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Home Care for Horses with Chronic Laminitis

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It seems odd that this topic has been discussed so little in the veterinary literature when at any given time most of us have at least one chronic laminitis case under our care that is being managed at home by the owner. Almost all of our knowledge on this aspect of laminitis treatment has been gleaned through experience, by wrestling individually with the medical, ethical, financial, and emotional challenges these cases can present. Much has already been presented on the medical management of the laminitic horse and on strategies for trimming and shoeing the laminitic foot. What we want to focus on in this chapter are the other challenges so often faced when directing the home care of a horse with chronic laminitis. A good outcome in all but the mildest of cases takes a team of dedicated people: veterinarian, farrier or trimmer, horse owner (or other daily caretaker), and perhaps a physical therapist or other licensed animal therapist. Even so, the horse owner usually is the principal caregiver and therapist when the case is managed at home. It is particularly important that we ensure the owner is well informed about the disease process in general and their horse’s case in particular, what is involved in recovery, whether recovery is likely to be complete, how long it is likely to take, and what challenges may be encountered along the way. Without the owner’s continued commitment and care, a good outcome is next to impossible.
Home Care for Horses with Chronic Laminitis
Christine King BVSc, MANZCVS, MVetClinStud
August 2020
It seems odd that this topic has been discussed so little in the veterinary literature when at any
given time most of us have at least one chronic laminitis case under our care that is being
managed at home by the owner. Almost all of our knowledge on this aspect of laminitis
treatment has been gleaned through experience, by wrestling individually with the medical,
ethical, financial, and emotional challenges these cases can present. Much has already been
presented on the medical management of the laminitic horse and on strategies for trimming and
shoeing the laminitic foot. What we want to focus on in this chapter are the other challenges so
often faced when directing the home care of a horse with chronic laminitis.
A good outcome in all but the mildest of cases takes a team of dedicated people: veterinarian,
farrier or trimmer, horse owner (or other daily caretaker), and perhaps a physical therapist or
other licensed animal therapist. Even so, the horse owner usually is the principal caregiver and
therapist when the case is managed at home. It is particularly important that we ensure the owner
is well informed about the disease process in general and their horse’s case in particular, what is
involved in recovery, whether recovery is likely to be complete, how long it is likely to take, and
what challenges may be encountered along the way. Without the owner’s continued commitment
and care, a good outcome is next to impossible.
Pain Management
Pain management is a crucial component of the home treatment plan for humane reasons, owner
compliance, and perhaps also for optimal tissue repair. Pain management is of chief concern to
the majority of horse owners, and owners often gauge the success or failure of the treatment and
rehabilitation plan based on their perception of the horse’s comfort. In this internet age, owners
will often go outside the team for help if they perceive that their horse’s pain is not being
adequately managed. Both good communication and an effective pain management plan are
important in dealing with these cases.
When devising a treatment plan for the chronically laminitic horse, the first step is to
determine the extent of the disease process and why the horse remains painful. Is the persistent
foot pain simply the result of displacement of the third phalanx (P3) and its consequences? Or
might there also be on-going insult to the feet, such as could occur with poorly regulated
pituitary pars intermedia dysfunction (PPID) or the hyperinsulinemia associated with obesity
(metabolic syndrome)? In other words, are you simply dealing with the aftermath of acute
laminitis or does this particular case represent a chronic-active process? Distinguishing between
these two possibilities is important in devising a comprehensive treatment plan, including a safe
and effective pain management strategy.
Pain management has been a focus of clinical and experimental laminitis research in recent
years. As a result, a multimodal approach has emerged as the optimal pain management strategy
in moderate to severe cases.Driessen, Hubbell,Jones,Yaksh But once the hospitalized laminitis case is
recovered sufficiently that it can be returned home, and in the less severe cases of laminitis that
can be managed entirely at home, nonsteroidal anti-inflammatory drugs (NSAIDs) such as
phenylbutazone may provide sufficient pain relief on their own. Of course, care should be taken
with chronic NSAID use to monitor the horse for signs of gastric or colonic ulceration, and to
ensure that the horse is drinking well.
The newer NSAIDs of the selective cyclooxygenase type 2 (COX-2) inhibitor class, such as
firocoxib, are showing promise as being both effective and safe for pain management in the
horse.Belknap,Doucet Although, it has recently been suggested that a nonselective COX inhibitor may
be best in the developmental and acute stages of laminitis, when the lamellar microvasculature is
activated or inflamed, as selective COX-2 inhibitors in humans have caused the most serious
problems in patients with vascular disease (e.g. rofecoxib [Vioxx] associated heart attack or
stroke). The COX-2 selective drugs may therefore be more appropriate in the treatment of
chronic laminitis, when vascular inflammation has subsided, yet a safe NSAID may be needed
for long-term use.Belknap
Some veterinarians have been using doxycycline for pain management, on the premise that
its effects as a matrix metalloproteinase (MMP) inhibitor render it a useful anti-inflammatory
and thus analgesic agent. While anecdotal reports are encouraging, no clinical studies have yet
been published to validate these observations, nor to determine the optimal dosage for this
purpose. In one recent study, neither doxycycline nor oxytetracycline sufficiently inhibited MMP
production to prevent the development of Obel grade 3 lameness in experimentally induced
laminitis caused by carbohydrate overload.Eades
This approach to pain management carries with it several potential adverse effects. One is
disruption of the body’s normal microflora; another is the development of resistance to this class
of antimicrobial drugs. A third is the potential for nonspecific MMP inhibition to impede tissue
repair. As destructive as these enzymes can be when unleashed from their normally tight
regulation, the MMPs also have essential roles in normal tissue turnover and in tissue repair.
Similar in this regard to the cyclo-oxygenases, the MMPs as a class have essential constitutive
roles in normal physiological processes.Clutterbuck In fact, recent research indicates that the timing
of MMP-2 upregulation in experimentally induced laminitis suggests a greater involvement in
tissue repair than in tissue damage.Black,Pollitt While MMP regulation undoubtedly is important in
the treatment and prevention of laminitis, it is too soon in our understanding of the molecular
mechanisms of laminitis to know how best to restore MMP regulation in the laminitic foot.
Other substances that have been tried with some clinical success include opioids (e.g.
fentanyl, tramadol), gabapentin, acetyl-L-carnitine, and various medicinal herbs, such as
turmeric, ginger, devil’s claw, salicylate-containing plants (meadowsweet, white willow bark,
etc.), and Gynostemma pentaphyllum (jiaogulan). However, the safety and efficacy of many of
these substances are little studied in the horse,Tinworth so broad recommendations cannot be made
at this time.
Appropriate hoof care and footing are every bit as important as medical therapy for pain
management. Phenylbutazone is a very poor substitute for proper hoof care and comfortable
footing. In fact, we would venture to say that if a horse continues to require daily NSAIDs or
other pain medications several weeks or months beyond the laminitic event, then the case may
need to be reviewed. Perhaps the trimming, shoeing, and/or footing needs to be adjusted in some
way; or maybe there is a concurrent medical issue that isn’t being adequately addressed.
It also bears stating that pain medications can interfere with our ability to accurately evaluate
the horse’s current condition and needs. While the horse’s comfort is important, an equally
important goal of the treatment plan should be to get the horse off pain medications as soon as
possible. It is a milestone in the horse’s recovery when he can comfortably move around without
needing pain medications.
Concurrent Medical Issues
Any medical conditions that could have caused or contributed to the laminitic event or that might
now be impeding recovery must be addressed. Most common are PPID, obesity, and the
systemic inflammatory response triggered by endotoxemia or other microbial toxins. The
medical management of these conditions is discussed elsewhere.
Also important is the prompt identification and management of infection within the
compromised foot. With any laminitic horse, the owner must be warned of the potential for
infections to develop within the laminitic foot, even months after the laminitic event. Foot
abscesses are common in the months following the laminitic episode, but they can usually be
dealt with successfully as for any subsolar or submural infection. Fortunately, more severe
infections such as osteomyelitis of P3 are far less common. These cases generally require
debridement of the diseased bone and systemic or regional antimicrobial therapy. Such therapy is
best provided in a hospital setting.
Feeding the chronically laminitic horse can be a challenge. The diet must meet the body’s needs
for maintenance and repair, while at the same time addressing any special issues. For example, if
the horse has metabolic issues that render him particularly sensitive to starches and simple
sugars, then care must be taken to feed a diet which meets the horse’s daily caloric needs while
keeping the amount of nonstructural carbohydrates (NSC) low. A NSC content of 10% or less is
recommended for these horses.Geor At the other end of the spectrum is the late-term pregnant or
lactating broodmare, whose greater caloric needs may necessitate the inclusion of some
carbohydrate-rich foods, although digestible fiber sources such as beet pulp (without molasses)
and fats can safely be used to make up some of the shortfall in these mares. But in general, a diet
that is low in NSC and high in fiber is appropriate for the majority of horses with chronic
laminitis. Safe grazing and hay selection for horses needing a low NSC diet is discussed in detail
elsewhere, including at
Protein, amino acids. Very little clinical research has been conducted on the other
nutritional needs of the laminitic horse. It would seem reasonable to ensure that the protein
intake is moderate but not excessive (e.g. a crude protein content of 10% to 12% overall for most
nonpregnant, nonlactating adult horses), and of high biological quality and from species-
appropriate sources (i.e. grasses and legumes primarily).
Individual amino acids have been studied in the context of various medical conditions in
other species. For example, arginine has been touted as being useful in vasoconstrictive
conditions because it is a nitric oxide precursor and thus theoretically useful in improving blood
flow. However, studies involving L-arginine supplementation have shown inconsistent effects on
endothelial function in other species.Jahangir We don’t yet know if it is worthwhile supplementing
this or any other specific amino acid beyond what is found in the horse’s natural diet of grasses,
legumes, and various other herbage.
Vitamins, minerals, essential fatty acids. It should go without saying that the horse’s daily
vitamin, mineral, and essential fatty acid requirements must also be met. A body cannot recover
fully without all of the building blocks needed for tissue repair. A diet that consists of nothing
but inferior quality hay will likely be marginal for protein, frankly deficient in vitamin E, omega-
3 fatty acids, and probably other antioxidant complexes, and possibly some of the essential
primary and trace minerals as well.anon This commonly used diet is incomplete and should be
considered substandard in the care of the chronically laminitic horse. No horse ever recovered
fully on such a diet.
In 2007 the National Research Council (NRC) published its revised guidelines for feeding
horses.anon However, some equine nutritionists consider these guidelines too conservative and
advise supplementing vitamins and minerals at a rate of NRC + 50% for special-needs horses,
such as those with chronic laminitis.
Antioxidants. Antioxidants have received much attention in the lay press and on the internet,
both in the fields of human and animal health. While a diet that contains ample antioxidant
substances appears to be important for health, there is a lot of hype and very little science on
what constitutes “ample” for antioxidants in any species, including the horse. More to the point,
recent research suggests that oxidative stress plays a limited role in laminitis. Treiber et al.
reported that there was no difference in the serum levels of three markers of antioxidant function
(glutathione, glutathione peroxidase, and superoxide dismutase) nor increased oxidative pressure
between ponies with a history of pasture-associated laminitis and those that had never had
laminitis.Treiber Belknap et al. found that in both the black walnut extract and carbohydrate
overload models of laminitis, oxidative stress is minimal and does not seem to be primarily
involved in causing lamellar injury and failure.Belknap
Many different substances can act as antioxidants or reducing agents, including several of the
vitamins and trace minerals. Feeding a species-appropriate diet of high-quality forages, with
supplemental vitamins, minerals, and essential fatty acids as needed, should provide the
chronically laminitic horse with ample antioxidants. Fresh plant material is an especially good
source of antioxidant substances, not to mention being species-appropriate, for the horse.
However, this benefit must be tempered with concerns about the NSC content of improved grass
varieties, in particular, when managing carbohydrate-susceptible horses. In these cases it is wise
to limit pasture turnout time or simply hand-graze the horse along the edges of meadows, paths,
and hedgerows, where there is a variety of nongrass herbage on which the horse can forage.
Gut health. Restoring and maintaining gut health is an aspect of overall health that has yet to
be extensively studied in the laminitic horse, but we believe it is a crucial component of hoof
health, particularly in cases of laminitis caused by carbohydrate overload. We do know that the
gut barrier is compromised in these cases, potentially allowing substances normally confined to
the lumen to enter the systemic circulation and trigger a cascade of biochemical events which
culminate in laminitis.Weiss The severity and duration of this greater intestinal permeability
remain to be fully studied and probably are case-specific, but it would seem prudent to include
restoration of gut health in the list of nutritional goals for the laminitic horse.
What is required for gut health in this species will likely prove to be a diet that mimics the
horse’s natural diet, which is high in fermentable fiber and generally low in NSC. In some cases
the addition of soil- or pasture-based microbial species might prove beneficial, but the colonic
microflora is by nature highly adaptable and self-replenishing, so it may well be that providing
suitable substrate (i.e. fermentable fiber), along with judicious grazing (hand-grazing or hand-
picking suitable plant materials if necessary), is all that is required to restore a healthy microbial
population in most cases. Feeding a good quality, low NSC grass hay at a rate of 1.5% to 3% of
ideal body weight per day, according to the horse’s caloric needs (i.e. less for the fat ones, more
for the thin ones), should ably meet the need for suitable microbial substrate. The amino acid L-
glutamine is considered conditionally essential for enterocyte health in other speciesBergen and
presumably the horse, but it remains to be seen whether supplemental glutamine would be
helpful in most chronic cases of laminitis.
One other aspect of gut health that receives too little attention is gut motility. A healthy gut is
one that has healthy peristaltic activity. Two management practices that encourage restoration of
healthy gut motility are to mimic the natural feeding pattern of horses (i.e. “feed little and often”
if free-choice feeding is not advisable for the individual), and to encourage movement
throughout the day.
Movement is essential to both the physical and psychological health and well-being of the horse.
In our experience, it is also a crucial component of recovery from laminitis. Daily activity should
be introduced as soon as the horse can safely be walked without causing further damage to the
digital tissues. It is important to stay within the current constraints of the individual’s digital
pathology, but it is just as important to get the horse moving as soon as he can safely and
comfortably do so.
At one end of the spectrum is the horse who is so stiff and sore that slow hand-walking on a
forgiving surface for just a few minutes at a time is all the system can cope with at first. At the
other end is the horse who is now off NSAIDs, is walking and perhaps even trotting comfortably
and spontaneously, and is ready to resume light work. Regardless of the starting point, the goal is
to gradually increase the duration and intensity of activity as comfort and mobility improve;
otherwise, recovery is very slow and likely to be incomplete. No horse ever recovered fully by
just standing around in a dry lot.
Horses with even mild to moderate laminitis often are stiff and sore throughout the body, but
particularly through the muscles and connective tissues of the shoulder girdle, back, and
hindquarters. These patterns reflect the chronic attempt to relieve some of the load on the painful
feet. In addition to daily activity, physical therapy can improve the horse’s comfort, mobility,
willingness to exercise, and capacity to exercise, which speeds the overall recovery. A trained
physical therapist or licensed animal therapist (if state law allows) can be a valuable asset to the
If such a trained and licensed individual is not available, then there are some simple exercises
that can be taught to the horse owner and added to the horse’s daily routine. One is a forelimb
stretch in which the horse’s forelimb is lifted and gently drawn forward to extend all of the joints
in the limb and to stretch the myofascial tissues along the palmar and caudal aspects of the
forelimb all the way up to the trunk. This stretch is particularly useful because chronic tension in
the muscles of the shoulder girdle increases the tension in the deep digital flexor tendon, by
virtue of the strong interconnections among muscles and connective tissues throughout the limbs
and trunk.King
Performing this stretch 3 to 5 times on each forelimb, twice a day initially, can improve the
horse’s comfort and mobility after even just a couple of sessions. However, the stretch must be
performed gently, by slowly and softly drawing the limb forward rather than pulling on it. Being
too forceful or pushing the limits of a stretch can cause muscle soreness,Rose which is
counterproductive. The caretaker should also be instructed to keep the hoof in line with the
shoulder, keep the hoof close to the ground, make the entire stretch fluid and pleasurable, stay
within the horse’s comfortable limits, and be content with small gains each day. When done
correctly, there is minimal risk of harm in unskilled hands.
Another exercise that can easily be taught to the owner carries even less risk of harm. Based
on the work of Milton Trager, MD, it involves simple weight-shifting: standing beside the horse
and gently shifting the horse’s weight from side to side, front to back or back to front, and even
diagonally. The horse’s feet do not move, but rather the body sways slightly over the static feet.
The movements should be gentle, slow, and of small amplitude, working with the elastic recoil of
the tissues.
The owner is instructed to gently push on the horse’s body and then let the body roll back
toward the person, at which time it can be gently moved away again to create a slow, rhythmic
rocking or swaying motion. With as much pressure as it takes to gently throw a beach ball to a
small child, and working with the rhythm and rate of the horse’s tissues, chronic myofascial
tension can be greatly relieved and a more healthy stance restored even in one session.
Another often-overlooked element of physical activity for the recovering horse is play. Not
only is play important for mental health, but it can also be remarkably useful for physical
rehabilitation, particularly if the play becomes spontaneous and self-directed. In general, it is best
to encourage play with other horses, rather than with the owner. And if play is not possible or
advisable under the present circumstance, then it can be sufficient for the moment to bring a
playful attitude to the horse’s physical therapy and other daily management.
Nursing Care
In many cases, nursing care for the chronically laminitic horse is not a lot different from good
basic horse management. If the horse spends much of his time lying down, then extra care to
prevent or treat pressure sores, muscle compression, and other consequences of excessive
recumbency is needed.Floyd For ambulatory cases, nursing care may simply involve some extra
TLC (tender-loving care) for the horse’s mental health and whatever daily activity and physical
therapy are advised.
Housing and Footing
There are several elements to housing and footing for the chronically laminitic horse. The aim is
to ensure that the horse’s environment is safe and conducive to repair and rehabilitation. The
housing should be warm, dry, comfortable, safe, and spacious. In particular, there should be
ample opportunity for the horse to lie down and rest if he chooses. It is important for tissue repair
that the body get plenty of rest and deep, restorative sleep. For that, the bedding or footing must
be comfortable and the horse must feel safe. There must also be plenty of room for the horse to
get up and down without risk of being cast or otherwise caught up
Compatible company is important to the sense of safety and security as well. Horses
generally feel safer in the company of others, so a sense of safety often necessitates keeping at
least one other horse nearby. That is also important because healthy social interactions can
facilitate recovery. The importance of good mental health in these chronic cases cannot be
overemphasized. No horse ever recovered fully by standing around on his own, isolated to a stall
or a dirt lot. The company of healthy horses can greatly speed recovery.
The footing requirements often change as healing progresses. Initially, while the feet are still
quite sore, the footing should be soft and supportive, but not so deep that it increases the work of
moving. Clean sand or fine gravel is ideal; deep sawdust, shavings, or other soft stall bedding
can also be suitable. Later, as the horse becomes more comfortable and more mobile, the horse
can tolerate a wider range of footing materials. In fact, footing that is comfortable but which
engages the hoof and encourages the growth of a healthy hoof capsule is best. Such footing can
include typical arena surfaces, wood-chip covered pens or paddocks, grassy pastures (with all the
usual caveats about limiting the NSC intake), coarser gravel, and loose dirt.
Regardless of the type of material, the chosen footing should be dry and kept clean of manure
and urine. Although mud is soft underfoot, and may even be useful during the acute phase of
laminitis, standing in mud or mucky footing greatly increases the potential for foot abscesses in
the chronically laminitic hoof.
Hoof Care
Management of the chronically laminitic foot is discussed at length elsewhere. Suffice it to say
that it is essential to trim the hoof in order to optimize blood flow within the digital circulation
and normalize the biomechanical forces on the compromised digit. That generally requires
trimming to restore the normal orientation of P3 in relation to the other phalanges, to the normal
portion of the hoof capsule, and to the ground.
Communication. The element of hoof care we want to focus on here is interpersonal. It is
important to work closely with the farrier or trimmer, and have frequent dialogue about the
horse’s progress and current needs. It is equally important to have the horse owner in on the
discussion. With the explosion of information available to horse owners on the internet and in
magazines, it is understandable that they may feel confusion or conflict about the plan of care at
times. Teamwork and good communication are crucial in these cases.
Frequent reassessment, with repeated radiographs as needed, also is essential to success. This
aspect of home care may be where many of us trip up the most. A “call me if you need me”
approach may work well with some horse owners, but with many others it places too great a
responsibility on someone with too little knowledge of this disease process. It is up to us, as the
team leaders, to direct the management of the horse. That involves frequent monitoring of the
horse, factoring in the farrier’s perspective and the horse owner’s daily observations, and
charting the course accordingly. Trying to save the owner money by not arranging revisits on a
schedule we feel is appropriate for the case may not be in the horse’s best interest.
Sole protection. Whether to use a shoe, glue-on pad (wood, leather, plastic, etc.), pour-in
material, or removable boot to protect the compromised hoof depends on many factors, including
the owner’s wishes. An increasing number of clients want to keep their horses barefoot. This
approach does not need to compromise the horse’s comfort or recovery. There are now many
different kinds of hoof boot on the market. All of them have the benefit of providing sole
protection to the vulnerable or sensitive-soled foot. Some are designed specifically for the
painful foot, and they generally include a cushioned insole with or without frog support. Others
are designed primarily for the healthy horse, to be used during exercise, but they can be suitable
for use in the chronically laminitic horse as well.
When managing the barefoot laminitic horse, boots should be used as much as needed to
protect the sensitive sole and ensure that the horse is comfortable. It is important that the horse
be comfortable enough to move around at will, and if that necessitates the use of boots during
turnout, then so be it. Having said that, though, no-one has yet designed a boot that fits perfectly
on every horse and that can be used without issue all day, every day. If boots are used instead of
shoes, glue-on pads, or some other form of sole protection, then it is important to ensure the best
possible fit, and advise the owner to check daily for rubbing. While it is important to use the
boots when needed, it is equally important to leave them off for as much of the day and night as
possible, relying instead on clean, dry, comfortable footing. The newer pour-in sole protection
products such as Sole GuardÔ (Vettec, Inc.) are useful in some cases, but they are not as
effective in the flat-soled horse as in those with normal concavity to the sole.
Ensuring Owner Compliance
In closing, it is worth reemphasizing the importance of the owner’s active and on-going
participation in home care. Owner compliance problems are minimized by discussing at the
outset the time and financial commitments required in these cases and by setting realistic goals,
expectations, and protocols. Equally important is providing frequent assessment, feedback, and
encouragement. Celebrate even the small measures of progress, but remain the voice of reason,
particularly with regard to expectations for return to athletic function.
It is easy for the owner, who sees the horse every day, to miss small but significant changes,
and to become discouraged by persistent or recurrent foot pain or by common sequelae such as
foot abscesses, white line disease, and vulnerability to sole bruising. Most horse owners are
willing to put in the time and money, as long as they have sufficient support and realistic
expectations. These cases can turn out very well, but it takes considerable commitment by
everyone on the treatment team, most especially the horse owner.
Author’s note: This book chapter was written by me (Christine M. King) on commission in 2009 and
published under the names of three other people. This chapter is some of my best work to date, yet it is
credited to others—an act of intellectual dishonesty, the ramifications of which I did not appreciate at the
time. This chapter is entirely my own original work, exactly as I submitted it. I retain the copyright.
anon. Nutrient Requirements of Horses, 6th revised edition. National Research Council,
Committee on Nutrient Requirements of Horses; The National Academies Press, Washington
DC, 2007.
Belknap JK. Pharmacology: Is there a scientific basis for anti-inflammatory therapy in laminitis?
In Proceedings, 5th International Equine Conference on Laminitis and Diseases of the foot,
Palm Beach, FL, 2009, pp. 88-89.
Bergen WG, Wu G. Intestinal nitrogen recycling and utilization in health and disease. J Nutr
2009; 139:821–825.
Black SJ. Enzymes: What role do they play? In Proceedings, 5th International Equine
Conference on Laminitis and Diseases of the foot, Palm Beach, FL, 2009, pp. 82–83.
Clutterbuck AL, Harris P, Allaway D, Mobasheri A. Matrix metalloproteinases in inflammatory
pathologies of the horse. Vet J 2008; [epub ahead of print]
Doucet MY, Bertone AL, Hendrickson D, et al. Comparison of efficacy and safety of paste
formulations of firocoxib and phenylbutazone in horses with naturally occurring
osteoarthritis. J Am Vet Med Assoc 2008; 232:91–97.
Driessen B. Review of equine pain medications in laminitis. In Proceedings, 4th International
Equine Conference on Laminitis and Diseases of the foot, Palm Beach, FL, 2007, p. 66.
Eades SC. Laminitis research: Louisiana State University. In Proceedings, 5th International
Equine Conference on Laminitis and Diseases of the foot, Palm Beach, FL, 2009, pp. 34–35.
Floyd AE. Environmental management of the severely laminitic horse. Equine Podiatry, Floyd
AE and Mansmann RA (eds), Elsevier Health Sciences, 2007. pp. 359–367.
Geor R. Nutritional management of the prelaminitic and laminitic horse. In Proceedings, 5th
International Equine Conference on Laminitis and Diseases of the foot, Palm Beach, FL,
2009, pp. 48–49.
Hubbell JAE. Systemic pain therapy in the horse with laminitis. In Proceedings, 4th International
Equine Conference on Laminitis and Diseases of the foot, Palm Beach, FL, 2007, p. 91.
Jahangir E, Vita JA, Handy D, et al. The effect of L-arginine and creatine on vascular function
and homocysteine metabolism. Vasc Med 2009; 14:239–248.
Jones E, Vinuela-Fernandez I, Eager RA, et al. Neuropathic changes in equine laminitis pain.
Pain 2007; 132:321–331.
King C. Equine anatomy in perspective: an integrative view of equine musculoskeletal anatomy.
In Proceedings, 3rd International Symposium on Rehabilitation and Physical Therapy in
Veterinary Medicine, 2004; pp. 89–93.
Rose NS, Northrop AJ, Brigden CV, Martin JH. Effects of a stretching regime on stride length
and range of motion in equine trot. Vet J 2009; 181:53–55.
Tinworth KD, Harris PA, Sillence MN, Noble GK. Potential treatments for insulin resistance in
the horse: a comparative multi-species review. Vet J 2009; [epub ahead of print]
Treiber K, Carter R, Gay L, et al. Inflammatory and redox status of ponies with a history of
pasture-associated laminitis. Vet Immunol Immunopathol 2009; 129:216–220.
Weiss DJ, Evanson OA, Green BT, Brown DR. In vitro evaluation of intraluminal factors that
may alter intestinal permeability in ponies with carbohydrate-induced laminitis. Am J Vet Res
2000; 61:858–861.
Yaksh T. Pain management I and II. In Proceedings, 5th International Equine Conference on
Laminitis and Diseases of the foot, Palm Beach, FL, 2009, pp. 84–87.
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Studies with L-arginine supplementation have shown inconsistent effects on endothelial function. The generation of guanidinoacetate (GAA) from L-arginine with subsequent formation of creatine and homocysteine and consumption of methionine may reduce the pool of L-arginine available for nitric oxide generation. Experimental studies suggest that creatine supplementation might block this pathway. We sought to determine the effects of L-arginine, creatine, or the combination on endothelium-dependent vasodilation and homocysteine metabolism in patients with coronary artery disease. Patients with coronary artery disease were randomized to L-arginine (9 g/day), creatine (21 g/day), L-arginine plus creatine, or placebo for 4 days (n = 26-29/group). Brachial artery flow-mediated dilation and plasma levels of L-arginine, creatine, homocysteine, methionine, and GAA were measured at baseline and follow-up. L-arginine and creatine supplementation had no effects on vascular function. L-arginine alone increased GAA (p < 0.01) and the ratio of homocysteine to methionine (p < 0.01), suggesting increased methylation demand. The combination of creatinine and L-arginine did not suppress GAA production or prevent the increase in homocysteine-to-methionine ratio. Unexpectedly, creatine supplementation (alone or in combination with L-arginine) was associated with an 11-20% increase in homocysteine concentration (p < 0.05), which was not attributable to worsened renal function, providing evidence against an effect of creatine on decreasing methylation demand. In conclusion, the present study provides no evidence that L-arginine supplementation improves endothelial function and suggests that l-arginine may increase methylation demand. Creatine supplementation failed to alter the actions of L-arginine on vascular function or suppress methylation demand. The unexpected increase in homocysteine levels following creatine supplementation could have adverse effects and merits further study, since creatine is a commonly used dietary supplement.
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The aim of this study was to quantify the effects of two different 8-week stretching regimes on stride length (SL) and range of motion (ROM) in the equine trot. Eighteen horses were divided into three matched groups: a 6 days/week stretching regime (6DSR), a 3 days/week stretching regime (3DSR) and a control no-stretching regime (NSR). SL and ROM data were collected at weeks 0, 2, 4, 6 and 8 for trot in-hand. Stretching had no significant effect on SL. A number of significant differences were found in joint ROM between treatments in the shoulder, stifle and hock, suggesting some negative biomechanical effects of the 6DSR. Stretching daily may be too intensive and cause delayed onset of muscle soreness. Further examination of stretch frequency may establish its potential to enhance performance and welfare.
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To compare efficacy and safety of paste formulations of firocoxib and phenylbutazone in horses with naturally occurring osteoarthritis. Randomized controlled clinical trial. 253 client-owned horses with naturally occurring osteoarthritis. Horses were treated with firocoxib (0.1 mg/kg [0.045 mg/lb], PO, q 24 h) or phenylbutazone (4.4 mg/kg [2 mg/lb], PO, q 24 h) for 14 days. Physical examinations and lameness evaluations were performed prior to treatment and after 7 and 14 days. Clinical improvement was defined as a reduction of at least 1 lameness grade or a combined reduction of at least 3 points in scores for pain during manipulation or palpation, joint swelling, joint circumference, and range of motion. Proportion of horses clinically improved on day 14 for the firocoxib group (104/123 [84.6%]) was not significantly different from the proportion for the phenylbutazone group (103/119 [86.6%]). Proportion of horses that were improved on day 14 was significantly greater for horses treated with firocoxib than for horses treated with phenylbutazone with regard to score for pain on manipulation or palpation (P = 0.028), joint circumference score (P = 0.026), and range of motion score (P = 0.012), but not for overall lameness score or joint swelling score. No direct treatment-related adverse effects were detected during the study. Results suggested that overall clinical efficacy of a paste formulation of firocoxib in horses with naturally occurring osteoarthritis was comparable to efficacy of a paste formulation of phenylbutazone.
Insulin resistance and hyperinsulinaemia increase the risk of laminitis and horse owners and veterinarians should attempt to enhance insulin sensitivity in at-risk groups. In obese animals this may be achieved, in part, by promoting weight loss and increasing exercise, but such intervention may not be appropriate in non-obese insulin-resistant animals, or where exercise is contra-indicated for clinical reasons. An alternative approach to controlling insulin sensitivity in obese and non-obese horses may be the use of certain herbal compounds that have shown promise in humans and laboratory animals, although little is known of the effects of these compounds in horses. The herbs can be grouped according to their primary mechanism of action, including activators of the peroxisome proliferator-activated receptors, anti-obesity compounds, anti-oxidants, compounds that slow carbohydrate absorption, insulin receptor activators and stimulators of glucose uptake, with some herbs active in more than one pathway. Certain herbs have been prioritised for this review according to the quality and quantity of published studies, the reported (or extrapolated) safety profile, as well as potential for efficacy, all of which will hopefully motivate further research in this field.
The role of intestinal microflora in digestive and metabolic processes has received increasing attention from researchers and clinicians. Both enterocytes and small intestine luminal microorganisms can degrade peptides and amino acids (AA). Further, enterocytes can utilize ammonia via glutamate, glutamine, citrulline, and urea synthesis, whereas luminal microbes will deaminate AA, hydrolyze luminal urea, and recycle this ammonia by synthesis of new microbial cells. Although, undoubtedly, some indispensable AA may arise from N cycling and microbial synthesis in the intestinal lumen, the actual net impact on protein nutrition status appears to be limited in humans and animals. Moreover, potential contributions of the recycled N as colonic luminal microbial proteins to AA in blood depend on colonic protein digestion and AA absorption. Finally, new evidence indicates that gut microbial metabolism may be enhanced by prebiotics and probiotics, with the prospects of new treatment paradigms for eliminating undesirable secondary N metabolites and ameliorating complications in whole-body N metabolism under the conditions of intestinal stress, liver disease, and kidney failure.
Inflammatory and redox signals could render lamellar tissue susceptible to damage and contribute to higher risk for laminitis in obese or insulin resistant ponies just as these factors contribute to health risks in humans with metabolic syndrome. This study evaluated circulating markers of inflammatory and redox status in ponies that had a history of recurrent bouts of pasture-associated laminitis (PL, n = 42) or had never developed clinical laminitis (NL, n = 34) under the current management conditions. There were no differences (P > 0.05) between PL and NL ponies for markers of antioxidant function (glutathione, glutathione peroxidase, superoxide dismutase) or increased oxidative pressure (malondialdehyde, apoptosis, 3-nitrotyrosine). Inflammatory status, as indicated by fibrinogen concentration, was also not different between pony groups (P = 0.84). However, PL ponies had higher (P < 0.001) plasma concentrations of the pro-inflammatory cytokine TNF-alpha than NL ponies. This suggests that a predisposition to laminitis is associated with increased circulating inflammatory cytokines. TNF-alpha could also represent a contributing factor to increased insulin resistance observed in laminitis prone ponies. These results provide new insight into potential mechanisms and risk factors underlying laminitis.
The extracellular matrix (ECM) of connective tissue is constantly being remodelled to allow for growth and regeneration. Normal tissue maintenance requires the ECM components to be degraded and re-synthesised in relatively equal proportions. This degradation is facilitated by matrix metalloproteinases (MMPs) and their proteolytic action is controlled primarily by the tissue inhibitors of metalloproteinases (TIMPs). Both MMPs and TIMPs exist in a state of dynamic equilibrium, with a slight excess of one or the other depending on the need for either ECM breakdown or synthesis. Long-term disruption to this balance between MMPs and TIMPs will have pathological consequences. Matrix metalloproteinases are involved in a number of diseases in mammals, including the horse. Excess MMP activity can cause ECM destruction, as seen in the lamellar basement membrane in laminitis and the articular cartilage in osteoarthritis. Matrix metalloproteinase under-activity can potentially impede healing by preventing fibrinolysis in fibrotic conditions and the removal of scar tissue in wounds. Matrix metalloproteinases also degrade non-ECM proteins and regulate cell behaviour via the release of growth factors from the substrates they cleave, increasing the scope of their effects. This review looks at the involvement of MMPs in equine health and pathologies, whilst exploring the potential consequences of therapeutic intervention.
To study the in vitro effects of cecal contents incubated with corn starch on colonic permeability in horses. 4 healthy adult ponies. Mucosal specimens were obtained from the right ventral colon and mounted in Ussing chambers. Changes in short circuit current, conductance, and large-molecule permeability in response to addition of cecal contents and cecal contents incubated with corn starch were evaluated for 120 minutes. Incubation of cecal contents with corn starch for 8 hours resulted in a decrease in cecal content pH and an increase in lactic acid concentration. These changes were similar to those reported in vivo for ponies given corn starch. Exposure of colonic mucosa to cecal contents incubated with corn starch resulted in an increase in tissue conductance and permeability of technetium Tc 99m pentetate, compared with mucosa exposed to cecal contents alone. In vitro exposure of colonic mucosa to cecal contents incubated with starch resulted in increased paracellular permeability. Fermentation of excessive amounts of carbohydrate in the intestinal lumen of horses may directly induce increased intestinal permeability associated with carbohydrate-induced laminitis.
Laminitis is a common debilitating disease in horses that involves painful disruption of the lamellar dermo-epidermal junction within the hoof. This condition is often refractory to conventional anti-inflammatory analgesia and results in unremitting pain, which in severe cases requires euthanasia. The mechanisms underlying pain in laminitis were investigated using quantification of behavioural pain indicators in conjunction with histological studies of peripheral nerves innervating the hoof. Laminitic horses displayed consistently altered or abnormal behaviours such as increased forelimb lifting and an increased proportion of time spent at the back of the box compared to normal horses. Electron micrographic analysis of the digital nerve of laminitic horses showed peripheral nerve morphology to be abnormal, as well as having reduced numbers of unmyelinated (43.2%) and myelinated fibers (34.6%) compared to normal horses. Sensory nerve cell bodies innervating the hoof, in cervical, C8 dorsal root ganglia (DRG), showed an upregulated expression of the neuronal injury marker, activating transcription factor-3 (ATF3) in both large NF-200-immunopositive neurons and small neurons that were either peripherin- or IB4-positive. A significantly increased expression of neuropeptide Y (NPY) was also observed in myelinated afferent neurons. These changes are similar to those reported in other neuropathic pain states and were not observed in the C4 DRG of laminitic horses, which is not associated with innervation of the forelimb. This study provides novel evidence for a neuropathic component to the chronic pain state associated with equine laminitis, indicating that anti-neuropathic analgesic treatment may well have a role in the management of this condition.