Term
| What sort of things do you want to know in the history when investigating weight loss and ill thrift? |
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Definition
- number of cattle affected
- number of mobs affected
- signalment
- duration of clinical signs
- TReatment history
- Response to tx
- Farm history of disease
- Stock movements (on, off and within farm)
- Management changes
- Prophylactic treatments (Vacc, drench etc) |
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Term
| What sort of things do you want to know about the environment when investigating weight loss and ill thrift? |
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Definition
- Pastures
- potential soruces of toxins
- Water
- Feed
- Fences
- Amount of faeces |
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Term
| How are you going to go about examining the cattle in an investigation of weight loss and ill thrift? |
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Definition
- From a distance
- Lameness
- Isolation from herd
- Demeanour
- Estimation of % affected
- Close examination
- Physical exam of affected cows
- Take samples (swabs, bloods, biopsies)
- Post mortem |
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Term
| How would you determine if it is a herd problem? |
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Definition
The numbers affected is a big indicator, though it depends on how early you catch the disease (too early and some cases may not have developed clinical signs, you say it is not a herd problem and then it explodes 2 days later)
To know it can help to
- determine prevalence
- determine incidence
- establish how many animals are at risk
- Know the dx and ddx as well as basic epi |
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Term
| What is the causative agent in Bovine Johne's Disease? |
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Definition
| Mycobacterium paratuberculosis C |
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Term
| WHat species can get BJD? |
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Definition
| Cattle, goats, deer, alpaca, wildife |
|
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Term
| How do animals contract BJD? |
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Definition
From their dams by suckling, other calves may become infected through cross nursing
Animals up to 12 months old may pick the infection off the ground
If th damn is showing clinical signs of BJD, there is a 50% chance the calf will be infected in utero |
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Term
| How old are cattle when they begin to show clinical signs of BJD? |
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Definition
|
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Term
| What is usually needed before cattle show clinical signs? |
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Definition
Well infection.
Idiot.
But they ususally undergo a period of stress, such as calving, poor nutrition stuff like that |
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Term
| Which state of Aus is considered to be free of BJD? |
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Definition
|
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Term
| What are the risk factor for BJD in an area? |
|
Definition
Swampy, muddy conditions, so high rainfall.
Kind of explains why Vic and TAS are management zones, and WA is free |
|
|
Term
|
Definition
Individual animal
- Fecal culture
- Takes a really really long time. Like 3 months
- High Sn and High Sp though
- Serology!
- Ab ELISA
- Results in 1-2 weeks, lots of false positives
- Cheap, good screening test, used for MAP
- Post mortem
- tissue culture
- Histology
- Both really good, but make cow dead
- Herd
- Pooled faecal sample
- if positive, individual testing
- Herd environmental culture |
|
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Term
| How does BJD cause disease? |
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Definition
Bacteria lodge in the wall of the SI and cause thickening and distortion of the gut wall following inflammatory response
This leads to an decrease in absorption of all the things, = decrease in nutrients and increase in, well, water out put through the arse |
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Term
|
Definition
| Through the Peyer's Patches in the intestine, at some point, the infection travel to the lymph nodes around the GIT and for reasons that are not understood, the infection spreads to the rest of the animals, leading to clinical signs |
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Term
| What is the incubation period for Johne's? |
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Definition
|
|
Term
| What species does OJD affect? |
|
Definition
|
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Term
| What is the main method of transmission of OJD? |
|
Definition
| Shedding onto pasture (faecal-oral) |
|
|
Term
| How can OJD be transmitted? |
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Definition
| Shedding in faeces, contaminated feed or water, nursing from an affected dam, possible infection in utero, infected internal parasites |
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Term
| What are the risk factors for infection with OJD? |
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Definition
| <30 day old, merino, immunosupression |
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Term
| What are the differential diagnosis for weight loss and ill thrift in cattle? |
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Definition
Malnutrition (this is the biggie)
Nutritional deficiencies
- Copper
- Cobalt
- Phosphorous
- Selenium
- Magnesium
Lead poisoning
Parasitism
Mycotoxines
Diseases
- BVDV
- Johne's
- Lepto |
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|
Term
| What is the PAC format for writing communications? |
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Definition
| Purpose, audience, context |
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Term
|
Definition
| Situation, Mission, Execution, Admin and logistics, command and communication |
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