Anaemia in sheep

Question 1

List 5 causes of sudden death in sheep

Answer 1

is anthrax until proven otherwise
clostridia
lightening
parasite- haemonchus contortus, nematodirus battus, fasciola hepatica, coccidiosis
HYpomagnesium- staggers

Question 2

why do we not rely on FEC results to identify when to treat sheep for nematodirus battus

Answer 2

as soon as it hits 10 degrees (warm enough for them to mature and become infectious)- huge numbers are taken in and animals will die before they start to excrete eggs in faeces
Use a forecaster to predict when to worm

Question 3

coccidiosis is normally a …… finding in sudden death

Answer 3

secondary
generally causes issues when animal is already immunosuppressed

Question 4

In any anaemia: initially blood count remains ……., before we start seeing anaemia and ……. (so doing blood count at this initial stage may not be very useful)

Answer 4

normal
hypoproteinaemia

Question 5

What is the most common parasitic cause of blood loss in sheep

Answer 5

Haemonchus contortus

Question 6

where are Haemonchus contortus adults generally found in animal

Answer 6

abomasum

Question 7

Describe the features of haemonchus contortus which make it good at killing animals

Answer 7

has short life cycle - one of the reasons animals don’t develop immunity to it
survives well at pasture
high daily egg output
no diarrhoea seen

Question 8

Describe the appearance of animals with an acute infection of haemonchus contortus

Answer 8

animals weak
pale mucous membranes
hyperpnoea
tachycardia
still in good body condition
sudden death

Question 9

why does chronic Haemonchus infections cause microcytic anaemia

Answer 9

chronic nature depletes iron reserves - not enough to generate appropriate levels of erythrocytes in blood stream

Question 10

List 5 possible differentials for bottle jaw in sheep

Answer 10

heart failure- not very common in sheep
Johne’s disease
liver fluke
Haemonchus contortus
cardiac dysfunction
anything that causes hypoproteinaemia

Question 11

what could you use on the farm as a temporary haemostat (stop blood)

Answer 11

Cobwebs

Question 12

In overt blood loss would complete blood count remain normal at first

Answer 12

yes

Question 13

when would see start seeing regeneration of RBCs after overt blood loss

Answer 13

a couple of days after

Question 14

can you put ruminator blood through haematology machines

Answer 14

needs to be suitable for ruminant blood as it is sticky

Question 15

what can we use instead of haematology machines to asses blood in cows

Answer 15

blood smears

Question 16

What is the primary differential for haemolysis in sheep

Answer 16

a result of toxin ingestion

Question 17

List 4 common toxins ingested that can cause haemolysis in sheep

Answer 17

Copper toxicity
sulphue toxins- onions and brassicas
nitrates and nitrites - from overfertilized land

Question 18

List the signs seen with copper toxicity in sheep

Answer 18

anorexic
depressed
diarrhoea
abdominal pain
weakness
found dead

Question 19

what is seen on PM of animal with chronic copper toxicity

Answer 19

jaundice- of sclera and skin
urine- black in colour
liver- bronzed
kidneys- metalic appearance

Question 20

why are copper blood levels not a good indicator of chronic copper toxicity

Answer 20

• due to liver storage - copper levels may be normal
• it is only when liver storage capacity is exceeded that we get high blood copper levels

Question 21

Which breeds are particularly prone to copper toxicity

Answer 21

texels and suffolks

Question 22

Describe how you would treat copper toxicity

Answer 22

usually furtile
supportive of acute renal failure
fluid therapy blood transfusion if indicated

Question 23

List the 4 possible causes of water poisoning

Answer 23

1. Excess Na ingestion with adequate (normal) water intake
2. Normal Na ingestion with inadequate water intake
3. Consumption of high Na water
4. Administration of hypertonic oral electrolytes

Question 24

List the clinical signs seen with water toxicity

Answer 24

thirst
reduced mentation
hyperthermia
tachycardia
rumen stasis
diarrhoea
mucoid faeces
nasal discharge
convulsions
found dead

Question 25

Describe how you treat water toxicity

Answer 25

restrict water intake- little and often
corticosteroids to reduce CNS oedema

Question 26

List 3 common causes of blood loss in sheep

Answer 26

parasites
major trauma
post-op complications

Question 27

What is the most common cause of parasitic anaemia in sheep

Answer 27

haemonchus contortus (barber pole worm)

Question 28

Describe how haemonchus contortus infection leads to bottle jaw

Answer 28

loss of oncotic pressure due to anaemia - leads to leaky vessels and submandibular oedema

Question 29

List 4 secondary differentials for haemolysis in sheep

Answer 29

parasitism of RBCs (babesia)
IV injection of hyper/hypotonic solutions
bacterial toxins
water intoxication