Laminitis -- inflammation of the laminae.
What IS the laminae?
It's the 'sticky' tissue that holds the hoof capsule onto the foot. Plain and simple.
It is comprised of connective tissue that acts like velcro.
"The hair-brush like structures are called the sensitive laminae. These things interlock with some similar structures of the inside of the hoof wall called the insensitive laminae. The hoof itself grows from a structure near the hairline called the coronary band. The coronary band is homologous to our cuticle, and the hoof to our fingernail. The sensitive laminae, as they look, are sensitive with nerves and flush with blood supply to provide nutrients to the structures of the horse's foot."
So what are some of the CAUSES of Laminitis?
There are many causes of laminitis. The following is a fairly intensive list outlining all the situations that can cause a laminitic horse.
- Excess carbohydrates; too much grain, lush pasture, too much sugar
- Excessive weight, especially unilateral weight. Draft horses and ponies are particularly susceptible to obesity and laminitis.
- GI (Gastro-intenstinal) problems and stress/shock including:
--Enteritis, intestinal occlusion
--Metrititis, retained placenta
- Management Factors:
--Lengthy time in transport
--Excessive work on hard surfaces
--Bedding containing black walnut shavings
--Rapid Ingestion of large quantities of cold water when horse is overheated
- Endocrine Abnormalities
--Cushing’s Disease (Hyperadrenocorticism)
--Insulin Resistance (Diabetes Type II)
--Addison’s Disease (Hypoadrenocorticism)
--Administration of glucocorticoid drugs
- Renal Issues (Kidney)
- Immune Disorder
- Respiratory Issues
- Mechanical – Poor trimming of hooves and/or shoeing; imbalances
- Adverse reactions to Drugs – vaccines, dewormers and other chemical compounds
- Exposure to Neurotoxins
There are about 550 - 600 pairs of primary epidermal laminae in each hoof along with 150-200 secondary laminae.
These interdigitate with equivalent structures on the surface of the coffin bone, known as dermal laminae. The secondary laminae contain basal cells which attach to the basement membrane which, in turn is attached to the coffin bone by way of the connective tissues of the dermis.
Because the horn of the hoof capsule is absolutely unforgiving and unyielding from pressure within the foot, the pain that is caused by laminitis stems from the pressure of the inflammation of those tissues along with the necrotizing that occurs from lack of blood flow due to the extraordinary pressure inside the foot.
Laminitis is not something to fool around with. Once the animal has progressed to the Acute stage of Laminitis (see last week's blog post), if not halted before 72 hours then advancement to Founder occurs.
While there are no guarantees, ever, that a laminitic horse will recover and be fully rehabilitated, the natural care provided by excellent hoofcare will go a long, long way in setting the parameters for the hooves to fully recover. Prevention, of course, is the first line of defense against Laminitis but even with the most diligent of care some horses will founder in spite of it all depending on their natural constitution and systems. It is almost inevitable that horses with Cushing’s Disease will contract Laminitis sometime during their lifetime. The same holds true for Insulin Resistant horses and those with other Endocrine issues. Ensuring that the hooves are balanced, leveled and well attended can help in preventing many of these attacks but if not combined with adequate diet and nutritional vigilance as well as regular exercise and movement, even the best trimmed hooves will succumb to the body’s imbalances as a whole. One cannot separate the hooves from the rest of the horse – what goes in, grows out. Most everything that happens with the horse’s body and mind will be evident in the hooves.
Next week we'll discuss further actions that can be taken to prevent Laminitis ...
Gwenyth Browning Jones Santagate is the best-selling author of 10 Secrets to Healthy Hooves as well as a noted author for various international equine publications includingThe Horses Hoof, Equine Wellness, Natural Horse Planet as well as a contributing author for the 2001 United States Federal Mounted Border Patrol Training Manual. For the last 37+ years, she has maintained healthy hooves with natural trimming on thousands of horses and specialized in pathological rehabilitation hoofcare for the last 18 years. She and her husband John keep a small herd of their own equine in SW Florida and continue to offer consults for horses in need. For further information please click here: www.thepenzancehorse.com