Geriatric ImmunologyGeriatric Immunology

Clare Ryan, DVM, PhD, DACVIMClare Ryan, DVM, PhD, DACVIMBadger Veterinary HospitalBadger Veterinary HospitalClient Education SeminarClient Education Seminar

February 7, 2013February 7, 2013

GeriatricGeriatric

≥ ≥ 20 years old20 years old

Equine Geriatric PopulationEquine Geriatric Population

Maximum lifespan is Maximum lifespan is 35-40 years35-40 years

15% of the equine 15% of the equine population over 20 population over 20 years of age years of age (1997)(1997)

““Age is not a disease”Age is not a disease”

But with age come But with age come some changes:some changes:

Decline in body Decline in body condition and muscle condition and muscle tonetone

Changes to the Changes to the immune system can immune system can lead to increased lead to increased infectioninfection

Immune System:Immune System:White Blood CellsWhite Blood Cells

http://www.nobelprize.org/educational/medicine/immunity/index.html http://www.nobelprize.org/educational/medicine/immunity/index.html

Neutrophils- eat invading organismsNeutrophils- eat invading organisms

Macrophages- eat invading organismsMacrophages- eat invading organisms

Lymphocytes- make “memory” responsesLymphocytes- make “memory” responses

Immune System Signals: CytokinesImmune System Signals: Cytokines

Tell immune cells to ramp inflammation up or downTell immune cells to ramp inflammation up or down

Immunization (Vaccination)Immunization (Vaccination)

Immunizations Create Immunizations Create Immune System “Memory”Immune System “Memory”

Immune System “Memory”Immune System “Memory”

““Immunosenescence”Immunosenescence”

A decline in immune function and immune A decline in immune function and immune response that occurs with aging. response that occurs with aging.

Researchers believe immunosenescence Researchers believe immunosenescence accounts for the increase in cancer and accounts for the increase in cancer and infections such as influenza and pneumonia infections such as influenza and pneumonia in people of old age. in people of old age.

White Blood Cells in the ElderlyWhite Blood Cells in the Elderly

Decreased numbers of Decreased numbers of lymphocyteslymphocytes

Decreased function of Decreased function of lymphocyteslymphocytes

Immunization Responses in the ElderlyImmunization Responses in the Elderly

Decreased response to immunizationDecreased response to immunization Decreased duration of immune responseDecreased duration of immune response

Geriatric HorsesGeriatric Horses

Reduced response to immunization with Reduced response to immunization with Rabies and Influenza vaccinesRabies and Influenza vaccines

Vaccinating Geriatric HorsesVaccinating Geriatric Horses

In the past, some people recommended not In the past, some people recommended not vaccinating geriatric horses, or not vaccinating geriatric horses, or not vaccinating them as frequentlyvaccinating them as frequently

Geriatric horses need to be vaccinated!! Geriatric horses need to be vaccinated!!

Supporting the Geriatric Immune Supporting the Geriatric Immune SystemSystem

Keep adequate (but not too high) body conditionKeep adequate (but not too high) body condition Adequate parasite controlAdequate parasite control Reduce exposure to infectionReduce exposure to infection Minimize stressMinimize stress Vaccinate according to riskVaccinate according to risk No proven benefit to using immune stimulants in No proven benefit to using immune stimulants in

geriatric horses (yet)geriatric horses (yet) NutritionNutrition

Questions?Questions?

Aging horses: Aging horses: “Inflamm-aging”“Inflamm-aging”