1. THE IMMUNE SYSTEM UNIT 7 IMMUNITY AND VACCINES VETERINARY ASSISTING PROGRAM

2. RESPONSIBILITIES The immune system is responsible for protecting the animal from potentially harmful organisms attempting to invade. It is a VERY complicated system It must be able to recognize substances that are foreign to the body by recognizing what is naturally occuring

3. ANTIGENS Antigens are large, complex molecules that are foreign to the body. Once they enter the body, the stimulate an immune response for which antibodies are made. Antibodies: specific protein produced to protect against a disease. Attacks the pathogen. Pathogen: microorganism that causes disease

4. LYMPHATIC TISSUE The body has lymphatic tissue distributed throughout to detect antigens quickly. Within the lymphatic system are lymph nodes, which is lymph tissue encased in connective tissue. These lymph nodes can be palpated on almost any dog. Location of Lymph Nodes in the Dog. Digital image. Immune System Tumors in Dogs. Merck Manuals, July 2011. Web. 22 Aug. 2014.

5. Large reddish-brown organ within the abdomen that is involved in the immune system and filtering blood. Contains areas where immune cells scan incoming blood for antigens. Houses the cells responsible for producing antibodies. Important but not necessary Lymph nodes also house the cells responsible for antibodies and other organs also help filter the blood If damaged, extensive bleeding can occur Common site for tumors Digital image. Lymphatic System Anatomy and Function. PetEducation, n.d. Web. 22 Aug. 2014. SPLEEN

6. BONE MARROW Essential for the immune system Produces WBC’s Complicated process When the body recognizes an antigen, neutrophils and macrophages phagocytize the antigen It is then broken down within the cell A substance is release to begin immune response. This release kills the virus or slows replication, attracts other immune cells to the area, and kills the already damaged cells. This substance also affects the hypothalamus

7. LYMPHOCYTES AND ANTIBODIES Specific lymphocytes come in contact with specific antigens Stimulates repeated mitosis Results in a large number of lymphocytes Designed to react to this particular antigen, this is called clonal expansion. B lymphocyte or B cell B cells plasma cells secrete antibodies=humoral immunity Antibody is Y shaped, arms of the Y detect the antigen Pathogens have many antigenic determinate sites on its surface to which antibodies bind Antigen-antibody complex stimulates phagoctyic cells so pathogens are phagocytized (destroyed) T-Cells- type of lymphocyte associate with cell-mediated immunity Antibodies are produced primarily in the lymph nodes but also in the spleen and bone marrow.

8. HYPOTHALAMUS Any time the hypothalamus if affected, it elevates the body temperature. FEVER! Fever is designed to aid in the fighting of the pathogen A high body temperature hinders the replication of an infectious organism or can even kill it. It also stimulates the activity of lymphocytes, phagocytes, and antibodies.

9. INFLAMMATION Can be a result of physical injuries or reaction to invasion of a pathogen This response delivers more WBC’s and antibodies to the infected area 4 signs of inflammation Pain Heat Redness Swelling The swelling is referred to as edema. This is a build up of fluid under the skin due to increased capillary permeability.

10. INFECTION Not antibody related, cell mediated response only This is when a large number of cells invade a specific site A combination of WBC’s, invading pathogens, dying and destroyed tissue creates pus When describing pus, the term is purulent!! Pus trapped in a pocket is referred to as an abscess Digital image. Abscess on Dog's Shoulder. BerryHaven Veterinary Group, n.d. Web. 22 Aug. 2014.

11. VACCINES IMMUNITY CONTINUED…

12. CREATING IMMUNITY Immunity can occur one of two ways: Active immunity Passive immunity

13. ACTIVE IMMUNITY Active immunity results from exposure to a pathogen, either through a vaccine or natural infection Any exposure thereafter will trigger the immune system’s memory and quickly destroy the pathogen This can last for different periods of time, ranging from 6 months to years Dog Receiving Vaccine. Digital image. Bordetella and Pets. VPI Veterinary Pet Insurance, n.d. Web. 22 Aug. 2014.

14. PASSIVE IMMUNITY Immunity resulting from the transfer of antibodies from one animal to another Mother to offspring through colostrum Commercial diets (Esbilac) Plasma donation This immunity is temporary and usually only lasts several weeks to months

15. TYPES OF VACCINES 1.Modified live vaccines Uses altered antigens created from a pathogen and places a small amount of the disease into the animal’s body Pathogen is weakened, so it can divide but not cause clinical disease Boosters can be given but not always needed 2.Killed vaccines Uses killed pathogens Can no longer divide but still has antigens to trigger an immune response Must get a booster Slower

16. MLV Vaccine box. Digital image. Nobivac Canine 1- DAPPv (Galaxy DA2PPv). Valley Vet Supplies, n.d. Web. 22 Aug. 2014. KILLED Rabies Vaccine Vial. Digital image. Nobivac 3 Rabies - 10 Dose Vial. KV Supply, n.d. Web. 22 Aug. 2014.

17. VACCINE ROUTES Most vaccines come in an injectable form Subcutaneous Intramuscular Others are intranasal (Bordetella) Intranasal Vaccine. Digital image. Kennel Cough. MarvistaVet, 11 Dec. 2012. Web. 22 Aug. 2014.

18. ALLERGIC REACTIONS Not all immune responses are to prevent disease. Some occur against antigens that are not harmful Allergens are substances that create an allergic response, such as pollens, dust mites, and flea saliva An animal’s sensitivity to this causes a release of histamine. This release causes itchiness, eye and nasal discharge, sneezing, rubbing at eyes, and redness of the skin. Drugs given to help treat this are antihistamines Atopy is an allergic condition of the skin involving pruritus and alopecia

19. SEVERE ALLERGIC REACTIONS An allergic reactions that is generalized and life threatening is called anaphylaxis. Causes bronchoconstriction and leaky vessels which lead to respiratory distress and shock Epinephrine counteracts physiologic effects of histamine. Must be given quickly!

20. TITER These tests measure the level of antibodies in the bloodstream against a specific disease Results are reported as a ratio A titer of 1:256 has more antibodies than 1:64 A high titer proves that an animal has been exposed to a pathogen Not when the exposure occurred, could be from a vaccine

21. REVIEW Lymphatic is a highly complex system with lymph nodes throughout the entire body Many organs are involved with the immune system Infection is not antibody related Vaccines can be killed or modified live The types of immunity are passive and active Allergens can cause a life threatening event known as anaphylaxis