SA anaemia Flashcards
CS - anaemia
- none/vague if mild/ chronic
- non-specific (lethargy, anorexia, collapse
- Specific (pale MM, increased HR and RR, heart murmur, hyperdynamic pulse
What does CS severity reflect? 3
- cause
- chronicity
- severity
2 differentials - pale MM
- poor peripheral perfusion
- anaemia
- distinguish by CRT. If
How may signalment be relevant to pale MM cases?
- young: lower PCV than adults (remember fleas, parasites etc)
- older: neoplasia, renal, underlying problmes
Hx questions to ask with pale mm
- lifestyle
- stable or deteriorating
- site of bleeding ID’d
- access to drugs/ toxins
- travel
PE - with pale MM
- patient stable
- HR
- RR
- demeanor
- icterus
- concurrent dz
- pleural and peritoneal speaces
- masses/ pain anywhere
- rectal for melena
How do diagnostically differentiate poor peripheral perfusion and anaemia
- Manual PCV and TP
When does TP decrease and increase:
- decrease: haemorrhage
- increase: haemolysis or non-regenerative anaemia
key question with anaemia
regenerative or non-regenerative
What to examine for on blood smear
- signs of regeneration (polychromasia, nRBC
- evidence of underlying cause
- immune-mediated destruction (spherocytes)
- mechanical destruction (fragmentocytes)
- infectious agents
What does reticulocyte percentage need to be corrected for?
- for the degree of anaemia
- absolute reticulocyte count better: if > 60,000/microl in dogs or > 40,000 in cats then regenerative. Less than these figures suggests non-regenerative
2 causes regenerative anaemia
- blood loss
- haemolysis
Describe regenerative anaemia
- INTERNAL HAEMORRHAGE: spleen (dogs), thorax, trauma, amyloidosis (hepatic in cats)
- EXTERNAL: epistaxis, gut, severe parasitic infestation (young), urinary tract
What might you want to check with a regenerative aneamia d/t haemorrhage
- TP (always)
- coagulation profile
- PLT count
- faecal lungworm (only A.vasorum causes bleeding)
- ACTH stimulation test (addisons associated with GIT ulcer leading to haemorrhage)
- search body cavities
Tx - blood loss anaemia
- treat or remove underlying cause
- remove spleen or piece of GIT etc
- gastro-protectants if ulceration but not sx case
- remove cause of ulceration
- tx lungworm
Describe TP and blood smear for regenerative anaemia d/t haemolysis
- TP usually WNL, possible increase
- smear: evidence of underlying cause
Outline regenerative anaemia d/t haemolysis
- accelerated RBC destruction
- intravascular or extravascular
- EXTRA: macrophages in spleen, liver, mainly IgG mediated
- INTRA: RBC lysis in circulation, IgM (possibly IgG)
- autoagglutination? coombs?
- haemoglobinuria?
- bilirubinaemia?
Causes - haemolytic anaemia
- IMHA (primary or idiopathic, secondary)
- inherited (pyruvate kinase = PK deficiency, phosphofructokinase = PFK deficiency)
- Infectious causes
- Miscellaneous causes
Signalment - IMHA
spaniels
Dx - IMHA
- regenerative anaemia?
- no sign of blood loss
- suggestion of haemolysis (jaudice, auto-agglutination with in-saline aggl test), spherocytes, ghost cells
- r/o underlying dz (Babesia, Ehrlichia and non-blood cell infections)
pIMHA - tx
- IVFT/ blood transfusion (hboc - oxyglobin not available0
- immunosuppressive tx
- ? aspirin, clopidrogel (as increased risk of PTE)
- ? gastroprotectant meds
- good nursing care (careful IV catheter maangement, cage rest with gentle walks)
What immunosuppresives can you give to pIMHA?
- mainstay
- second drug choice
- others
- PREDNISOLONE: suppression of macrophage activity, impaired complement and Ab binding, suppression of IgG production
- Azathioprine (NOT in cats)
- 2nd drug choice: cyclosporine, chlorambucil (cats)
- others: mycophenolate
Prognosis - pIMHA in dogs
- GUARDED: icterus, haemoglobinuria/ anaemia (poorly regenerative), all poor prognostic indicators
- PTE common cause of death (causes acute dyspnoea)
- May relapse in future
- monitor (regular PCV/ TP and haematology prior to each dose reduction and regular biochem for drug toxicity)
Outline IMHA in cats
- primary (idiopathic) less common
- more difficult to diagnose
- giving blood products (if needed) tends to be more challenging to arrange than dogs
2 features - feline RBCs
- no central pallor
- more prone to agglutinate
- (both vs. dogs)
Infectious causes - haemolytic anaemoa
- Babesia canis in dogs - europe: travel scheme. B.gibsoni in some areas. Tx - imidocarb
- Mycoplasma spp in cats (and dogs after splenectomy). Tx with doxycycline
- any infxn can theoretically act as an immunological trigger –> secondary IMHA
Miscellaneous causes - haemolytic anaemia
- OXIDATIVE DAMAGE: paracetamol - cats, onions, garlic, Zn, Cu
- Hypophosphataemia (DKA = diabetic ketoacidosis dogs prone to this)
- shear injury (microangiopathic): damaged endothelium
How can reticulocytes indicate non-regenerative anaemia?
- reticulocyte %: needs to be corrected for the anaemia
Features - non-regenerative anaemia
- mild or severe
- obvious or not on PE
- approach varies with severity and if underlying cause obvious
- non-regenerative anaemia patient may present in a variety of ways
List 5 causes of non-regenerative anaemia
- anaemia of chronic dz
- anaemia of renal dz
- FeLV infxn
- misc.
- BM dz
Outline non-regenerative anaemia d/t chronic dz
= anaemia of chronic inflammation
- commonest cause of mild/moderate anaemia
- mild to moderate anaemia is PCV of 25-36% in dogs and 18-26% in cats
- chronic infxn and non-infectious disorders
- d/t poor Fe storage/ utilisation, shortened RBC survival, impaired erythrocyte production
- these animals don’t always come in with an anaemia label
Outline non-regenerative anaemia d/t renal dz
- essentially all normocytic, normochrom.
- pathogenesis: inadequate EPO production, decreased RBC lifespan, decreased BM response to EPO, other factors (haemorrhage d/t uraemic ulcers)
- not always obvious
Outline non-regen anaemia d/t FeLV infxn
- always test for this in anemic cats
- macrocytic normochrom, or normocytic normochromic with chronic dz
- may induce IMHA/ primary BM dz
- in past, >75% anaemic cats were FeLV positive
Miscellaneous causes of non-regenerative anaemia - 3
- NUTRIENT DEFICIENCY: Fe, Cu, folate or cobalamin
- ENDOCRINE: hypothyroid or hypoadrenocorticism (both cause mild anaemia), hyperoestrogenism, usually only mild to moderate anaemia, severe panctypaenia with hyperostrogenism,
LIVER DISEASE: e.g. PSS, usually mild-moderate anaemia
Outline non-regen. anaemia d/t BM dz - 5
- pure red cell aplasia
- aplastic anaemia
- neoplasia (myelophthisis)
- myelodysplasia
- myelofibrosis
Approach to non-regenerative anaemia
- depends on severity
- similar investigation path to regenerative anaemia but ddx different - look for dz
- if severe and no cause found on screening tests then do bone marrow aspirate/ biopsy
- look for bi-/pancytopaenia on BM
Define pancytopaenia
deficiency of all 3 cellular components of blood (RBCs, WBCs, PLTs)
Method - BM samplign
- clip and prep aseptically (esp if on immunosuppressive tx)
- aspirate (once obtained smear quickly as clots within seconds/ minutes)
- core: roll preparations then into formalin
Tx - non-regenerative anaemia d/t BM dz
- pure red cell apalsia: similar to IMHA tx
- aplastic anaemia: depends on cause (infxn, drug)
- neoplasia (myelophthisis)
- myelodysplasia
- myelofibrosis: depends on extent, if primary dz under control then myelofibrosis reverses
What should you examine RBC count/ PCV in light of?
in light of TP
