Pseudomonas infection in Angora goats
By Dr Mackie Hobson BSc(Agric),BVSc

1. Diseases

Pseudomonas spp. particularly P. aeruginosa are opportunistic bacteria and not often of importance. In sheep it is the cause of fleece rot and causes pigmented wool. In Australia fleece rot with flystrike is one of the most important production losses.

In Angora goats it has been diagnosed in the distal limbs following moist conditions where it causes an acute superficial exudative dermatitis. It has also been diagnosed in cases of mastitis.

Where does the bacteria Pseudomona occur?

Pseudomonas favours moist areas and are widely found in soil and water. It grows everywhere, and it likes moisture. Only a few of the many species cause disease. The most common species that causes infection is called Pseudomonas aeruginosa.

How do Angora goats become infected?

The wet conditions provide a suitable environment for bacterial proliferation which can occur 24hrs after wetting.

When the Angora goat skin becomes compromised through wetting, inflamed or a break in the skin occurs such as in cases of interdigital dermatitis, tick bites and wounds. It can progress from ‘sweerklou’ (Foot abscess).

If a goat is immune compromised such as when having a high worm/parasite burdens or under stress the infection is more common.

What happens when Angora goat skin becomes infected?

If the skin becomes compromised through a wound or break in skin through irritation or abrasion it may lead to a pseudomonas infection resulting in exudative dermatitis and skin necrosis (blackening and hardening of the skin).
Pseudomonas species are both invasive and toxigenic. The 3 stages

1.Bacterial attachment
2.Local infection
3.Bloodstream dissemination and systemic disease

Why is Pseudomonas infection a concern?

It is especially important because the pseudomonas bacterium is resistant to most antibiotics. In swabs cultured from Angora goat infections the Pseudomonas aeriginosa was resistant to 30 antibiotic tested.

It is opportunistic and aggressive, readily taking advantage of weakened immune systems.

The bacteria is better known in humans as a major cause of ventilator- and sepsis-related deaths of hospitalized humans.

In mammals, including goats, pseudomonas typically infects the airways (including lungs), urinary tract, burns, and wounds, and can cause blood infections and gangrene.

What can be done if infections on the farm occur?

Remove the underlying cause such as moist conditions, soft muddy soil and any cause of skin abrasion or penetration such as tick bites.

Ensure goats are not immune compromised. (Worm burdens, weaning and nutritional stress)

Treatment?

Isolate the goats and if possible take a swab of the infection for culture and antibiogram - treat accordingly (if there are effective antibiotics. In most cases there are no effective antibiotics)

Superficial disinfectants can also be used topically on the skin as well as anti-inflammatory (pain treatment) treatments.

Honey and vinegar can also be used topically

Pseudomonas infections can resolve over time.

REFERENCES:

Infectious diseases of livestock, Coetzer,Thomson, Tustin

Grootfontein laboratory (Middleburg)