Hematopoietic disorders - Infectious causes of Anemia Flashcards
Definition of anemia
- absolute reduction in circulating red cell mass
- Inadequate oxygen transport
- Interference with organ function
History of anemia
- Trauma
- Dietary history
- Parasite (Haemonchus)
- Hemorrhage or other illness
Clinical presentation of anemia
- Weakness
- Depression
- Lethargy
- Dementia or disorientation
- Exercise intolerance
- Pale mucous membranes
- Tachycardia
- Tachypnea
- Debilitation associated with chronicity
Where to check mucous membranes?
- Conjunctiva
- Vulva
PE findings of canemia
- Pallor
- Icterus if RBC destruction (won’t happen as much with liver disease)
- Fever
- Systolic murmur
- Signs of blood loss (epistaxis, melena, hematuria, hematochezia)
- Edema from protein loss
Diagnosis of anemia
- Decreased PCV or HCT
- Decreased Hemoglobin
- Decreased RBC count
- Indices (MCV, MCHC) work well in ruminants
What does MCV represent?
- Average RBC volume (Mean Cell Volume)
Increase in MCV
- Regenerative anemia
Decrease in MCV
- Fe and Cu deficiency
- Or healthy calves
MCHC meaning
- Cellular hemoglobin concentration per average RBC
- Mean cell hemoglobin concentration
Meaning of a decreased MCHC
- Fe deficiency anemia
Increased MCHC
- Usually always false
- Hemolyzed, icteric, or lipemic samples
- Heinz bodies
What are the two main categories of anemias?
- Regenerative
- Non-regenerative
How long for regenerative bone marrow response to occur?
- 5-7 days
What are the two categories of regenerative anemias?
- Hemorrhage (blood loss)
- RBC destruction
Non-regenerative anemia
- Bone marrow doesn’t respond
- Inadequate erythropoiesis
What characterize regeneration in ruminants and camelids?
- Reticulocytes and nucleated RBCs
How long for camelids to regenerate?
- Can tkake months
Causes of acute blood loss
- Epistaxis
- Surgical procedures
- Ruptured liver, spleen or lung
- Large vessel bleed
- Clotting defect
- Gastric ulcer
- Hemoperitoneum
- Hemothorax
Signs of acute blood loss
- Obvious source of loss (although might not see in deep chested ruminants, GI loss, or animals with omentum that can wall it off)
- Hypovolemic shock (tachycardia, tachypnea, cold extremities, pale mm, muscle weakness, and death eventually
Diagnosis of acute blood loss a
- Change in PCV/TP
- Hemoperitoneum and hemothorax (ultrasound, abdominocentesis, thoracocentesis)
Treatment for acute blood loss
- Stop hemorrhage
- Treat hypovolemic shock (shock rate with isotonic crystalloids +/- small volume hypertonic saline +/- whole blood transfusion)
- Whole blood transfusion really only feasible in small ruminants and calves
At what % of total blood volume do you see signs of hemorrhagic shock?
- 30%
What is total blood volume?
- 8% total BW in kgs
When do you start seeing signs of overt blood loss/anemia?
- 8% of blood volume
In a 500 kg Holstein:
- What is total blood volume?
- How much blood loss for signs of anemia?
- how much blood loss for signs of hemorrhagic shock?
- 40 L
- 3.2 L for signs of anemia
- 12 L for signs of hemorrhagic shock
Blood typing for whole blood transfusion
- High variability among blood groups and types amongst ruminant species
- single transfusion is generally safe
Monitoring during whole blood transfusion
- Temperature
- Urticaria
- Vomiting
- Dyspnea
- Increased HR
- Have banamine or diphenhydramine ready to give if signs of reaction
Chronic blood loss - when will you see clinical signs?
- PCV is <15%
- Physiologic adaptation masks signs until then
- Slow progression
Common causes of chronic blood loss (remember)
- Haemonchus
- Bleeding GI lesions
- Some renal disease
- Hemostatic dysfunction
- Blood sucking external parasites
Clinical signs of chronic blood loss
- Ill thrift
- Poor body condition and hair
- Pallor of MM
- Edema if protein also chronically lost (albumin)
- Weakness, lethargy
FAMACHA
- Aenmia guide for owners to get certified
- Trying to figure out when to do deworming
What are the two parts of hemostasis?
- Coagulation and fibrinolysis
Inherited coagulation disorders
- Rare
- Examples are hemophilia A and Factor XI deficiency (autosomal recessive)
Hemophilia A is a deficiency of what
Factor VIII deficiency
Acquired hemostatic disorder
- Sweet clover toxicosis
Which species of clover can lead to sweet clover toxicosis?
- Melilotus officinalis and M alba
What type of sweet clover leads to sweet clover toxicosis?
- Moldy sweet clover hay or silage containing dicoumarol
Which states have a problem with sweet clover toxicosis?
- Northern Plains States
- Includes Idaho and Montana
Pathogenesis of sweet clover toxicosis
- Coumarins in legumes and alfalfa converted by molds to dicoumarol
- Same as warfarin toxicosis
- Interferes with hepatic synthesis of clotting factors, II, VII, IX, and X by inhibiting Vitamin K
- Need a certain amount of Dicoumarol over several weeks
Which clotting factors are impacted by moldy sweet clover toxicosis?
- II, VII, IX, and X
- By inhibiting vitamin K synthesis
Which pathways (intrinsic, extrinsic, common) are impacted by moldy sweet clover toxicosis?
- Intrinsic (IX)
- Extrinsic (VII)
- Common (X)
- Also impacts prothrombin (factor II)
Signs of sweet clover toxicosis
- Stiffness and lameness (hemorrhage into joints)
- Early signs include epistaxis and melena from dark, digested blood
- Death by massive hemorrhage
Dfdx for sweet clover toxicosis
- DIC, Bracken Fern toxicosis, mycotoxicosis
Clin path for sweet clover toxicosis
- Prolonged PT and PTT
- +/- Hematuria (not platelets, just clotting factors)
- Normal platelet count to differentiate from DIC and bracken fern
How do you differentiate sweet clover toxicosis from DIC and bracken fern on CBC?
- Normal platelet count
Treatment for sweet clover toxicosis
- Vitamin K (4 weeks of high dose
- Whole blood transfusions for severe loss
Anaplasma that impacts cattle vs sheep
- A. marginale (cattle)
- A. ovis (sheep)
Vector for anaplasma
- Dermacentor species
- Biing flies
- Mechanical vectors
Transmission of Anaplasma
- Intrauterine
- Also mechanical vectors
Spread of Anaplasma
- In most states
Reservoir for Anaplasma
- Asymptomatic cattle
- Stressed carriers can break with disease
Time of year for Anaplasma?
- Late spring and summer
Incubation of Anaplasma?
Primary exposure?
At what % decrease in RBCs do you see clinical signs?
- Highly variable - acute severe to subclinical
- 15-30 day incubation
- Primary exposure at calfhood
- Clinical signs seen when 35-50% decrease in RBCs
- Peracute death
Acute signs of anaplasma
- Pyrexia (103-106°F)
- Subsides in 12-24 hours
- Subnormal at death due to hypovolemia
- Anorexia, lethargy, drop in milk production
- Signs of anemia
- Mucous membranes pallor or icteric
- +/- dark brown feces, pollakiuria
- Abortion
- DO NOT SEE HEMOGLOBINURIA**
Do you see hemoglobinuria with Anaplasma?
- NO
- Extravascular hemolysis in Anaplasma
- Intravascular hemolysis required for hemoglobinuria
Hemoglobinuria
- Plasma reflects a hemolytic state with icterus potential
- Deep red to black urine
Where is the discoloration in the urine with hemoglobinuria?
- Throughout urination
Hematuria
- blood in urine
- Red, brown, or pink
- RBCs seen on microscopic exam
Where can you localize hematuria if seen at beginning of urination?
- Urethra, repro tract
Where can you localize hematuria if seen at end of urination?
- Bladder
Where can you localize hematuria if seen throughout of urination?
- Kidney
- Ureters
- Differentiate from hemoglobinuria
Clinical signs of Anaplasma in sheep
- Typically subclinical
Clinical signs of Anaplasma in goats
- Rare, severe anemia
Clinical signs of Anaplasma in camelids
- rare anemia
Clin path of Anaplasma
- IDentify organism on a blood smear
- Wright’s stain, New methylene Blue, Giemsa stain
- May see RBC regeneration chronically
Where will death occur for a rapid vs gradual PCV drop?
- <20% at rapid
- <10% at gradual drop
Diagnosis of Anaplasma
- Serology to ID persistently infected (difficult)
- Competitive ELISA*** (high sensitivity and specificity; approved by USDA and OIE)
- PCR (seroconversion in acute disease; confirm diagnosis in acute infection)
Which test for diagnosing Anaplasma is approved by USDA and OIE?
- competitive ELISA
- High sensitivity and specificity
- Looks for antibody
Treatment for Anaplasma
- Oxytetracycline in acute disease
- Supportive care if needed with whole blood transfusion
Will treatment for Anaplasma eliminate persistent infection?
- No
At what PCV will prognosis for Anaplasma be considered poor?
<8%
Prevention of Anaplasma
- Decrease transmission by getting rid of tick vectors
- In endemic areas with low transmission rates, there is some conditional vaccination
For prevention of Anaplasma in a herd free of it an a non-endemic area?
- Quarantine and serological screening
Babesiosis - is it reportable?
- YES
Babesia in the US
- Eradicated in the US
Organism involved in babesiosis?
- Babesia bovis
- Obligate intracellular parasite of RBCs
Transmission of Babesiosis?
- One-host tick
- Rhipicephalus spp
- Formerly Boophilus
Incubation of babesiosis
- 2-3 weeks
Clinical signs of babesiosis
- pyrexia (104-107.6°F)
- Depression, icterus, anorexia
- Aenamia with intravascular destruction of RBCs
- Hemoglobiniemia
- Hemoglobinuria***
- Abortion
- Death
- Cerebral babesiosis (low RBC, grave prognosis)
Clin path of babesiosis?
- Anemia with regeneration
Diagnosis of babesiosis?
- ID on Giemsa-stained blood smear in acute infections
- Serology (IFA and ELISA)
- PCR
Poor prognostic indicators for babesia
- <10% PCV and neuro signs
Treatment of Babesia
- Imidocarb
- Diminazene
- Phenamidine
- Amicarbalide
Prevention of Babesia
- Tick vector eradication
- Useful in US
- Immunization
Hemobartonellosis cause
- Hemotropic mycoplasmas
Which Mycoplasma causes hemobartonellosis in camelids? ***
- Eperythrozoon sp (M. Haemolamae)
Which Mycoplasma causes hemobartonellosis in cattle?
E. wenyonii
Which Mycoplasma causes hemobartonellosis in sheep?
- E. ovis
Where is hemobartonellosis?
- world wide but generally minor disease
Who gets hemobartonellosis?
- Most often stressed animals
- Younger more likely than old
- Immunosuppression (e.g. splenectomy)
- carrier animals
Transmission of hemobartonellosis
- Blood (insects, needles, castration)
- Intrauterine
How long do infections with hemobartonellosis last?
- Life long
Incubation period for Hemobartonellosis
1-3 weeks
Clinical signs of hemobartonellosis in cattle
- Rare clinical disease in cattle
- Fever, stiff gait
- < Milk production - udder edema
- Diarrhea
- Lymphadenopathy - prefemorals
- Scrotal swelling
- Swollen legs
Clinical signs of hemobartonellosis in sheep
- “yellow lamb disease”
- Rare sudden death with hemoglobinuria and icterus
- Less severe disease with fever, depression, anemia, and weight loss
Clinical signs of M. haemolamae (hemobartonellosis in camelids)
- Variable clinical signs: anemia, depression, fever, weight loss
- Hypoglycemia is common in camelids
Mode of transmission of M. haemolamae
- Unknown
- Biting insects
- In utero transmission
Diagnosis of M. haemolamae
- PCR
- Can also do a gram stain on a blood smear
- Epicellular parasite on RBC
- Anemia
- CF, ELISA, PCR
What should a primary differential in a camelid with anemia be?
- M. haemolamae
Treatment for hemobartonellosis
- Oxytetracyclines
- LA (brand) 200mg/mL (LA 200)
- Up to 50 days
- May not eliminate carrier state
Leptospirosis issues
- Zoonotic
Syndromes associated with Lepto
- late term abortion
- Hemolytic anemia
- Septicemia
- mastitis
- Combo
Etiology - which Leptospira serovars are responsible for majority of disease?
- Leptospira interrogans serovars Pomona and icterohemorrhagia
Clinical signs of hemolytic form of leptospirosis
- Young calves, lambs, kids, crias (adults??)
- Incubation 3-7 days
- Fever
- Anorexia, depression
- Petechiation
- Hemoglobinuria**
- Anemia
- Icterus
- Tachycardia and sypnea
- Death in 2-3 days
Slow recovery
Clin Path for Leptospirosis
- Moderate leukocytosis
- Hyperfibrinogenemia
- Hemoglobinemia
- Hemoglobinuria
Definitive diagnosis of leptospirosis
- Based on demonstration of organism in urine, milk or fetal tissues
- MAT, PCR FAT
Treatment for Leptospirosis
- Oxytetracycline
- Streptomycin
- Procaine Pen-G
- Supportive care
Prevention of leptospirosis
- Vaccination
- Removal of carriers
- Hygiene
What to do if you suspect leptospirosis?
- Go into isolation!
Bacillary hemoglobinuria
- Acute fatal clostridial disease
- Liver infarct, toxemia, intravascular hemolysis
Etiology of bacillary hemoglobinuria
- Clostridium novyi type D (C. hemolyticium)
Major toxin in bacillary hemoglobinuria
- Beta toxin
- Phospholipase C
- Causes hepatic necrosis, hemolysis, and damage to capillary endothelium
Timing of bacillary hemoglobinuria
- Summer and early fall
What events do bacillary hemoglobinuria outbreaks usually follow?
Flooding
Pathophysiology of bacillary hemoglobinuria
- Spores ingested by animal –> cross intestinal mucosa and transported to liver via mcarophages –> persist in Kupffer cells
- Localized anaerobic areas promote germination (liver flukes)
- Release of toxins –> increase anaerobic environment –> further bacteria growth and hepatic necrosis
- Abrotpion of toxins leads to intravascular hemolysis, icterus, hemoglobinuria, and death
Clinical signs of bacillary hemoglobinuria
- Sudden death
- Antemortem signs are uncommon
- Depression, anorexia, fever, tachypnea
- Rectal bleeding
- Severe hemoglobinuria (port wine colored)
- pale and icteric mucous membranes
Necropsy findings of bacillary hemoglobinuria
- Necrosis in the liver grossly
- Can do an impression smear
Clin path of bacillary hemoglobinuria
- rare to get BW and diagnostics antemortem
- Anemia, high AST, and GGT, high bilirubin
- Hemoglobinuria
- FAT on impression smears of liver infarct
- Area, history, clinical signs, and necropsy
Dfdx for bacillary hemoglobinuria
- Anthrax, lightning
Treatment for bacillary hemoglobinuria
- Grave prognosis
- High dose penicillin or tetracycline
- Supportive care could give blood transfusions
Prevention of bacillary hemoglobinuria
- Liver fluke control
- Vaccination with commercial bacterin/toxoids
- Highly effective but short immunity
- Time with liver fluke season
Destroy the carcasses
Infectious causes of anemia that have intravascular hemolysis
- Bacillary hemoglobinuria
- Leptospirosis
- babesiosis Hemobartonellosis
