HEMATOLOGIC AND IMMUNOLOGIC DISEASES

1. HEMATOLOGIC AND IMMUNOLOGIC DISEASES BY JEANNE STALL , R.V.T. Textbook References: 1. Common Diseases of Companion Animals by Alleice Summers MS, DVM 2. Livestock Disease Prevention by Joe Harper

2. Erythrocyte Disorders • 1. Decreased production • 2. Increased destruction • 3. Inappropriate loss of RBC’s (Hemorrhage)

3. ANEMIA • Common laboratory finding Secondary to a Primary Disorder Causes: Hemorrhage, Hemolysis, Blood parasites, Iron deficiencies, Immune- mediated disease, toxins • Regenerative vs. Nonregenerative (hemorrhage/hemolysis)(bone marrow) Determine by reticulocyte count

4. HEMORRHAGE ANEMIAS • Trauma primary reason • Other reasons: Platelet abnormalities or Abnormal clotting chemistries • External hemorrhage- easily determined/visible • Internal hemorrhage- PCV can’t show severity due to fluid shift compensation for loss/shock Treatment: Hemorrhage control/ replace volume • Generalized bleeding d/t Thrombocytopenia Less obvious/ diagnosis more difficult Signs: Petechial hemorrhage on ear flaps, mucous membranes, abdomen Treatment: Steroids, whole-blood or platelet-rich transfusions Eliminate further trauma

5. IRON – DEFICIENCY ANEMIAS • Chronic external blood loss Due to: Lg. flea infestation, G.I. parasites, gastric ulcers, bleeding tumors Lost iron/hemoglobin create altered RBC’s with reduced life span Treatment: Stop blood loss / Rx Iron per os x 30-60 days

6. HEMOLYSIS- (Hemolytic anemia) • Immune components attach to RBC membrane & alter cell structure Body defenses “remove” these altered cells in attempt to regain homeostasis Macrophages dealing w/ altered cells create extravascularhemolysis In K-9’s - d/t inflammatory process In cats- Haemobartonella / Fe. Leuk. Virus Signs: Exercise intolerance, pale mm, tachycardia, icterus

7. Hemolytic Anemia con’t……. • Trt: Suppress immune system w/ steroids Supportive care/therapy Transfusion in severe cases Rx Tetracycline for haemobartonella Neonate issues: Primarily foals (also pups/kittens) “Anti-fetal RBC” antibodies passed in colostrum AB attach to RBC’s which get attacked & lysed Prevent issues by blood typing breeding animals or foster those born to incompatible mothers

8. BLOOD – BORNE PARASITES • Mycoplasmahemofelis: Creates anemia in cats -Attach to RBC membranes = destruction of cell. Signs: wt. loss, anorexia, fever, hepatomegaly, splenomegaly, icterus • Babesiacanis & Babesiagibsoni: Canine anemias Vector: Rhipicephalussanguineus(brown dog tick) Intracellular parasite / Dx blood films/serology test • Cytauxzoonfelis: Protozoan / fatal dz. in cats “clinical signs to death” timeframe = days Intracellular- causes anemia Extracellular-Proliferates in vascular macrophages causing blood stasis & vascular occlusion

9. TOXIN –INDUCED ANEMIAS HEINZ BODY ANEMIAS • Drugs/oxidants in plasma form: 1.Reversible hemichromes 2. Nonreversible hemichromes - denatured hemaglobin forms aggregates called Heinz bodies: Cat- More suseptable, lg. eccentric, pale intracellular structures Dog- Multiple sm. intracellular structures Causes: Onion toxicity- K-9’s Acetaminophen - K-9’s & Cats As little as ½ tablet creates issues Methylene blue- Cat urinary antiseptic

10. IMMUNE-MEDIATED HEMOLYTIC ANEMIA IMHA cause unknown but Ab attach to RBC cell membrane then immune system “removal” Ab causes agglutination/destruction of RBC • Most common: 2- 8 yr.old female dogs ,Poodles, Old Eng. Sheep., Irish setters, Cocker spaniels • Signs: Anorexia, listlessness, weakness, pale mm, depression, tachycardia, tachypnea, +/- icterus/hepatomegaly/splenomegaly, distal extremity necrosis • Dx: CBC(leukocytosis; left shift neutrophilia, regenerative anemia • Trt: ↑ tissue O2, control immune response w/drugs

11. IMHA Rx • Glucocorticoids: Dexamethasone/ Pred to suppress immune response • Cimetidine: To prevent G.I. ulceration • Sucralfate: Protect G.I. ulceration • Heparin: To prevent thromboembolism or disseminated intravascular coagulation(DIC) Prognosis : Guarded ( 30% - 40 % death rate) Relapses common Advise OHE if intact female

12. IMMUNE-MEDIATED THROMBOCYTOPENIA • Similar to IMHA but involves platelets not RBC’s Ab attach to platelets which get destroyed in the liver, spleen or bone marrow • Drug induced cause????(Sulfonamide, Arsenicals, Digitoxin, etc…) • Most common in: Female, 5 – 6 yr. old dogs • Signs begin when platelets < 30,000/mm3 blood Bleeding/epistaxis/petechial hemorrhages/ bloody bm’s or vomitus/lethargy/weakness Dx: Bone marrow(budding megakaryocytes & ↑ in plasma cells) Response to Trt. Trt: Prednisone/ Vincristine/Platelet-rich transfusion Cimetidine OHE / Splenectomy • Prognosis: Good to guarded (20% death rate) / Relapses

13. EHRLICHIOSIS • Ehrlichiacanis- 1st recognized in U.S. in 1963 Via : Tick vector- Rhipicephalussanguineus Blood transfusion Multiplies in liver,spleen, lymph nodes Causes : Platelet consumption, RBC destruction & Vascular endothelial damage Bone marrow suppression Aplastic anemia

14. Ehrlichiosiscon’t… • Clinical signs: Depression, anorexia, fever, wt. loss, dyspnea, edema in the extremities, bleeding tendencies, Trt: Doxycycline, Tetracycline

15. von Willebrand’s Disease Most common inherited hemostasis disorder Normally, vW factor (vWF) allows platelets to clump Decreased / absence of vWF = bleeding disorder Involves 54 breeds- Dobies/ G.Shep./ Labs Signs: Bruising, prolonged bleeding (heat cycle/venipuncture/sx…) Diagnosis: Buccal mucosal bleeding time > 4 min. ELISA test + (enzyme-linked immunosorbant assay Low plasma levels of vWF

16. Lymphoma • Feline: 90% of all feline hematopoietic tumors 70% of cases are FeLeuk Positive cats Onset 3 yrs( FeLeuk + cats) to 7 yrs (FeLeuk-) Mediastinal, Alimentary, Multicentric Signs: Dyspnea, wt. loss , anemia, V, D, enlarged lymph nodes Trt: Chemotherapy, Prednisone, Radiation therapy NO CURE –Goal to put it in remission Lifespan of 2 months to 42 months post Dx

17. Lymphoma • Canine: Lymphosarcoma most common hematopoietic tumor Clinical signs: Enlarged peripheral lymph nodes, lethargy, Wt. loss, V, D W/O Trt have 4-6 week survival time Trt: Chemotherapy, Prednisone Victims: Boxers, bullmastiffs, basset hounds, St. Bernards, Scottish terriers

18. Feline Immunodeficiency Virus • “ Feline Aids” a.k.a. F.I.V. Not ZOONOTIC to humans Lentivirus Spread via cat fights mostly, but can be passed to nursing kittens or possibly incidental transmission via bowls, grooming

19. FIV con’t… • Acute Stage: Mild symptoms • Subclinical Stage: Typically no clinical signs, but disease is present and lurking • Chronic Clinical Stage: Opportunistic infections Stomatitis, wt. loss, Upper Resp. inf. retinal degeneration Tumors….. Trt: AZT Retrovir, supportive care NOTE:

20. FIV con’t… • Average lifespan: Dx to death ~ 5 yrs • Prevent Dz. By keeping cats indoors, test all new additions to household, vaccination • NOTE: Be aware, vaccinated cats will test positive on all future FIV tests!!!!!

21. Equine Infectious Anemia • EIA is a reportable Dz. • If a case is found, must contact State Vet • Transmission: Biting flies, shared needles or equipment • Clinical signs: Fever, Depression, Anemia Clotting disorders Horses can be “carriers”, showing few signs of dz. Coggins test If positive, horse must be euthanized or branded & quarantined

22. Red Maple Toxicosis • Wilted or dried red maple leaves( Acer rubrum) • Ingested leaves have a toxin which causes oxidation damage to the RBC’s RBC’s can’t carry O2 effectively Clinical signs: Jaundice, brown urine, weakness, depression, petechiae Trt: Supportive care Blood transfusions

23. Sheep • Caseous Lymphadenitis Corynebacteriumpseudotuberculosis Signs: Swollen lymph nodes Thick, creamy abscesses Trt: Isolate ill stock from flock Antibiotics not usually effective

24. Malignant Edema • Clostridium septicum • Via wounds • Fever, local pain, edematous swelling • Trt: Supportive care

25. Blackleg • Clostridium chauvoei • Wounds • Signs: Fever, shock, death, swelling