth and vacuum the contents using a syringe. After removing the contents, they’ll rinse the crop using warm water, Pedialyte, or Lactated Ringer’s solution.
When bacteria cause sour crop, a vet will administer antibiotics.
If the crop has some motility, the vet will provide oral antibiotics. However, if the crop has stopped functioning, the vet will inject antibiotics.
Nystatin, an antifungal medicine, is used for yeast infections.
Apple Cider Vinegar
Apple cider vinegar (ACV) has antibacterial and antioxidant properties.
ACV encourages the digestive system’s acidity, promoting healthy bacteria. Therefore, to ease symptoms, add diluted apple cider vinegar to water or food.
If a foreign body causes sour crop, surgery will be required, especially if the foreign body is an inedible object, like plastic or string.
If the blockage is caused by digestible food, you can massage the crop to trigger it to empty.
How Long Does It Take Sour Crop Treatment to Work?
If you’re treating a parrot with a water-only diet, sour crop symptoms should resolve within 48 hours. In less severe cases, parrots may feel better in 24 hours.
You may discover that a parrot has frequent bouts of sour crop during recovery. While this isn’t uncommon, it could indicate a virus is responsible.
How To Prevent Sour Crop?
You can take steps to reduce the likelihood of sour crop, including the following:
- Cutting food into small, bite-sized pieces.
- Removing the food after 2-4 hours prevents it from turning moldy.
- Regularly changing the drinking water.
- Removing broken toys and games to prevent obstructions.
- Avoid zinc cages and accessories.
- Keep newborn chicks at the right temperature.
- Never feed formula that’s too hot or thick.
- Add probiotics to the parrot’s diet.
These measures will keep the digestive system and intestinal tract healthy.
Is Sour Crop Fatal?
Sour crop is seldom fatal if diagnosed and treated by a veterinarian early. However, if it remains undetected, some of the causes of sour crop can kill a parrot.
A tumor, obstruction, or metabolic disease is more severe because it can’t always be resolved. Bacterial and yeast infections are easier to clear up after antibiotics.
Check that the parrot’s crop has emptied each morning.