Image above: One of the steers demonstrating poor body condition score. 

Image above: Bilateral hindlimb oedema in steer 2 (causing the claws to separate)

What does this mean?

Although these samples were not further analysed, the most likely ‘type’ of chlamydial infection was with Chlamydia pecorum. In livestock, C. pecorum infections are typically associated with arthritis and conjunctivitis in ruminants, as well as encephalomyelitis (swelling of the brain and spinal cord) in cattle. It is now believed that C. pecorum infection is endemic in livestock worldwide, particularly in the gastrointestinal and reproductive tracts, including of non-affected animals.

Transmission is believed to be via the faecal–oral route, or via ingestion or inhalation of infective Chlamydia in secretions from those infected (e.g. mutual grooming, inhalation, and overcrowding). Clinical signs of disease in carrier animals are thought to be triggered by stress, although the pathogen is not highly transmissible.

In young cattle (usually less than a year old), C. pecorum infections can cause a fatal syndrome called Sporadic Bovine Encephalomyelitis (SBE), characterised by encephalomyelitis, systemic infection, and polyserositis (inflammation of different serous membranes). T/pain clinical signs noted include pyrexia (high temperature), depression, keratoconjunctivitis (pink eye), ptyalism (salivating), weight loss, limb stiffness, arthritis, and neurological signs such as staggering and circling.

The steers in this case demonstrated many of these signs, and it is highly likely that the stress and subsequent immunosuppression from being trucked, handled through the yards, a considerable time off feed, mixed with cattle from other consignments, and recently being exposed to pestivirus is what induced a similar event as to SBE.

What can be done for treatment?

Antibiotic treatment has been utilised in veterinary chlamydial infections; however this also raises potential issues of inducing latency (that is, the bacteria “hiding” in the animal), rather than eliminating the infection and is why some producers report arthritis and/or conjunctivitis relapsing in their livestock 3 to 6 weeks after treatment, or reports of chronic persistent infections.

What can be done for prevention?

Development of C. pecorum vaccines that might provide protection of sheep and cattle from an early age would offer a more attractive approach to infection control, compared with use of antimicrobial drugs. Currently no such vaccines exist although field studies are being conducted. The role of herd management, nutrition, environmental conditions, animal susceptibility and how these interact in development of disease remain to be established.

For more information: 
Chlamydiosis (DPI)

Local Land Services team of Biosecurity Officers and District Veterinarians have been busy conducting swill feeding audits at pig producers’ properties in the Riverina. Swill feeding audits are performed to ensure correct feed products are being fed to pigs, and therefore are not putting our livestock industries at risk. This is also an opportunity for our pig producers to meet LLS staff, ask for animal health advice or request assistance in meeting NLIS or food safety obligations.

Watch the video: Little Piggies - The Real Story (Murray LLS)

What is swill?

Prohibited pig feed (‘swill’) includes meat (raw, cooked or processed), bone, blood, offal or hide derived from a mammal and anything that has come into contact with these materials.

Swill feeding is illegal in Australia.

In NSW it is legislated as an offence under Part 2, Division 9, Clauses 36 and 37 of the Biosecurity Regulation 2017 to feed swill to pigs and to allow pigs access to swill. Running pigs with other mammalian stock, such as cattle or sheep, is called ‘commingling’ and is also prohibited under the Biosecurity Act.

Common Question: Why can I feed some meat meal?

1. Infected livestock are processed into meat products overseas
2. Infected meat or meat products may be illegally imported into Australia undetected by quarantine
3. Food scraps containing infected meat or meat products are illegally fed to pigs
4. Pigs become infected with a serious exotic disease such as African swine fever
5. Disease spreads quickly to other pigs by pig movements and infected materials.

When to call us

• It is illegal to keep, move or consume feral pigs
• When selling live domestic pigs, they must be identified with either a visual ear tag or swine brand prior to leaving the property and must be accompanied with a PigPass NVD. It is the responsibility of the person buying the pigs to 1) have a PIC 2) be registered with PigPass 3) ensure the movement of the pigs is recorded on the Pig Pass database within 2 days of the movement occurring
• When buying meat (e.g., for salami, cultural practices) it must be sourced from a licensed meat business (e.g., abattoir, butcher’s shop). The slaughter of animals outside the strict NSW legislated controls and/or in an unlicensed abattoir, with the sale or intended sale of the meat as food for human consumption is illegal and is a criminal offence carrying significant penalties
• A producer who legally owns pigs can privately slaughter on farm and consume the meat on that property.

For our NSW producers, your NLIS obligation is legislated in the Biosecurity Act 2015 and in the supporting Biosecurity (National Livestock Identification System) Regulation 2017. As producers you also agree to comply with this legislation when you join the Livestock Production Assurance scheme. Your NLIS database is reviewed when LPA conduct their audits.

Key Points