Sour crop (or crop infection) isn’t one specific condition. It’s most commonly seen in hand-reared chicks due to inadequate feeding techniques. But adult parrots can also develop sour crop as a result of infections and diseases.
Sour crop treatment in parrots depends on the cause of the condition. In many cases, a course of antibiotics or fungal medicine will suffice. Other times, a crop wash to remove the stuck food contents is the only solution. This can either be done manually by carefully massaging the crop or taking your parrot to the vet, who will use a catheter and syringe. When a foreign object is the cause of sour crop, surgical removal is required.
Sour crop affects all parrots differently but can be fatal if it’s left untreated. It’s can also be a sign of a much more serious health condition, so always get your parrot’s symptoms checked out by an avian vet.
What Is Sour Crop?
As mentioned, sour crop, or crop stasis as it’s also known, describes any crop infection. It’s an unpleasant condition where the crop can’t empty properly or empties too slowly. This causes food to remain stuck in the crop, where it ferments and breaks down, causing an infection.
Crop infections are common in parrots as the organ is susceptible to the same things that infect the gastrointestinal tract. Bacteria usually cause crop infections, but yeast infections are also to blame. Other causes include:
- Foreign objects
These things are likely to stop food from leaving the crop properly, resulting in an infection that can make the affected parrot unwell.
As discussed, sour crop is also more common in hand-reared baby birds that aren’t fed properly. If the formula’s too hot or cold, the formula’s too thick, or their incubation temperature isn’t within the proper parameters, they’re at risk of developing crop problems.
Do Parrots Have Crops?
VCA Hospitals describes the crop as a muscular pouch that appears above the top of the chest or sternum. In adult birds, healthy crops are barely visible to the human eye.
The crop acts as a storage bag for parrots to store excess food. This benefits wild birds who don’t know when they’re next going to find food. Parrots can’t digest this food as quickly as they find it, so the crop keeps the surplus food safe until the parrot gets hungry within 24 hours after ingesting it.
This also allows them to stay out of harm’s way and prevents the risk of starvation. Adult birds also produce crop milk from the crop, which is a secretion of the cells that line it. They use this milk to feed their newly-hatched birds.
How to Tell if a Parrot’s Crop Is Full
In young birds, the crop is visible, so you can see whether it’s full or not just by looking at it. You can check the crop’s fullness in older birds by gently feeling it with your thumb and index finger.
A full, healthy crop feels soft and mushy, a bit like a balloon filled with water. When the crop’s impacted infected, it’ll feel hard and swollen. The crop also won’t empty overnight, remaining firm in the morning when it should be empty.
How Long Does It Take for a Crop to Empty?
Once food enters the crop, it empties between 8-12 hours. However, it can sometimes take up to 24 hours for all the food to be completely gone. If the crop does not empty by the time the parrot wakes up, it likely has sour crop. That means the bird will need some form of treatment to fix the problem.
What Causes Sour Crop in Parrots?
As one of the most common parrot conditions, there are multiple causes for a sour crop, including problems with the digestive tract, toxicities, and metabolic diseases. The most likely causes of crop issues include:
Harmful bacteria comes from other parrots, dirty food and water bowls, or foods that have been left in the cage for too long, particularly fruits and vegetables that quickly spoil.
Sometimes, bacteria found in the intestinal tract overpopulates and weakens the parrot’s immune system. It’s also a more significant problem if the parrot’s stressed, as the bird’s body is susceptible to health conditions. This causes disease and leads to the crop not working properly. Inappropriate antibiotic use can lead to this bacteria overgrowth.
Fungal and yeast infections are another primary cause of sour crop. When food stays in the crop for too long, the acidity inside it changes and throws the digestive system off balance, disrupting the natural balance of bacteria.
In particular, Candida, which is a fungal species, overpopulates and proliferates into large white plaques, impairing the crop’s ability to function properly. When the infection becomes severe, Candida grows into the esophagus and mouth, causing visibly white patches.
As a result of too much Candida within the body, the crop slows down altogether, and leftover food ferments inside it. This creates a foul smell, giving the condition its name, “sour crop.”
Roundworms and tapeworms are a problem. Similarly, trichomonas, which are protozoan parasites, are responsible for sour crop in smaller birds, such as budgerigars and cockatiels.
As described by Science Direct, the parasites colonize the crop, preventing it from functioning in the way it should and impairing its ability to empty itself of food.
A foreign body inside the tract can impact the crop, preventing it from working correctly. In severe cases, the impact affects the proventriculus, which is also known as the glandular stomach. This is where the food gets softened and broken down by gastric acid. Common obstructions include:
- A piece of food that’s too large, such as celery
- String, rubber, or plastic toys
- Wood shavings
To prevent crop impaction in parrots, cut all food into bitesize pieces and throw toys away whenever they become old and broken.
As mentioned, insufficient weaning hand-feeding methods are likely to cause sour crop in newborn parrots. If the formula’s too hot, cold, or thick, it’ll affect the crop’s ability to empty itself, causing the food to ferment. This leads to secondary bacterial and yeast infections.
Insufficient fluids are another cause of sour crop. That’s because the parrot becomes dehydrated, and fluid gets pulled from the intestinal tract, causing an obstruction because of the thickened, dry food.
Improper Environmental Temperature
Incorrect incubation temperatures can cause newborn chicks to develop crop stasis. If the temperature’s too warm or cold, a parrot’s at risk of dehydrating or overheating. If the chick’s chilled, it’ll use all its body heat to keep warm, leaving no energy for digesting food.
As described by MSD Vet Manual, the recommended temperature for newborn parrots is between 92-94°F. Owners mustn’t allow this to drop by even a fraction, as chicks can’t regulate their own body temperature.
Several viral diseases cause crop stasis, including:
- Proventricular dilation disease
- Herpes virus
While all symptoms vary between the viruses, they all cause the movement of food to slow down. Each virus does this differently, but the outcome of sour crop is the same.
Heavy metal toxicity from the consumption of lead or zinc is common in parrots and affects the gastrointestinal tract. This is commonly caused by powder-coated cages and zinc-based water and food bowls. Worryingly, some birds go on to develop crop stasis and neurological symptoms, leading to permanent damage.
Goiter most commonly occurs in budgies with iodine deficiencies or parrots on 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 are also responsible for sour crop, as they prevent the proper function of the organ and disrupt the digestive and intestinal tract. These diseases include:
- Liver disease
- Diabetes mellitus
- Renal disease
These are some of the most serious avian diseases and cause permanent damage if they’re not treated quickly. In this case, sour crop is simply a symptom of these diseases and a warning sign for owners to get their birds checked out.
Signs of Sour Crop in Parrots
While there are several causes of sour crop, it’s relatively easy for owners to diagnose. That’s because the symptoms show soon after the condition develops. The most common sour crop symptoms in parrots include:
As mentioned, a healthy, full crop feels soft and mushy, like a water-filled balloon. But once it’s impacted, it’ll become hard and noticeably swollen. This is known as crop overdistention. The crop should empty by the time morning rolls around. If it hasn’t, a crop infection is likely to blame.
By gently pressing on the crop, you may also hear gurgling sounds from the gases that are being produced. Be careful not to press too hard on the crop, as it’s likely to feel sensitive and sore.
Crop stasis is known as “sour crop” because infected crops emit a foul, musty odor caused by a combination of bacteria, yeast, and fermenting food. As the food rots, it releases various gasses that exit the body through the mouth.
Owners recognize the smell as sour crop almost instantly, as unpleasant-smelling breath is most commonly the result of a crop infection disrupting the body’s delicate balance of bacteria.
Regurgitation and Vomiting
Regurgitation is another primary symptom of sour crop. Regurgitation is normal and allows parrots to clear their crop at least once a day – more often in the morning than any other time. But frequent or chronic regurgitation is a sign that something’s wrong.
Your might may regurgitate clear liquid or fully undigested food. It all depends on how serious the sour crop is. Your bird will also vomit if it has crop stasis. This is less frequent but signifies that the infection is serious. When vomiting:
- Parrots appear visibly stressed
- They uncontrollably expel the contents of their stomach
- The food will be partially or mostly digested
At this point, your parrot will need veterinary care to prevent the bird from becoming even more unwell.
Undigested Food in Droppings
Undigested food in your parrot’s droppings indicates that its digestive tract isn’t working properly. It’s usually the sign of an infection, which links directly to sour crop. As well as undigested food, parrots with crop stasis develop diarrhea and foul-smelling stools. The amount of droppings sometimes even decreases.
You should continuously monitor your parrot’s poop a couple of times a week for any changes. Any changes to your bird’s feces or toilet habits could be a cause for concern, particularly if you notice any other worrying symptoms of sour crop alongside them.
Because your parrot’s crop is full, your parrot won’t want to eat anything else until the food that’s stuck gets removed. In severe cases of crop stasis, where burns or lacerations are the cause, it’s likely too painful for your parrot to eat at all. As a result, the parrot will fail to gain weight or lose the weight it has. In newborn chicks, this can be fatal.
Long periods of appetite loss aren’t normal and should be investigated to rule out or treat sour crop.
Parrots with sour crop become dehydrated, and their skin color changes from a healthy pink to a much brighter red, depending on how severe the condition is. The skin will also lose its elasticity.
According to Avian Medicine, parrots with sour crop quickly become listless as the disease progresses. That’s because parrots with the condition have no energy from the lack of food they’re able to digest. Similarly, the body has to draw on its energy reserves to function correctly.
Lack of Feeding Response
The feeding response in birds with sour crop varies from normal to absent. This is more common in newborn chicks. While feeding them their formula, you may notice they refuse to eat it.
This is a serious problem because fragile chicks become weak quickly if they don’t stick to their regular feeding schedule and get the essential nutrients their bodies need to grow.
How Is Sour Crop Diagnosed?
In many cases, it’s easy to tell that your parrot has sour crop from the crop’s fullness and foul smell alone. That’s because the odor is one of the most noticeable signs.
However, there are cases where a vet will need to take a closer look. Also known as a crop lavage or crop infusion, a crop wash is one of the most effective ways to diagnose sour crop. Only vets or highly experienced owners with a history of caring for parrots should attempt this.
During the procedure, the vet will place a small amount of water into the crop through a feeding tube. Some of the fluid is then removed and tested for organisms.
A direct microscopic examination is sometimes enough to diagnose sour crop, but if it’s not, the vet will swab the crop, take an x-ray, or perform a biopsy. They may also take a blood profile to determine the cause. Other testing methods include:
- A thorough physical examination
- A sampling of the parrot’s feces to test for evidence of infection and inflammation
- A serum biochemistry panel
- A Barium contrast study to detect the slowing of intestinal motility, foreign objects, and tumors
- Infectious disease testing
- An endoscopy
Treatment for Sour Crop in Parrots
There are various treatments available for crop stasis in parrots. They vary depending on the cause and severity of your bird’s sour crop and include:
Stop feeding your parrot until you resolve the problem. That’s because adding more food to a crop that can’t empty itself is likely to cause a further blockage, and the food will ferment, making the condition worse. Your parrot also won’t benefit from the nutritional content because the body can’t use it.
Your parrot can last a couple of days without food, so don’t worry about it being hungry within this time. However, make sure you provide plenty of water because dehydration will worsen the symptoms.
Once your parrot’s intestinal tract motility returns, feed it easy-to-digest foods to help it get its strength and energy back. This should also prevent the risk of further digestive problems.
Parrots with crop stasis are commonly severely dehydrated as a result of the condition. To provide them with the fluids they need, vets will use either an:
- Intravenous catheter
- Interosseous catheter (into the bone marrow)
- Subcutaneously (under the skin)
Which one your vet uses all depends on the severity of your parrot’s dehydration.
You can manually empty the crop to remove fermenting food. To do so, hold the parrot with its head facing down and get as close to the bottom of the crop as possible. Gently massage it, being careful not to push it up, as the parrot may aspirate the food into its trachea.
Use a cotton pad or Q-tip to wipe away any formula or liquid that exits the mouth. Also, depending on how large your bird is, you might have to use another person for assistance. If you’re inexperienced, leave this for a qualified vet to do, as it’s not an easy process.
In severe cases of sour crop, a crop wash is the only way to remove fermenting food. A vet will place a large catheter into the mouth and vacuum the contents out using a syringe. After the contents are removed, the vet will rinse the crop using warm water, Pedialyte, or Lactated Ringer’s solution.
Where bacteria cause sour crop, your vet will administer a course of antibiotics to treat the infection. If the crop has some motility, they will provide oral antibiotics. But if the crop has stopped working altogether, your vet will inject them into your parrot’s system.
Nystatin is most commonly used for yeast infections. It’s not an antibiotic but an antifungal medicine that clears up yeast overgrowth quickly and effectively.
Apple Cider Vinegar
Apple cider vinegar can also help clear up yeast infections, as it has antibacterial and antioxidant properties. It naturally encourages the digestive system’s acidity, promoting the growth of healthy bacteria. Therefore, add diluted apple cider vinegar to your parrot’s water or food to help ease its sour crop symptoms.
Remove the Foreign Body
If a foreign body causes the parrot’s sour crop, surgery is likely required to remove it, especially if the foreign body is an inedible object, such as plastic or string. This will need to be carried out quickly to prevent death.
However, if the blockage is caused by digestible food, you could also try massaging the crop using the techniques we’ve already given to remove it naturally. This procedure stimulates the crop and encourages it to empty itself.
How Long Does It Take Sour Crop Treatment to Work?
If you’re treating your parrot with a water-only diet, the main symptoms of sour crop should disappear within 48 hours. Sometimes parrots feel better in as little as 24 hours, but this all depends on the severity of the bird’s crop stasis.
You may discover that your parrot has frequent bouts of sour crop during its recovery. While this isn’t uncommon, it could indicate that there’s an underlying health condition, such as a virus or disease, causing your parrot’s sour crop. This will take longer to treat.
How to Prevent Sour Crop?
While sour crop is a common condition, there are specific steps you can take to reduce to likelihood of it occurring in the first place. The best preventative measures include:
- Cut up food into small, bitesize pieces that are easy for parrots to eat
- Remove food after 2-4 hours to prevent it from germinating or going moldy
- Change their drinking water often
- Remove all broken toys and games to prevent obstruction
- Avoid zinc parrot cages and accessories and choose stainless steel
- Always keep newborn chicks at the right temperature
- Never feed formula that’s too hot or thick
- Add probiotics to your parrot’s diet
These steps will help keep your bird’s digestive system and intestinal tract as healthy as possible, protecting against sour crop.
Is Sour Crop Fatal?
If you catch your parrot’s sour crop early enough, the condition is rarely fatal with the proper treatment. However, if it lies undetected, it’ll quickly kill your bird. Similarly, the mortality rate of sour crop depends on the cause. For example, a tumor, obstruction, or metabolic disease is more serious and can’t always be cured.
On the flip side, bacterial and yeast infections, while potentially serious, are much easier to treat and clear up after a course of antibiotics. These are all reasons you should consistently monitor your bird for any symptoms of sour crop or changes to your bird’s physical health or mood.
Sour crop isn’t a pleasant condition and can make life severely uncomfortable for your bird. That’s why you must monitor your parrot every morning to check that the crop has emptied properly. Similarly, if you notice any symptoms that give you cause for concern, take your bird to the vet straight away.