HOW TO PERFORM FIELD ANESTHESIA AND PAIN MANAGEMENT


Table 1. How to Manage Laminitis Step 1: Evaluate the patient Step 2: Medications


If significant pain or no response to NSAIDs


Pain level: pain score scale of 1–10


Medication


Phenylbutazone Traumeel


Detomidine Butorphanol


Lidocaine patches


Veggie or Sarapin blocks or soaker catheter


Understand owner expectations: return to full work? Pasture sound?


Type/Use


Homeopathic, alternative to NSAIDs: anti-inflammatory, analgesic


Analgesic sedative Opioid: analgesic


Analgesic for neuropathic pain Analgesic


NSAID, nonsteroidal anti-inflammatory drug; IM, intramuscular; SC, subcutaneous.


Make a treatment plan with a schedule or humanely euthanize the horse


Dosage/duration NSAID: analgesic, anti-inflammatory 2 mg orally once daily 15 tablets orally twice daily


1–2.2 mcg/kg IM, every 4–6 hours as needed


0.04–0.05 mg/kg SC every 4–6 hours as needed


700-mg patch cut to size, changed every 12 hours


2.5 ml Sarapin at each site for abaxial nerve block


with a farrier or podiatrist is essential. Trimming the feet on a weekly basis and applying appropriate pads, wedges, or shoes should be organized as a joint effort with the farrier. The patient’s comfort level should be evaluated on


a daily basis during the initial week of onset of laminitis. Develop a simple pain scale by using attitude, appearance, appetite, mobility, heart rate, and gastrointestinal motility as indicators of pain intensity. Tailor the analgesic protocol on a daily basis using these parameters. Analgesics will not result in “too much comfort,” resulting in worsening of injury to laminae. Instead, analgesia is neces- sary to prevent long-term damage to the central nervous system and to allow adequate appetite. Treating chronic laminitis pain involves develop-


ing a balance between budget restraints placed by the owner, analgesic options, and patient drug tolerance. Nonsteroidal anti-inflammatory drugs remain the standard of care. Gabapentin,i methadone,j and tramadolk are additional options for long-term care. Gabapentin, an anticonvulsant, is used in human medicine for neuropathic pain and postneurological injury. The drug acts by quieting hyperexcitable nerves and is reported in humans to prevent the “tingling” feeling post-nerve injury. Although gabapentin does not produce analgesia alone in most patients, it allows other drugs to be more effective. Although pharmacokinetics studies of gabapentin in horses have not been completed, anecdotal dosing in horses is anywhere between 2.5–20 mg/kg orally twice daily. From the author’s experience, start with 2.5 mg/kg orally three times a day for the first day then back down to twice daily. Long-term dosing can be used and should not be discontinued without tapering the dosing regimen. Methadone (an opioid with mu receptor agonist and N-methyl-D-aspartate activity) can be used as a long-term treatment for chronic laminitis pain but is a Schedule II drug with the Drug Enforcement Administration. Therefore, dosing requires veteri-


nary administration. The author has used 0.1 mg/kg orally twice daily of the 40-mg fast-dissolving tablets for 1–2 month durations in chronic cases with no clinical negative effects. Tramadol has shown lim- ited effectiveness in horses but can be used as an alternative when a patient is refractory to other medications. Dosing should start at 5 mg/kg orally twice daily and can be increased to 10 mg/kg orally twice daily.1


3. Discussion


Every patient has a different response to pain. It is dangerous to think that every patient will re- spond the same way to analgesics. Be aggressive with treatment in the early phase of disease and find a balance with long-term care that is suited to each patient. If the owner is unable to commit to long- term care strategies, euthanasia is recommended early in the disease process rather than later.


Acknowledgments


Declaration of Ethics The Author has adhered to the Principles of Veter-


inary Medical Ethics of the AVMA.


Conflict of Interest The Author has no conflicts of interest.


Reference and Footnotes 1. Guedes AG, Knych HK, Soares JH, et al. Pharmacokinetics and physiological effects of repeated oral administration of tramadol in horses. J Vet Pharmacol Ther 2014;37:269–278.


aEqui-Phar Bute Paste, Vedco, Saint Joseph, MO 64507. bBanamine, Merck Animal Health, Kenilworth, NJ 07033. cGastrogard, Merial Inc., Duluth, GA 30096-4640. dTraumeel, MediNatura, Berwyn, PA 19312.


eDormosedan, Zoetis Animal Health, Parsippany, NJ 07054. fTorbugesic, Zoetis Animal Health, Parsippany, NJ 07054. gLidoderm Patches, Endo Pharmaceuticals, Dublin, Ireland. hSarapin, High Chemical Company, Levittown, PA 19056. iNeurontin, Pfizer, New York, NY 10017. jMethadone Tablets, Generic.


kUltram, Janssen Phamaceuticals, Beerse, Belgium.


AAEP PROCEEDINGS  Vol. 64  2018 281


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