Anaemia and haemolytic conditions Flashcards
(44 cards)
1
Q
3 most common causes of anaemia in farm spp
A
- abomasal ulcer
- hypophosphataemia
- parasites
2
Q
Which of these are generally more common in dairy cattle?
A
- abomasal ulceration
- hypophosphataemia
3
Q
Which of these conditions is generally more common in youngstock?
A
- parasites
4
Q
Abomasal ulceration - cause
A
- lymphosarcoma
- BVD
- bovine leukaemia virus
- bovine malignant catarrhal fever
- abomasal disorders (displacement or volvulus)
- stress
5
Q
Abomasal ulceration - main CS
A
- anorexia
- bruxism
- abdominal pain
- melena
- tachycardia
- acute rumen stasis
- dehydration
- dull
- mm pallor
- weakness
6
Q
Abomasal ulceration - diagnosis
A
- transabdo ultrasound
- abdominocentesis (when perforated abomasal ulcers are suspected)
- haematology
7
Q
Abomasal ulceration - tx
A
- improve dietary intake
- decreasing acid secretion in the abomasum (antacids/omeprazole
- blood transfusion in severe cases
- broad spec ABs for perforating ulcers
8
Q
Abomasal ulceration - prevention
A
- reduce stress
- avoid feeding coarse roughage to veal calves with an underdeveloped rumen
- keep the animals eating
9
Q
Hypophosphataemia - cause
A
- inadequate feed intake or inadequate phosphorous content in diet over an extended time
- Chronic renal tubular disease (due to impaired renal reabsorption of phosphorous), primary or secondary hyperparathyroidism (causing increased renal phosphorous excretion)
- May occur after oral or parenteral carb admin and after parenteral insulin admin (as a result of increased cellular phosphorous uptake in combination with glucose)
- Alkalaemia and resp alkalosis enhance cellular phosphorous uptake and therefore also have a hypophosphataemic effect
10
Q
Hypophosphataemia - main CS
A
youngstock
- reduced DLWG, rickets, rough hair coat
adults
- lethargy, anorexic, weight loss
- In later stages animals may develop pica, osteomalacia, abnormal gait and lameness, recumbent
- Decreased milk production and fertility
- periparturient hypophosphataemia in dairy (~10d after calving) – anorexia, muscle weakness, muscle and bone pain, rhabdomyolysis, intravascular haemolysis.
also neurologic signs related to altered energy metabolism impaired cardiac and resp function, and dysfunction of WBCs and platelets
11
Q
Hypophosphataemia - diagnosis
A
- biochemistry - blood phosphorous measurement
- feed samples
12
Q
Hypophosphataemia - tx
A
- oral or parenteral admin of phosphate salts
- feed with adequate phosphorous
13
Q
Hypophosphataemia - prevention
A
- currently no effective approach to prevent hypophosphataemia and phosphorous depletion at the onset of lactation is known
- Feeding higher amounts of dietary phosphorous during the last weeks of gestation is contraindicated as it decreases the intestinal absorption rate of phosphorous and increases the risk of periparturient hypocalcaemia
14
Q
Lice - cause
A
4 spp of bloodsucking lice – Linognathus vituli, Solenoptes capillatus, Haematopinus eurysternus & Haematopinus quadripertusus
15
Q
Lice - main CS
A
- Decreased DLWG
- mild yield
- damaged hide and hair - Young calf mortality and pregnant cows may abort
- anaemia
16
Q
Lice - diagnosis
A
- Skin scrapings and microscopy
17
Q
Lice - tx
A
- oral/topical/injectable meds: pyrethrins, pyrethroids, organophosphates, macrocyclic lactones, fipronil, imidacloprid
18
Q
Lice - prevention
A
- Treat contact animals.
good biosecurity and hygiene - reduce stocking density, improve feed quality, treat underlying health problems, quarantine new stock
19
Q
What is regenerative anaemia?
A
- RBCs are being produced normally but are not remaining in circulation
- the body is capable of replacing losses although production can’t keep up with the rate of loss which leads to anaemia
20
Q
What is non-regenerative anaemia?
A
- RBCs are either not being produced, or are being produced in too small a number
- the body can’t replaced RBCs at the end of their natural life which leads to anaemia
21
Q
Do cattle more commonly get intravascular or extravascular haemolysis?
A
- intravascular (cf most other spp which are primarily affected by extravascular haemolysis)
22
Q
Intravascular haemolysis
A
- RBC destruction occurs in the blood vessels (i.e. circulating RBCs are affected)
- Clinically, intravascular haemolysis is associated with haemoglobinaemia (this is usually visible as pink/red discolouration of plasma) and haemoglobinuria (this occurs when haptoglobin (a protein that binds haemoglobin) is saturated and excess haemoglobin is excreted in urine)
- If you observe haemoglobinaemia and haemoglobinuria in an anaemic pt, this pt has intravascular haemolysis (to make this conclusion you must 1st rule out haemolysis caused by poor blood sampling technique and poor handling/storage of blood samples)
23
Q
Extravascular haemolysis
A
- RBC destruction of non-circulating RBCs occurs at a site outside of the bloodstream
- The most common sites for this to occur are the liver and spleen, and sometimes bone marrow
- Because RBC destruction is achieved through phagocytosis by macrophages, haemoglobin isn’t released into circulation - it remains within the macrophage
- Clinically the relevance of this is that haemoglobinuria and haemoglobinaemia are not observed in pts with extravascular haemolysis (unless the animal has intravascular haemolysis at the same time, which is possible)
- By contrast, jaundice is observed in pts with extravascular haemolysis because unconjugated bilirubin is released by macrophages (after RBC destruction) and when the hepatocyte capacity for conjugation of bilirubin is exceeded, bilirubin accumulates in plasma and causes yellow discolouration of plasma and tissues.
24
Q
Differential diagnoses for anaemia in cattle:
Blood loss anaemia (regenerative)
A
○ Abomasal ulceration - common
○ Trauma/injury/laceration - common (some farms where this might be more common than others)
○ Fasciola hepatica infection - very common but anaemia is not usually the primary presenting sign and is often only evident when disease is severe
○ Blood sucking ectoparasites - lice most commonly cause this but high tick burden also result in anaemia - very common but anaemia is not usually the primary presenting sign and is often only evident when disease is severe
○ Coccidiosis - very common but anaemia is not usually the primary presenting sign and is often only evident when disease is severe
○ Caudal vena cava syndrome - fairly common
○ Blood loss may also occur if animals have a bleeding disorder - overall bleeding disorders are uncommon in cattle
25
Differential diagnoses for anaemia in cattle: Haemolytic anaemia (regenerative) - intravascular haemolysis
- these are also differential diagnoses for haemoglobinuria
○ Hypophosphataemia
○ Babesia divergens infection (Locally common in some areas of the UK)
○ Water intoxication
○ Clostridium haemolyticum infection (Not very common, Termed 'bacillary haemoglobinuria')
○ Chronic copper toxicity
26
Water intoxication
§ Not commonly seen in the UK but can occur if there has been an event where water supply stops for a period of time before being restored
§ Seen when water-deprived cattle consume large quantities of water in a short period of time
§ Serum osmolality decreases and lysis of RBCs
27
Chronic copper toxicity - prevalence in cattle
§ Not very common in cattle - more so in sheep
§ Jersey cattle are more susceptible to this than other breeds
§ Other clinical signs would be expected before haemolysis occurs
28
Differential diagnoses for anaemia in cattle: Non-regenerative anaemia
* Anaemia associated with chronic disease
* Bracken toxicity
29
Anaemia associated with chronic disease
§ The mot common non-regenerative anaemia in cattle
§ Renal conditions such as polynephritis are often associated with non-regenerative anaemia but chronic pneumonia with abscessation, multiple abscesses secondary to MSK problems, endocarditis, and visceral abscesses have all been implicated
□ Chronic inflammation related to these conditions result in hepcidin release from the liver. This causes sequestration of macrophages and iron malabsorption. The resultant effect of this is secondary iron deficiency that leads to moderate anaemia. In cases of chronic renal disorders, depressed erythropoietin synthesis contributes to anaemia
30
Bracken toxicity
§ Rare although more common in cattle grazed where there's lots of bracken
§ Causes bone marrow depletion and a marked anaemia concurrently with leukopaenia and thrombocytopaenia. Animals with this condition suffer both non-regenerative anaemia and bleeding disorders (this may present as spontaneous bleeding). Haematuria is observed due to bleeding of the bladder mucosa. Prolonged exposure (several weeks) to bracken is required before animals show clinical disease
31
Haemoglobinuria - definition, when does it occur
= haemoglobin in the urine
- occurs when there's intravascular haemolysis and haemoglobin is excreted by the kidneys
- this presenting sign is typically associated with anaemia (due to haemolysis).
32
Haematuria - definition, when does it occur?
= blood in the urine
- occurs when there's bleeding of the kidneys or urinary tract (and sometimes genital tract) and whole blood is in urine
- this presenting sign may be associated with anaemia if blood loss is severe, however anaemia may not be present
- Haematuria is not very common in cattle
- A cause that might affect several cattle is bracken toxicity (enzootic haematuria)
- Other causes include polynephritis and urogenital tract trauma (e.g. after calving), these typically affect individual animals.
33
3 tests to do when investigating a cow presenting with red urine
1. CBC
2. serum biochemistry
3. coagulation test
34
F. hepatica tx & prognosis
- Appropriate anthelmintic treatment
- Prognosis good if chronic hepatic changes not yet present.
35
F. hepatica CS
- Pallor
- weakness
- ill thrift
- ventral oedema (brisket and submandibular)
36
Babesiosis CS
- Haemoglobinuria
- pallor
- weakness
- dull demeanour
- pyrexia
- diarrhoea
37
Babesiosis tx and prognosis
- Imidocarb dipropionate +/-Blood transfusion (if PVC < 15%)
- Ensure tick control (I. ricinus is vector)
38
Babesiosis herd/flock implications
- Multiple animals can be affected
- Only animals > 6 months old affected
- Natural immunity occurs if youngstock exposed to ticks.
39
Is babesiosis common in the UK?
- B.divergens is seen locally in some areas in the West (e.g. Somerset) – low disease level in general in UK
- Other Babesia species are not seen in the UK. - NB. B.major is also seen in the UK – this may cause haemolytic disease but it possibly non-pathogenic.
40
Postparturient haemoglobinuria CS
- Haemoglobinuria
- pallor
- weakness
- dull demeanour
- recent history of calving (within 10 days)
- Lactating dairy cow
- Hypophosphataemia evident on biochemistry.
41
Postparturient haemoglobinuria tx
- Treatment with phosphorus
- blood transfusion if required
- address phosphorus-deficient diet
42
Mycoplasma wenyonii - type of anaemia
- Regenerative
- IMHA
43
Mycoplasma wenyonii CS
- Pallor
- recent calving
- hindlimb and udder/scrotal oedema
- haemoglobinuria
44
Mycoplasma wenyonii tx and prognosis
- Antiobiotics (oxytet, macrolides – NOT penicillins, β-lactams, cephalosporins)
- +/- immunosuppressive dose steroids
- +/- blood transfusion
- Px is guarded due to poor tx response and carrier status
