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Early detection of
bovine respiratory disease (BRD)
in feedlot cattle: why and how?
Dr. E. Timsit DVM, PhD, Dip. ECBHM
Dr. S. Assié, DVM, PhD, Dip. ECBHM
Introduction
• Heifer, 28 days after arrival (i.e. days on feed)
• Found dead in pen, treated once the day before
• Fatal fibrinous pneumonia (M. haemolytica)
Detected and treated too late!
Introduction
1. Why is an early detection of BRD crucial?
2. How to early detect BRD?
Outline
Early BRD detection
• Maximize antibiotic action
• Avoid irreversible pulmonary lesions
• Prevent emergence of antibiotic resistances
Early antibiotic treatment in the
disease process
- Maximize clinical and bacterial cure
- Limit BRD impact on performances
Why early detect BRD?
Mannheimia haemolytica
Pasteurella multocida
Mycoplasma Bovis
Histophilus somni
Commensal organisms
M. haemolytica
(Griffin et al.,2010)
Why early detect BRD?
Viral infection, stress
and/or suboptimal
environment
Proliferation of bacteria in the
nasopharynx
Bacteria gain access to the
lung via aerosolized droplets
Adherence, colonization and
replication in the lung
Bacterial pleuro/broncho-pneumonia
Tissue destruction and inflammation
Why early detect BRD?
1) Secretion of enzymes and
toxins Lipopolysaccharide (LPS),
Leukotoxins (LKT),
Lipoolysaccharide (LOS), etc.
Lung damage Inflammation
When bacteria colonize and replicate:
Evolution of the disease process
Inflammation can lead to
tissue damage
(Panciera et al., 2010)
Why early detect BRD?
When bacteria replicate:
2) Emergence of bacterial resistances
Antibiotic-sensitive bacteria
Time-lag before treatment
Antibiotic-resistant bacteria
(Lipsitch & Levin, 1997; Ferran et al., 2011)
Total bacterial population > mutational frequency to resistance (10-6 to 10-8)
=> Presence of resistant population very likely (before any treatment)
Why early detect BRD?
When bacteria replicate:
2) Larger bacterial inoculum
Time-lag before treatment (Ferran et al., 2011)
Higher dose of antibiotic required to eradicate the bacterial inoculum
Early treatment = lower dose of antibiotic needed
Why early detect BRD?
Obstruction
alveolar hypoxia
Hypoxic pulmonary vasoconstriction
reduced blood flow
Normal blood flow
Normal blood flow
When pulmonary lesions and atelectasia => reduced antibiotic distribution
Reduced antibiotic distribution
Early treatment = few (or no) obstructions Increased antibiotic action
Why early detect BRD?
Study of Ferran et al. (2011)
Experimental lung
infection (P. multocida)
Control group
Early treatment
group
Late treatment
group
Antibiotic treatment
10 h post-infection
Antibiotic treatment
32 h post-infection
Euthanasia (48 h)
Euthanasia (48 h)
Euthanasia (70 h)
Why early detect BRD?
Control group Early treatment
group
Late treatment
group
% of mice with P. multocida 93% (26/28) 36% (5/14) 0% (0/14)
% of surviving mice 64% (18/28) 71% (10/14) 100% (14/14)
% of lungs with resistant bacteria 33% (6/18) 10% (1/10) 0% (0/13)
Better bacterial and clinical outcomes
Less frequent selection of resistant bacteria
Early antibiotic treatment:
Study of Ferran et al. (2011)
Why early detect BRD?
“Early” BRD treatment “Late” BRD treatment
Use of rumen
temperature boluses Distant examination
if BRD signs: rectal temperature
Preliminary results (30 YB in each group)
Study design
Cefquinom 2.5 mg/kg once Cefquinom 2.5 mg/kg twice
Treated animals: 22
Relapse: 6 (27%)
Global antibiotic consumption:
22*2.5 mg/Kg = 55 mg/Kg
Treated animals: 13
Relapse: 4 (30%)
Global antibiotic consumption:
26*2.5 mg/Kg = 65 mg/Kg
Study of Assié et al. (unpublished data)
BRD detection: BRD detection:
Why early detect BRD?
30 young bulls 30 young bulls
• To maximize antibiotic action
• To avoid irreversible pulmonary lesions
• To prevent emergence of antibiotic resistances
- Maximize clinical and bacterial cure
- Limit BRD impact on performances
In summary:
Why early detect BRD?
1. Why is an early detection of BRD crucial?
2. How to early detect BRD?
Outline
– Distant examination
• Owner and/or staff
• Once or twice daily
– Detection of clinical signs
• Depression
• Anorexia/dysorexia
• Increased respiratory rate
• Lacrimal and nasal
discharges, cough, etc.
• How are cattle with BRD detected?
(Duff & Gaylean, 2006)
How to early detect BRD?
• Does distant examination enable an early BRD
detection? Study of Timsit et al. (2011a) Answer: No
Rumen temperature bolus
How to early detect BRD?
Solution: By using automatic health-monitoring systems
B) Changes in feeding behavior => Growsafe system, ENGS system
A) Changes in body temperature rumen T°C boluses, IRT, ear mounted
thermometers
Schaefer®
Growsafe®
C) Changes in physical activity => pedometers, accelerometers
How to early detect BRD?
A) Monitoring body temperature to early detect BRD
Fever occurs very early in the disease process (within hours)
Experimental infection of 3 heifers (181±19 kg) with M. haemolytica (-21 h)
BRD Treatment (0 h)
(Fajt et al., 2004)
How to early detect BRD?
A) Monitoring body temperature to early detect BRD
Study of Timsit et al. (2011b)
Treatment
Drinking
Fever episode
Rumen temperature of a feeder bull
BRD affected animals detected 12 to 177 h (mean = 51h)
prior to BRD treatment
How to early detect BRD?
A) Monitoring body temperature to early detect BRD
Study of Schafer et al. (2007 & 2012)
BRD affected animals detected 4 to 6 days prior
to the onset of clinical symptoms of BRD
How to early detect BRD?
A) Monitoring body temperature to early detect BRD
Fever Tags® (old version)
Promising tools Cheap <15€
But low sensitivity (21/46 = 46%)
• Inadequate probe
placement
• Probe displacement
• High threshold for activation New version with adjustable probe size and activation threshold
Study of McCorkell et al., accepted
“Fever Alert” distributed by Merck Animal Health (France)
need to be evaluated
How to early detect BRD?
Solution: By using automatic health-monitoring systems
B) Changes in feeding behavior => Growsafe system, ENGS system
A) Changes in body temperature rumen T°C boluses, IRT, ear mounted
thermometers
Schaefer®
Growsafe®
Yes
How to early detect BRD?
B) Monitoring feeding behavior
Study of Sowell et al. (1999)
Diseased feedlot cattle spent on average 30% less time at the feed
bunk than healthy cattle (46 min/day versus 60 min/day)
Growsafe®
(Sowell et al., 1998)
How to early detect BRD?
B) Monitoring feeding behavior
Study of Quimby et al. (2001)
Growsafe®
Decreased frequency and duration of feed bunk visit
Detected as sick by the Cusum test
Diseased cattle detected on average 4.1 days earlier than pen checker
How to early detect BRD?
Solution: By using automatic health-monitoring systems
B) Changes in feeding behavior => Growsafe system, ENGS system
A) Changes in body temperature rumen T°C boluses, IRT, ear mounted
thermometers
Schaefer®
Growsafe®
C) Changes in physical activity => pedometers, accelerometers Yes
Yes
How to early detect BRD?
C) Monitoring physical activity
Study of Hanzlicek et al. (2010)
Experimental infection of 14 steers
(199 kg) with M. haemolytica
M. Haemolytica infection
How to early detect BRD?
C) Monitoring physical activity
Study of White et al. (2012)
Experimental infection of 20 Holstein
calves (5-9 week old) with M. bovis
<10% consolidated
lung tissue
>10% consolidated
lung tissue
M. bovis infection
How to early detect BRD?
Solution: By using automatic health-monitoring systems
B) Changes in feeding behavior => Growsafe system, ENGS system
A) Changes in body temperature rumen T°C boluses, IRT, ear mounted
thermometers
Schaefer®
Growsafe®
C) Changes in physical activity => pedometers, accelerometers Yes
Yes
Yes
How to early detect BRD?
• Why are health-monitoring systems not currently
used in feedlots?
1st explanation = costs $$$
• Rumen temperature bolus = $35-100
• Infrared camera = $7000
• Growsafe system = $25 per head
2nd explanation = low specificity!
• Numerous “false-positive” detection
Costs are decreasing rapidly!
How to early detect BRD?
• Lack of specificity of fever and abnormal feeding behavior:
Up to 75% of the fever episode detected by rumen T°C bolus lasted less
than 47 hours without any treatment => viral infection only? Successful immune response? Hyperthermia?
Vaccination?
1) Study of Timsit et al. (2011b)
2) Study of Wolfger et al. (2012)
Pulling cattle only based on abnormal feeding behavior during the first
weeks on feed could lead to pull as much as 90% of the healthy animals => Adaptation to the bunk?
How can the specificity of fever and anorexia/dysorexia be improved?
How to early detect BRD?
• How to improve specificity of fever?
– by taking into consideration the duration of fever
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0 to 24 h 24 to 48 h >48h
No BRD signsBRD signs and treatment
n=45 n=29 n=21
75% of fever episodes lasting longer
than 48 hrs led to clinical BRD
(Timsit and Assié, personal communication)
48 hrs was also proposed by
Radostits et al., 2010
Recommendations: treat cattle with fever
48 hrs after onset (if no other signs)
How to early detect BRD?
• How to improve specificity of fever and abnormal
feeding behavior?
– by combining this parameters (i.e. series testing)
+
Pull and treat only cattle having concomitantly fever and
anorexia/dysorexia
How to early detect BRD?
• To describe the changes in body temperature,
feeding behavior and physical activity associated
with BRD
Objective
• 560 steers studied during first 50 DOF
• Simultaneous monitoring of body temperature,
feeding behavior and physical activity
Materials and methods
On-going study (Timsit and Booker)
How to early detect BRD?
On-going study (Timsit and Booker)
Preliminary data (n = 12 sick animals)
• Fever (n =12): onset = 2 to 9 d before detection/treatment; med = 4 d
• Anorexia/dysorexia (n = 9): onset = 0 to 3 d after fever; med = 2 d
• Decreased activity (n =8): onset = 0 to 3 d after fever; med = 2 d
Steer n°9569 Steer n°9569
Treatment
Treatment
How to early detect BRD?
• Early BRD detection i) limits impact of BRD on
performance, ii) maximizes clinical and bacterial
cure and iii) reduces emergence of bacterial
resistances
• Distant examination alone cannot enable an
early BRD detection
• Health monitoring systems can enable an early
BRD detection but further research is needed
and is performed already!
Take home message
Thank you very much for your attention!
Source: Dr. Eugene Janzen
• Duff G et al.. 2007. Board-invited review: recent advances in management of highly stressed, newly received feedlot cattle. J Anim Sci. 85:823-40.
• Fajt V et al. 2004. Effect of danofloxacin and tilmicosin on body temperatures of beef calves with pneumonia experimentally induced by inoculation with Mannheimia haemolytica. Am J Vet Res. 65:610-615.
• Ferran A et al. 2011. Impact of early versus later fluoroquinolone treatment on the clinical: microbiological and resistance outcomes in a mouse-lung model of Pasteurella multocida infection. Vet Microbiol. 148: 292-297.
• Griffin D et al. 2010. Bacterial pathogens of the bovine respiratory disease complex. Vet Clin North Am Food Anim Pract. 26:381-394.
• Hanzlicek G et al. 2010. Serial evaluation of physiologic, pathological, and behavioral changes related to disease progression of experimentally induced Mannheimia haemolytica pneumonia in postweaned calves. Am J Vet Res. 71: 359-369.
• Lipsitch M et al. 1997. The population dynamics of antimicrobial chemotherapy. Antimicrob Agents Chemother. 41:363-73.
• McCorkell et al. 2014. Limited efficacy of Fever Tag® temperature sensing ear tags in calves with naturally occurring Bovine Respiratory Disease or induced Bovine Viral Diarrhea Virus infection. Can Vet J. Accepted.
• Panciera RJ et al. 2010. Pathogenesis and pathology of bovine pneumonia. Vet Clin North Am Food Anim Pract. 26:191-214.
• Quimby W et al. 2001. Application of feeding behaviour to predict morbidity of newly received calves in a commercial feedlot. Can J Anim Sci. 81: 315-320.
• Schaefer A et al. 2012. The non-invasive and automated detection of bovine respiratory disease onset in receiver calves using infrared thermography. Res Vet Sci. 93: 928-935.
• Schaefer A et al. 2007. The use of infrared thermography as an early indicator of bovine respiratory disease complex in calves. Res Vet Sci. 83: 376-384.
• Sowell BF et al. 1999. Feeding and watering behavior of healthy and morbid steers in a commercial feedlot. J Anim Sci. 77:1105-1112.
• Timsit E at al. 2011a: Early detection of bovine respiratory disease in young bulls using reticulo-rumen temperature boluses. Vet J. 190: 136-142.
• Timsit E at al. 2011b: Fever episodes without visually apparent clinical signs in newly-received beef bulls at fattening operation: occurrence, duration and impact on performance J Anim Sci. 89: 4272-4280.
• White BJ et al. 2012. Clinical, behavioral, and pulmonary changes in calves following inoculation with Mycoplasma bovis. Am J Vet Res. 73:490-497.
• Wolfger B et al. 2012. Pattern recognition of feeding and drinking behaviour as a tool in early identification of diseased feedlot animals. 13th ISVEE. Maastricht. Netherland.
Literature cited