Cattle 1 Flashcards
What is the relationship between exotic and notifiable disease
Notifiable disease does not always mean exotic
- Such as anthrax -> not in this lecture
ALL EXOTIC ARE NOTIFIABLE -> not all are emergency
- Must notify the department within
- Foot and mouth disease - ASAP
What are 2 common exotic disease categories and disease within
Vesicular Diseases = blister - Foot and Mouth Disease - Vesicular Stomatitis Erosive Diseases = erosion - Rinderpest - Jembrana Disease
List the 13 main exotic diseases of cattle
- Bovine Spongiform Encephalopathy
- Rabies
- Screw Worm Fly
- Contagious Bovine Pleuropneumonia
- Bovine Tuberculosis
- Bovine Brucellosis
- Enzootic Bovine Leucosis
- Haemorrhagic Septicaemia
- Theileriosis (East Coast Fever - east coast of africia)
- Rift Valley Fever
- Lumpy Skin Disease
- Bluetongue
- Heartwater (Cowdriosis)
Foot and mouth disease, what caused by, incubation period, transmission and what species affected with susceptibility
- Viral disease
- High contagious but low mortality
- Longer incubation period - 2-8 days -> able to spread before detection of clinical signs
- Transmission -> direct contact (infected foodstuff, meats), airborne (robust virus so can travel long distances - generally in low temperature), fomites (boots, vehicles, people)
○ If infected food stuff from overseas is illegally imported and then given to pigs - most likely how will enter -> swill feeding is illegal - Hooved animals (ungulate)-> NOT HORSES -> 2 claws or more
○ Pigs, sheep, cattle, camelids, antelope
§ Pigs are super incubators -> sheds 3000 times more virus than cattle in the air
§ Cattle are highly susceptible to infection and show obvious clinical signs -> detect in these first generally in an outbreak
What are the clinical signs in cattle of foot and mouth disease and general time it takes for these to occur
- Inflammation -> Blisters short-term -> rupture (tags of epithelium present then heal - painful
○ Takes 4-5 days -> if have vesicles only RECENT INFECTION
§ Resolving lesions -> within the herd for a few weeks -> NEED TO TRACEBACK
○ Shifting lameness, reluctance to move
○ Between claws, around coronary bands - Mouth -> excess salivation (drooling) -> due to painful stomatitis
- Generally also get fever -> listlessness
- Highly susceptible generally
What are the clinical signs seen in sheep and pigs for foot and mouth disease
PIG
Snout and foot lesions, shifting lameness, inflammation of coronary band, can also get abortions so reduced litter size
SHEEP
- clinical expression is low -> hard to detect’
- Shifting lameness often the clinical signs -> can look like footrot
What are the main effects of a foot and mouth disease outbreak
○ Mortality of the animals
○ Decrease in trade - major economically loss
○ Environmental -> smoke, burning cattle, large grave yards
○ Depression - suicides -> social consequences
Vesicular stomatitis what look like, what species effect, where found and mortality
- Clinically very similar to FMD. Insect vectors.
- Affects cattle, horses and pigs - IF HORSE AND LOOKS LIKE FMD -> think this
○ also many New World (Americas) wildlife such as deer, antelope, raccoons, monkeys and rats - Occurs in Western Hemisphere
○ USA, Central and Sth America - Vesicles on mouth, feet, teats
- Low mortality - just young, immunosuppressive, and those killed for control purposes
○ Is still a welfare issue, cannot just leave -> takes months to recover
Rinderpest when eradicated, mortality and morbidity, species found, transmission and what signs similar to
- Eradicated in 1905
- High morbidity and high mortality
- Found in goat, sheep, pigs, cattle, buffalo, giraffes
- Transmission -> direct contact - milk, urine, faeces
○ Indirect transmission not important as fragile organisms
Differential - Mucosal disease (BVDV) and malignant catarrhal fever -> endemic in Australia
○ Malignant catarrhal fever -> generally sporadic and high mortality - JUST NOT HIGH MORBIDITY AND MORTALITY like rinderpest
Rinderpest Clinical signs and progression of the disease
Erosive lesions, fever, salivation, severely depressed and reluctance to
- Fever generally the first clinical signs - 2 day after infection
- Pregnant cows may abort
- Discharge from eyes and nose -> may become purulent
- Salivation and drooling
- Nasal discharge will dry and form crusts
- Developed of erosions in mouth and palate
- Diarrhoea -> temperature will start to fall -> blood and mucous in diarrhoea
- Emaciated and weak looking cows
- Die 6-12 days after infection
Screw worms fly what is it, where found, where could do and impact
- Old World Screw Worm Fly
○ Chrysomya bezziana - Endemic in PNG (~150km away) - VERY CLOSE
○ Have had infections but hasn’t established itself - Modeling indicates it could establish in Oz especially in Northern Queensland
- Economic impacts -> may not be able to castrate or dehorn due to risk of infection within open wounds
○ Loss of condition -> production losses, fertility losses
Contagious bovine pleuropneumonia (CBPP) what causes, is it in australia and the disease with types caused
- Mycoplasma mycoides subsp. mycoides
- Eradicated from Australia 1967 before than was endemic
- Respiratory disease
○ Acute
§ Fever, depression and rapid respiration
○ Chronic
§ Mild fever, loss of body condition
§ Dyspnoea on exercise
Bovine tuberculosis main importance, caused by, clinical signs and diagnosis
ZOONOTIC - Mycobacterium bovis - Infected cattle often clinically normal - Signs are usually respiratory ○ coughing, dyspnoea then weight loss ○ Sometimes alimentary and mammary - Herd surveillance using intra-dermal testing - Confirmation post-mortem ○ culture or histopathology
Bovine tuberculosis is it in Australia and what countries within
- Eradicated from Australia (BTEC. Free in 1997)
- Endemic in many countries, incl NZ (possum) & UK (badgers)
○ Eradication based on identification and removal of infected cattle
○ Complicated by existence of wildlife reservoirs (badgers & possums)
Bovine brucellosis importance, cause, main issues, where is ti located
ZOONOTIC
- Brucella abortus
- Contagious.
- Late term (5 – 7 months) abortion & infertility
- Zoonotic (infected material or milk)
○ “Undulant fever” -> comes and goes
- Eradicated from Australia (since 1989) & NZ
○ ‘Strain 19’ vaccination (do not inoculate yourself) and culling
- Still widespread elsewhere
○ Mediterranean, Latin America, Africa, parts of Asia
Enzootic bovine leukosis what caused by, age of animals, what occurs, transmission and is it in aus
- Infectious. Bovine Leukosis Virus (Retroviridae)
- Tends to occur in older animals
- Most (95%) asymptomatic
- Some (30%) have lymphocytosis
- Spread by fomites (vets… needles, gloves etc)
- Eradicated from Australia dairy herd (2012) using bulk tank and individual cow serology
Sporadic bovine leukosis when occurs, age, 3 forms and is it exotic
NOT EXOTIC
- Not infectious, nor due to BLV -> sporadic prevalence
- Tends to occur in younger animals
- Three clinical forms
○ Juvenile: Generalised lymph node swelling. Dead in 4-6 weeks
○ Thymic: Thymic enlargement at thoracic inlet associated with signs of cardiac and respiratory dysfunction, or metastases
○ Skin: Multiple hyperkeratotic plaques. May resolve spontaneously but usually recur. Widespread metastases in other organs is terminal
List 6 other exotic diseases - generally spread by vectors
- • Haemorrhagic septicaemia
- • Theileriosis (East Coast Fever) [cf Benign Theileriosis (endemic in Australia)]
- Rift Valley Fever
- • Lumpy Skin Disease
- • Bluetongue
- • Heartwater (Cowdriosis)
Haemorrhagic septicaemia what is it, caused by, species found in, located and transmission
EXOTIC
- pasteurella multocida (B:2 & E:2 strains)
- esp Buffalo… Cattle… Bison
- In Sth East Asia, Middle East & Africa
- Transmitted by direct contact or via feed
- ~ 2 % carriers in endemic areas
Haemorrhagic septicaemia morbidity, mortality, incubation, clinical signs
- Morbidity in outbreaks 5 - 90 %
- Case fatality close to 100 %
- Incubation 2 - 5 days
- Acute or peracute (6 - 48 hours)
- Clinical signs - SEPTICAEMIA
○ High fever, dullness
○ Excess salivation, nasal discharge
○ Oedema of throat and brisket
○ Respiratory distress and death
Theileriosis what is it, transmission, signs and mortality
EXOTIC - Tick-borne protozoal disease ○ Theileria parva (East Coast Fever) ○ Theileria annulata (Mediterranean, tropical) - Signs ○ Lymph node enlargement ○ Fever ○ Hydrothorax - Case fatality 100% in naïve cattle
Benign theileriosis what is it, transmission, where found and signs
NOT EXOTIC - Tick-borne protozoal disease ○ Theileria orientalis - Endemic in Victoria (not Tas, SA) - Signs ○ Variable symptoms § Anaemia, Fatigue, Abortion… ○ An interesting emerging disease in Victoria
Rift valley fever importance, transmission and what leads to
- Mosquito-borne viral disease
- Abortions and mortality of young
- Zoonosis
○ Influenza like disease
Lumpy skin disease pathogen, clinical signs, mortality, is it in aus and what also looks like
- Viral (Poxviridae)
- Multiple skin nodules.
- Few die, but infected animals debilitated
- Never been recorded in Australia -> risk to australia is low
○ There is surveillance - Differentiate between:
○ Allergy
○ Insect attack
○ Pseudo Lumpy Skin Disease
§ BovHerpes2 (endemic in Aust)
○ Sporadic bovine leukosis
Bluetongue transmission, location and symptoms
- Arthropod borne (Culicoides midges)
- Widespread globally
○ Detected in Northern Australia, but does not cause clinical disease - Symptoms overseas
○ Morbidity is low (<5%). Mortality also low.
○ Mild fever. Oral/nasal erosions, discharge, crusts.
○ Mild lameness and stiffness.
Heartwater (cowdriosis) transmission, location adn signs
- Tick-borne Rickettsial disease ○ Erlichia ruminantium - Southern Africa - Signs ○ Fever ○ +/- Diarrhoea ○ Nervous signs
Animal health economics what are the basics with production animal medicine
- patients have a finite monetary value
- clients have different preferences -> changes with value of those animals in the market
○ As Increase more likely to invest in animal health and vice versa - treatments have different efficacies (and costs)
Animal health economics what are the basics with companion animal medicine
- patients have a highly variable ‘value’
- clients have different preferences
- treatments have different efficacies (and costs)
Why is animal health economics important
Knowing a bit about economics will help you to offer animal health ‘solutions’ that
- are compatible with your client’s ability to support and care for the animals under their care
- represent value for money
-Being able to do this will ultimately enhance the standing of the veterinary profession in the wider community
•There’ll be many occasions during your career when you’ll want to ‘do something’
- employ a new associate veterinarian
- build a new operating theatre
- implement a control program for a disease at the regional or national level
Cash flow document what is it, what does it provide information on
- A cash flow documents expected incomes and expenses over a specified period of time (generally by month)
- Provide an idea of an enterprise’s ability to pay for a proposed intervention -> when farm in net surplus
- Provide no information about whether or not a proposed intervention represents a good investment
Partial budgeting what is it used for, what are considered and the 4 main categories with equation
- A technique useful when you want to work out the likely economic impact of a single intervention in a livestock enterprise
○ Introducing vaccine, AI instead of natural, building new shed - Only those costs and returns affected by the intervention are considered
Costs and returns categorised under four headings:
A. Additional returns obtained as a result of the implementation of the program
B. Costs no longer incurred if the program is implemented
C. Returns no longer obtained if the program is implemented -> granuloma from vaccine resulting in increase carcass cutting at abbatioir
D. Additional costs incurred from implementing the program
Net change in income equals returns minus costs: (A + B) - (C + D)
Partial budgeting what does the cost estimated result mean, advantages and disadvantages
- If the estimated change in net enterprise income is greater than zero, the change is expected to return a net positive economic effect
Advantages - suitable for analysing small changes in an enterprise e.g. change in the replacement policy of dairy cows, adoption of a new breeding method
- the only information required is the four factors which change as a result of the proposed intervention
Disadvantages - analyst must decide what aspects of the production process are likely to change as a result of the proposed intervention
- sometimes difficult to clearly identify the likely costs and benefits associated with the change
Partial budgeting what need to add, why, how done
put sensitivity around it
○ Sensitivity analysis is a technique that allows you to identify those inputs that have the biggest effect on the net change in income
○ Sensitivity analyses important for working out if your conclusions are robust enough to errors in assumptions
○ How to do it?
§ Spreadsheet and change the values that may change such as cost of feed and change in ADG (average daily gain) and determine the profit for the changed values
- if sensitive to changes around a parameter should be conservative in the estimate and get values from a good source - metanalysis
Benefit-cost analysis why do you need to use this
- If responses to interventions are immediate
○ we can add up the expected costs and benefits of the proposed intervention
○ Compare the costs with the benefits - But often responses take a while
○ when interventions are large and complex, costs can extend over many years
○ similarly, benefits accrue over many years
○ estimates of benefit and cost need to account for time
Benefit-cost analysis what is it based on
- Benefit-cost analysis is based on discounting the benefits and costs attributable to a project over time and then comparing the present value of costs (PVC) with the present value of benefits (PVB)
○ If have to wait a long time to get return that return is worth less to us
What are the 3 aspects of the benefit cost-anaylsis
1) The present value of benefits is the sum of the discounted values of benefits in each year:
2) The present value of costs is the sum of the discounted values of costs in each year:
3) The discount rate i should reflect the real rate of interest (or of return) on investments (highly dependent on the interest rate)
○ It can be:
§ a rate comparable to the real rate of interest that could be earned if the sum involved was put into a bank or invested in another project
§ a social time preference rate, reflecting the preference society has for present as opposed to future consumption
The discount rate (i) in benefit-cost anaylsis what should be though as, what common values and what if high discount rate
○ The discount rate should be thought of as a ‘price’ set on the use of money -> what is costs to use money instead of putting in the bank
○ Discount rates usually chosen for projects in developing countries range from 8% to 12%
○ High discount rates penalise projects with high initial expenditures and a low level of benefits returned over a long period of time
§ disease eradication projects often fall into this category
§ this problem should be acknowledged while realising that a reasonably high discount rate often needs to be applied in order to reflect the opportunity cost of capital
Dealing with inflation when do and don’t rely on
- if relative prices don’t change (everything going up at the same rate), don’t worry about adjusting for the effect of inflation, estimates are made on the basis of today’s prices
- if a change in relative prices is expected, the price of those items which are getting cheaper or more expensive over time can be decreased or increased as necessary
- > it is simpler and safer to use present-day prices
What is the consumer price index
- Change in price of multiple items is recorded and used to create consumer price index
- Can be used to determine how much certain money will be worth in the future
Payoff tables what situations used in
- With sporadic and rare diseases, the benefits of a control program centre around defining
a. the probability of disease occurring
b. the severity how severe an outbreak could be if it does occur - Pay-off tables are a useful tool in this situation
How to use a payoff table
- A decision (A1, A2, … Ai) can be represented in the following mathematical form:
○ EG decisions -> vaccinate or we don’t, OR vaccinate, medicate, or vaccination an medicate
○ Outcome = A - the decision we decided ○ Each decision has a value from cost-benefit ratio (with sensitivity) AND likelihood of outcome occurring with the intervention - The Expected Monetary Value (EMV) for each decision (Ai) is the weighted average of the returns from the j possible outcomes arising from each decision
Using ADG as an example how to use a payoff table
- In this case, the possible outcomes are 0%, 5%, 10%, 15%, and 20% improvement in ADG
- Since the choice of intervention rests heavily on the increase in ADG, it’s important that we’re conservative in assigning probability estimates
++++ = probably that the intervention will lead to the ADG - Probably is the clinical judgement -> guided by the literature and collages
EMV = expected momentary value of the decision we make - Is a weighted average
20% of the time lose $79996 = 0.2 x -79996 ECT for all situations to give the overall momentary value of that interventions
Why is it hard to make decisions and what can decision analysis do
Why hard to make a decision
- Complexity
- Uncertainty
- Multiple objectives and stakeholders involved
Decision analysis
- an analytical method used to ensure consistency in decision making
- doesn’t provide solutions, but insights into the situation, uncertainty, objectives and trade-offs involved in the decision making process
- a good decision is an action we take that is logically consistent with
○ the alternatives available
○ the information available to us
○ our preferences
- a good outcome is a future state that we value relative to other possibilities
What are the 5 elements in making a decision
- Defining the problem
- Identifying the choices available
- Identifying the uncertainty associated with each choice
- Identifying outcomes
- Assigning values to each of the outcomes
The structure of decision making what are the 2 approaches and how applied
1) Influence diagram
- a graphical representation of a decision problem -> QUALATATIVE WAY
2. Decision trees
- problem described in a ‘tree’ format; probabilities associated with each branch of a chance node
Influence diagrams what are they, the elements and what do they do
- a graphical representation of a decision problem -> QUALATATIVE WAY
- each element is called a node
○ decisions (squares)
○ chance events (circles)
○ outcomes –values (diamonds) - provide a systematic approach to displaying the structure of a decision problem, but tend to hide detail
- a descriptive tool that makes it easier to communicate details of the problem to a non-technical audience
Decision trees what are they, elements and what does it do
- problem described in a ‘tree’ format; probabilities associated with each branch of a chance node leading to outcome nodes
- utilities (values)
○ associated with the terminal nodes of the tree
○ expressed on a numerical scale common to all nodes
○ net benefit from a particular decision will be the estimated income minus costs incurred from making the decision - ‘solution’ typically obtained by choosing the alternative which returns the highest expected monetary value
The binomial distrubution what does it do, how used
provide uncertainty
- if we know the number of trials (n) and the number of successes (r)
- we can calculate the expected probability of success, r ÷n
- the binomial distribution allows us to quantify the uncertainty in our estimate of the probability of success
- > will get a variation in the expected monetary value not just single number
- If decisions are questioned by the board then have this to fall back on -> evidence of decision making
- Practice protocols also help with this
Sensitivity analysis with decision trees what does it allow us to do. why and the 2 ways it can be done
- Sensitivity analysis allows us to identify parameters (i.e. costs, chance) that are important in the decision tree
○ one or more inputs are varied and the effect on the decision tree solution assessed
○ one of the outcomes of a sensitivity analysis will be a set of threshold values for which the optimal decision would change
1. One way sensitivity analysis - at a certain point of the variables - Point of interest is this change over point - At this point will change from outcome 1 to outcome 2
2. two way sensitivity anaylsis - Providing uncertainty around the probably of two interventions - most of the time which intervention is best
How would you use decision trees in practice
- developing treatment protocols [‘practice policies’] for routine cases (down cows, blocked cats, cases of dystocia)
- matching ‘less experienced’ graduates up with clinical tasks where they’re more likely to succeed
Feedlot numbers population within, average period, annual value, employees, percentage sourced from there, how much beef exported and major markets for these
- At any one time – 2% of Australia’s cattle population located in feedlots
- Average feeding periods 100 – 120 days
○ h/e Wagyu / Friesian > 300 days - Annual production value approximately $2.5 billion
- Employs 28,500 people directly and indirectly
- 450 accredited (NFAS) feedlots
- 80% of beef sold in major domestic supermarkets is sourced from feedlot sector
- 60% of Australia’s beef production is exported
- Major markets for grain fed slaughtered beef are: Japan, South Korea, United States
What are the 2 main issues with feedlots and the 3 main diseases and 5 main causes of death
Main issues
1. Heat stress
2. Bovine respiratory
Main diseases
1. Bovine respiratory disease
2. Infectious musculoskeletal - foot abscess, septic arthritis, dermatitis
3. Buller syndrome -> riding behaviour
Death
1. Bovine respiratory disease
2. Digestive -> acidosis, bloat, abdominal ulcer
3. Non-infectious musculoskeletal - lameness, laminitis, fractures
4. Other -> unknown
5. Septic arthritis
Musculoskeletal combine non-infectious and septic is the second largest cause of death and disease on feedlots
Viral-bacterial synergism in Bovine Respiratory Disease in feedlot, what is the main driving factor and pathogens involved, what ultimately lead to
Stress - weaning, overcrowding, transportation, co-mingling’
○ Main stress when they FIRST enter -> better adaption is needed
○ Autumn generally worse -> environment, come out of low summer (reduced weight), lots of animal come in
Viral infection - BHV-1, BVDV, BRSV, CRBV -> compromise mucociliary clearance
○ Generally immature, young, naïve to viral infections
Bacterial infection - H. somni, M. bovis, M. haemolytica, Pasteurella multicoida
○ COMMENSUAL ORGANISMS -> opportunistic -> all about immunocompromise
-> BRD -> economic loss
What part of the feedlot systems lead to the most stress/immunocompromise
- Co-mingling
○ Procurement channels: saleyards
○ Vendor sources per pen - Viral infections – effect on mucociliary clearance
○ Seronegative BVDV / BHV - Placement weight – maturity
- Site disease prevalence; BRD at-risk occupancy (0 – 60 days on feed)
- Transport and handling
- Breed, pen sizes, season, water sources
What are the main things that lead to economic loss with bovine respiratory disease on feedlots
- Morbidity - cost/performance
- Mortality
- Subclinical illness -> reduces carcass value
- Wastage
○ Unsuitable for primary market or transportation (illegal)
○ Carcass condemnation
○ Chronic illness/sequalae
§ Mycoplasma bovis -> pericarditis, pleural pneumonia, dissemination to the joint
What are the 3 main reasons bovine respiratory disease is such a large issue (why are cattle so susceptible)
- Smaller lung volume
- Low reserve volume -> no cattle races -> high oxygen consumption just to
- Selection for other factors -> digestive capacity, muscle -> reduce lung capacity
- > LUNGS ALREADY UNDER STRESS
What are the 2 main ways to diagnose bovine respiratory disease on feedlots and main issues with these
1) Subjective scale – visual assessment
○ Depression and respiratory scores = basis of assessment
○ On average = 0.2 seconds / head examinations
○ Typically only a.m. hours pen riding
2) No gold standard – autopsy, slaughter most reliable -> WAIT FOR IT TO DIE THEN DIAGNOSE? BAD
○ Ultrasound, stethoscope -> low accuracy so not using ALSO with feed staff not clinicians so hard to train with more technical
○ Smart tags? -> track their activity in the pen, water intake, feeding -> sick generally drink more, infrequent at eating and move around the pen less
§ Seem to be more sensitive then visual assessment
- Low sensitivity and specificity -> treating those that aren’t sick and not treating those that are
Therapeutic management of bovine respiratory disease in feedlots
- Optimal timing of identification of BRD morbidity and efficacious treatment
○ Macrolides: tilmicosin, tulathromycin - Good supportive therapy
○ Hospital pen husbandry and comfort
○ Ancillary (injectable) therapy doesn’t usually improve treatment outcome
○ Note limitations of clinical setting: fluid therapy, surgical intervention, ICU monitoring - Metaphylaxis -> prevent progression (infection already occurred)
○ Global meta-analysis supports efficacy
Reduction in mortality and wastage, improvements in carcass value
In terms of preventative measures for bovine respiratory disease what can be done pre-feedlot
1) Backgrounding
2) Respiratory vaccines
§ Premium feeder pricing grids -> pay more for those cattle that have been vaccinated -> some feedlots will then buy the cheaper ones without vaccine and mix with these -> bad
3) Procurement strategy -> sale yards are high risk
§ (note pricing on low risk feeders)
In terms of preventative measures for bovine respiratory disease what can be done at the feedlot
○ Induction procedures, vaccination
○ Bio-containment strategies -> firewall the high risk cattle with adapted cattle
○ Nutritional management
○ Removal of BVDV PI’s? -> remove persistently carriers of Pestivirus
§ Type 1a / 1c BVDV in Australia
Once cattle have been introduced to the feedlot what 4 procedures then occur and what ISN’T DONE
1. Anthelmintic ○ Lice in autumn - winter 2. Hormone Growth Promotant ○ For some markets 3. Respiratory vaccines ○ Bovine Herpesvirus 1 § Modified live § Intranasal § Rhinogard™ (Zoetis) ○ Mannheimia haemolytica / BoHv1 § Inactivated – killed § Subcutaneous injection § BovilisMH (+ IBR)™ (Merck) ○ May boost if given at pre-feedlot (backgrounding) 4. Ear tag Clostridial vaccines? -> NOT USED -> not on young actively growing pastures
The 2 methods of weaning what is the effect on feedlot health and performance
Paddock -> just remove calves from mothers
- Much higher rates of sickness -> more stress and also less conditioned to humans and machinery
Yard weaning -> calves removed from mothers but kept in the yards - monitored, handled, fed
- Lower rate of sickness -> Act like backgrounding -> exposed to stresses, pathogens, noises, conditioning to humans, machines
Feedlot lameness how common, result from and result in
- Second highest cause of feedlot wastage
- Primary injuries to feet and limbs
- Sequalae to BRD
○ Mycoplasma bovis
○ Histophilus somnii - High wastage results from
○ High incidence
○ Substandard treatments - Significant issue for feeder transport
Feedlot lameness treatment
\: staff training - Toe and heel abscesses can be treated -> via tilt table (expensive to get this - need to convince farmer saving money) Therapy - Procaine penicillin ○ Fusobacterium spp ○ Bacteroides spp - Foot podiatry: paring, blocks - Foot baths: ○ Copper sulphate ○ Formalin ○ Organic acids - Hospital pen bedding: ○ Woodchips ○ Straw, rice hulls - Response to therapy assessments: fit to load
Feedlot lameness prevention and what need to provide
- Note also handling principles:
○ Limit on tub numbers
○ Low stress stock handling
○ Best practice, minimum injury - Note also design principles in new facilities based on:
○ Put rubber in the feeding areas
NEED TO DEMONSTRATE COST BENEFIT ANAYLSIS to get them to buy this stuff
In terms of veterinary roles on feedlot what is involved in staff training
- Diagnosis of common feedlot diseases and conditions – also grading and prognosis
- Hospital management and treatment
○ Design and monitor treatment protocols on a site-by-site basis
○ Supportive therapy – husbandry, hospital pens - Autopsy technique and interpretation
- Paraveterinary procedures -> need to go through compensatory program in order to perform these
○ Dystocia, prolapse reduction and fixation
○ Stomach tubing
○ Podiatry
○ Regional analgesia (prolapse, podiatry)
○ Pregnancy diagnosis
○ No instruction on digit amputation, caesarean section, rumenostomy, urethrostomy or similar - On-site training and produce instruction material: manuals, audio-visual, competency certification (web support)
What are some roles as a veterinary consultant at a feedlot
- Optimise animal herd health and welfare (audits / accreditation)
- Assessment of treatment modalities, efficacy – make recommendations
- Conduct clinical trials, comparative studies – make recommendations
- Abnormal disease and/or disease prevalence investigations – make recommendations. Also biosecurity plan
- Specific veterinary procedures – surgeries
- Industry benchmarking and analysis e.g. return on investment – make recommendations
In terms of the 5 station exam what involved the GIT
Tail - condition score - abdominal size and contour Sides - Check contour of abdomen - Palpate, auscultate rumen - Percuss and auscultate body wall - Percuss and ballottement of lower flank Tail revisitied - per-rectal examination
Auscultation of the rumen and left flank how perform and what should hear
- The head of the stethoscope is placed in the middle of the left paralumbar fossa
- Listen for at least 2 minutes (or until you have heard a couple of contractions)
- Rumen movements are heard as booming, crackling sounds, and you can feel the rumen move
When palpating and auscultating the rumen what is normal and abnormal to detect
- Normal:
○ Palpate doughy rumen, often with a small gas cap
○ Primary contractions approximately every minute
○ Secondary cycle approximately every 2 minutes - Abnormal:
○ Palpate large gas cap which distends fossa
○ Hypermotility (eg vagus indigestion) - only one diagnosis (not lecture)
○ Hypomotility (eg hypocalcaemia, rumen atony)
○ “ping” (rumen distension)
Percussing and auscultating the body wall what occurs, where should perform and what should do
- Sound waves produced on striking the body wall will vary according to the material situated beneath the wall that reflects them.
- Auscultate and percuss over the last 3‐4 ribs
- Auscultation and percussion‐ head of stethoscope placed on one rib, tap firmly on adjacent rib
- Localize any abnormal sounds and “Pings”
what are the requirements for pings when percussing and auscultating the body wall
§ Gas distended viscus -> resonate
§ Gas/Fluid Interface
§ Gas under pressure
§ Gas distended viscus must be against body wall
§ Both percussor and stethoscope must be over gas distended viscus
§ (viscus is singular of viscera)
Left sided pings what are the main differentials
§ Left Displaced Abomasum § Rumen Gas Cap - not eructating enough § Pneumoperitoneum (eg peritonitis) § Air in intestines § Physometra (air in uterus) § Gas in more than one place! Eg Hypocalcaemia - common
What is the difference between a abomasal and rumen ping
§ Abomasal ping □ High Pitched / resonant (metal on metal sound) □ Classic location □ Beware Milk Fever! Rumen Ping - A bit “duller” (wood on wood) - Less resonant - Dorsal location - Can often palpate the gas cap
Diagnosing a ping what are the 4 things that need to be done
1) Position
2) Pass a Stomach tube and blow whilst listening over the ping
□ the sound of bubbling in the is muffled if an LDA is in the way
3) Centesis over the area of the ping
□ Ventrally (or you may just get gas)
□ Abomasal pH = 2‐3
□ Rumen pH = 6‐8
4) Succussion -> splash and tinkle in abomasum
Auscultation and ballottement what generally hear and the 2 main differentials with different sounds
- Presence of a fluid tinkling or splashing sound
- “Succussion”
○ left displaced abomasum splash and tinkle
○ rumen containing excess quantity of fluid (eg grain overload) may splash but probably not tinkle
Examination of the liver, where located, can you feel and main thing to consider
- Behind right costal arch
- Often cannot feel it
- Very thin cows or enlarged liver makes it more obvious
- If it’s significant, it won’t be the only sign!
○ Jaundice
○ Anaemia
○ Submandibular oedema … bottle jaw
What are some differentials for a ping heard on the right side
○ Right Displaced Abomasum - sounds like left displaced abomasum ○ Right Abomasal Volvulus ○ Cecal Dilatation/Volvulus ○ Spiral Colon / Small intestinal Gas ○ Physometra - air in the uterus ○ Pneumoperitoneum ○ Air in rectum after per‐rectal exam
What does an intestinal ping sound like and differentials for fluid splashing sounds on deep ballottement on the right side
- Intestinal ping (xylophone -> varies in pitch like trying to play a song)
- Fluid splashing sounds audible on deep ballottement (succussion):
○ Fluid filled intestines as in enteritis
○ A fluid filled abomasum (eg torsion of the abomasum)
○ Fluid filled intestine due to intestinal obstruction
○ (Subclinical Milk Fever can also cause pings and splashes!)
Per-rectal examination what can palpate and normally cannot
○ Can palpate:
§ The rectal wall and caudal sacs of the rumen
§ The bladder and left kidney, and the cervix, uterus, oviducts and ovaries
§ The deep inguinal lymph nodes and bony rim of the pelvis and sacrum
§ Normally, cannot palpate intestines
List some abnormal rectal findings
○ dilated and distended loops of gut (caecum, large or small intestine) - more common in horses
○ a solid intussusception - banana
○ a dilated abomasum
○ a very enlarged liver
○ solid lumps of bovine lipomatosis (fat necrosis), enlarged lymph
○ thickened ureters and fibrous adhesions in the caudal abdomen
○ abnormal findings in the uterus
If find something abnormal during the rectal what is the next steps
Gross examination of bovine faeces.
- The amount of faecal material, its consistency, colour, odour and content often provide the key to diagnosis especially in diseases of the alimentary tract.
In terms of diagnosing GIT issues what are the 9 ancillary tests can use and the most common
- Rumenocentesis - common
- Abdominal paracentesis - common
- Withers pinch Test - common
- Grunt test - common
- Haematology
- Biochemistry
- Radiography
- Endoscopy
- Exploratory Laparotomy - common
Rumenocentesis what examine and normal parameters and the technique
- Technique
- technique
○ Below paralumbar fossa, half way between knee and rib
○ Use a long needle (16‐18g 10cm ideally) - Assess
○ pH - normal 6.2-7.2, <5 suggestive of carbohydrate engorgement
§ via pH paper put abdominal fluid on (greater range than dipstick)
§ Via pH meter
○ protozoal motility - possible
○ Rumen chloride (>30meq/L consistent with abomasal reflux)
Abdominal paracentesis how effective and the 3 main sites
- It is sometimes possible to obtain a sample of fluid by abdominal paracentesis.
- This is not always possible because the omentum of the cow is extremely efficient at trapping fluid and many attempts at - paracentesis do not yield a sample.
Paracentesis sites
1. To the left of midline, 3 to 4 cm medial to and 5 to 7 cm cranial to the foramen for the left subcutaneous vein.
2. 2. 5 cm caudal to the xiphisternum and 5 cm to left or right of mid‐line
3. The right ventral abdominal wall in the area of the skin under the flank fold above the udder
Peritoneal fluid from paracentesis what is abnormal and what suggests
- Abnormal fluid is sensitive indicator that there is disease, but it’s not particularly good indicator of the type of disease:
○ Large amounts (10 to 20 ml) of thin, red tinged fluid suggests infarction or necrosis of gut wall.
○ Heavily blood stained fluid or whole blood ‐ likely to result from puncture of a blood vessel or from bleeding into the abdominal cavity
○ Large quantities of yellowish coloured fluid suggest acute diffuse peritonitis.
○ Food particulate indicates gut perforation
What are the 2 main tests for abdominal pain and how perform
- In the “grunt test” a sharp pressure is applied over the xiphoid whilst listening for an audible grunt from the cow.
- Wither’s pinch test -> normal is to react to the pinch by moving back, HOWEVER if painful then won’t react and move as painful
Abdominal pain in the bovine signs and causes
- Signs
○ animal being uneasy,
○ stretching
○ kicking at the abdomen - most have photosensitivity
○ getting up and lying down - Causes
○ May be seen in conditions of the gastro‐intestinal tract such as:
○ volvulus , intussusception , phytobezoars, salmonellosis
○ abomasal torsion, spasmodic colic
BUT ALSO
○ diseases of the liver, associated with distension of the organ capsule
○ inflammation of the serous surfaces of the peritoneum
○ with pyelonephritis, urethral obstruction and distension of the bladder.
○ early cases of photosensitization
Exploratory laparotomy why done and what are the 3 main parts of the surgery
- Why done
○ a standing, right flank, exploratory laparotomy is most useful diagnostic tool.
○ it is a relatively quick, easy and innocuous technique,
○ provides a wealth of information and in surgical diseases of the abomasum and intestine also provides access for treatment. - Technique
1) Anaesthesia
2) incision
3) closure
What is involved with the anaethesia in the exploratory laparotomy
§ Inverted L or paravertebral block
□ Inverted L block -> infiltration of anaesthetic solution along the length of the transverse process and the last rib, entire paralumbar fossa is anaesthesia
® Place in until going into abdomen, 45 degree angle, injecting as bring back in an L-shape
◊ NEED TO PLACE BLOCK CRANIAL TO INCISION SITE
§ Clip area and prepare for surgery
What is involved with the incision for exploratory laparotomy
§ about 20 cm incision right paralumbar fossa
§ 3 steps:
□ incise skin and subcutaneous/ external abdominal oblique with vertical incision
□ split internal abdominal oblique in direction of fibres
□ blunt dissect through transverse abdominous, peritoneum
What is involved in the closure of exploratory laparotomy
§ use 7 metric catgut or other absorbable suture to close
□ peritoneum and transverse abdominous
□ internal abdominal oblique
□ subcutaneous/ external abdominal oblique
§ skin with heavy Vetafil or other non‐absorbable ‐ blanket or cruciate
List the 7 main diseases of the abomasum and intestines that need surgery
- Left displaced abomasum (LDA)
- RDA – Abomasal dilation and torsion
- Dietary Abomasal Impaction
- Intestinal Phytobezoars
- Intussusception
- Intestinal Torsion
- Dilatation, Volvulus and Torsion of the caecum
Left displaced abomasum (LDA) typical history, clinical signs and other differentials
- Typical history ○ A recently calved cow that looks fairly normal but is gradually losing weight and/or “going off her milk” - Typical clinical signs ○ A ping on the left side ○ fluid splashing signs on succussion ○ Ketonuria - mild ketosis on urine exam -> 90% LDA ○ scant (if any) faeces on per rectal examination - Differential Diagnosis: ○ Other causes of pings ○ Rumen atony (hypocalcaemia) ○ Indigestion ○ traumatic reticulo‐peritonitis ○ Ketosis
Left displaced abomasum aetiology
○ The aetiology is not fully understood § Subclinical milk fever - not contracting gas should - gas accumulation § Peritonitis ○ Multifactorial syndrome ○ Heavy grain feeding ○ Nutritional factors implicated § Transition period management § Body condition score § Lead feeding § Ration physical formulation § Hypocalcaemia § Postpartum disorders
Left displaced abomasum pathogenesis
○ increases flow of ruminal ingesta to the abomasum
○ This increases the concentration of volatile fatty acids (VFAs)in the abomasum
○ This inhibits abomasal motility
○ Ingesta and gas then accumulates in the abomasum
○ The abomasum expands (into the left side)
○ There is room because of the contracting uterus
○ The gas makes the abomasum float and it becomes trapped
What are the 6 main ways to correct left abomasum dispalcement
1) Left flank omentopexy
2) Right flank abomosopexy/omentopexy
§ standard right flank laparotomy approach
§ confirm diagnosis by reaching around and over the top of rumen to palpate abomasum
3) Rolling
- Place on the ground
Tie legs so cannot kick
Roll onto back and shake the cow until enough momentum to move abomasum
- 20% recur
4) Rolling and blind suture
5) Rolling and “toggle”
6) Endoscopy and toggle
§ Once the abomasum has been identified, push the trocar through the body wall into the abomasum.
□ The trocar must be placed into the area with the high resonance ‘ping’.
□ For the caudal toggle, the ideal site is one hand‐width cranial to the umbilicus, to the right of the midline
Right flank abomosopexy/omentopexy what are the 5 steps within and post-surgery needs
- decompress via reaching over the top of rumen to abomasum
- poke with needle attached to the rubber tube (air out into the world)
- May cause peritonitis -> GIVE ANTIBITOICS - grab underneath and try to pull back towards you
- identify pylorus ‐ pull on omental attachment until the pylorus comes into view ‐ palpate and visualise
- Suture omentum to the body wall
Post-surgery
- Routine closure
- Broad spectrum antibiotics (Oxytetracycline is common)
- NSAIDs (long acting – tolfedine or metacam)
- Ketol (proplene glycol - help prevent ketosis)
What are the 2 main ways to prevent a LDA and the prognosis
- Prevention of LDA
○ Nutritional and management practices during the transition period must be closely evaluated
§ Careful management of concentrate feeding
§ Adequate amounts of fibre of adequate length
○ Minimize postpartum diseases, including ketosis, retained placenta ,hypocalcaemia. - Prognosis
○ After surgical correction ranges from good to excellent depending on duration of condition and adequacy of surgery
