There are 3 reasons for a horse to be underweight:
- the food isn’t available,
- the food is available but can’t be swallowed and
- the food is available, swallowed but isn’t absorbed.
Let’s look at each.
BCS 1 – Poor – Extremely emaciated with no fatty tissue anywhere. All the bones of the skeleton are visible. There is a large space between the inner thighs. This horse had just been rescued but is too far gone to recover.
The horse above was neglected and is the obvious result of having no food to eat. But there can also be a more sinister story as I have experience once.
I was floating 2 horses on a farm where I discussed the nutrition of their horses. They were both a BCS of 4. The owners insisted they were purchasing the feed but when they investigated they soon realized the farm was feeding their food to the bar’s horses and not these two. The result was still starvation.
BCS 1 but not from neglect. This mare had the best care in the world but was unable to absorb anything she ate.
The mare above was 38 years at the time of this picture. Her gut no longer was absorbing what she ate. she still chewed and swallowed grass and all other food was in the form of water soaked forage plus grains.
Inbetween these two reasons are the dental conditions that prevent the food in front of the horse into the digestive tract. They remain hungry but for reasons of obstruction, the food never gets into them. Beside bad teeth there are other reasons: foreign objects in the mouth (see the topic of oral foreign objects). esophagus dysfunction (partial paralysis, choke, diverticulum) and neurologic dysfunction affecting the swallowing mechanism.
Unfortunately this happened to a client’s husband who, after having a stroke, was no longer able to swallow. He passed away after refusing to be kept alive with a feeding tube.
Understanding the causes of starvation may help to correct this situation but unfortunately, most starved horses die. I have rescued and evacuated from farms many starved horses in my career but most, after passing a certain point, do not recover. One of the post mortem findings I have correlated are serrous atrophy of fat where the fat within the bone marrow is completely gone.