Calf Neurological Syndrome and CCN Diagnosis

Published on: Dec 20, 2022

A client recently contacted me about 6-7 month old calves with neurological symptoms and deaths.

Case History

These calves were purchased and housed since arrival. They were fed old clamp silage with a minimal amount of concentrate. The concentrate feeding was stopped around the time that the first case happened. The large amounts of silage spoilage led to suspicion of listeriosis. After the initial case, the group was switched to fresh baled silage with no spoilage, but unfortunately further deaths occurred rapidly.

Post-Mortem Findings and Diagnosis

A post-mortem examination revealed CCN (cerebrocortical necrosis) and a moderate to heavy worm burden. CCN is caused by low thiamine (vitamin B1) levels, affecting brain metabolism and causing swelling with resulting neurological signs.

Typical CCN Presentation

CCN is typically seen in 6-18 month old cattle fed on high concentrate and low-fiber diets. Symptoms include dullness, head pressing, blindness, opisthotonos (head held high and back), and nystagmus (eye twitching). The disease progresses rapidly to recumbency, paddling, convulsions, and death.

Cause of CCN in This Case

Cattle normally produce thiamine in their rumens. However, low-fiber, high-concentrate diets disrupt this process. In this case, sudden dietary changes can also cause CCN by altering gut microbes. This explains the unexpected CCN in these calves due to both diet changes at purchase and the removal of concentrates.

Worm Burden’s Impact

The worm burden likely reduced thiamine absorption due to gut lining thickening.

Treatment and Management

Affected animals received aggressive thiamine supplementation. The entire group’s diet was adjusted with 1.5 kg/100 kg body weight straw per day to improve rumen function. Deworming was also performed to maximize gut absorption. Close monitoring continues as rumen microbes adapt to increased fiber content, and gut healing progresses (expected to take 2-3 weeks).

Key Takeaways

This case highlights that rapid dietary changes can cause CCN in unexpected situations. Worm burdens can worsen thiamine deficiency. Early intervention with thiamine and dietary adjustments are crucial for successful management.