resp 4 Flashcards
BRD scoring system for pre-weaned calves? post weaned? (dairy)
- what is included
- scoring system
Pre-weaned:
- eye discharge (2)
- nasal discharge (4)
- ear droop or head tilt (5)
- cough (2)
- breathing (2)
- temperature (2)
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- add scores for all clinical signs, if total score is >=5, calf may be positive for bovine respiratory disease
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Post-weaned
- sunken eyes (4)
- low body condition (5)
- cough, breathing, diurnal temp fluctuation
BRD treatment? what is our first line of defence? what is our 3 pronged approach to this disease on the feedlot?
antimicrobial therapy goals:
* Treat early
* Treat just long enough
* Use appropriate therapeutic
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Trained caretakers/pen riders:
* First line of defence
* Provide presumptive treatment
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Unresponsive animals
* Diagnostic testing important for these ones > may reveal something different eg. resistance, new disease
feedlot systems of calf BRD scoring is based on what?
what about decision trees?
- more based on behaviour vs dairy, which is clinical signs
> how alert, responsive, quick
<><> - decision tree tells penrider what to do with calf, based on eg. rectal temp, previous treatments, responsive vs unresponsive, etc.
what is the most important factor for successful treatment of ruminant respiratory disease?
Early recognition of disease
BRD treatment:
* Factors impacting first-line antimicrobial choice
- Cost
- Route of administration
- Treatment interval
- Drug label restrictions
- Need of extra-label doses
- Withholding times
- Data from susceptibility testing
- Historic drug performance
- Published treatment trials
BRD treatment
- suggested response guidelines
> response rate, fatality, chronic:die
- duration of therapy
- mass medication?
Suggested response guidelines
* 70-80% respond to first treatment
* 4-7% fatality rate
* Chronic cases to cases that die > 0.5:1.0
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Optimal duration of therapy
* At least 48 hours past clinical signs
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Mass medication?
* If # of sick animals removed is:
* 10% of population for 3 consecutive days
* 25% or > of population in 1 day
BRD treatment - when to consider a second line antimicrobial
If first line is:
* Long-acting Oxytetracycline > No response after 2-3 days
* Ceftiofur crystalline free acid > No response after 5-7 days
* Tulathromycin > No response after 7-14 days
BRD treatment - drug classes we can consider adding aside from antibiotics
- Anti-inflammatories > considered effective
- Anti-virals > none available
- Immunomodulatory therapy > some can provide positive results
Management factors associated with respiratory disease in dairy calves
- poor passive transfer
- diarrhea at a young age
- group housing, indoors (individual housing outdoors decreases disease… but consider temp)
Feedlot and stocker management factors that can contribute to respiratory disease
- Poor nutrition
- Uncontrolled parasitism
- Sale through auction markets
- Prolonged time in market channels
- Excessive dehydration from transport
- Mixing cattle from multiple sources
- Castration at arrival
- Shared water between pens
- Starting diets > greater than 75% concentrate, High in corn silage, Feeding non-protein nitrogen
risk classification for cattle respiratory disease
High risk-exposed
* Little-no preventative care
* Little-no adaptation to hay/grain diet
* Group from multiple sources
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High risk-not exposed
* Little-no preventative care
* Little-no adaptation to hay/grain diet
* Single source group
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Low risk
* Vaccinated
* Weaned
* Turned out prior to shipment
Acute Bovine Pulmonary Edema and Emphysema (“fog fever”)
- who gets this?
- clinical signs
- Cattle > 2 yo
- Dry, sparse forage → lush pasture
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Clinical signs - Within 2 weeks of pasture change
- Acute onset severe dyspnea
- Tachypnea
- Expiratory grunt
- Frothing at the mouth
- Open-mouth breathing
- Extended head and neck
- Dilated nostrils
Acute Bovine Pulmonary Edema and Emphysema
- pathophysiology?
- morbidity, mortality?
- L-tryptophan (present in lush grass) converted by ruminal micro-organisms
- To 3-Methylindole metabolized in lung > results in pneumotoxic end products
- Necrosis of type I pneumocytes and Clara cells
- Edema
- Hyaline membrane formation
- Proliferation of type II pneumocytes
- interstitial pneumonia
<><> - Morbidity rate- ~50%
- Mortality rate- ~ 30%
Acute Bovine Pulmonary Edema and Emphysema
- diagnosis, treatment
- prevention
- Dx: presumptive
- Tx: None, handling may precipitate death
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Prevention - Gradually adapt to lush pasture > Start at 2 hours/day, Transition over 10-12 days
- Delay use of lush pasture until after hard frost
- Mow and windrow pasture prior to turnout
- Turnout young stock (<15mo), other livestock first
- Use pasture before it becomes lush
- Monensin for 1 day prior to pasture and for the next 10 days
- Lasalocid for 6 days prior to pasture and for the next 10 days
> both these products decrease L-tryptophan conversion
Feedlot Acute Interstitial Pneumonia
- cause, contributing factors
- Exact cause unknown
- Likely multifactorial
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Proposed contributing factors: - Pneumotoxins
- Chronic bacterial pneumonia
- Signalment
- Chronic small airway injury
- BRSV infection
- Heat/dust exposure
- Hypersensitivity reactions
