Respiratory diseases - cattle 1&2 Flashcards
Define BRD
Bovine Respiratory Disease (this a complex rather than a specific disease)
Signs - BRD
pain –> welfare problem
death
poor/reduced growth
What is the typical pattern of calf pneumonia?
consolidated cranioventral lung, normal caudodorsal lung
What environmental features are implicated in calf pneumonia
housing, ventilation, stocking density, mixing, sharing air space with other ages, changes in weather
What age does weaning occur in cows?
when they can eat enough concentrates (usually 1-1.2kg/day, usually at 50-80 days old)
Calf factors implicated in calf pneumonia
colostrum (6L in first 12 hours), mixing, transport, home bred/purchased, nutrition, husbandry standards
2 syndromes of BRD
Chronic which may develop into acute form (Enzootic pneumonia)
What are the respiratory signs of a calf with enzootic pneumonia (i.e. acute BRD)?
cough - dry or moist (often the first sign)
increased RR
What should you do for a general exam into a respiratory condition? 5
- listen (cough)
- Count RR (20-40 calves, 10-30 adults)
- air quality assessment
- ventilation
- stocking density
Above what temperature should you be concerned for a calf and thus want to treat?
> 39.5 degrees
Features of a respiratory exam into a respiratory condition
- temperature (concerning if >39.5)
- respiration (concerning if > 40bpm)
- ausuclatation (both lung fields and trachea, i.e. 1,2,3)
- discharge (oculo-nasal)
- conjunctivitis
- trachea pinch
2 other names for enzootic pneumonia
acute pneumonia and viral pneumonia
Outline enzootic pneumonia pathogenesis
primary pathogen (virus/mycoplasma) –> damages RT –> secondary pathogen (bacteria) invades –> more substantial damage
What bacteria are commonly implicated in enzootic pneumonia?
- Mycoplasma (distemper, bovis, canis)
- Ureaplasma spp.
- M. haemolytica (A1 and A6)
- P. multocida
- A. pyogenes
- H. somni
Which viruses are commonly implicated in enzootic pneumonia 5
- PI3
- BRSV
- IBR
- Bovine coronavirus
- BVDV
Which viruses are less commonly implicated in enzootic pneumonia? 6
- Reovirus (1-3)
- Adenovirus (1-4)
- Rhinovirus 1
- Enterovirus
- PI2
- Others
How do you manage a BRD outbreak?
- treatment
- environment
- PME dead calves
- ID pathogens
When would metaphylaxis be appropriate for BRD?
if over 25% of a group of calves are affected
2 main tx options for enzootic pneumonia
ABs
NSAIDs (decrease temperature, decrease lung inflammation and pain relief)
Define SPC
Summary of Product Characteristics.
This accompanies the datasheet nowadays with medicines
Risks of prolonged NSAID therapy
serious GIT damage (abomasal ulcers) and renal failure
Follow up for enzootic pneumonia
Revisit (24-48 hours later)
Measure temp.
Decide on follow up tx
Ensure data sheet recommendation is followed
How can the pathogen be identified?
Check with laboratory first of the methods for sampling:
- BALV
- Nasopharyngeal swab
- Serology - paired clotted samples, 14-21 days apart, complicated by MAb
- Faecal exam (Salmonella and parasites)
Outline BALV
- pass thin tube, via nostril into trachea
- flush with sterile saline (50ml)
- immediately withdraw (10ml)
How long do paired serology results take?
4 weeks
How can BRD be confirmed on PME? 3
- Distribution of lung lesions (typically cranioventrally. RSV typically has a bulla appearance in the lung lobes but this is not pathognomonic)
- Specific diagnostic tests on lung tissue
- Histology
Preventative measures - BRD - 5
- Environment
- Colostrum management
- Buying in
- Mixing
- Consider vaccination (dams 3-4 weeks prepartum, calves 3-4 weeks before mixing)
What causes Infectious Bovine Rhinotracheitis (IBR)?
Bovine Herpes Virus 1 (BHV1)
CS - IBR/BHV-1
- high temperatures
- conjunctivitis
- coughing
- tracheitis (upon tracheal auscultation)
Other than respiratory problems, what can BHV-1/2 cause?
- Genital form:
FEMALES - Infectious Pustular Vulvovaginitis (IPV), sporadic abortion
MALES - Infectious Pustular Balanoposthitis - Ocular form (nasal and ocular discharges)
Day 1-6: serous, pyrexia
Day 6-11: mucopurulent
Day 11+: purulent - Neurological form: encephalitis
Outline the respiratory disease seen with IBR
Rhinitis, tracheitis and conjunctivitis which can progress to pneumonia.
Outline BHV-1 Latency
Resides in the trigeminal ganglion (5) and this can last indefinitely. Can recrudesce (stress) and start shedding again after a very long period. You cannot reliably detect a latent infection as the animal may be sero-negative despite still carrying the infection therefore assume that all cattle from infected herds must be considered potentially infected/
4 stages of IBR control
- know herd status
- biosecutiry
- vaccination
- eradication (?)
How effective are IBR vaccines?
work well if in place before the natural exposure to the virus. Prevents respiratory disease and abortion. May reduce level of virus circulating int eh herd. May reduce excretion.
What are the types of IBR vaccine? 3
- MLV or dead/killed
- IM or IN
- Conventional or marker
What does it mean if a vaccine is labelled POM-V?
Prescription Only Medicine - Veterinary. Therefore YOU are responsible for informing, training client to use correctly.
Ouyline live vaccines doses broadly .
often only a single dose is needed. Young animals may need to 2 doses due to MDA
How fast is immunity acquired from live vaccines?
rapidly (40-96 hours)
Outline immunity from IN vaccines
local immunity (also IM vaccines)
Local produces local secretory IgA and IFN.
Often used in face of outbreak due to rapid protection (48 hours).
Careful administration essential due to nasal chamber
Define DIVA
Differentiate Infected from Vaccinated Animals
What does DIVA require? 2
- marker vaccine
2. specific lab test
Name 2 non-infectious causes of calf pneumonia
- aspiration pneumonia
- calf diptheria
Outline aspiration pneumonia
- very severe
- association with milk/liquid inhalation into LRT (commonest cause is stomach tubes)
- poor prognosis
What is another name for calf diphtheria
Necrotic laryngitis
What causes calf diphtheria
Fusobacterium necrophorum
CS - calf diphtheria -5
- Lesions - mouth, tongue, larynx
- Halitosis - trapped food
- Hypersalivation
- Swollen cheeks and abscesses in this region
- Increased respiratory noise (over larynx and trachea)
Causes -calf diphtheria 2
- mucosal injury (calves have sharp teeth, 1-4 months)
- poor hygiene of feeding equipment (tubes, coarse feeds)
Tx - calf diphtheria
- ABs - beta lactams
- Tracheostomy or surgery to debride lesions (severe)
What causes BRD in older calves (weaned to up to 2 years old)?
Shipping Fever = Transit Fever = Pneumonic Pasteurellosis
Outline Shipping Fever 4
- Normally seen 10-30 days after transport
- Sudden onset
- CS = pyrexia, decreased appetite, increased RR and noise, grunting
- Sudden death (PME essential)
Pathogens implicated in Shipping Fever - 4
- M. haemolytica
- P. multocida
- Various other bacteria and viruses
What happens to the lungs in cases of Shipping Fever?
Severe and acute bronchopneumonia. can become chronic. serious welfare problem as lung damage is often so bad that permanent lung compromise is likely.
What causes respiratory disease in adult cattle (i.e. > 2 years old)?
Fog fever = acute bovine pulmonary oedema and emphysema = atypical interstitial pneumonia.
Outline a presentation of fog fever
- within 2 weeks of moving to lush rich autumn pastures
- up to 50% group affected
Prognosis - fog fever
- commonly fatal and difficult to treat
Pathophysiology - fog fever
Lush pasture has high levels of l-tryptophan which forms indole acetic acid (IAA) in the rumen and this is converted to 3-methyl indole which is toxic to the lungs.
CS - fog fever
Sudden onset
- affects group
- can be severe respiratory distress but individual variation
- froths at mouth
- may get distressed or die when attempt to move
- SC emphysema (back and thorax)
Tx - fog fever
- remove from pasture immediately (care)
- Symptomatic - NSAIDs, diuretics, corticosteroids in emergencies (abortion risk)
Prognosis - fog fever
guarded
Prevention - fog fever - 5
- restrict access to lush pastures
- strip grazing
- feed hay before and during initial period of new pasture
- restrict access to 2 hours per day
- avoid over-fertilising (especially autumn pasture)
What is Bovine Farmer’s Lung?
= hypersensitivity following inhalation of allergens from moulds (Micropolyspora faeni, Thermoactinomyces vulgaris) usually from mouldy or poorly-made hay. Also seen in house cattle with poor ventilation
Acute signs - Bovine farmer’s lung 3
- mouth breathing
- coughing
- decreased milk yield
Chronic signs - Bovine Farmer’s lung 2
- weight loss
- coughing
What ages can lungworm be significant in cattle?
all ages.
