Quick response and recognition to laminitis results in better prognosis for horses
Riverton – Laminitis, known commonly as founder, in horses is one of the most common diseases of the foot in horses.
“We’ve all had a foundered horse,” said Amy Stockton of Stock Doc Vet Clinic. “There are some ways we can treat and prevent laminitis in our horses.”
Stockton presented on Feb. 7 during Fremont County Farm and Ranch Days in Riverton and overviewed new developments in caring for foundered horses.
“Many aspects of laminitis are a mystery to us,” she said. “We still don’t know the exact mechanism that causes the blood supply to not go to the foot, so it can stay oxygenated. Then, it just dies. It’s like an abscess in the foot.”
“Laminitis is defined as the inflammation of the laminae of the foot, but that is a gross over-simplification,” Stockton said.
When there’s a lot of pressure on the coffin bone or the hooves are too long, a tendon in the foot can pull the bone down, which can cause problems.
She said, “Laminitis is truly a complicated sequence of inter-related events that results in varying degrees of breakdown of that inter-digitation of the primary and secondary laminae.”
“Basically, the hoof capsule in the laminae gets inflamed and makes a little bit of ‘soup’ so it’s not firm, and it doesn’t hold the coffin bone up like it should,” she simplified.
A severe inflammation results in rotation of the coffin bone.
There are three phases of laminitis.
“The developmental phase is when whatever causes the laminitis is going on,” Stockton said, noting that cold water, too much grain, infection in the uterus, retain placenta or too much pressure may cause laminitis. “This stage is when the horse is exposed to those factors.”
“If we can stop laminitis here, we can prevent rotation and prevent the rest of the disease,” she said.
When the first signs of lameness appear, Stockton noted the disease has progressed from the developmental phase to acute laminitis.
She added, “This is the point of emergency. I can’t stress that enough. If we can get in and stop the inflammation, we may be able to save the horse and the feet.”
The acute phase encompasses first phases of lameness in the first 48 hours until the first signs of rotation.
The final phase, chronic, is after 48 hours.
“If a horse has had laminitis for a while, it has chronic laminitis,” Stockson said.
“The young are more likely to get acute laminitis and the old are more likely to get chronic laminitis,” explained Stockton. “Acute means it comes on hot and heavy, right now. They are sore and compressing very rapidly. Chronic means they get a little bit sore, then get better, then they get sore again.”
“Different syndromes lead to both of these scenarios,” she added.
Laminitis can be caused by grain overload, lush grass or legume consumption. Additionally, too much cold water, septicemia – when bacteria are present in their system, or endotoxemia – when endotoxins in the system, are important.
“Endotoxins are thought to be most important,” Stockton said. “Endotoxins are produced by bacteria. When bacteria die, the toxins are released into the system.”
When horses eat too much grain, the gut becomes very acidic, explained Stockton, which kills the bacteria, causing them to release naturally occurring toxins.
“The gastrointestinal tract absorbs the toxins, which are transported through the horse’s system, breaking down vasculature everywhere,” she said. “It’s most noticeable in the feet.”
In the feet, the blood is shunted from the veins to the arteries and doesn’t oxygenate the laminae, so the laminae begins to die.
Other diseases, including Cushing’s Disease, may make a horse more susceptible to laminitis, and steroids, viruses and more can all cause laminitis.
The first sign of a horse with laminitis is the animal’s stance.
“They are trying to get the weight off their toes, so they’ll have the toes camped out in front of them, with the weight on the heels,” Stockton said. “If the back feet are affected, too, they may also have the back feet camped up under them, but it’s usually the front feet that are affected.”
When a horse has laminitis, the feet are usually hot, particularly over the hoof well and the coronary band, Stockton said, and a digital radiograph can be used to visually see how much of a temperature difference is present.
She said, “We can use a digital radiograph to compare between the front and the back feet.”
The pulse will be increased in a horse with laminitis, Stockton explained, noting producers should regularly check the pulse of their horse in the feet to gain understanding of what is normal.
Elevated heart rate and respiratory rate will also be seen.
“When they are in pain, they may be breathing faster and their heart rate will go up,” she said.
The mucus membranes might be red, the horse may be shaky or in shock.
“Really bad laminated horses may have oozing from the coronary band,” she said. “It may also be present on the toe coming around the foot.”
To avoid laminitis or treat laminitis, producers should first check the water and make sure horses are on soft footing.
“Also, make sure there isn’t a uterine infection or something else that is predisposing the horse to laminitis,” Stockton said. “Then, we have to stop the pain hypertension cycle.”
The pain hypertension cycle results from increased blood pressure as a result of pain. Elevated blood pressure further affects the blood supply to the foot, which causes additional pain and hypertension, continuing the cycle.
“We stop that with pharmaceuticals,” she said. “We also have to prevent permanent laminar damage. If we let the tendon continue to pull, it causes damage, so we have to stop that and return blood supply to the foot.”
Using drugs that increase circulation, like acepromazine, can help to increase the blood supply to the foot. Nitroglycerine patches also result in similar impacts.
“We can use a nitroglycerine patch for 12 hours to increase blood supply to the foot,” she said, noting several other drugs have been used, including Banamine, may be used. “Banamine is the first drug we use because it’s analgesic, meaning it fights pain, but it’s also anti-endotoxic, so we kill the endotoxins.”
Finally, the foot should be supported using a sand stall to reduce pressure on the heel.
“We’d like our horses to lay down. If they want to lay down, let them. It reduces pressure,” Stockton said.
Foot pads can also support the foot.
“Then, we need to call the farrier in to help with corrective shoeing,” she said. “We can use surgery as a last-ditch effort.”
“In an emergency, call the vet,” Stockton said. “We need to try to get laminitis treated before it gets too far. Early diagnosis in the acute phase will improve prognosis, so call the vet in quickly to get care for our horses as soon as possible.”
Saige Albert is managing editor of the Wyoming Livestock Roundup and can be reached at firstname.lastname@example.org.