Unit 2 - Bovine Respiratory Diseases Flashcards
What stresses can cause, or exacerbate, respiratory diseases?
Weaning Change in diet Shipping and handling Dehorning Castration Vaccination
Who must sign the Iowa green or gold tag program form?
The owner and the veterinarian
How are calves in the green or gold tag program identified?
With a recorded tag number in their left ear
When does the owner receive the green or gold tag program certificate?
When the required 30 or 45 day weaning period and all immunizations are completed on time
For the green or gold tag program, how old must the calves be before the first vaccination is given?
4 months old
How many courses of vaccinations are given with the green tag program? Gold tag?
Green tag - 1 round
Gold tag - 2 rounds
When must the second vaccination for the gold tag program occur?
At least 14 days following the first and 14 days before the sale
What are the required vaccinations for the green and gold tag program?
Clostridial Group (7-way) Histophilus somni Mannheimia haemolytica IBR PI-3 BVD BRSV
Aside from vaccination, what are other requirements for the green and gold tag programs?
All calves must be dehorned and castrated at least 21 days before they are sold.
Record internal and external parasite treatment.
Preconditioning is only good for a single change of ownership
What are optional procedures that can be done with green and gold tag programs?
Growth implants and P. multocida bacterin
What metaphylactic steps can be taken to reduce the chance of developing respiratory disease in cattle?
Placing feeder cattle on antibiotics when they arrive
What issues may arise with the use of antibiotics as a metaphylactic step?
There can be a problem with antimicrobial resistance
What methods can be utilized to prevent respiratory disease in cattle?
Minimize stress Preconditioning-Green Tag/Gold Tag Program Good vaccine timing Vaccinate upon arrival Vaccination during a disease outbreak Metaphylaxis Test for BVD PI cattle Start cattle on feed Manage nutritional deficiencies
What are the three points to the epidemiologic triangle?
Host, agent, and environment
What are the main respiratory disease agents that affect cattle?
Manheimia haemolytica Bibersteinia trehalosi Pasteurella multocida Histophilus somni Mycoplasma bovis IBR PI3 BRSV BVD
What is the major serotype involved with respiratory disease due to Mannheimia haemolytica?
Serotype A1
What toxin does Mannheimia haemolytica release?
Leukotoxin
What is the role of leukotoxin?
Macrophages and neutrophils release reactive oxygen intermediates, eicosanoids, cytokines, and hydrolytic enzymes on pulmonary tissues
How is Mannheimia haemolytica infection prevented?
Preconditioning
Sound management practices
Immunization
In general, what guidelines are important for the treatment of bovine respiratory disease?
Assume that all agents may be contributing, but not necessarily to the same extent in all animals Treat early Correct drug Correct dose Treat long enough Identify research animals
T/F: Pasteurella multocida infection is almost always secondary
True
What type of Pasteurella multocida is common in mixed infections?
Type A
T/F: Pasteurella multocida is one of the easier respiratory infections to treat.
False - it is harder to treat
Are bacterins for Pasteurella multocida useful?
They have questionable benefit but seem to help if given early as part of a preconditioning programq
What type of respiratory disease does Bibersteinia trehalosi cause?
An acute, severe respiratory disease
What toxin does Bibersteinia trehalosi release?
The same leukotoxin as Mannheimia haemolytica
How does Histophilus somni spread in groups of calves?
laterally
In some herds, _____ combines with H. somni and produces what?
BRSV; a rapidly fatal pneumonia that may involve a type I hypersensitivity reaction
What weather does Histophilus somni like to spread/infect?
Fall weather, wet, changeable
What diseases occur in conjunction with Histophilus somni?
Respiratory disease, septicemia, joint infections, and TME
How is H. somni pneumonia diagnosed?
Culture, PCR-Panel, and a CF test
T/F: H. somni immunization is required for Iowa Green and Gold tag programs, but it is generally regarded as having poor immunogenicity
True
What is the possible hypersensitivity associated with H. somni immunization?
Vaccine reactions/immunized animals sometimes have worse disease
Reports say these reactions are more common with vaccines that combine BRSV and H. somni
What virus causes infectious bovine rhinotracheitis (IBR)?
Bovine herpesvirus-1 (BHV-1)
What has reduced the incidence of IBR?
Vaccination
In general, what diseases do herpesviruses cause in cattle?
Respiratory diseases, CNS diseases in neonates, and abortions
What clinical disease is associated with IBR?
Rednose, keratoconjunctivitis, abortion w/ or w/o evidence of respiratory disease, occasional meningitis
What is rednose?
Severe hyperemia and reddening of the muzzle
How does IBR effect the immune system?
Immunosupression
What immunosuppresive things does IBR do?
Defective neutrophil and alveolar macrophage function
Decreased T-helper cell activity
Destruction of ciliated respiratory epithelium
What is diagnosis of IBR based on?
History and clinical signs
Histopath
PCR
Serologic tests
What will you find on histopath in patients with IBR?
intranuclear inclusions
What types of vaccines are available for IBR prevention?
Intranasal modified live, parenteral modified live, inactivated
What is the recommended IBR vaccination for pregnant cows?
Killed vaccines
MLV vaccines are no longer recommended even if on label due to cases where the MLV vaccination is linked to abortions
According to one of the assigned readings, The MLV vaccine should provide enough immunity if given pre-breeding
Parainfluenza 3 usually produces a relatively _____ disease in cattle and is most commonly associated with _______ ______.
mild; shipping fever
What does PI-3 predispose a cow to and why?
Bacterial pneumonia because it inhibits alveolar macrophage function and clearing of bacteria from the lungs
How is PI-3 infection diagnosed?
Histopath and IHC
Is there a vaccine for PI-3?
Yes - good vaccines are available and included with IBR vaccines and other immunizing products
BVD is an _________ virus. According to Dr. Griffith, it ‘really knocks the socks off of the white cells.’
immunosuppressive
Clinical infection from Bovine Respiratory Syncytial Virus is what type of disease?
A lower respiratory tract disease
What clinical signs are associated with BRSV?
Sudden onset of high fever (104-108 F), nasal discharge, and respiratory distress
What does BRSV do to the respiratory tract?
It causes destruction of the ciliated respiratory epithelium and induces fusion of epithelial cells to form multinucleate syncytial cells
In what form of disease is BRSV associated with immediate hypersensitivity reacitons?
Peracute disease
How is BRSV diagnosed?
IHC, histopath, virus isolation, PCR panel
Are there vaccines available for BRSV?
Yes - both inactivated and MLV
What other disease process is BRSV infection associated with?
Corn silage disease - metabolic acidosis
What clinical conditions does Mycoplasma bovis cause?
Mastitis, lungers, railers, polyarthritis, and abscess formation
Where does M. bovis typically form abscesses?
Pulmonary, ear, kidney, and liver
What lesions does M. bovis causE?
Focal coagulative necrosis and lymphohistiocyic response
What is M. bovis resistant to?
Penicillins and other beta-lactams
What is used to treat M. bovis?
Long-acting macrolides - Draxxin and Tilmicosin
Bovine coronavirus is a pneumo-_____ virus.
enteric
What are the two main forms of Malignant Catarrhal fever?
African or Wildebeest-associated form
Sheep/American form
What does the sheep/American form of MCF cause?
Widespread subclinical infection in sheep that is shed (for less than 24 hours) and transmitted to cattle
What are MCF outbreaks often associated with?
Lambs or lambing season
Why is MCF not transmitted easily between cattle?
The viruses are highly cell-associated and not transmitted easily
What does MCF have a trophism for?
All mucosal surfaces and vascular endothelium
What clinical signs are associated with MCF?
High fever, mucopurulent nasal discharge, keratoconjunctivitis, weakness, ropey saliva, severe diarrhea, and sloughing of hooves
How is MCF diagnosed?
Clinical signs, gross and histopathologic lesions, PCR, ELISA, VN, IHC
T/F: MCF is not a reportable disease.
False - it is reportable in most states
How is MCF controlled/prevented?
Separate infected animals from the rest of the herd and keep cattle separate from sheep and African wildlife
Is there a vaccine for MCF?
Negative ghost rider
What causes hemorrhagic septicemia?
Pasteurella multocida types B and E
During what season does hemorrhagic septicemia typically occur?
Rainy season
What disease processes does hemorrhagic septicemia cause?
Septicemia and endotoxemia
When do cows with hemorrhagic septicemia typically die if untreated?
within 8-24 hours of disease onset
What clinical signs are associated with hemorrhagic septicemia?
Fever, dullness, listlessness, and edema of the head, neck, and brisket
Why do cattle with hemorrhagic septicemia die?
Because they develop respiratory disress
What lesions does hemorrhagic septicemia cause?
Edema of the head, neck, brisket, and musculature
Subserosal hemorrhages prominent in the pharyngeal and cervical lymph nodes
How is hemorrhagic septicemia prevented?
Killed oil-adjuvanted bacterin in endemic areas
How is hemorrhagic septicemia treated?
Penicillin or other antimicrobials if given early
What causes contagious bovine pleuropneumonia (CBPP)?
Mycoplasma mycoides subspecies mycoides SC
How is CBPP prevented?
Immunization - animals remain carriers
How is CBPP controlled?
Slaughter infected animals or antibiotics (animals remain carriers)
T/F - CBPP is not a problem in the US.
True
