Salmonella Infections in Angora Goats
By Dr Mackie Hobson BSc(Agric),BVSc

1. Diseases

Salmonella infections in Angora goats has not been a problem but potentially could arise under intensive conditions such as in a feedlot environment, intensive housing and kidding pens.

A septicaemia condition is possible precipitated by stress. Salmonella results in the development of diarrhoea (watery-green and blood tinged). Abortions due to salmonella have not been noted in South Africa.

Which goats may be susceptible?

All ages may be susceptible.

It may occur 4-6 weeks after introduction of the goats/sheep into intensive conditions.

Concentrate feed and lack of fibre as well as previously starved goats may be pre-disposing factors. Goats previously exposed to unhygienic conditions.

What are the clinical signs?

Mortality rates 2-50%

• Fever (40C)
• Listless, lack appetite, weak
• Watery green, blood tinged diarrhoea
• Become recumbent and die within 7 days

Survivors

• Dehydrated
• Weight loss
• Arched back, tucked up bellies
• Recover after 3-4 weeks

How long can Salmonella survive in the environment?

Salmonella typhimurium has been shown to survive in the soil for 251 days and pastures 168 days.

How does the disease develop?

The incubation period can be 1-7 days (6-30 days after predisposing factor-stress).

The disease may develop 24 hrs after intake of infection and after 3-8 days a blood stained mucus fluid can develop in the intestine.

A hepatitis and nephrosis develops by day 6.

Young animals may develop a pneumonia.

The diarrhoea is caused by the penetration of the intestinal mucosa by bacteria and a resulting inflammatory process.

Salmonella may enter the blood stream leading to septicaemia and circulatory shock. The effects of the diarrhoea of dehydration aggravates the situation leading to organ failure and death.

Treatment and control

• Trimethoprim and sulphadiazine antibiotic, Amoxicillin (culture and antibiogram advised)
• Treatment may cause endotoxin effects so anti-inflammatory treatment may be beneficial
• Electolytes/fluids critical
• Pro-biotics
• Treatment will not eliminate salmonella in carrier state animals

Predisposing factors to consider.

• Good quality roughage (lucern hay) before travel and holding pens
• Good hygiene
• Isolation of those with diarrhoea
• Burry or burn carcase
• Vaccine available for calves (OBP)

Can Goats and sheep become carriers?

Sheep and goats can become sub-clinical carriers and intermittently shed via their faeces.

Post Mortem

• Pulmonary oedema, congestion
• Hepatomegaly and splenomegaly
• Rumen atrophy, rumen may contain large amounts of water
• Necrosis of gall bladder mucosa
• Congestion of abomasal wall
• Contents of distal small intestine and large intestine watery and foul-smelling. Fibrinous necroharmorrhagic ileitis, typhlitis
• Enlarged congested mesenteric lymph nodes

REFERENCES:

Infectious diseases of livestock, J. Coetzer, G.Thomson, R.Tustin