LTCI product support for canine osteoarthritis, FeLV and FIV.

Frequently asked questions, information and documentation about LTCI’s treatment aid for osteoarthritis in dogs and FIV/FeLV in cats.

Frequently Asked Questions

What is FeLV and FIV?

Feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) infections are two of the most common and fatal feline diseases in the world. Infections can cause severe immunosuppression, anemia, and result in increased risk of other infections. LTCI is the first and only approved treatment aid* in the U.S. for cats suffering from FeLV and FIV infections.

I've read that FeLV / FIV are not treatable.

LTCI is new to the market as a treatment aid for feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) infections. As with any new product on the market, it will take time for the new product information to be distributed to animal health organizations and pet owners, and the information to be updated in literature and websites.

How does LTCI work in the treatment of FeLV / FIV?

LTCI is a naturally occurring immune modulating protein that helps restore your cat's ability to fight infection by increasing the production of lymphocytes.

What are Lymphocytes?

Lymphocytes are immune cells that help the body identify and destroy viruses and certain cancers.

What is Canine OA?

Osteoarthritis (OA) is one of the most significant diseases of dogs because of its overall prevalence in the canine population. Now that dogs live longer, OA is the most common form of arthritis and is almost universally present in older animals. In addition to reducing mobility, OA causes pain, stiffness and weakness that reduce quality of life. LTCI presents a revolutionary, USDA-approved treatment option for dogs suffering from OA. In clinical trials, over 90% of LTCI patients achieved significant improvements in symptoms.

Don't most vets treat OA with NSAIDs?

Osteoarthritis—as an immune mediated disease—should be treated as such. NSAIDs act by reducing pain via COX-1 and/or COX-2 ensymatic pathways, while LTCI addresses the underlying cause of osteoarthritis and the pain associated with the condition. Unlike NSAIDs, there are no known contraindications for the use of LTCI in patients diagnosed with OA.

Additionally, LTCI is safe treatment option for use in dogs who cannot use NSAIDs due to concomitant kidney, liver or heart problems, are elderly, or who have had previous, negative reactions to NSAIDs.

How does LTCI work in the treatment of OA?

Osteoarthritis–as an immune-mediated disease–should be treated as such. While NSAIDs act by reducing pain via COX-1 and/or COX-2 enzymatic pathways, LTCI addresses the underlying cause of osteoarthritis and the pain associated with the condition. By increasing T-Cell production, LTCI reduces the immune response within the joint, along with the progressive joint degeneration.

How safe is LTCI?

LTCI has passed a formal scientific, clinical safety study in which no significant adverse events were reported. In dogs, LTCI is USDA-approved for use in all dogs, over one-year-old, that have been diagnosed with OA.

Is LTCI natural?

Yes. LTCI is a naturally-occurring treatment aid and is not synthetically manufactured.

How can I contact you with additional questions?

Feel free to contact us at We're here to help!

How is LTCI administered and how often?

LTCI is administered by a veterinarian with a simple, painless injection under the animal's skin. In the first month of treatment, LTCI is typically administered 3 doses in weeks 1 and 2, and 2 doses in weeks 3 and 4. Subsequently, it can be administered monthly or bi-monthly, or as needed, depending on the animal‘s response and your veterinarian's advice. Veterinarians may use a more aggressive treatment schedule, depending on the animal's condition.

When should my pet feel better?

Response to treatment will vary, depending on the pet's condition and immune status. Clinical studies show that some pets respond in the first few weeks.

Where can I get LTCI?

In the United States, LTCI is only available through licensed vets. Contact your clinician to discuss LTCI treatment options or search below for clinics already administering LTCI to its patients. Order requests outside the United States can be directed to

Research Papers & Publications

Immunologic Effects of Human Thymic Stromal Grafts and Cell Lines

Esther F. Hays
Terry R. Beardsley


Lymphocyte T-Cell Immunomodulator (LTCI): Review of the Immunopharmacology of a New Veterinary Biologic

Daniel A. Gingerich, DVM, MS


Induction of T-Cell Maturation by a Cloned Line of Thymic Epithelium (TEPI)

Terry R. Beardsley
Michael Pierschbacher
Gayle D. Wetzel
Esther F. Hays


Lymphocyte T-Cell Immunomodulator (LTCI), a Potent Immune Modulating Biologic, Exhibits Safety and Efficacy in the Pain Management of Dogs with Moderate-Severe Osteoarthritis

Joel Ehrenzweig, D.V.M.1
Warren Jones, D.V.M.2
Christina Belew, D.V.M.2
Mary Ellen Goldberg, B.S., L.V.T., C.V.T., S.R.A., C.C.R.A.


Glossary of Terms

ANEMIA: A quantitative deficiency of the hemoglobin, often accompanied by a reduced number of red blood cells and causing pallor, weakness, and breathlessness.

BIOLOGICS: Any substance, as a serum or vaccine, derived from animal products or other biological sources and used to treat or prevent disease.

CONDITIONALLY APPROVED PRODUCTS: Products that have received a conditional license from the United States Department of Agriculture after demonstrating reasonable expectations of efficacy, safety, purity, and potency.

CYTOKINE: Any of several non-antibody proteins, such as lymphokines, that are released by a cell population on contact with a specific antigen and act as intercellular mediators, as in the generation of an immune response.

EFFICACY: The ability of a drug or biologic to produce the desired therapeutic effect.

FELINE IMMUNODEFICIENCY VIRUS (FIV): Also known as Feline Aids, is a retrovirus that may result in severe immune suppression in cats. FIV can attack the immune system of cats, much like the human immunodeficiency virus (HIV) can attack the immune system of human beings.

FELINE LEUKEMIA VIRUS (FeLV): A retrovirus that may cause severe immunosuppression, anemia, and result in increased risk of other infections. FeLV and FIV infections are two of the most common feline diseases worldwide.

GRANULOCYTOPENIA: Reduction in the number of granular leukocytes in the blood, such as neutrophils, eosinophils, and basophils.

IMMUNE RESPONSE: An integrated bodily response to an antigen, especially one mediated by lymphocytes and involving recognition of antigens by specific antibodies or previously sensitized lymphocytes.

IMMUNE SUPPRESSION: Causing the immune system to become compromised or suppressed to the extent that an adequate response to pathogens, cancer, or inflammation is reduced.

IMMUNODEFICIENCY VIRUS: A virus that induces a state in which the body's immune system's ability to fight infectious disease is compromised or entirely absent.

IMMUNOMODULATOR: Typically a biological product which produces an immune response, usually to modify an immune response or stimulate an immune response.

INTERLEUKIN: Interleukins are a set of cytokines which act as cell signals and often help elicit and direct immune responses.

LEUKEMIA: Any of various acute or chronic neoplastic diseases of the bone marrow in which unrestrained proliferation of white blood cells occurs and which is usually accompanied by anemia, impaired blood clotting, and enlargement of the lymph nodes, liver, and spleen.

LTCI: Lymphocyte T-Cell Immunomodulator, an immune modulating protein derived from a specialized thymic epithelial cell line.

LYOPHILIZED PRODUCT: A product which has been freeze dried, often to increase the shelf life of biologics.

LYMPHOCYTE: A white blood cell that plays a central role in immune responses to infections and cancer.

LYMPHOCYTE T-CELL IMMUNOMODULATOR: Lymphocyte T-Cell Immunomodulator, an immune modulating protein derived from a specialized thymic epithelial cell line.

LYMPHOMA: A type of cancer that originates in lymphocytes. It account for about five percent of all cases of cancer in the United States.

LYMPHOPENIA: A reduction in the number of lymphocytes within the blood.

RETROVIRUS: Enveloped viruses possessing an RNA genome, and replicate via a DNA intermediate. Retroviruses rely on the enzyme reverse transcriptase to perform the reverse transcription of its genome from RNA into DNA, which can then be integrated into the host's genome with an integrase enzyme. The virus then replicates as part of the cell's DNA.

SEPSIS: The presence of pathogenic organisms or their toxins in the blood or tissues.

T-HELPER CELLS: A class of lymphocytes which direct and coordinate the immune response.

THROMBOCYTOPENIA: The presence of relatively few platelets in blood. Decreased platelet counts can be due to a many different disease processes.

Find A Vet