Hemolymphatic System, Pt. 2 Flashcards

1
Q

What 3 conditions are associated with neonatal isoerythrocytosis? What does this result in?

A
  1. foals inherit RBC type (Ag) from sire
  2. Aa- or Qa- mares become sensitized to Ag and produce antibodies due to exposure from previous pregnancies, blood transfusions, or transplacental contamination
  3. colostrum with antigens are ingested and absorbed by the foal

destruction of foal RBCs by maternal Ab

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2
Q

In what horses is there a higher incidence of neonatal isoerythrocytosis? What blood groups are strongly antigenic?

A

10% in mules (1% in TB, 2% in STB)

  • Aa
  • Qa
  • donkey factor
  • occasionally Ua, Pa, Qc, and Db
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3
Q

What can possibly prevent neonatal isoerythrocytosis?

A

Ca —> antibody-mediated immunosuppression

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4
Q

When does neonatal isoerythrocytosis occur? What clinical signs are seen?

A

foal is born healthy but develops signs 24-36 hours (or several days if mild)

  • progressive lethargy and weakness
  • pale to yellow MM
  • tachycardia, tachypnea
  • discolored urine
  • seizure, death
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5
Q

What 2 laboratory results are seen in foals with neonatal isoerythrocytosis?

A
  1. hemolytic anemia: decreased PCV, RBC, and Hb
  2. increased bilirubin, hemoglobinemia, hemoglobinuria
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6
Q

How can immune reactions be confirmed in cases of neonatal isoerythrocytosis?

A
  • INDIRECT COOMBS: test mare serum or colostrum for antibodies
  • DIRECT COOMBS: presence of antibodies attached to foal RBC
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7
Q

What test is done on foals to confirm neonatal erythrocytosis?

A

jaundice foal agglutination test —> foal RBC exposed to mare colostrum or serum, detecting agglutination and NOT hemolysis

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8
Q

What treatment is recommended in foals within or after 24 hours of developing neonatal isoerythrocytosis?

A

< 24 hours = withhold milk (muzzle, strip mare) and offer alternative sources

> 24 hours = decrease stress, give fluids and antibodies, and offer a blood transfusion of washed mare RBCs or compatible donors

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9
Q

What 4 complications are associated with neonatal isoerythrocytosis treatment with blood transfusions?

A
  1. hyperbilirubinemia - kernicterus (exchange transfusions)
  2. iron toxicity
  3. sepsis
  4. liver failure
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10
Q

In what 3 ways can neonatal isoerythrocytosis be prevented in the mare?

A

identify risk —> Aa, Qa, previous NI foal

  1. screen serum 2 weeks before the due date and repeat every 2 weeks
  2. check colostrum for reactivity
  3. Domperidone before foaling
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11
Q

In what 2 ways can neonatal isoerythrocytosis be prevented in the foal?

A

provide alternative sources of colostrum

  1. withhold milk with a muzzle or strip the mare
  2. provide frozen colostrum for NI- mare or milk from goats, NI- mare, or Mares Match
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12
Q

How is the jaundiced foal agglutination test performed?

A
  • collect colostrum from mare
  • collect EDTA tube from foal before nursing
  • set up 6 tubes and add 1 mL of saline and perform serial dilutions
  • add 1 drop of foal blood to each tubes and mix
  • centrifuge tubes for 2-3 mins
  • invert each tube and pour liquid out to observe clumping
  • if positive at 1:8 dilution, don’t let foal nurse
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13
Q

Neonatal isoerythrocytosis:

A
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14
Q

What are the main colostrum and foal causes of failure of passive transfer of maternal antibodies? What risk is associated?

A

COLOSTRUM - none produced, poor quality or quantity

FOAL - cannot get up, suckle, or absorb

sepsis!

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15
Q

How is failure of passive transfer diagnosed?

A

SNAP foal IgG test using foal’s blood

  • < 400 mg/dL IgG = complete failure (spot lighter than both references
  • 400-800 mg/gL IgG = partial failure (intermediate spot color)
  • > 800 mg/dL IgG = proper nursing (spot darker than both references)
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16
Q

How is failure of passive transfer prevented?

A

early recognition is key - often too late by time of diagnosis

  • educate owner/manager: monitor foal, assist with colostrum administration, clean environment
  • evaluate pre-suckle colostrum, should be sticky, yellow, and thick and > 1.060 SG
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17
Q

At less than 12 hours post-partum, what treatment is recommended for foals with failure of passive transfer?

A

1-2 L of good-quality equine colostrum from a bank of healthy, blood typed, and vaccinated mares (200-250 mL can be collected)

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18
Q

At over 12 hours post-partum, what treatment is recommended for foals with failure of passive transfer?

A

at this point colostrum cannot be absorbed, commercial plasma that is from vaccinated mares with known IgG concentrations and negative for Aa and Qa alloantigens

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19
Q

What should be done if there is no blood typing available for foals treated with plasma in failure of passive transfer?

A

can use plasma from untransfused geldings that are fully vaccinated and negative for Aa and Qa

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20
Q

What adverse reactions are associated with plasma transfusions in foals with failure of passive transfer?

A
  • muscle fasciculations
  • increased HR, RR, and T
  • distress
  • abdominal pain
  • pale MM
  • collapse
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21
Q

What is the most common hematopoietic neoplasm in the horse? What are 5 forms?

A

lymphoma/lymphosarcoma —> > 4-10 yrs

  1. cutaneous
  2. alimentary
  3. mediastinal
  4. multi-centric or generalized
  5. leukemia (rare)
22
Q

What are the most common clinical signs of lymphoma?

A

non-specific signs depend on body system affected, extent, and duration (often diagnosed when advanced)

  • weight loss, anorexia
  • depression
  • edema
  • recurrent fever
  • lymphadenopathy
23
Q

What is multicentric lymphoma? What changes clinical signs?

A

most common and widespread lymphoma associated with lymph nodes and multiple organs

correspond to organs involved

24
Q

In what horses is alimentary lymphoma most common? What organ is most affected? What clinical signs are associated?

A

older horses

SI > LI

  • colic
  • diarrhea
  • malabsorption
25
Q

What is the most common neoplasm of the thorax? What clinical signs are associated?

A

mediastinal lymphoma

  • respiratory distress
  • coughing
  • distended jugular vein
  • muffled heart sounds
  • pleural effusion
26
Q

What form of lymphoma carriers the best prognosis? What clinical signs are associated?

A

cutaneous - surgical removal easier

  • multifocal SQ nodules
  • yellow exudate from nodules
  • ulcerations
27
Q

Lymphoma:

A
28
Q

What is seen on blood work is horses with lymphoma?

A
  • anemia, erythrocytosis
  • leukocytosis and altered morphology
  • hyperfibrinogenemia
  • hypoalbuminemia
  • hyperglobulinemia
29
Q

What 4 treatments are most common for lymphoma?

A
  1. excision of solitary masses
  2. radiation
  3. glucocorticoids*
  4. chemotherapy (expensive!)
29
Q

What is the main reservoir for Corynebacterium pseudotuberculosis? What causes entry? How is it transmitted?

A

ground, feces, hay, shavings

small scrapes or wound in skin or MM abrasions

direct, indirect, insects

29
Q

What causes Pigeon fever (dryland distemper, pseudotuberculosis)? What are the 2 most common biotypes?

A

Corynebacterium pseudotuberculosis - G+, pleomorphic, intracellular, facultative anaerobe found worldwide

  1. HORSES: nitrate reduction positive
  2. SMALL RUMINANTS: nitrate reduction negative
    (cattle can get both)
30
Q

What are the 3 most common clinical signs of pigeon fever?

A
  1. EXTERNAL ABSCESSATION - pectoral, abdomen, mammary glands, prepuce, limbs, head —> edema, fever
  2. INTERNAL INFECTION - liver, lungs, kidney, spleen —> abscesses, fever, lethargy, inappetence, colic
  3. ULCERATIVE LYMPHANGITIS - limb swelling, cellulitis, fever, lethargy, draining tracks, sores, severe lameness
31
Q

What is used to diagnose pigeon fever? In what cases is synergistic hemolysis inhibition (SHI) helpful?

A
  • blood work
  • ultrasound
  • culture

internal infection and ulcerative lymphangitis

32
Q

What 3 things are seen in blood work in patients with pigeon fever? How is it cultured?

A
  1. anemia of chronic disease
  2. leukocytosis with neutrophilia
  3. hyperfibrinogenemia, hyperproteinemia (globulins)

blood agar 24-48 hr on samples from abscesses

33
Q

What serology is used to diagnose pigeon fever?

A

synergistic hemolysin inhibition - measures IgG against exotoxins, helpful for internal abscesses (NOT external)

34
Q

How are external abscesses from pigeon fever treated? What is prognosis like?

A
  • drainage allows faster resolution
  • lavage to prevent environmental contamination

excellent

35
Q

How is internal infection from pigeon fever treated? What is prognosis like?

A
  • antimicrobials: rifampin and ceftiofur, doxycycline, enrofloxacin able to penetrate tissues
  • guided ultrasound and clinical pathology

30-40% mortalities, can be 100% without medication

36
Q

How is ulcerative lymphangitis from pigeon fever treated?

A
  • early aggressive antimicrobials: penicillin G or ceftiofur and rifampin
  • NSAIDs
  • physical therapy for lameness
37
Q

How is pigeon fever prevented?

A
  • reduce environmental contamination
  • fly control (sheets, spray, ointment)
  • feed-through products with insect growth regulators
  • manure management and sanitation
  • PPE, barriers, cleaning, disinfection
  • wound care and prevention
38
Q

How should suspected abscesses from pigeon fever be approached?

A

culture and sensitivity —> can also be Strangles or MRSA (re-assess practices)

39
Q

What are 2 signs of primary hemostasis? Where should these be looked for?

A
  1. excessive bleeding from mucosa or trauma sites
  2. bruising, ecchymosis, petechia, hematomas

mucosal surfaces and inner pinnae of ear

40
Q

What are 2 signs of secondary hemostasis?

A
  1. spontaneous bleeding
  2. shock with severe blood loss

(depends on organ system)

41
Q

Why must primary hemostasis be carefully diagnosed? What is pseudothrombocytopenia?

A

venipuncture can cause excessive bleeding and must be collected directly into anticoagulant

blood collected in EDTA or heparin tubes, which destroys platelets —> use citrate or look at blood smear

42
Q

How is primary hemostasis diagnosed on blood work?

A
  • PLT count
  • PLT function testing —> temporal bleeding time, flow cytometry
  • vWF
43
Q

How is secondary hemostasis diagnosed?

A

clotting times > 120% above range

  • PT = extrinsic, common
  • APTT = intrinsic, common
  • ACT = intrinsic, common
  • TCT = fibrinogen to fibrin
44
Q

What is disseminated intravascular coagulation?

A

acquired hypercoagulable state (NEVER PRIMARY) resulting from widespread fibrin deposition in microvasculature and activated coagulation or depression of anticoagulation

45
Q

What are 5 causes of DIC?

A
  1. sepsis (endotoxemia)
  2. acute GI disease
  3. renal disease
  4. neoplasia
  5. hemolysis
46
Q

What clinical signs are seen in DIC?

A
  • petechiae, ecchymosis, prolonged bleeding
  • thrombosis (thrombophlebitis)
  • ischemic organ damage
  • hemorrhage

by the time signs are seen, death is close

47
Q

What is seen on lab results in cases of DIC (FYI)?

A

PROCOAGULANTS - low platelets, increased clotting times, decreased fibrinogen

ANTI-COAGULANTS - decreased antithrombin

FIBRINOLYSIS - increased FDP, D-dimer

48
Q

How is DIC treated?

A
  • treat underlying disease
  • support: treat shock, decreased perfusion, and acid-base/electrolyte abnormalities
  • NSAIDs
  • antimicrobials
  • fresh platelet-rich plasma
  • LMWH, aspirin, pentoxifylline
49
Q

Can thrombocytopenia be due to a laboratory error?

A

YES —> make sure citrate tubes are used (NOT EDTA or heparin)