Raising healthy chicks is crucial for any poultry farmer, whether they are working on a small-scale backyard farm or managing a large commercial operation. One common issue that can affect young chicks is perosis, also known as slipped tendon or twisted legs. This condition can lead to lameness and deformity in growing chicks, potentially impacting their mobility, health, and overall productivity as they mature.
In this post, we’ll dive into the causes of perosis, how to recognize it in your flock, and, most importantly, how to prevent it to ensure your chicks grow strong and healthy.

1. What Is Perosis?
Perosis is a nutritional disorder that affects the development of the chick’s bones and joints, primarily in the legs. It is often characterized by swelling of the hock joint and the displacement of the gastrocnemius tendon (the main tendon in the leg). As the tendon slips out of place, it causes the leg to twist, which can severely impair the chick’s ability to walk or stand.
In severe cases, the deformity may become permanent, affecting the chick’s ability to forage, move around, or even reach food and water, leading to stunted growth and, in some instances, mortality.

2. Causes of Perosis
Perosis is most commonly caused by nutritional deficiencies, particularly during the critical early stages of a chick’s development. The most common deficiencies that lead to perosis include:
Manganese Deficiency
One of the primary causes of perosis is a lack of manganese in the chick’s diet. Manganese is an essential mineral that supports the proper development of bones and tendons. When chicks do not receive enough manganese, it can lead to bone and joint deformities, including perosis.
Choline Deficiency
Choline is another vital nutrient that plays a significant role in muscle development and bone structure. A deficiency in choline can lead to improper formation of cartilage and tendons, increasing the risk of perosis in chicks.
Biotin Deficiency
Biotin (vitamin B7) is important for overall growth and development in chicks. Inadequate levels of biotin can also contribute to leg deformities like perosis.
Other Nutritional Imbalances
Deficiencies in other vitamins and minerals, such as niacin (vitamin B3), folic acid (vitamin B9), and zinc, can also contribute to skeletal issues, including twisted legs and other deformities. Maintaining a balanced diet with all necessary nutrients is crucial for preventing perosis.

3. Recognizing the Symptoms of Perosis
Early detection of perosis is key to managing the condition and preventing long-term damage to your chicks. Some common symptoms of perosis include:
Swollen Hock Joints
One of the earliest signs of perosis is swelling in the hock joints. These joints may appear enlarged or inflamed, which is a sign that the tendons and bones are not developing properly.
Twisted or Bent Legs
As perosis progresses, the affected leg(s) may begin to twist or bend abnormally. The chick may have difficulty standing or walking, and you might notice a limp or unusual gait.
Slipped Tendon
In severe cases, the gastrocnemius tendon will slip out of its normal position in the leg. You may be able to feel or see this displacement by gently examining the hock joint.
Lameness or Immobility
Chicks with advanced perosis may become unable to walk or move around freely. This lameness can impact their ability to eat and drink, leading to further health issues.

4. Prevention of Perosis
While perosis can be a serious condition, it is also highly preventable through proper nutrition and management practices. Here’s how you can reduce the risk of perosis in your flock:
Provide a Balanced Diet
The most important step in preventing perosis is ensuring that your chicks receive a well-balanced diet that meets all of their nutritional needs. Make sure your feed contains adequate levels of manganese, choline, biotin, and other essential vitamins and minerals. Commercial chick feeds are usually formulated to include these nutrients, but it’s important to choose a high-quality feed from a reputable supplier.
Supplementation
If you suspect that your feed may be lacking in certain nutrients, or if your chicks are showing early signs of perosis, consider adding supplements to their diet. Manganese, choline, and biotin supplements can help address deficiencies and promote healthy bone development. Be sure to consult a veterinarian or poultry nutrition expert before adding supplements to ensure you’re using the correct dosage.
Avoid Overfeeding Carbohydrates
High-carbohydrate diets that lack essential vitamins and minerals can exacerbate the risk of perosis. Ensure that your chicks’ diet is not overly reliant on grain-based feeds without the appropriate balance of nutrients.
Monitor Feed Quality
Be mindful of the quality of feed you provide to your chicks. Poorly stored feed can lose its nutritional value over time, leading to deficiencies. Make sure feed is stored in a cool, dry place to preserve its nutrient content.
Proper Brooder Management
While nutrition is the primary factor in preventing perosis, proper brooder management is also important. Ensure that chicks have enough space to move around freely and that they are growing in a clean, dry environment. This reduces the risk of injury and supports healthy development.

5. Treating Perosis
If you detect perosis in your chicks early, there may be ways to correct the condition and prevent long-term damage. Here are some treatment options:
Nutritional Correction
The first step in treating perosis is to correct the underlying nutritional deficiency. Increasing the intake of manganese, choline, and biotin can help improve the condition. Consult a veterinarian to determine the best course of action for supplementation.
Supportive Care
Provide extra care for chicks with perosis, including ensuring they have easy access to food and water. You may need to separate affected chicks from the rest of the flock to prevent further injury or competition for resources.
Tendon Realignment
In some cases, manual realignment of the slipped tendon may be possible, but this should only be done by an experienced professional or veterinarian to avoid further damage.
Preventative Measures for the Rest of the Flock
If one or more chicks in your flock develop perosis, it’s important to immediately check the diet of the entire flock and make necessary adjustments to prevent the condition from affecting other chicks.

Conclusion
Perosis is a preventable yet potentially harmful condition that can impact the health and productivity of your chicks. By ensuring that your chicks receive a balanced, nutrient-rich diet and practicing good management techniques, you can reduce the risk of perosis and support healthy development in your flock.
Regularly monitoring your chicks for signs of perosis and acting quickly if symptoms appear will help you maintain a healthy and productive flock, ensuring that your poultry operation thrives.
Tags: Perosis in Chicks, Slipped Tendon, Twisted Legs in Chicks, Poultry Health, Chick Nutrition, Manganese Deficiency, Poultry Farming, GroSpace, GrowSpace, Growth Space