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Clinical Trial

Clinical trials are crucial to learning.  These trials are required for FDA licensing of therapeutic drugs.  Field trials that are required by FDA to licence treatments are called effectiveness studies.

  • Effectiveness studies are placebo or "active" controlled studies using natural disease (field) cases.
  • Effectiveness studies that were used to license drugs are available to the public. Search using the key words "Freedom of Information Summary (fill in the drug name here).
  • A client consent form is required for this type of study.
  • The studies are conducted in compliance with CVM Guidance for Industry 85 Good Clinical Practices for Clinical Effectiveness (VICH GL9).
  • Join the group discussion about the pathology of polyneuritis equi

Some of our trials are designed to gather data from animals suffering from EPM or EPM related diseases, they are potential clinical benefit studies.

  • Potential benefit studies aren't always controlled studies.
  • Potential benefit studies are used to support the FDA submissions.
  • A veterinarian is involved in this type of study.

Please read the entrance requirements for each study. Studies vary, some are placebo controlled or are designed to use an active control (the "placebo" is a licensed EPM medication in an active control study).  Some studies are designed to show potential benefits of the treatment and are uncontrolled. A PLACEBO CONTROLLED STUDY WILL BE CLEARLY EXPLAINED BEFORE YOU ENROLL.  YOU MAY NOT ENTER A PLACEBO CONTROLLED STUDY WITHOUT SIGNING AND RETURNING THE INFORMATION FORM.


Pathogenes donates some services and medications used to diagnose and treat horses in need.  Follow these 2019 guidelines.  The horse should be under the control of the rescue and under the care of a licensed veterinarian. To participate in our Rescue Program please submit:

  • a serum sample with our submission form clearly marked rescue,
  • the horses history and prior treatment entered on the submission form,
  • veterinarians diagnosis of EPM or polyneuritis equi,
  • the method the veterinarian used for the diagnosis*,
  • a brief description of the need,
  • the 501 (c) 3 tax ID number for the organization,
  • a signed owner consent form,
  • CSF testing (the sample will be tested at no charge).

*The diagnosis of "EPM" or Polyneuritis equi is supported by specific criteria. Please call and get a copy of the Rescue Program paperwork. We will accept serology results from EDS, UC Davis, or Antech reference laboratory that supports a diagnosis of EPM or Polyneuritis equi.

Horses that don't require a 501 (c) 3:

  • miniature horses (mini's weigh less than 300 pounds),
  • zoo animals,
  • horses with penile paralysis, urinary incontinence, bowel stasis may be exempt from the 501 (c) 3 status.



The protocol is designed to determine the difference between treatment success for Orogin when compared to Protazil.  This is a non-inferiority study. Medication will be provided to qualified horses that enroll into the study.  There is no charge for the qualification paperwork to enroll into the study.  To qualify a veterinarian must have made a presumptive diagnosis of EPM supported by the FDA criteria for disease, a signed Owner Consent Form, and a signed Veterinarian Participation Form. Other qualification parameters include:

  • an adult horse of any breed,of either sex,
  • clinical signs characterized by a gait assessment score of > 2 and < 5,
  • the diagnosis of EPM supported by IFAT testing (serum CSF ratio of <65), or ELISA positive serum: CSF ratio <100;
  • a diagnosis of EPM supported by additional diagnostic work up to rule out other causes of ataxia;
  • and has not been treated for EPM with an anti-protozoal drug within 90 days of enrollment.

Exclusion criteria are the same as those that are found in the Freedom of Information Summary for Protazil. FIS Protazil.  Veterinarians are invited to inquire and receive the protocol for this study. Please provide the Owner Consent that is required for participation and the ability to receive medication. Potential Field Investigators should read VICH9 outlining the responsibilities to participate in this GLP study.

The medication used in the Orogin Field Effectiveness trial contains a new animal drug for use in investigational animals in clinical trials.  These drugs are not to be used in humans. Edible products of investigational animals are not to be used for food unless authorization has been granted by the US FDA or USDA.



This study has FDA concurrence.  The study objectives are intended to evaluate the effectiveness of NeuroQuel over a placebo for the treatment of residual or recurrent clinical signs of EPM. The entrance requirements are:

  • a horse between 2-20 years weighing at least 600 pounds of either sex;
  • an original diagnosis of EPM that includes:
    • A positive test for EPM (CSF testing required);
  • treated for EPM using an FDA approved treatment within 90 days of enrollment;
  • residual signs of EPM that include a gait assessment score (GAS) of 2 by the end of treatment or that signs recurred after the cessation of therapy.

A signed consent form must be completed for this study. NQ Owner Consent.  Veterinarians are invited to call and receive the protocol for this study.

The medication used in the NeuroQuel Field Effectiveness study contains a new animal drug for use in investigational animals in clinical trials.  These drugs are not to be used in humans. Edible products of investigational animals are not to be used for food unless authorization has been granted by the US FDA or USDA.

Post EPM Treatment Study

Sometimes EPM treatments don't resolve all the clinical signs associated with EPM or the horse relapses soon after treatment.  If the diagnostic workup to treat for EPM included a CSF (cerebrospinal fluid) analysis, please refer to the study above.  If the workup did not include a spinal tap please look at the requirements for this study.  It is placebo controlled, that means your horse has a 1:3 chance of receiving a placebo for the 14 days of treatment.  Click HERE to read the important points of this study.



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This study protocol has FDA concurrence. The study is intended to evaluate the effectiveness of NeuroQuel for the control of clinical signs associated with polyneuritis equi (PNE).  Eligible horses are:

  • between 2-30 years old, weighing at least 605 pounds, of either sex;
  • have a presumptive diagnosis of PNE that includes:
    • a negative serum test for Sarcocystis neurona (CSF not required);
    • a Clinical Score using the Fordyce scale of 4 or greater ;
    • no recent history of trauma, respiratory disease, WNV or rabies or the horse has been vaccinated for EHV-1, WNV, and rabies;

A signed Owner Consent form and Veterinarian Participation Form must be completed to enroll in this study. The period of pre-treatment is within 10 days of Day 1 (treatment).  After enrollment study medication will be shipped.

Veterinarians are invited to call and review the protocol for this study.


Useful link: module 29 Veterinary Feed Directive

Veterinary Feed Directive PDF form for veterinarians

For the veterinarian: some things you should know:




Any medication provided in a Clinical Trial listed above will have package labeling or package insert labeling  that includes contact information to report the response to treatment including side effects.  Adverse events or drug related side effects should be brought to the attention of your veterinarian.  You may report adverse events directly to Pathogenes by phone, email, or using the Case Analysis form for Horse Owners. Please email supporting information such as examinations by veterinarians, blood analysis, or any treatments that were administered for the abnormal signs.