oedema and liver fluke

Question 1

what is the differentials for oedema?

Answer 1

• high altittude disease
• malignant oedema
• liver fluke
• johnes disease
• PGE
• other clostridial disease - eg struck
• heart disease
• reduced venous return - udder oedema
• non-parasitic liver disease

Question 2

what is high altitude disease?
what isthe treatment and prevention?

Answer 2

Low oxygen saturation in the air
- Pulmonary hypertension
- Oedema in ventral tissues of chest and abdomen (ascites)

Move to a lower altitude area
- diuretics
- appetite stimulants (B Vitamins)
- Thoracocentesis is really helpful

Breed for more resistant stock - do not breed from affected animals

Question 3

what is malignant oedema?
what is the cause?
what are the clinical signs?
what is seen on PM?
what is the prevention?
what is the treatment?

Answer 3

Classified as an acute wound infection caused by organisms of the genus Clostridium
(C. Perfringens often found also but not considered significant in this case)

Two most common causes:
- Cl. Chauveoi (black leg (black quater))
- Cl. Novyi

Clinical signs:
Rapid multiplication deep in tissues so clinical signs in < 48hrs
Occasionally seen in animals without an overt trauma, and occasionally in groups which suggests may have latent spores which are activated by perhaps bruising

All ages affected
Anorexia, depression, fever, death. May have local swelling at source of infection

PM:
- Skeletal muscle – dry, friable red/black, emphysematous (spongey)
- Heart, myocarcial necrosis

Prevention: Clostridial vaccine

can treat if catch early with penicillin (betamox)

Question 4

what are the thought behind the causes of udder oedema?
what are the lab results of cows with udder oedema?

what is the tretment and prevention?

Answer 4

causes:
- Correlation with reduced dry matter intake. - transient liver dysfunction, probably linked to feed ration deficient in dry matter may be involved.
- poor blood return due to reduced venous flow through the pelvis as a result of the heavily pregnant animal having no space

Total protein, calcium, phosphorus as well as high and low density lipoproteins all significantly decreased in cows with udder oedema.

Diet during the dry period is most effective form of prevention

Treatment may be split into nursing care and medication:
- Massage and hot compresses to stimulate circulation
- Diuretics – frusemide at 1mg/kg twice daily intravenously (Dimazon®)
- Corticosteroids once calved – 1mg/12.5kg intravenously or intramuscularly (Colvasone®)

Question 5

what is the pathogenesis of liver fluke?

Answer 5

• Fluke ingested as metacercaria.
• Migrate intestine –> peritoneum –> liver (48H)
• Wanders around the liver to settle in the bile ducts (upto 6 weeks)
• Matures and begins to lay eggs (8 weeks)

Question 6

what are the clinical signs of liver flukes?

Answer 6

Acute – 3 weeks after lots of immature fluke are eaten by sheep

Sub-acute – rapid loss of body condition and fleece quality. Some sheep weaker and may be recumbent. Mortality can be high, but after a period of clinical signs, no egg production

Chronic – very poor body condition, poor fleece quality, bottle jaw. May die in an emaciated state at times of high metabolic demand. (due to blocking bile duct, lose protein as damage gut PLE and protein can’t make albumin in liver, affects colloid pressure)

Question 7

how is fluke diagnosed?

Answer 7

Fluke egg counting is more time consuming than worm egg counting
Requires faecal egg flotation
Sometimes see rumen fluke (paramphistomes) eggs

Remember that we highlighted that blood samples may help guide – hypoproteinaemia

Post mortem examination: Fluke and haemorrhage in the liver
Acute – anaemic, damage obvious around the edges, entry points visible
Chronic – massive damage to bile ducts, adult fluke evident

Question 8

what is the control of liver fluke?
what is the treatment?
what about for quarantine tretment?

Answer 8

• Stop the sheep shedding eggs – either kill the parasite or the sheep – don’t buy it in – treat effectively during quarantine
• Stop the sheep ingesting the metacercaria – pasture management
• Stop the miracidium entering the snail – pasture management

Treatment:
Salicylanilides (oxyclozanide and closantel)
Benzimadazoles (Allbendalzole and triclabendazole)
(There is considerable resistance to benzimadazoles)

Quarantine doses – triclabendazole followed by closantel is considered a good approach
Remember that they will shed eggs for 3 weeks after killing the mature fluke so keep off pasture for that period

Acute- TCBZ. This is the only way of killing immature fluke
Resistance will develop, so use different drugs in late winter or spring when no immatures are around.
Chronic fluke - Albendazole - for mature chronic fluke, preturn out (will not have nematodes and will not contribute to resistance)

Nitroxynil (halogenated phenol) - no longer effective