Sudden severe lameness. What are the signs of a hoof abscess?

QUESTION:
I left for work this morning and my 9 year old gelding was moving normally at that time. When I returned home, he was extremely lame, not wanting to place any weight on his Left front foot. After looking him over, I could not find any swelling or heat in the leg. I talked with my veterinarian over the phone, and he explained that it was likely a hoof abscess. Could you discuss hoof abscesses here?

ANSWER:
This is a very common scenario…one day the horse is fine, and the next, he is extremely lame with no apparent injury. Without swelling on the limb, and any other marks / wounds, this is most likely a hoof abscess.

Hoof abscesses occur when bacteria make their way into the sensitive portion of the foot, and begin to create pus within the confines of the foot. With no easy way to expand, and the growing amount of pus, the pressure increases, and begins to cause severe pain. The bacteria usually finds its way in with the assistance of moisture, making abscesses much more common during the winter and spring months.

The signs associated with hoof abscesses are usually severe lameness, and often a more distinct or throbbing pulse in the affected foot. There can be pain associated with palpation of the coronary band on the affected foot.
Hoof abscesses are certainly a common issue within our practice, and with proper treatment and care, can resolve quickly. It is certainly a condition that an owner should involve a vet quickly, to prevent any complications and assure that an abscess is the correct diagnosis.

What does it mean when a horse has locking stifles or a locking patella?

QUESTION:
We were at a barrel race last week and my mare suddenly did not want to move. We initially thought that she may be tying up. The vet came out and said that since she wasn’t sweating, she wasn’t likely tying up. After a brief exam, he pushed her hind end a bit, and then she began to move, explaining that her stifles were “locked”. He was in a hurry and did not have time to discuss the issue at length. Could you please discuss “locking stifles?”

ANSWER:
The actual term for this condition is “upward fixation of the patella.” According to Adams’ Lameness in Horses “upward fixation of the patella (UFP) occurs when the medial patellar ligament becomes caught over the medial trochlear ridge. If it becomes fixed in that position, the hind limb cannot be flexed.”

This condition is more likely to occur in a horse with straight hind limb conformation or upright stifles. Though UFP often presents in one limb, both limbs are likely affected. In addition to the conformation of the horse, another significant factor is the fitness level (under conditioned) of the horse. With the out of shape horse, there can be a laxity in the patellar ligament, allowing for the upward fixation. This fixation can occur in different severities, leading to varied levels of lameness. There are multiple treatment options available, but it is best to consult a veterinarian for each individual case.

What is equine founder/ laminitis?

QUESTION:
I have a 6-year-old Quarter mare that foundered a couple of months ago. She has been on a diet and needs to lose quite a few pounds. Is there any possibility that in the future I could let her out in the pasture for a couple of hours or so?

ANSWER:
To answer your question, there is a VERY limited possibility of pasture time, but most likely that will involve wearing a grazing muzzle, and strictly controlling the length of time that the mare is allowed to graze.  This would also presume that before trying this schedule, the mare had already been controlled enough to return to a “normal” weight and was not concurrently experiencing any foot pain associated with founder.
Founder is a disease that most commonly affects the front (toe) region of the foot, but can affect the whole foot.  The cause of founder can be varied, but is usually due to inflammation in a hoof tissue called the lamina.  This inflammation (also called laminitis), can be caused by a primary (like too much grain), or secondary (such as severe colic) reason, both of which can be complicated by metabolic factors and obesity.  Most obese horses are set up to be “at-risk” for founder/laminitis, and only need a small change in feed to cause the inflammation in the lamina.  This change can be as simple as getting into the grain or as innocent as some extra time on rich pasture.
With this in mind, in your mare’s situation it would be VERY important to monitor her pasture time and feed intake.  This would also include monitoring the time of day she is on pasture (nights and mornings are better than the heat of the day) and the season of the pasture (first cutting vs. spring growth vs. late fall) to limit her exposure to simple sugars in the pasture.