Term
| What are the othernames for Bovine Resp Dz Complex? |
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Definition
-shipping fever
-fatal fibrinous peumonia
-old name: pasteurellosis
-undifferentiated fever of feedlot cattle |
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Term
| Why can we not properly replicate BRD? |
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Definition
| -interaction of microbial, host, management, and environmental factors |
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Term
| What is the most expensive dz of beef cattle in N. America? |
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Definition
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Term
| Has our BRD issue been improving over the last few decades? |
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Definition
| -nope, no significant dec in deaths |
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Term
| Where is BRD usually a problem? |
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Definition
-feedlot problem w/ WEANED CALVES
-if the calf is not weaned, it is called Dust/Summer Pneumonia |
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Term
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Definition
-operation with calves confined, switch diet to concentrates, get them immunologically stable for the real world, get them rpepared for growing
-here for 45-60d |
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Term
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Definition
| -operation that relies on forage-based diet and keeps calves for longer to get them ready for growing (try to put on cheap wt) |
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Term
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Definition
| -high concentrate ration, very large operations, add wt |
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Term
| What is the typical weaning age & wt in cattle? |
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Definition
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Term
| What are the risk factors for BRD? |
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Definition
-Stress!!
-ex: processing (castration/dehorning), shipping, weaning, co-mingling, diet changes, lifestyle changes |
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Term
| Does BRD have an obvious seasonality? Explain. |
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Definition
-fall
-when most cattle are weaned, inc population at risk, weather stress, feedots process more cattle in fall
-we can't totally explain it |
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Term
| What are some viral pathogens that cause BRD? Bacterial? |
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Definition
-IBR/BHV, BVD, BRSV, Corona Virus
-M. haemolytica, Histophilus, P. multocida, Mycoplasma |
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Term
| Which type of BVDV is most prevelant w/ BRD? |
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Definition
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Term
| What direct contribution does BVDV have in regards to BRD? Indirect? |
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Definition
-Direct: damage to resp epi
-Indirect: immunosuppression |
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Term
| What is considered to most common source of BVDV infection w/ BRD? Discuss. |
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Definition
-PI's considered most common
-Prevalence of PIs in feedlot only 0.2-0.4% thus iffy |
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Term
| Describe the impact of PI's on their own health and the health of others. |
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Definition
-PI's themselves are about 10X more likely to die of infectious dz
-we don't know how PI's affect the chances of those around them |
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Term
| True or False: All strains of BRD are essentially the same in their role w/ BRD. |
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Definition
| -FALSE, not all strains are created equally |
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Term
| Describe how people approach testing for BVDV PI's. |
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Definition
-we can test for it but has a high NPV and iffy PPV
-we don't have a good solution w/ what to do w/ positive calves thus most people don't test for it and hope for the best
-do vx for it! |
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Term
| What direct contribution does BHV-1 (IBR) have to BRD? Indirect? |
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Definition
-Direct: causes direct problems in resp tract
-Indirect: immunosuppression |
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Term
| What is the significance of distinguishing initial BHV-1 infection vs recrudescence w/ BRD cases? How does this concern MLVs? |
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Definition
-none, herpesvirus is with you for life
-if you use MLV, you have created a crhonic infection thus creating a potential for recrudescence |
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Term
| How does IBR/BHV-1 interact w/ M. haemolytica infection in regards to BRD? |
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Definition
| -they are synergistic in the sense that IBR amplifies the effects of M. haemolytica's leukotixin |
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Term
| Is Mannheimia haemolytica contagious, opportunistic, or both? |
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Definition
-it is commensal thus opportunistic for sure
-microbial resistance is evident thus must have at least a partial contagious component |
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Term
| What are the virulence factors of Mannheimia haemolytica? |
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Definition
-LPS (gram-neg) = endotoxic
-capuslar polysaccharides, adhesins, other surface proteins
-leukotoxin
-other secreted proteins: immuogenic but not understood |
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Term
| Describe the behavior of M. haemolytica lipopolysaccharide (LPS). |
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Definition
-released in small amounts during active infection
-released in large amounts as cells are killed due to immune response
-causes inflammation & impairs ciliary clearance |
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Term
| Describe the behavior of M. haemolytica capsular polysaccharides, adhesins, and other cell surface proteins. |
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Definition
-assist in attachment and colonization
-interfere w/ phagocytosis adn complement-mediated killing
-some immuno-modulating activities |
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Term
| Describe the behavior of M. haemolytica leukotoxin. |
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Definition
-specific to ruminant leukocytes: complexes with LPS, inc cytotoxicity
-impacts rage from impairment to cell lysis at higher doses
-if it kills neutrophils, causes massive release of reactive oxygen spp release into the lungs |
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Term
| Is Pasteurella multocida a cause of acute or chronic BRD? |
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Definition
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Term
| In which cows is Pasteurella multocida most commonly seen as a cause of BRD? |
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Definition
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Term
| In general, what are the virulence factors of Pasteurella multocida? |
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Definition
-Lipopolysaccharide
-capsular pllysaccharides, adhesion, & other surface proteins
-few other factors well described |
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Term
| In addition to BRD, what other clinical presentations are seen w/ Histophilus somni? |
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Definition
-heart dz +/- sudden death
-TEME thromboembolic meningoencephalitis |
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Term
| In general, what are the virulence factors of Histophilus somni? |
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Definition
-lipooligosaccharide: phase variation
-capsular polysaccharides, adhesins, and other surface proteins
-immunoglobulin binding proteins
-biofilm formation
-Histamine: pdc'd by bateria itself |
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Term
| What is the geographic trend of Histophilus somni? |
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Definition
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Term
| What are the purposes of HIstophilus somni's immunoglobulin binding proteins? |
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Definition
-forms filaments on bacterial surface
-binds Fc portion of bovine IgG2
-imparts reistance to complement-mediated killing
-cytotoxic to macrophages |
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Term
| What is Bibersteinia trehalosi? |
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Definition
| -trehalose-fermenting gram-negative rod |
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Term
| Which species are most commonly affected by Bibersteinia trehalosi as a BRD pathogen? |
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Definition
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Term
| Describe Bibersteinia trehalosi as a BRD pathogen. |
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Definition
-recently described in severe, fulminant respiratory and septicemic disease in cattle
-virulence factors
+/- Lkt |
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Term
| Is Mycoplasma bovis more commonly associated with acute or chronic BRD? Explain. |
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Definition
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Term
| In addition to BRD, what other clinical presentations occur with Mycoplasma bovis? |
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Definition
-joint issues
-otitis externa: head tilts w/ ear droops |
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Term
| In general, what are the virulence factors of Mycoplasma bovies? |
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Definition
-variable surface proteins: adhesins, EVASION OF IMMUNE RESPONSE
-modulation of host immune response
-biofilm |
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Term
| What is the time to administer first BRD treatment? |
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Definition
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Term
| What is the peak mortality of BRD? |
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Definition
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Term
| What are the clinical signs of BRD? |
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Definition
-DART
-Depression
-Appetite
-Respiratory: cough, labored breathing, nasal discharge
-temperature |
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Term
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Definition
-weaning
-avoid shipping
-castrate early
-used polled genes
-vaccination: over-emphasized but still important
-good nutrition at feedlot: as much as 75% concentrate to compensate for anorexia
-keep hydrated |
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Term
| When is the best time to vaccinate for BRD at the feedlot? |
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Definition
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Term
| What kind of BRD vaccine is best? Which agents should we specifically target? |
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Definition
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Term
| In regards to BRD, what does the term "high-risk exposed" mean? |
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Definition
| -cattle that have had a lot of things done incorrectly & have high chance of succumbing when they are exposed to BRD which they have been |
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Term
| In regards to BRD, what does the term "high-risk non-exposed" mean? |
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Definition
| -cattle that have had a lot of things done incorrectly and have high chance of succumbing when they are exposed in the future |
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Term
| Where do we encounter high-risk exposed cattle w/ BRD? |
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Definition
-put-together cattle
-sale barns/auction markets
-buying station
-commingled |
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Term
| Describe the environment of high-risk exposed cattle in regards to BRD. |
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Definition
-stressed out
-unknown heatlh status
-has been exposed to dz pathogens
-may be incubating BRD upon arrival |
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Term
| Describe the environment of high-risk non-exposed cattle in regards to BRD. |
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Definition
-generally from 1 source
-rach-raised cattle
+/- waned, castrated, dehorned
-not exposed and not vaccinated = minimal immunity |
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Term
| What kind of cattle are considered low-risk for BRD? |
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Definition
-preconditioned cattle: everything has been done and correctly
- |
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Term
| Describe a preconditioned bovine. |
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Definition
=castrated & healed
-dehorned & healed
-vaccinated for resp viruses
-weaned
-bunk broke (water & feed)
-may even be identified (EID) |
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Term
| What are our expectations for high-risk exposed cattle w/ BRD? |
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Definition
-can be sick upon arrival or within a couple of days
-may be stale
-response may be less than desired |
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Term
| What are our expectaitons for high-risk non-exposed cattle w/ BRD? |
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Definition
-generally observe morbidity 5-7d after arrival when commingled
-response depends upon: challenge dose of the dz agent, virulence of dz agent, individual's response |
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Term
| True or False: Preconditioned means no risk of illness with BRD. |
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Definition
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Term
| What are our expectations w/ low-risk cattle w/ BRD? |
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Definition
-generally observe illness around 7-10 days when commingled
-response to tx generally favorable: already sme immunity from health program already administered, memory response from immune system |
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Term
| How do we treat/manage BRD from a group-level? |
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Definition
-metaphylaxis at arrival for high-risk/exposed
-reserve metaphylaxis for use after threshold for high-risk/unexposed
-re-vax |
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Term
| How do we treat/manage BRD from an individual-level? |
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Definition
-antimicrobials: avoid stacking
-NSAIDs
-tx must be based on standardized criteria |
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Term
| Describe herd monitoring for BRD? |
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Definition
-recognize variability among classes of cattle: manage accordingly, set benchmarks accordingly
-track population metrics: morbidity, tx success, mortality |
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Term
| What might be happening if BRD mortality is too low? |
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Definition
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Term
| What is summer/dust pneumonia? |
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Definition
-resp dz in pre-weaned calves
-typically calves are on pasture
-frequently in summer
-NUMBER ONE CAUSE OF MORTALITY IN CALVES > 3 weeks |
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Term
| There is limited epidemioloic info available about summer/dust pneumonia. What factors may it be associated with? |
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Definition
-longer calving season
-long-distant mobing of herd (on foot)
-intensive management = higher risk
-limited mangagement |
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Term
| How do we diagnose summer/dust pneumonia? |
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Definition
-exercise intolerance
-dec performance
-resp signs |
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Term
| How do we prevent summer/dust pneumonia? |
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Definition
-vaccination
-similar management to BRD |
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Term
| How do we treat summer/dust pneumonia? |
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Definition
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Term
| What is enzootic calf pneumonia? |
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Definition
-dz of airy calves: weaned at 60-70 days
-generally pre-weaning |
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Term
| What are the most common etiologies of enzootic calf penumonia? |
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Definition
-P. multocida <= most common
-Mycoplasma bovis |
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Term
| How do we prevent enzootic calf pneumonia? |
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Definition
-passive transfer
-nutrition
-ventilation
-vaccination |
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Term
| How do we treat enzootic calf pneumonia? |
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Definition
-antimicrobial
-improved management |
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Term
| What bugs are commonly behind small ruminant pneumonia? |
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Definition
-Pasteurella multocida
-Mannheimia haemolytica
-Mycoplasma spp
-Bibersteinia trehalosi
-virals generally less important than in cattle |
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Term
| How do we treat small ruminant pneumonia? |
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Definition
-NOT tilmicosin in goats b/c cardiotoxic
-essentially same meds as w/ BRD |
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