Anaemia and Haemolytic Conditions

reasons for anaemia

-haemorrhage

-haemolysis

-failure in RBC production

regen anaemia causes

-loss of RBCs

-destruction of RBCs

RBCs produced but not remaining in circ.

body can replace but cannot keep up with rate of loss

non regen anaemia causes

failure to produce RBCs i.e. bone marrow disease or EPO reduction

RBCs either not being produced at all or being produced in too small number for body to replace RBCs at end of natural life

what anaemia is seen more in cattle

regenerative

intravascular haemolysis

RBC destruction occurs in blood vessels

-cells in circulation affected

assoc clinical signs with intravascular haemolysis

-haemoglobinaemia (pink/red plasma)

-haemoglobinuria (pink/red urine)

-anaemia

why haemoglobinuria in intravascular haemolysis

available haptoglobin (protein that binds haemoglobin) becomes saturated so excess haemoglobin starts to be excreted in urine

Haemoglobinuria + haemoglobinaemia + anaemia

intravascular haemolysis

what needs to be ruled out for intravascular anaemia

poor sampling technique and poor sample handling

extravascular haemolysis

RBC destruction occurs outside blood vessels

-cells not in circ affected

-spleen, liver, bone marrow

associated clinical signs with extravascular haemolysis

-jaundice (yellow mm)

-anaemia

why jaundice with extravascular haemolysis

• RBC destruction bc phagocytosis by macrophages

• haemoglobin not released into circulation (remains within macrophage).

• after RBC destruction, unconjugated bilirubin released by macrophages and taken up by liver.

• when hepatocyte capacity for process exceeded, bilirubin accumulates in plasma and causes yellow discolouration of plasma and tissues

in rumininants is intra or extravascular more common

intravascular

high and low pcv meaning

High = haemoconcentration (most likely dehydration)

Low = anaemia

MCV and MCHC of young calves

-low compared to adults

-care when using adult ref

similar to adults by 3 months

ruminants RBCs

-smaller than other species esp small ruminants

-need to recalibrate blood machine for animal

check Hct with manual PCV

reticulocytes in ruminants (and camelids)

always indicative of disease

-only when anaemia

-none circulate normally

ruminant blood smear

-RBC small and less obvious central pallor compared to small animals

-small degree of anisocytosis

blood smear to see blood parasites

-blood parasites can separate from RBC very soon after blood sampling so make fresh smears immediately wherever poss

blood loss anaemia in cattle differentials

-abomasal ulceration→ esp high yielding dairy cattle

-trauma

-fasciola hepatica

-blood suckign ectoparasites like lice or ticks

-coccidiosis

-caudal vena cava syndrome

-bleeding disorder

is anamia due to liker fluke more common in cattle or sheeo

cattle adult fluke causing obstruction is the most likely clinical sign

sheep presenting signs more related to migration of immature fluke → cause significant haemorrhage as they migrate → so anaemia is more common

when are you more likely to see coccidiosis as a cause of anamia

calves

• smaller with less blood reserves

blood loss anaemia in sheep differentials

-trauma

-fasciola hepatica

-haemonchus contortus→ esp autumn

-coccidiosis

-blood sucking ectoparasites like lice and ticks

-bleeding disorder

aetiology of haemorrhage

-injury to blood vessel or highly vascular area (trauma, f.hepatica)

-GI mucosal bleeding (abomasal ulcer, H,contortus)

-chronic bleeding (lice, ticks)

clinical signs of haemorrhage

-pale or white MM

• oral not as reliable

-tachycardia and tachypnoea

-weakness and/or collapse, wont move if try to

-delayed CRT

-GI causes may lead to concurrent GI signs like diarrhoea or melena

diagnostics for haemorrhage

-routine PCV and TP

-haem bloods (EDTA tube)

-other diagnostics rule in/out

-faecal sample for GI parasites

PCV of acute blood loss

presents normal for 12-24 hours due to splenic contraction releasing RBCs into circ

how to counteract splenic contraction in acute blood loss

check TP at same time

-decreases quicker than PCV due to dilution effect from compensatory blood volume expansion to stop hypovolaemic shock

when does RBC regeneration occur

-takes few days

-can look like non regen anaemia in early stages→ but remember this is rare too

-if concerned repeat after few days

blood loss treatment

address blood loss and underlying condition

what is prevention and control focused on

the underlying condition

when considere euth

Humane euthanasia may be more appropriate than attempting treatment if the prognosis is poor, welfare is severely compromised, or ongoing haemorrhage cannot be stopped

options for stopping haemorrhage

-ligation/surgical repair

-thermocautery→ dehorning equipment if need quick

-packing (+/- haemostatic material→ expensive)

restoring blood volume options

-iv fluid therapy

-blood transfusion

fasciola hepatica treatment

-flukicides

-triclabendazole advised for sheep

ectoparasite treatment

treat with relevant product

Lice treatment needs to be effective vs. sucking lice

coccida ttreatment

-coccidiostats e.g. salinomycin

-TMPS

abomasal ulcer treatment

symptomatic treatment

abomasal ulcer prevention and control

-min risk factors like stress and NSAIDs

trauma or injury prevention and control

identify and min risks

-careful handling, careful use of machinery and equipment

-careful calving assistance

intravascular haemolytic anaemia in cattle differentials

-hypophosphataemia (postparturient haemoglobinuria)

-babesia divergens

-water intoxication

-clostridium haemolyticum

-chronic copper toxicity

hypophosphataemia

-mod common

-occurs in 1st 1-2 weeks after calving

-presents as haemoglobinuria

-can present as neuro and cant stand

-need to supplement

babesia divergens

-geo variable

-more common in areas with rough pasture

-more common in west of UK

-transmitted by ixodes ricinus

water intoxication

-occur if cattle deprived of water and not reintroduced carefully

-calves more than adult cattle

-occurs secondary to hypotonic plasma

-rare

clostridium haemolyticum

-mod common

-mortality high as sudden death more common than anaemia

chronic copper toxicity

-over supp of Cu in dairy herds recognised as problem esp if multiple methods of supp provided

-max 40mg/kg DM allowed→ public health risk if too high

-variable

sheep intravascular haemolytic anaemia differentials

-clostridium haemoliticum

-chronic copper toxicity

chronic copper toxicity in sheep

-breed variatiosn in susceptibility

-lambs more susceptible than adults

-more common in sheep than cattle

-•North Ronaldsay sheep more sus bc readily abdorb from diet

Clostridium haemolyticum (also called C. novyi Type D) infection in sheep

mod common

high mortaltiy

extravascular haemolytic anaemia in cattle differentials

-mycoplasma wenuonii

-candidatus mycoplasma haemobos

-neonatal isoerythrolysis

mycoplasma wenyonii and candidatus mycoplasma haemobos

-uncommon but re emerging potentially

-type of mycoplasma that resides in RBCs and causes IMHA

neonatal isoerythrolysis

-not in UK

-very rare IMHA assoc with certain vaccines and seen in newborn calves.

extravascular haemolytic anaemia in sheep differentials

-anaplasma phagocytophilum

-mycoplasma ovis

-neonatal isoerythrolysis

anaplasma phagocytophilum

-geo variable esp wales, n england and scot

-spread by ixodes ricinus (tick borne fever)

-zoonotic

mycoplasma ovis

-asymptomatic but may cause extravascular haemolysis in young or sheep with concurrent disease

neonatal isoerythrolysis in sheep

occur if lambs fed cow colostrum due to bovine colostrum commonly containing antibodies to sheep erythrocytes

haemolytic anaemia diagnostics

-blood sample for routine haem and fresh blood smear

-saline agglutination test or coombs test

-biochem

-urinalysis

how does blood smear help haemolytic anaemia diagnostics

important for blood parasites and rbc morphology

how does urinalysis help haemolytic anaemia diagnostics

Haemoglobinuria

how does biochem help haemolytic anaemia diagnostics

Helps rule in/out some ddx

Bilirubin

how do reticulocytes stain on diff quick

purpleish due to RNA content called polychromasia

indicators of regen anaemia

-reticulocytes

-basophilic sippling

-polychromasia

-macrocytes

treatment for intravascular haemolytic anaemia

-first aid for blood loss

-treat others

hypophosphataemia treatment

-phosphate supplement

-ensure phosphate sufficient in diet

clostridium haemolyticium treatment and prevention

-high dose penicillin

-prognosis poor so consider euthanasia

-vaccinate herd/flock to prevent

-adopt appropriate liver fluke control programme

copper toxicity treatment and prevention

-take care with copper supplement

-ensure farmer knowledge

-esp careful with sheep

-do not feed cattle concentrates to sheep as too high in Cu

babesia divergens treatment and control

-blood transfusion

-imidocarb dipropionate has very long WDP

• milk = 504hrs; meat = 213 days

-tick control

-calves less than 9-12 months old show resistance so expose when young to develop immunity

• raise on high risk pastures

extravascular haemolytic anaemia treatment and control

-first aid for blood loss

-if IMHA then steroids

prevention of neonatal isoerythrolysis in lambs

do not feed bovine colostrum to lambs

mycoplasmas treatment

appropriate antibiotics like oxytetracycline and consider PTS

haematuria

blood in urine

why does haematuria occur

bleeding of kidneys or urinary tract and whole blood in urine.

presenting signs assic with anaemia if blood loss severe but anaemia may not present

why should you differentiate between bleeding of the kidneys or UT with haematuria

have different causes

haemoglobinuria

haemoglobin in urine

why hameoglobinuria

intravascular haemolysis and haemoglobin excreted by kidneys.

presenting sign assoc with anaemia due to hamolysis

cause of haematuria in cattle as herd

bracken toxicity

cause of haematuria in cattle as individuals

-pyelonephritis

-urogenital tract trauma after calving or lambing

bracken poisoning (enzootic haematuria)

-causes coagulopathy

-once clinical signs then prognosis hopeless and affected animals should be euthanised

-platelet count is indicator of prognosis

prevention of bracken poisoning

do not graze animals where a lot of bracken (or making hay/silage from fields with lots of bracken)

pyelonephritis and urogenital tract trauma treatment

-treat both symptomatically

pyelonephritis

-often corynebacterium renale

-prolonged course of penicillin or TMPS

-if caught early then prognosis good

-more common in cattle