Anaemia Flashcards
What 3 things can anaemia be define by?
–PCV
–Red blood cell count
–Haemoglobin
Name 2 normal occassions there would be a raised PCV (3)
Greyhounds and other sight hounds often naturally have a higher PCV (>50)
Stress/ excitement causes splenic contraction e.g. going to vets
Anabolic steroids
Name 2 normal occassions there is a decreased PCV (3)
Age – puppies and kittens< 6-12 months have a lower normal range
- Puppies 25-34% vs adult 37-55%;
- Kittens 24-34% vs adult 24-45%
- Always say the age!!! They have a different reference range at the lab
ACP (relaxes splenic capsule so more RBCs in storage) – keep this in might if you use ACP to image the spleen
Reproductive status (late pregnancy)
Name 2 causes of regenerative anaemia
- Blood loss
- Haemolysis
Name the cause of non regenerative anaemia
Supression o erythropoiesis whether it is intra or extra marrow
Where and how can you get regenerative anaemia?
Where?
- External blood loss
- Blood loss into body cavity (haemothorax, haemabdomen)
How?
- Trauma e.g. RTA
- Coagulopathy
- What should normally be okay is being dramatic
- Endo or ectoparasites
- GI blood loss (tumours, ulcers
What is haemolysis?
•Erythrocytes removed prematurely from circulation by macrophages in spleen, liver or bone marrow (extravascular haemolysis)
–Phagocytic system getting rid of them
•Destruction of erythrocytes within the vascular space
Name causes of haemolysis (5)
- Immune mediated haemolytic anaemia (IMHA)
- Neonatal isoerythrolysis (NI)
- Infection (Babesia spp, Mycoplasma haemofelis)
- Oxidative damage
- (Heavy metals, onions, paracetamol toxicities)
- Also oxidative damage from drugs eg paracetamol in cats.
- Rare genetic disorders
- Hereditary non-spherocytic haemolytic anaemia
- Pyruvate kinase deficiency
- Phosphofructokinase deficiency
- Feline porphyria
- Haemolysis in Abyssinian & Somali cats
Name 2 haemolytic infections
Mycoplasma haemofelis
Babesia ssp
(protozoon)
(bacterium)
What is the epidemiology of Babesia sp.?
Endemic in cattle in some areas in UK
Emerging infectious diseases in dogs (pet travel, climate change)
How can oxidants induce haemolysis?
–Oxidation of haem iron to form methaemoglobin (no longer carrying Oxygen)
–Oxidation of haemoglobin to form Heinz bodies
Name 2 things which cause oxidative damage causing haemolysis (4)
- Heavy metals (Zinc, Copper)
- Onion digestions, garlic (usually dogs)
- Rape, kale and cabbages
- Drugs
- Paracetamol
Name 3 primary disorders of erythropoiesis (intra-marrow) (5)
- Iron deficiency
- Aplastic anaemia (damage to haemopoietic stem cells)
–Ehrlichia canis, canine and feline parvovirus, idiopathic
–Drugs including chemotherapeutics (often white cell lines affected too)
•Pure red cell aplasia – RBC just not produced
–Immune-mediated, FeLV C
•Myelofibrosis
–Scarring in bone marrow
•Myelodysplastic syndromes (MDS)
–Stem cells not forming properly usually a neoplasia
Name 3 secondary disorders of erythropoiesis
(extra-marrow) (5)
- Anaemia of chronic disease
- Anaemia of chronic renal failure
–Not more hormone production signalling
- Secondary to endocrine disorders
- Oestrogen-induced bone-marrow suppression
–Or a prolonged oestrous
•FeLV (additionally to specific disease of FeLV-C)
Name clinical signs of anaemia
- Often absent adaptation to chronic anaemia
- Inadequate perfusion/ oxygenation
- Pale mucous membranes
- Lethargy, exercise intolerance
- Compensatory mechanisms
- Tachypnoea
- Tachycardia
- (making up for lack of)
- Other signs
- Poor pulse quality
- Flow murmur
- Pica – eating weird things. Mineral based are common
- Signs related to underlying pathology
- Splenomegaly, lymphadenopathy, pain, icterus, melaena (due to bleeding into GI tract
What is different about cat mucous membranes?
The are naturally paler
What is different about clinical signs of chornic anaemia?
May not show signs as they are used to it
Name clinical signs associated with an increase in haemoglobin catabolism
Haemoglobinemia
Haemoglobinuria
icterus (jaundice)
What is this and when is it seen?
Icteric serum when serum bilirubin levels >20mmol/L
When do you see icteric tissues?
When seerum bilirubin levels >50 micro mol/L
How long might regenerative anaemia lag for?
2-4 days
What haematology diagnostic tests can we do for anaemia?
•Red cell parameters:
–PCV (Packed Cell volume)
–Hb (O2 carrying capacity)
–MCV (how big)
–MCHC (how pale)
–Morphology +/- Blood parasites
–Reticulocyte count
- Platelet
- WBC, WBC differential
Other than haematology what other tests can we do for anaemia?
- Serum biochemistry
- Urinalysis
- Virology
- Faecal analysis
- Coombs’ test
- Coagulation profile
- Imaging
- Bone marrow biopsy
- Dehydration
- Bilirubinaemia (jaundice) or carotene (cattle)
- Haemolysis
- Lipaemia
- Leukocytosis or thrombocytosis
What should we interpret PCV with?
•Interpret with Total Solids:
–High TS indicates dehydration which can mask severity of anaemia.
–Normal TS indicates non-regen or haemolysis
–Low TS indicates blood loss
What is the affect of acute blood loss on PCV and toal solids?
May not change for a few hours
What mild PCV results mean?
Anaemia of chronic disease
Acute blood loss
What does severe PCV suggest? (2)
- Haemolysis
- Bone marrow disease
What blood smear features are seen with regenerative anaemia? (7)
- Reticulocytes
- Anisocytosis
- Poikilocytosis
- Normoblastosis
- Howell Joly bodies increase
- Heinz bodies increase
- Reactive leukocytes
RBC Indices
Possible causes
Macrocytic
Hypochromic
1
Normocytic
Normochromic
2
Microcytic
Hypochromic
3
Macrocytic
Normochromic
4
Microcytic & nucleated RBCs
5
- Regenerative anaemia (Haemorrhage or haemolysis)
- Non-regenerative anaemia
(Acute haemorrhage or haemolysis, anaemia of chronic disease, bone marrow suppression/destruction)
- Iron deficiency
(external blood loss)
- FeLV, myeloproliferative disease, Vit B12 and folic acid deficiency, Chemotherapy (eg. with methotrexate)
- Lead intoxication
What does this smear show?
Regenerative anaemia
What causes regenerative anaemia?
–Haemorrhage
–Haemolysis
–Oxidative injury
What do horses and cattle show poor of on slides? What might the only change be?
Poor reticulocytosis
- mild increase in MCV
What is this?
Non-regenerative anaemiaNon-regenerative anaemia
What is seen nnon regenerative anaemia?
•Normocytic and normochromic anaemia
–MCV, RDW, MCH, MCHC all within normal ranges
•Primary (intramarrow suppression) versus secondary (extramarrow suppression)
Why does severe anaemia require symptomatic treatment? (2)
–Reduce oxygen expenditure
–Increase oxygen carrying capacity
What would be seen with acute haemorrhage of:
A) >20% los
B) 30-40% loss
C) >50% loss
A) Peripheral vasoconstriction and tachhycardia
B) Reduced cardiac outut, hypotension, collapse
C) Shock and death
How can you manage acute haemorrhage?
- Prevention of further bleeding
- Fluid replacement
- Blood transfusion support
- Treatment of underlying disorder
What is the distribution of Mycoplasma haemofelis and how is it transmitted?
Worldwide and vertical transmission
What are the Mycoplasma haemofelis clinical signs?
•Variable related to haemolytic anaemia:
–Regenerative anaemia
–Jaundice
–Pale mucous membranes
–Pyrexia, depression, weakness, anorexia, weight loss.
What is this?
Mycoplasm
Blood smear with Romanowsky stain or acridine orange
How can you treat mycoplasma?
- Doxycycline first choice
- 10mg/kg SID
- Alkaline: beware oesophageal stricture if not swallowed properly – can scar the oesopahus.
- “Give with or just before food” – bolus food into stomach helps
- Enrofloxacin second choice
- 5mg/kg SID
- Side effect retinal degeneration and blindness
- Treat for 2-8 weeks
- Repeat PCR
- clinical cure (rather than remission) may be difficult
- Supportive tx eg transfusion may be necessary
What is babesia?
- Tick borne intracellular protozoon
- Endemic in cattle (South west England)
What is this?
Babesia spp
What is this?
Ehrlichia canis
What is Ehrlichia canis transmited by?
Rhipicephalus
How can we treat oxidant anaemia?
- Immediate removal of oxidative agent (induce emesis if < 4hr)
- Activated charcoal to reduce further GI absorption
- Supportive care
- Monitor haematological parameters – may need transfusion
- Paracetamol only – acetyl cysteine (dogs and cats) and ascorbic acid (cats only)
Which species is most susceptible to copper poisoning and how does it have effects?
- Sheep most susceptible
- North Ronaldsay, Texel, Suffolk
- Capacity for Cu storage in liver exceeded
- Sudden release of Cu stores into circulation:
- haemolysis
- Liver damage
Name feed sources high in copper
Silage where pig or chicken manure has been used
Brewer’s mash from copper stills
What are clinical signs of copper poisoning?
- Lethargy, anaemia, teeth grinding, polydipsia
- Pale, icteric mms and haemoglobinuria
- Death usually occurs 1 to 2 days after the onset of clinical signs.
- At post-mortem, tissues are pale to dark yellow and the kidneys are a very dark color
How can you treat copper poisoning?
- Oral or injectable ammonium tetrathiomolybdate
- Can add other copper binders, such as sulphur
- Often expensive to treat and prognosis poor if severe
- Diagnose, and recommend management changes
Iron deficiency anaemia:
A) What is the aetiology?
B) How do you diagnose?
C) How do you treat?
A)
- Late feature of chronic blood loss
- Bone marrow stores deplete before anaemia develops
B)
- Normo to microcytic, hypochromic
- Non regenerative
- ↑platelet count (cause unknown)
- Red cells become fragile
- schistocytes, keratocytes and target cells
C)
•Long term treatment required to replenish bone marrow
Name oestrogen-inducd bone marrow supression casues (2)
•Persistent oestrus in ferrets
–Proligestone to end oestrus
–She isn’t mated – severe anaemia
•Oestrogen-secreting tumour
What is the relationship between older cats and anaemia?
- Common in animals with CKD
- Reduced renal erythropoietin production
- Check for other sources of blood loss such as GI ulcers
- Treatment with recombinant human EPO
