UNDERSTANDING CAPRINE ARTHRITIS ENCEPHALITIS (CAE) IN GOATS

(Diagnosis, Transmission, and Prevention Strategies)

Caprine Arthritis Encephalitis (CAE) is a viral disease that presents significant health risks and economic challenges for goat farmers. Although it often remains undetected for years, CAE can lead to long-term health problems, including reduced mobility, lower productivity, and compromised quality of life for affected animals. Early detection and preventive strategies are critical for controlling the spread of the disease. This article integrates findings from North Carolina State University (NC State), Purdue University, and Langston University to offer a comprehensive approach to managing CAE.

Enlarged knees are a common symptom of CAEV in goats. Photo by MSU Extension

What is Caprine Arthritis Encephalitis (CAE)?

CAE is caused by a lentivirus that primarily affects a goat’s immune system, leading to chronic inflammation in various systems, particularly the joints, udder, and nervous system. The disease progresses slowly, often going unnoticed for several years, which complicates early detection and management. Research at NC State has shown that the virus can be present in herds long before symptoms appear, making proactive testing essential. Over time, the disease can cause severe damage to affected goats, leading to mobility issues, reduced milk production, and, in some cases, neurological symptoms.

How is CAE Transmitted?

The primary mode of transmission for CAE is from infected does to their kids through colostrum or milk. This vertical transmission is often the most significant route, especially when kids consume milk from infected mothers early in life. Additionally, indirect transmission through contaminated equipment such as needles, syringes, and grooming tools is also a concern, particularly in environments where biosecurity practices are not strictly followed.

According to Purdue University, it’s vital to implement strong biosecurity measures, such as disinfecting equipment between uses and isolating new or sick animals until they are tested for CAE. Maintaining closed herds, meaning no new animals are introduced without thorough testing, is one of the most effective ways to limit the risk of disease transmission.

Recognizing the Symptoms of CAE

Many goats infected with CAE remain asymptomatic for extended periods, but certain clinical signs are commonly associated with the disease:

• Arthritis: One of the most distinctive symptoms, particularly in adult goats. Swollen, stiff joints, especially in the knees, hocks, and pasterns, can make movement difficult and painful. Langston University researchers have noted that this symptom often leads to chronic lameness and significantly affects a goat’s ability to move freely.

• Lameness: Affected goats may show intermittent or persistent limping, reluctance to stand, or difficulty moving. Over time, this can worsen, leading to permanent immobility in some cases.

• Poor Coat Quality: Goats with CAE often have rough, patchy coats. This can be due to nutritional stress or a weakened immune system, both of which are commonly seen in infected animals.

• Hard Udder Syndrome: Infected does may develop a firm, swollen udder that produces little or no milk. This condition, though not painful, severely limits milk production, making it a concern for dairy farmers.

• Neurological Symptoms (Kid Paralysis): In young kids, the virus can cause sudden paralysis, often starting in the hind legs and potentially spreading to the front limbs. This is a particularly concerning aspect of CAE, and, if untreated, can result in permanent disability or death.

Strategies for Preventing CAE

Preventing the spread of CAE requires a combination of proactive herd management, routine testing, and stringent biosecurity practices. Here are the most effective strategies:

1. Routine Testing: Regular blood tests are the cornerstone of managing CAE. NC State and Purdue University recommend annual testing of the entire herd and testing new animals before bringing them into the herd. This helps identify infected goats early, even before clinical signs are visible.

2. Kid Management: To prevent mother-to-kid transmission, it is common practice to remove kids immediately after birth and feed them heat-treated colostrum or CAE-free milk replacer. This approach significantly reduces the risk of the virus spreading from infected does to their offspring.

3. Biosecurity Protocols: Proper sanitation is essential in preventing the spread of CAE. Purdue University advises disinfecting all equipment between uses and avoiding the reuse of needles. New animals should be quarantined until they are tested for CAE, and sick animals should be isolated from the rest of the herd until a diagnosis is confirmed.

4. Closed Herds: The introduction of new goats poses a significant risk for CAE transmission. NC State highlights that maintaining a closed herd or sourcing animals only from CAE-negative herds with proper certification is one of the most effective ways to reduce risk.

Managing Goats with CAE

While there is no cure for CAE, infected goats can still lead healthy, productive lives with proper care. Management focuses on alleviating symptoms and improving quality of life:

• Arthritis Management: Anti-inflammatory medications such as NSAIDs can help manage joint pain and improve mobility, allowing infected goats to remain active and less stressed.

• High-Quality Nutrition: Goats with CAE often suffer from immune suppression and nutritional deficiencies. Providing a balanced diet rich in essential nutrients, including protein, vitamins, and minerals, is crucial for maintaining their health and mitigating some of the disease’s impacts.

• Reducing Stress: Goats with CAE are more susceptible to stress, which can exacerbate symptoms. Creating a calm and low-stress environment is essential for managing the disease. Langston University emphasizes the importance of minimizing environmental stressors, such as overcrowding, sudden temperature changes, and excessive transportation.

• Herd Separation: Many producers choose to separate CAE-positive and CAE-negative animals to prevent cross-contamination. This requires dedicated pens or barns for infected goats and strict protocols for managing movement between groups.

Final Thoughts

Caprine Arthritis Encephalitis (CAE) is a chronic, lifelong disease that can severely affect goat health and productivity. However, through proactive testing, biosecurity measures, and effective management practices, the spread of CAE can be minimized, and the quality of life for infected goats can be maintained. Regular monitoring and informed decision-making are key to managing this disease and ensuring the long-term success of goat operations.

By following the recommendations from institutions like NC State, Purdue University, and Langston University, goat owners can stay ahead of CAE and reduce its impact on their herds. With the right combination of prevention, management, and care, goats can continue to thrive even in the presence of this virus.