Small Rum 3 Flashcards
What is involved with planning for footrot eradication program
- Labour ○ DYO or Contractors - Fencing ○ Eliminate source!!!!!! - Infrastructure ○ Footbaths ○ Laneways ○ Inspection equipment - Sheep ○ Replacement sheep ○ Stock numbers (hold back cfa rather than sell)? - Budget ○ Cost benefit ○ Cash flow ○ Peak debt
In terms of control for eradication program for footrot what are the objectives and the 3 options
○ Objectives § Minimise production losses § Improve welfare § Maximise chance of eradication □ Less lesions □ Quicker inspection time □ Less salvage required ○ Options 1. Foot-bathing 3. vaccination 3. do nothing - not a good option but most common
Footbathing for the control of footrot during eradication program what chemicals use for the 2 types, how respond to treatment, logistics and when to cut out
□ Walk through 8m+ - formalin or 10% zinc sulphate weekly □ Stand in - footrite, 10-20% zinc sulphate, radicate 12-16 days - Permanent v portable □ Infrastructure cost □ Efficiency of chemical use □ Zinc sulphate tester - Response to treatment □ Lambs>>chronic adult lesions - Logistics □ Makes frequent footbathing difficult □ Good to do with short spread period or low virulent strains (<5- 10% severe lesions) □ When to cut out before summer
Vaccination for control of footrot during eradication program when use, which recently registered and requirements for efficacy
ONLY DO IF HAVE 1-2 SEROTYPE ON THE FARM
□ With the more virulent strains
□ Commercial footvax vaccine not currently available
□ New vaccine recently registered
- Mono/bivalent vaccine in development/restricted release
◊ Shows high efficacy in field but expensive if >1-2 serogroups
□ Requirements
- Lab diagnosis
◊ Serogroups $1000
◊ Virulence (in greater than 2 SG) $2000
- Vaccination 2 doses per 2 strains ($2.20/dose)
- Up to 12 months protection
- Annual booster or eradication
Eradication for footrot when start and the 2 ways to perform the cull and where get new sheep
- Start once conditions have dried out ○ 3-4 weeks since last footbath – care 1. By inspection 2. Destocking • Change over cost – depends on year • Old sheep • Poor genotype • Change enterprise • Not interested in destocking • Disease free source » OJD? » Footrot (good luck) » Lice – not a big issue
footrot control and eradication timetable for a farm
- Winter - Spring ○ Control ○ Prepare for first inspection - Summer (or when conditions dry out) ○ December 1st inspection ○ Late January 2nd inspection ○ February 3rd inspection ○ March – April 4th inspection - Late Autumn ○ surveillance
footrot eradication objective and what is involved with the inspection process
- Objective ○ Remove all infected sheep from property by the autumn break ○ First inspection: 5-30% (salvage) ○ Second inspection <1% ○ Third inspection 1/1000 ○ Fourth inspection 0 - Inspection ○ Every claw 4,000 sheep = 32,000 toes! ○ 1 person 400 sheep inspect per day ○ So many - repeat inspections - to help prevent human error ○ Keep sheep with 4 normal feet ○ If in doubt chuck it out ○ Two options ○ Red head infected ○ Blue head clean
Footrot eradication salvage some sheep why would you do it, how and reinspection process
- Salvage
○ Cost effective to maintain stocking rate
○ One-off antibiotic treatment
○ Oxytetracyclines ESI (export slaughter interval) 90 days
○ How?
1. Shaping pare
2. Inject
3. Footbath
4. Shed for 24 hours
5. Reinspect in 4 weeks – expect 10% culls - Reinspection process
○ Continue over autumn
○ Cull all remaining infected sheep
○ Two clean inspection
○ Final inspection probably ok just at autumn break
Surveillance for footrot eradication program how perform and when inspect
- Chance of break down
- Separate paddocks to decrease chance
- Follow the 7 day rule
- Don’t let clean sheep walk where suspect sheep have been within 7 days
- Crutching
- Shearing
- Inspect the following spring
- Clearance after normal spring
Prevention of footrot during eradication program what need to consider with stock on property and new stock
- Fences - 100% effective needs to keep everything out
- Roadways
-> Communicate with neighbours
-> If infected neighbours sheep down the road can then walk your sheep down 7 DAYS LATER - New stock (do not let any other sheep walk across where new sheep have walked in the previous 7 days)
-> Bigger mobs
○ Do your home work before buying - inspect
○ Avoid buying from yards
○ Footbath – won’t guarantee freedom from footrot
○ inspection when they get home
○ Quarantine until they have been through a spring spread period
Foot abscess what are the main bacteria involved, risk factors and what makes treatment harder
- Foot/Heel abscess: Fusobacterium necrophorum and Arcanobacter pyogenes - main ones
- Toe abscess: often associated with shelly toe various pyogenic bacterium
- Risk factors
- Wet muddy conditions, heavy late pregnant ewes or heavy rams
- Breeds merino, xb
- Older sheep more vulnerable
- If invade joint space then poorer prognosis as treatment harder
Foot abscess treatment
- Drainage
- Remove to dry ground
- Antibiotics with individual valuable animals - will result in quicker recovery
- Oxytetracyclines - longer duration of action
- Pain relief: flunixin?
- Manage pregnancy toxaemia risk - as very painful and pregnant ewes may stop eating enough
- Cull chronic lame ewes/rams - increase susceptibility of recurrence especially when getting older
Foot abscess 3 prevention strategies and what wouldn’t you use
- Manage body condition of ewes
- Avoid over fat ewes and ewes too light -> increase mortality with condition score less than 3 and over 3.5 - Run older/at risk ewes in dry paddock
- Gravel in yards not too rocky?
- Footbathing may exacerbate condition - wouldn’t specifically get them in for Footbathing as moving and stressing them will INCREASE the rate of foot abscess
Scabby mouth what caused by, zoonosis?, is there immunity, location, environment present in, treatment and prevention
- Orf/scabby mouth virus
- Zoonosis
- Generally only occurs once a generation in the herd as get acquired immunity
- NOT THE HOOF -> just up the coronate
- Lush conditions, young sheep and lambs
- Mouth lesions with dry rough feed, thistles
- Supportive treatment for individuals with secondary infection -> will recover in 3 weeks
- Vaccination available but not always used -> in the peringuinal area
Strawberry footrot how common, cause, location, conditions present in and treatment
- Generally quite rare
- Dermatophilosis congolensis: same bacterium that causes lumpy wool or mycotic dermatitis
- Swab/smear for diagnosis
- Above the heel, NOT IN HOOF, more commonly on the hindlimb
- Only in extremely wet humid conditions - generally in young hoggets
- Antibiotic treatment - will help resolve
Laminitis or founder what is the general history, treatment and possible chronic issue
- history of introduction of grain feeding/change ration
- Need to slowly introduce the ration with impression feeding
- usually recover with no treatment (acidosis may need treatment)
- Will result in distortion of the hoof will growing so will see where the laminitis occurred
Arthritis how common and causes
- Really common
- Causes
- Chlamydia
- Erysipelothrix rhusiopathiae
- Purulent arthritis (such as joint ill) caused by various bacterium:
○ Arcanobacter pyogenes
○ Fusbacterium necrophorum
○ Histophilus ovis
○ Staph sp, Strep sp
Arthritis pathogenesis, which sheep more vulnerable, diagnosis, treatment and prevention
Pathogenesis
- Infection via parentral, post marking or haematogenous route
- Younger lambs more vulnerable- Colostrum
- Post dipping lameness - to prevent this dip 10 days post shearing to allow shearing wounds to heal
Diagnosis: Swabs - smear culture and sensitivity - should figure out the bacteria cause
Treatment
- Penicillin preferred Erysipelothrix rhusiopathiae
- Oxytetracycline Chlamydia
- Occasional anti-inflammatory Rx (flunixin)
Prevention
- Hygiene marking, dipping, tail length, time of shearing
- Vaccination Eryvac® for Erysipelothrix rhusiopathiae - another reason for diagnosis of the bacteria involved
How would you differentiate between benign and virulent footrot
- Examine 100 sheep at random, footscore them and reassess them in mid spring - THE BEST
○ Why reassess -> if mainly early lesions -> cannot be sure if benign or virulent footrot
§ DON’T KNOW WHETHER HAD TIME FOR CLINICAL MANIFESTATION - need to allow time
Nitrate/nitritie poisoning origin, what effect and why effect in respiratory and clinical signs
○ Nitrate from feed -> nitrite -> ammonia -> microbial protein
Nitrate has a direct caustic effect on the GIT
• Diarrhoea and vomiting.
• Salivation.
• Abdominal pain.
Nitrate/Nitrite poisoning
- If high levels of nitrite formed absorbed into circulation
○ Converts haemoglobin to methaemoglobin -> unable to carry enough oxygen
Clinical signs
- The signs of nitrite poisoning usually appear 6–24 hours after the toxic material is consumed.
- These include:
○ Rapid, noisy and difficult breathing.
○ Blue/chocolate-coloured mucous membranes.
○ Rapid pulse.
○ Salivation, bloat, tremors, staggering.
○ Weakness, coma, terminal convulsions, death.
○ Dark ‘chocolate-coloured’ blood.
○ Abortions – pregnant females that survive nitrate/nitrite poisoning may abort due to a lack of oxygen to the foetus.
Ocular conditions in sheep what are the 2 main ones and describe cause, treatment
- Pink eye:
- Sporadic, often self-limiting if just a few cases
- Consider carefully whether it is worth yarding the mob or not
- Organisms are typically Chlamydophila or Mycoplasma (was Rickettsia)
○ Not zoonotic
- Not as strongly seasonal as cattle disease
- Grazing around spiky plants can contribute to the condition
- Can use parenteral oxytetracycline.
- Farmers may use ‘Pink eye aerosol’ – contains oxytetracycline. Short duration. - Foreign bodies
Grass seeds – especially barley gras
What are the 4 main clinical signs of respiratory disease
- Nasal discharge, sneezing, coughing, open-mouth breathing
- Dyspnoea, swelling (lymph nodes)
- Exercise intolerance
- Mortality - collapse and death
What are 6 ways to diagnose respiratory disease
- Respiratory sound - nature, location ○ Can be hard to evaluate - Haematology - Necropsy - important as lead to death ○ Ocular fluid therapy - Bacteriology - Toxicology - Response to treatment
What are the risk factors for respiratory disease
- Intensive systems -> poor ventilation - build of gases
- Mixing of animals and pathogens
- Damage/irritation of respiratory tract defences - due to poor ventilation
- Stress and depressed immunity
- Easy transmission between individuals
- Antibiotics resistance
- Ineffective vaccination
- Pathogen introduction via fomites
List the 2 main diseases of the upper respiratory tract and lower respiratory tract
1) drenching disease
2) oestrus ovis - nasal bot
UPPER
1) pneumonia
2) pleural/superficial pulmonary abscess
Drenching disease what are the 2 main forms and what leads to
- retropharyngeal trauma - when drench capsule is given into the lungs instead of rumen
§ Sheep neck needs to be elongated and lifted -> need to swallow the device then put in capsule - aspiration pneumonia - liquid anthelmintic isn’t correctly given -> too far into throat -> drench given into trachea
○ Leads to sudden death
Oestrus ovis clinical signs how to control at herd level and for hobby farm
○ Ongoing snotty noise but doesn’t affect body system
○ Controlled by ML anthelmintics -> when drenching sheep for other parasites will be control
○ Injectable Ivermectin can also be given if on hobby farm
§ Secondary bacterial infection generally occurs -> long course of oxytetracycline
Pneumonia causes what are the 4 main ones and diagnosis
Causes
1. Iatrogenic - aspiration pneumonia from drenching incorrectly
2. Viral
3. Bacterial - mycoplasma ovis “summer pneumonia”
§ +/- complicated Mannheimia, Pasteurella - commercials - COMMON when chronic
4. Parasitological
§ Lungworm -> usually incidentally controlled by ML
Diagnosis
- Necropsy, history, bacteriology
Pneumonia treatment/prevention
○ Empirical (oxytetracycline) - treat those with clinical signs and growing poorly
○ Occasional other respiratory ‘big guns” (tulathromycin, tilmicosin)
○ Vaccines used overseas
Pleural/superficial pulmonary abscess what common in, clinical signs, diagnosis and treatment
○ Common/underdiagnosed in rams
§ Weight loss, mild pyrexia, hyperpnoea
○ May detect with chest ultrasound (or find at necropsy)
○ Seem to respond to long courses (6 weeks) of penicillin
Cheesy gland prevalence, immunity, significance and transmission
- Flock prevalence 30-100%
- Good immunity against subsequent infections
- Significance - COST
○ Condemned meat
○ Lost milk production - Transmission
○ Carrier animal with cheesy gland in the lung that rupture - cough onto other animal skin (where have cuts and is wet)
§ These conditions are met during shearing or sheep dips
§ Increase risk -> when young sheep in dip AFTER old sheep (old sheep contaminate)
○ Environmental contamination of ruptured abscess from post mortem etc.
Cheesy gland vaccine, how long last and which groups of animals would you and would you not vaccinate
- Only lasts a year - vaccinate with 5 in 1 (ewes - minor cost to add) ○ Wethers -> not vaccinated every year so unlikely to be a benefit of vaccinating UNLESS prevalence if very high
- 2 initial doses than annual boosters
Caprine arthritis and encephalitis cause and significance
- Lentivirus - goat equivalent of sheep exotic diseases
- Notifiable
- Widespread australia and world
○ 82% of NSW flocks - Slow incubation, difficult detection, no treatment
- Costly disease
○ Decreased milk production in sub-clinicals
○ Culled clinical animals
○ Surveillance and eradication needs lots of testing
Caprine arthritis and encephalitis what are the 5 syndromes and transmission
Clinical signs - 5 syndromes - COMBINED AFFECT
1. Leuko-encephalomyelitis
2. Arthritis
3. Chronic wasting
4. Interstitial pneumonia - respiratory issue
○ Generally non-suppurative
5. Hard udder
- All have characteristics mononuclear-cell inflammation
Transmission
- Vertical (milk and colostrum) - NEED TO BE SNATCHED REARED
- Horizontal (Secretions) -> strictly quarantine the herd from clean to diseased - if possible cull the diseased
Caprine arthritis and encephalitis diagnosis and certification qualifications
- Clinical signs
- Characteristic non-suppurative inflammation (mononuclear cells on joint tap or histopathology)
- Complete serological diagnosis is difficult
○ Maternal Ab = offspring +ve until 2 months
○ Often low Ab levels
§ Not protective anyway
§ Develops late (>8monts)
○ Can relapse to negative - DON’T TRUST THE FIRST NEGATIVE TEST
○ Need 2 herd negative tests 6-12 months apart to be accredited free
§ Re-rest every 1-2 years for ongoing accreditation
Caprine arthritis and encephalitis control and eradication
- Surveillance
○ Repeated blood testing - determine whether negative
○ Cull reactors AND or run infected and uninfected herds - Prevent transmission
○ Vertical - snatch rearing, don’t pool colostrum
○ Horizontal - strict biosecurity between herds and only buying in from certified free herds
List the 4 main exotic diseases that present with respiratory signs
1) other retroviruses
2) nasty mycoplasma disease
3) sheep and goat pox
4) bluetongue
What are the 2 main retrovirueses that present with respiratory signs and what lead to
- Maedi visna/ovine progressive pleuropneumonia
§ Dyspnoea wasting
§ Ovine equivalent of CAE (no cross-species infections observed in the field) - Jaagsiekte/pulmonary adenomatosis
§ Pulmonary tumours caused by another retrovirus
Bluetongue what transmitted by and clinical signs
○ Transmitted by culicoides (not contagious)
○ Clinical signs
§ FEVER, FACE (oedema - due to vasculitis)), FEET (lameness - due to vasculitis), coronet swelling)
§ Nasal discharge
§ Dyspnoea
