Hemolymphatic Diseases Flashcards
What are the different causes of anemia?
- Blood loss
- Intravascular hemolysis
- Extravascular hemolysis
- Decreased production
What are the general laboratory findings seen with blood loss?
- anemia + hypoproteinemia
What are the general laboratory findings seen with intravascular hemolysis?
- Pink plasma
- hemoglobinuria
- regeneration +/-
- hyperbilirubinemia
What are the general laboratory findings seen with Extravascular hemolysis?
- Icterus
- +/- Regeneration
What are the general laboratory findings seen with decreased production of erytherocytes?
- No regeneration
- Hyperproteinemia
- ⇡ globulins
- dehydration
- possibly hyperfibrinogenemia
What clinical signs are seen with anemia due to blood loss?
- Exercise intolerance
- tachycardia
- tachypnea
- pallor
- aggression (hypoxia)
What are common causes of blood loss anemia?
- Acute:
- Trauma
- Surgical
- Coagulopathy
- DIC
- Sepsis
- Post-Caval Syndrome
- Uterus (prolapse)
- Chronic:
- Parasites
- Ulcers
- Trauma
- Urinary - Bracken Fern
What are causes of whole blood loss in cattle?
- Trauma (external/internal)
- Parasites
- Abomasal Ulcers
- Coagulopathy
- Moldy Sweet Clover
- BVD
- Post-Caval Syndrome (Terminal)
- Enzootic Hematuria (chronic Brackenfern)
What causes Abomasal ulcers?
- High producing animals, show animals
- Diets high in starch, low fiber content
What are the types of abomasal ulcers?
- 4 Classifications based on severity
- Type I - mucossal
- Type IV - perforation, hemorrhage
What clinical signs/pathology are seen with abomasal ulcers
- Signs:
- anorexia, decreased forestomach motility, +Fecal occult blood/melena
- Pallor, decreased milk production, shock, sepsis
- Pathology:
- Fecal occult blood + (usually)
- ⇣ PCV, normal to ⇣ Protein
- W/ perforation expect peritonitis:
- leukocytosis/leukopenia
- hyperfibrinogenemia
- fever
- scleral injection
What is the treatment for abomasal ulcers?
- Dietary and stress managment
- High quality hay, stall rest
- Oral alkalinizing agents (i.e. Megnalax)
- Pepto?
- Sepsis: blood transfusions, antibiotics
What happens when cattle eat moldy sweet clover?
- Natural coumarins are converted to dicumarol by the mold
- degree dependent upon moisture content of hay
- Decreased synthesis of factors II, VII, IX, X by inhibition of Vit K
- Pathology:
- prolonged PT, followed by prolonged APTT
- Normal platelet count
- Absence of fever and liver failure
- Signs:
- Epistaxis
- melena
- swollen joints
- hematomas
- effusive hemorrhages in body cavity
What is the “Lee-White” clotting time?
- blood should clot in a red top tube w/in 5 minutes
What happens when cattle ingest Bracken Fern?
- Toxic compound - ptaquiloside
- all parts, live or dried
- Acute:
- coagulopathy
- septicemic crises w/ bone marrow suppression
- Chronic:
- Enzootic Hematuria
- hemorrhagic cystitis w/chronic blood loss anemia
- Enzootic Hematuria
How can Bracken fern toxicity be differentiated from other causes of hemorrhagic cystitis?
- Hemoglobinuria by red cell sedimentation
- No hemoglobin
- Thickened bladder
- Obstruction or pollakiuria
- Usually multiple cases, mild bacteriuria, pyuria, and anemia
How is Enzootic hematuria diagnosed at necropsy?
- Marrow hypoplasia
- Urinary bladder pathology
What hemolytic diseases commonly effect food animals?
- Anaplasmosis
- Mycoplasma Haemollama (camelids)
- Bacillary Hemoglobinuria
- Leptospirosis (calves/feedlot)
- Babesia
- Water intoxication
- Neonatal Isoerythrolysis
What is Anaplasmosis?
- Anaplasma marginale - cattle, wild ruminants
- Most prevalent tick-transmitted disease of cattle
- Intracellular parasite of RBCs
- Cattle become lifelong carriers and serve as reservoirs
- Transmission:
- Boophilus annulatus, D. andersoni, Tabanids, Chrysops
- Iatrogenic (dehorners, tattoos, etc)
- severity:
- Calves <1yr - subclinical
- Acute but rarely fatal in animals <2yrs
- Often fatal in animals >2yrs
What happens with persistently infected cattle with anaplasmosis
- Low-level (~0.1%) of parasitized erythrocytes
- Permanent cycles of rickettsemia occurring at 3-5wk intervals
- New antigenic variant of A. marginale arises
- structural changes of surface antigens msp2 and msp3
- Immune response to each new variant
- New antigenic variant of A. marginale arises
How often is anaplasmosis transmitted in utero? (vertical transmission)
- 16 - 20% of calves born to PI cows are infected in utero
What are the clinical signs and pathology of Anaplasmosis?
- Signs:
- weakness, lethargy
- exercise intolerance
- dyspnea/tachycardia
- aggression due to hypoxia
- GI forestomach hypomotility - constipation
- Icterus (often profound)
- Extravascular hemolysis!
- Pathology:
- Enlarged orange liver
- marked icterus/pallor of tissues
- splenomegaly
How is anaplasmosis diagnosed?
- direct blood smear - visualize intracellular parasite
- cELISA
- PCR
How is Anaplasmosis treated?
- Parenteral Oxytetracycline
- Baytril 100-CA1 conditional approval
- 100 mg/ml:
- 22mg/kg IM/IV SID x5d
- 11mg/kg IM/IV SID x10d
- 200 mg/ml:
- 20 mg/kg SID for 4 treatments at 3 day interval
- Blood transfusions in acute cases
How is anaplasmosis controlled (medically)?
- Oxytetracycline 200mg/ml
- 20mg/kg SC q 21-28 days
- Chlortetracycline in feed
- control of active infection
- NOT clinical disease, and NOT prevention
- NO ELDU
- <700lbs: 2.0mg/lb/day
- >700lbs: 0.5mg/lb/day
- control of active infection
What is Mycoplasma haemollama
- Camelid RBC “Epi”-cellular parasite
- Attaches to membrane via small fibrils
- a clear zone separates parasites from the membrane
- easily dislodged w/ blood smear
- Clinical signs and treatment similar to anaplasmosis in cattle
- Definitive diagnosis and screening with PCR
What are health impacts of Mycoplasma haemollamae
- Variable severity
- mild to severe anemia
- Depression, lethargy
- weight loss
- Death - especially in crias
- fever
- tachycardia/tachypnea
- May be an incidental finding in clinically “normal” animals
- “cyclical” in peripheral blood
How is Mycoplasma haemolamae diagnosed?
- Poor sensitivity and specificity w/ direct visualization
- Low numbers of parasites to visualize when animal is also anemic
- organisms easily fall off and may look like stain precipitate
- PCR assay- Oregon State
How is Mycoplasma Haemolamae treated?
- Oxytetracycline (1st choice), Florfenicol (2nd)
- Camelids may become chronic carriers
- Normal, healthy camelids may clear infection w/out treatment
- Blood transfusion
- Fluid therapy
- Rule out other diseases
- aplastic anemia
- myelofibrosis
- Myelodysplastic syndromes
- Anemia of chronic disease
What is Mycoplasma Weyoni
- Eperythrozoonosis
- Blood borne protozoal disease
- Animals <3yrs
- Signs (short <1 wk)
- Edema of ventrum, limbs, udder, scrotum
- Fever (103-106)
- hyperpnea
- rales
- anorexia
- depression
- Pathology
- Mild anemia
- normocytic to microcytic
- leukocytosis
- Organisms present on periphery of RBC, stain poorly
- pleomorphic - tennis rackets to signet ring
- Mild anemia
What is Babesiosis?
- Eradicated from US
-
B. bigemina, B. bovis
- tick vector - Boophilus annulatus
- Signs:
- Fever
- icterus
- anemia
- tachypnea
- tachycardia
- hemoglobinuria/hemoglobinemia due to intravascular hemolysis
- abortions
- death
What causes Bacillary Hemoglobinuria?
- Focal hepatic infection with C. hemolyticum
- releases toxins (phospholipase C beta toxin)
- produces hepatic necrosis and degradation of lipid membranes ⇢ intravascular hemolysis
- Bacterial spores reside in liver until anaerobic conditions present allowing de-sporulation and toxin production
- Hepatic damage often caused by liver fluke, primary inciting cause
When does Blood loss result in death vs anemia?
- Acute los of >⅓ of circulating blood volume (~8% bw) ⇢ death from shock
- Gradual loss (>24hr) of up to ½ (50%) of blood volume may be tolerated (anemia)
What is hemolytic anemia? signs?
- RBCs either become fragile and burst (toxicity) or are targeted by the immune system (infectious)
- Signs:
- Icterus (usually circulatory in cattle, rather than liver disorder)
- hemoglobinemia/hemoglobinuria
- fever
- tachycardia
- tachypnea
- depression
How can extravascular destruction of RBCs be differentiated from intravascular destruction?
- Icterus without hemoglobinuria is associated with extravascular destruction