AVS 471 Cattle Disease

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 do�ers, 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