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Learning Objectives. Learn the major disease conditions that affect cattle
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1. AVS 471 Cattle Disease Lecture #13
3. Why concern ourselves with cattle disease?
4. Signs of Respiratory Disease Cough
Nasal discharge
Stridor
Abnormal sounds
Dyspnea
Cyanosis
5. Signs cont
Abducted elbows
Exercise intolerance
Nasal erosions, ulcers, etc.
Distortion of nasal bones
12. Disease of the Sinuses
13. Sinusitis Common in cattle, less so in sheep, goats and camelids
Cornual (post dehorning), maxillary (tooth rot), frontal (extension of cornual)
Usually ___________ infection
Clinical signs:
Non specific: anorexia, lethargy, fever
Nasal discharge, swelling, changes in air flow, ozena, stridor, head tilt, head ache (pressing), dull percussion
16. Sinusitis DDx: fractures, tumors, actino.., lymphosarcoma, retrobulbar abscesses
Dx: PE, radiology, CT
Treatment:
__________________________________
Post dehorning cornual/dorsal frontal sinusitis: flush with peroxide, and apply mastitis treatment ointment
17. Pharyngeal trauma and abscess Diagnosis: Hx, PE, painful swelling, visual or digital exam of pharynx, endoscopy, radiology
Treatment:
_________________
Systemic antibiotics
NSAIDS
Support (fistula, etc)
19. __________________________ Infection of laryngeal mucosa (acute) and/or cartilage (chronic)
Pathophysiology:
Upper resp. tract (URT) infection
Reflex coughing
Mucosal damage and laryngeal contact ulcers develop
Invasion and infection by F. necrophorum
21. Necrotic laryngitis Clinical signs:
Calves (3-24 mo)
Acute onset moist, painful cough
_______________________________________
Stertorous breathing, inspiratory dyspnea
Ozena
Palpably and visibly enlarged larynx
Aspiration pneumonia and chronic poor doers, common
22. Necrotic laryngitis Dx: Hx, signalment, PE, visualization of lesion, necropsy
DDx: pharyngeal trauma, laryngitis, laryngeal edema, abscess, neoplasia
Necropsy: artenoid cartilage, vocal processes, laryngeal mucosa edematous, hyperemic, necrotic, malformed
Treatment : PPG, sulfonamides, NSAIDS, tracheostomy, surgery, support
23. Tracheal stenosis, collapse, stricture Etiology:
Trauma: __________________________________
Congenital
Clinical signs: inspiratory dyspnea, stridor, exercise intollerance cough, secondary pneumonia, fainting
25. Tracheal stenosis, collapse, stricture DDx: foreign body, tumor, actinobacillosis, bronchopneumonia, anterior mediastinal mass (abscess, thymoma, etc.)
Treatment: _____________, anastamosis, internal/external prosthesis, resection
26. Bronchopneumonia Invasion via pulmonary tree
Characterized by:
Fever, depression, sepsis
________________________________
Final manifestation of BRD complex
Viral diseases included (due to role in BRD)
29. Bronchopneumonia
30. Major Bacterial Agents of Bronchopneumonia Pasteurella hemolytica A1
P. multocida
Haemophilus somnus
Actinomyces pyogenes
Opportunistic e coli, salmonella etc.
31. Major Viral Agents of Bronchopneumia IBR - Infectious bovine rhinotracheitis
___________________________________
PI3 parainfluenza virus
___________________________________
33. Bovine Herpesvirus 1BHV-1 IBR Alpha-herpesvirus (enveloped DNA virus)
Rapid growth, lysis of cells
Fragile, ________________________________
Transmission requires contact
Single serotype, three types
BHV1.1- respiratory infection, abortion
BHV1.2- respiratory and genital infection
BHV1.3 neurologic disease (now called BHV 5 Bovine Encephalitis Herpesvirus
34. IBR Infectious bovine rhinotracheitis Epidemiology
Found throughout the world
Disease of all phases of production cycle, beef (feedlot and range) and dairy
Feedlot cattle: highest morb. & mort.
High stress and population density
Low mortality (unless secondary bacterial inf.)
Adults likely reservoir
Latent infections reactivated w/ stress
MLV vaccines a source of latency
35. IBR Clinical signs respiratory =/- conjunctivitis, corneal edema
Coughing
Decreased milk production
Fever abating in 3-4 days
Recovery in 10-14 days
Complications: bacterial bronchopneumonia, tracheitis, bronchitis
38. BVH-1, IBR Treatment No specific threatments for BHV-1
Support (feed, water, shelter, decrease stress, etc.)
Prevention and treatment of secondary infections (bacterial)
39. BVH-1, IBR Prevention and Control Vaccination
Hallmark of control
Goal: develop immunity at youngest age possible
Vaccinate at earliest possible age (4-6 weeks)
Booster prior to stress
3 vaccines in first year
40. Parainfluenza virus Type 3 (PI3) RNA virus, paramyxovirus family
Common isolate from cattle, sheep and goats (different strains)
Can cause clinical disease (interstitial pneumonia) independent of its role in BRD (damage to URT mucosa)
Ubiquitous
41. PI3 Clinical signs Fever
Nasal discharge
Cough harsh, dry, tracheal
Dyspnea, polypnea
Auscultation increased anterioventral region
Recovery 4 to 7 days if uncomplicated
Secondary bacterial pneumonia
42. PI3 Diagnosis/Treatment Nasal swab VI during acute phase (not present during convalescence)
Lungs: extended period after infection
Serology: evidence of recent infection
Treatment : no specific, support, antibiotics for secondary infection
43. Bovine Respiratory Syncytial Virus (BRSV) RNA virus, paramyxovirus
Affects all ages (young predominantly)
_______________________________
________________________________
Cattle probably reservoir, but carriers have not been found
44. BRSV Clinical signs Fever ( 104-108 F)
Anorexia, depression, nasal/ocular discharge,polypnea, salivation
Pronounced dyspnea, mouth breathing,expiratory grunting
Crackles bronchiolitis, emphysema
SC emphysema
Bottle jaw
45. BRSV Diagnosis History, PE
VI - virus very labile, best at acute phase (febrile, no clinical signs)
Serology - presumptive evidence
46. BRSV Treatment/Prevention Treatment: support
Prevention: MLV and inactivated vaccines
Both require 2 doses (21 days for protection)
Booster every 2-6 months
Management procedures same as for other respiratory viruses
47. Bovine Viral Diarrhea Virus (BVD) ____________________________
Often isolated in BRD
Synergistic w/ P. hemolytica
Experimental
Immunosuppressive
Impairs viral clearance
Allows secondary bacterial infections
48. Bacteria associated with BRD P. haemolytica, serotype A1
Most common isolate, highly virulent
P. multocida
Less fulminant pneumonia
_______________
Normal inhabitant of nasal pharynx but not lung
Infect lung when pulmonary defenses are impaired (stress, malnutrition, viral infection)
Damage tissues via toxins and recruitment of inflammatory cells and mediators
50. Shipping Fever Acute respiratory disease characterized by inflammation of respiratory system, fibrinous pneumonia, and/or bacterial bronchopneumonia
51. Shipping fever, Epidemiology and Economics Most common disease of feedlot cattle world wide
Colorado study:
75% of feedlot disease
64% of feedlot mortality
National losses? Billions of dollars.
52. Host and Environment Risk Factors At farm of origin
Wean, creep feed, perform surgeries at least 3 weeks prior to shipment
Vaccinate against respiratory pathogens at least 3 weeks prior to shipment
Avoid nutrient deficiencies (Vit A,E,Se,Cu,Zn)
At transport
Adequate energy prior to shipment
Avoid prolonged transit time
Avoid going through multiple actions
53. Cont
At feedlot
Avoid surgery and MLV vaccines on arrival
Minimize mixing
Minimize large groups
Avoid rapid feeding of high concentrate diets
Avoid feeding NPN on arrival
Antibiotics in water may decrease water intake
Temperature fluxes and high dust = pneumonia
54. Shipping fever Pathophysiology Similar mechanism to enzootic calf pneumonia
Stress
Viral infection compromised pulmonary defenses
Bacterial colonization of lower respiratory tract
55. Shipping Fever Clinical Signs Onset 6-10 days after insult (transit, etc)
Depression, fever (>105F), anorexia, weight loss, nasal/ocular discharge
Rapid, shallow respiration
Coughing
Anterioventral consolidation
Crackles and wheezes later
Pleural friction rubs, pain
Severe dyspnea, terminally
56. Shipping Fever Sequelae Cor pulmonale: pulmonary hypertension => right heart hypertrophy, dilation, failure
Lung abscessation
Pericarditis
Pleuritis
Pleural abscessation
57. Shipping Fever Treatment Similar approach to that of enzootic pneumonia
Antibiotics
NSAIDS
Support
58. BRD Vaccines Points to consider
Vaccination is a management tool!!!
Success of human vaccines has likely produced unrealistic expectations from veterinary vaccines
More controversy and uncertainty exists about the efficacy of vaccines than any other topic in livestock production
59. BRD VaccinesThe ideal vaccine Life long protection against clinical disease from wild-type organisms
Protect vaccinate and fetus
Free from adverse effects
Stable
Inexpensive
Stimulate response distinguishable from natural infection
Not be associated with shedding, immunosuppression, or blocked by passive transfer
60. Metaphylaxis Term for the use of specific products (Mycotil, tilmicosin) upon entry into feedlots
Data suggest beneficial effects (reduced morbidity)
Administration on arrival (post shipment) was superior to pre-shipment treatment*
More work
timing, other stresses, etc.
*McClary and Vogel. The Bovine Practitioner. 33(2) May 1999,pp 155)
61. Questions