Diet related laminitis
The effects of lush, carbohydrate-rich spring grass on our equine friends are well recognised and many of you will be aware of potential risks of diet related laminitis (inflammation of the soft tissue beneath the hoof) with or without the onset of founder (when the pedal bone in the hoof rotates). Despite the focus being on ponies (and all small equine alike), horses and donkeys can also be affected.
In the spring, grass is loaded with higher than normal soluble sugar content, called non-structural carbohydrates (NSC). The amount of NSC exceeds the small intestine's absorptive capability and so reaches the large intestine, primarily the caecum. This excess NSC shifts caecal fermentation to a state of acidosis (due to proliferation of certain bacterial types). The net effect being reduced blood flow and nutrient supply to the foot leading to laminitis and/or founder.
The levels of NSC in spring grass vary during the day. Concentrations tend to rise in the morning, reach maximum in the afternoon, and decline overnight. There are also seasonal variations associated with varying energy demands at different stages of growth. Concentrations are highest in late spring, lowest in mid-season, and intermediate in autumn.
To help prevent problems due to spring grass:
- Make available a good supply of quality, summer hay.
- Monitor and control the weight of the animal. Excessive weight adds mechanical pressure to the feet so, if laminitis occurs, chances of pedal bone rotation are much higher.
- Ensure teeth are in good condition by investing in regular dental checks.
- Ensure good hoof condition by regular trimming.
- Monitor trace element status, most importantly selenium.
- Provide a suitable environment, including, if at all possible, having a "mud free" area where animals can stand.
- Plan a suitable grazing rotation. Do not starve your animal but limit the supply of fresh, NSC rich grass in early spring. Graze grass early in morning but limit access in the afternoon.