Grasses containing oxalates include: buffel grass, kikuyu, setaria, para grass, pangola grass, signal grass, guinea grass, and purple pigeon grass. Under rapid growth conditions (i.e. following heavy rainfall), grasses may exceed 6% oxalates which is enough to bind the entire calcium content of the grass.
Symptoms may include:
- Lameness and stiffness of the joints,
- Swelling of facial bones,
- Weight loss,
- Rough coat,
- Muscular weakness (preferring to canter than trot),
- Higher susceptibility to avulsion of ligaments and fracturing,
- Dirt eating and chewing problems (due to loosening of teeth).
While the swelling of the facial bones is a common symptom, it is not found in all cases of big head. It can take 4 to 12 months to re-mineralise bones but the big head appearance may not change.
The treatment for big head aims to correct the calcium: phosphorus imbalance & daily supplementation is the most effective method to avoid and treat big head.
Author: Elsie Dodd