Term
What are the types of vaccines available? |
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Definition
Live attenuated,inactivated, subunit/recombinant and DNA vaccines |
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Term
Describe the primary and secondary response to vaccines |
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Definition
Primary - 2-3 weeks for naive cos to develop antibodies for pretection as the antibodies are derived from the division and multiplication of lymphocytes following exposure Secondary - Re-exposure (following 1st booster)will lead to the lymphocytes encountering antigen. These lymphocytes (which have encountered the antigen before) then produce antibodies. The 2nd response is much faster and much more refined, working within hours of days rather than weeks |
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Term
Which vaccine type does not often require a yearly booster? |
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Definition
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Term
What is a live attenuated vaccine? |
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Definition
A vaccine made from live bacteria or virus that has been modified through a process to weaken and reduce the virulence. |
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Term
How is the tick fever vaccine attenuated? |
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Definition
The virus is passed between immunologically naive and splenectomised calves |
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Term
What are the issues with live attenuated vaccines? |
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Definition
Possible return to virulence and disease causing |
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Term
What are inactivated vaccines? |
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Definition
Do not contain live bacteria or virus. They have been killed by chemicals, heat or radiation. They also stimulate a weaker immune response. |
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Term
What is a subunit vaccine? |
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Definition
A vaccine that does not use the entire microbe, but rather the section that causes the largest/most powerful immune response. |
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Term
What is a conjugate vaccine? |
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Definition
A vaccine made of the outer polysaccharide shell of an encapsulated bacteria |
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Term
What is a toxoid vaccine? |
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Definition
A vaccine developed from a toxoid rather than the whole bacteria, the toxoid can be inactivated with formalin |
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Term
Which vaccinations require refrigeration? |
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Definition
Live, subunit, toxoid and conjugate vaccines |
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Term
What are some causes of vaccine failure? |
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Definition
Incorrect serotype or strain Incorrect formulation Incorrect or insufficient adjuvant Incorrect storage Incorrect preparation Improper administration Incorrect dose Immunocompromised animals Malnourishment Poor enviromental ygiene |
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Term
What are the advantages and disadvantages of using the frozen vaccination for tick fever? |
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Definition
Adv: - Protects against babesia bovia and bigemina as well as anaplasma marginale - Can vaccinate cattle of any age - Long ass shelf life (5 years when stored well) Disadv: - has to be kept at -21 degrees (liquid N) - Only dispatched on Fridays, just order 24hrs prior - only comes in 25 and 100 dose packs |
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Term
What are the advantages and disadvantages of using the chilled vaccine for tick fever? |
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Definition
Adv: - Covers same 3 pathogens as frozen - Orders shipped on tuesdays and thursdays - comes in 10, 20, 23, 50 and 100 dose packs - Store at 2-8 degrees - Can vaccinate at any age Disadv - shorter shelf life - $4.27/dose |
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Term
How are the tick vaccines developed? |
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Definition
Parasitic blood is collected from calves with attenuated lab strains Vaccine donor calves are housed in insect free air conditioned units The calves are inoculated IV with one ot the lab strains and monitored daily Blood is collected from calves when parasitaemia occurs Parasitic blood is then diluted with sterile isotonic cell free diluent |
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Term
What is endemic stability? |
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Definition
An epidemiological state in a population in which clinical disease is scarce despite a high level of infection or where the relationship between host, agent, vector and environment is such that clinical disease occurs rarely or not at all |
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Term
How does endemic stability relate to tick borne diseases? |
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Definition
There is a high rate of tick infection in cattle (esp young cattle), though there is an absence of clinical signs as calves have an higher innate resistance to tick borne diseases. This means that they are able to develop immunity, leading to low incidence of clinical disease in adults |
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Term
To what age do calves remain resistant to tick diseases? |
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Definition
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Term
Where are ticks present in Australia and how is it limited? |
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Definition
Limited by legislation movement controls, Tick zones include the area east of the Great Dividing Range and north of the great northen rail line They are also considered to be in the northen areas of WA and NT |
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Term
What tick fever cause is the most common? |
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Definition
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Term
How do you treat tick fever? |
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Definition
Babesia - Imidocard @ 1ml/kg SC Anaplasma - Imidocard @ 2.5ml/kg SC
Remove the ticks Assess severity Vaccinate all at risk animals DO NOT VACCINATE TREATED ANIMALS Monitor cattle Protect rest of herd |
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Term
What are the agents that can cause tick fever? |
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Definition
B. bovis B. Bigemina Anaplasma marginale Theileria orientalis/ikeda |
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Term
Which of the babesia are the most common in Aus? |
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Definition
Bigemina, though bovis causes the most cases of disease as it is more pathogenic |
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Term
Which of the tick fever agents is the most common worldwide? |
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Definition
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Term
What are the host risk factors tick fever? |
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Definition
Bos taurus Age (older animals are more resistant) Seasonal variation |
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Term
How do you identify types of what type of agent you have? |
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Definition
Examination of a blood smear, you look at the RBCs, the protozoan can be seen within the cells |
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Term
What is the incubation time for babesia bovis? |
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Definition
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Term
How does B bovis cause disease? |
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Definition
Over production of cytokines and other inflammatory agents causing vasodilation, increased capillary permebility, vascular collapse, coagulopathies Infected RBCs aggregate in lungs and brain capillary beds |
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Term
What is the incubation period for B bigemina? |
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Definition
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Term
What are the clinical signs of Babesia infections? |
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Definition
High fever Haemoglobin uria Increased HR and RR Jaundice and anaemia Diarrhoea and rapid weight loss Recumbency and coma Possible abortion due to fever Temporary infertility in bulls (due to fever) |
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Term
How is anaplasma transmitted? |
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Definition
In Aus - ticks Other countries - ticks as well as biting flies |
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Term
What is the incubation time for anaplasma? |
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Definition
3-4 weeks, though they remain carriers for life |
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Term
How does anaplasma cause disease? |
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Definition
Multiply by binary fission to produce 2-8 infective bodies which infect other RBCs. Parasitised RBCs are destroyed by the reticuloendothelial system, leading to a progressive anaemia |
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Term
What are the clincial signs of anaplasmosis? |
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Definition
Anaemia fever Increased HR and RR No haemoglobinuria Decrease in production Pregnant cows abort |
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Term
How is theileria transmitter? |
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Definition
Bush tick (rather than cattle tick) |
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Term
What is the incubation time of theileria? |
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Definition
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Term
What are the clinical signs of theileria? |
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Definition
Lethargy, anorexia, exercise intolerance, pale, yellow gums, abortions or still borns |
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Term
Is there a vaccine available for theileria? |
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Definition
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Term
What supportive therapy should be considered for the treatment of tick fever? |
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Definition
For anaplasma and babesia, blood transfusion is PCV <12%, if less than 8%, then treatment prognosis is decreased |
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Term
How does natural immunity work to prevent tick fever? |
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Definition
- Colostrum provides protection for ~ 2 months - Innate immunity covers the calf from 3-9 months - Exposure to a tick burden from 6-9 months will usually cause no clinical signs and will result in long lasting immunity |
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Term
Which breeds of cattle have a genetic resistance to tick fever? |
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Definition
Bos indicus animals (an crosses that are >50% bos indicus) |
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Term
What percentage of their time do ticks spend on the ground/pasture? |
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Definition
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Term
How can you reduce the number of ticks in an environment? |
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Definition
Pasture rotation/spelling is particularly useful as the tick requires a host |
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Term
Can you use 'spot on' treatments to control tick fever? |
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Definition
Not really, as the tickicide does not target the larval stage when the tick is most likely to transmit disease |
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Term
What samples would you need to take to diagnose tick fever in a live animal? |
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Definition
Blood (EDTA) - haematology (anaemia/presence of protozoa) Blood (plain/clotted) - serology |
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Term
What is the benefits of taking peripheral blood for testing for tick fever? |
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Definition
There is a higher chance of detecting the organism in peripheral blood |
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Term
What samples would you need to take to diagnose tick fever in a dead animal? |
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Definition
Fixed tissue - spleen, liver, bone marrow and brain Blood/organ smears - peripheral blood, kidney(if fresh), heart muscle, spleen, liver, lung, brain Decomposing animals - spleen, brain, heart muscle |
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Term
How low is the number of circulating protozoa in general blood compared to peripheral blood? |
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Definition
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Term
What is the life cycle of the cattle tick? |
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Definition
Rhipicephalus (boophilus) microplus Engorged female drops to ground and hides amongst plant litter Lays eggs over a week in summer (longer in winter) Eggs hatch into larvae at 2-21 weeks (depending on temp and humidity) 6-legged larvae climb up grass and other things and rub off on cattle as the walk past. They can also be wind blown for 20M Larave attatch themselves to a host and feed for ~1 week Then become nymphs for 1 week They moult into adults and then mate and feed and stuff |
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Term
When is the cattle tick most active? |
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Definition
Late spring to early winter |
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Term
What does the cattle tick look like? |
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Definition
Pale cream legs ( a wide distance from snout) Oval/rectangular body |
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Term
What are some of te effects of a heavy tick burden? |
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Definition
Decrease in production Decreased feed intake Immunosuppression Hide damage Labour increases for treatment |
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Term
What is the threshold for a 'heavy' tick burden? |
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Definition
150-300 engorged ticks/cow |
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Term
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Definition
A tickicide, does not affect the larval ticks, might decrease overall numbers though |
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Term
What is an example of an acaricide? |
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Definition
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Term
In general, how often do you need to reapply acaricides? |
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Definition
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Term
What's the problem with the buffalo fly? |
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Definition
They irritate the cattle, cause hide damage and transmit stephanofilaria worms |
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Term
How can you control the buffalo fly? |
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Definition
Chemical control - self applicators (backrubbers and dusting appliances) - Ear tags that slowly release organophosphates and synthetic pyrethroids Non-chemical - flytraps - Dung beetles - Culling of highly affected cattle |
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Term
For the purposes of tick control, how is Qld divided? |
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Definition
Infected Control Free zones |
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Term
What do you have to do if you want to move a cow from an infected zone to a controlled or free zone? |
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Definition
They must be inspected, cleaned and treated under the supervivion of a Qld biosecurity officer. |
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Term
To move cattle from Qld to NSW what must you do? |
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Definition
Ensure the cattle have a NLIS tag Notify the NLIS database of the movement Be treated and cleared free of ticks |
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Term
What forms do you need to move stock in relation to tick areas? |
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Definition
Qld travel permit Qld livestock movement system - waybill or national vendor declaration Cattle tick preliminary treatment - Owner declaration Cattle tick cert of inspection and treatment |
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Term
What is the longest you can transport a cow over 6 months old by land? |
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Definition
48 hrs followed by a min spell of 36hrs |
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Term
What is the longest you can transport a cow between 30 days and 6 months old by land? |
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Definition
24 hrs followed by a min spell of 12 hrs |
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Term
What is the longest you can transport a lactating cow by land? |
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Definition
24hrs followed by a min spell of 12 hrs |
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Term
What is the longest you can transport a calf 5-30 days old (w/o mum) by land? |
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Definition
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Term
Can cattle be transported in the last 3 months of pregnancy? |
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Definition
Yes, but only when vital and signed off on by a vet |
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Term
What are some considerations when moving stock between states? |
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Definition
MUST HAVE AN NLIS TAG AND VENDOR DECLARATION!!! Animal health statement is also good Climate, temp, humidity, inclement weather Disease Vaccination Age Class (e.g. lactating, pregnant..) Time off water Distance Stopping points Type of terrain (actual speed possible by road) |
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Term
What are some diseases of concern regarding interstate transportation of stock? |
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Definition
Ticks Johne's Enzoontic bovine leukosis Liver fluke Foot rot |
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Term
What are some of the most common causes of anaemia in cattle? |
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Definition
Abomasal ulceration Bracken-fern poisoning Acute blood loss Parasitic diseases Lepto Clostridium novyi Tick fever Chronic Cu tox Zn tox Iron, Co, Cu, Se, Mg deficiency Chronic liver disease Pb poisoning |
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Term
What are some ddx of red urine in cattle? |
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Definition
Bracken fern - on PM there is thickening and scarring of the bladder Enzootic bovine pyelonephritis - Rectal exam (ureters and caudal pole of L kidney is often swollen and painful) Post parturient haemoglobinuria - history, regen anaemia, no sediment on urin exam Bacillary haemoglobinuria - sudden death, widespread hemorrhages on PM, characteristic single large liver infarct Lepto - heard antibody titres, leptospired in urine or foetal kidney Chronic Co tox - clinical signs, jaundice, gun-metal black kidneys Babeisosis and therileriosis- clinical signs, exam of blood smear Brassica - Clinical signs, history of exposure |
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