Approach to resp cow

History

·    How long been going on?

·    One animal affected or herd problem? Whole herd = IBR, PI3, individual animal = MCF, lungworm

·    What signs have they seen?

o  Coughing? Sound? – BRD, mycobacterium bovis, lungworm, NO COUGH = fog fever, IBR, MCF

o  Nasal discharge? Nature of d/c? – BRD, MCF (mucopurulent), IBR

o  Increased respiratory effort? – IBR, BRD, contagious bovine pleuropneumonia, lungworm, fog fever

·    Any other clinical signs? – head tilt due to otitis media = mycoplasma bovis, abortion/mastitis = mycoplasma bovis, conjunctivitis = IBR, dermatitis on udders/inner thighs = MCF

·    What age animals affected? - >6m = IBR, young calves = RSV, PI3, contagious bovine pleuropneumponia

·    Any change in production? – milk drop = IBR, weight loss = mycobacterium bovis, contagious bovine pleuropneumonia, decreased DLWG = BRD

·    Vaccination protocols? – for IBR, lungworm, RSV, BVD, PI3

·    Recent management/diet changes? – cusing stress -> PI3

·    Cows kept with sheep? – MCF (ovine herpes virus) can only spread sheep -> cow

·    What has the weather been like recently? – turned out when wet = lungworm

·    Closed herd? Any new stock brought in recently? – IBR, mycobacterium bovis

·    Any abortions recently? = IBR

·    Recently wormed? When? How?

Investigations

Full clinical exam:

·    Examine nose

o  Nasal discharge? – IBR (purulent), MCF (mucopurulent), BRD

o  Sloughing of nasal mucosa = MCF

·    Eyes – conjunctivitis = IBR, corneal opacity = MCF, ocular d/c = BRD

·    Mouth – sloughing of oral mucosa = MCF

·    Lymph nodes – enlarged LNs = mycobacterium bovis, MCF

·    TPR – pyrexic = IBR, MCF, BRD, mycoplasma bovis, contagious bovine pleuropneumonia, tachypnoea = IBR, fog fever, lungworm

·    Auscultate lungs and trachea – crackles = lungworm

Further investigations:

·    Nasal and conjunctival swabs for PCR - IBR

·    PM exam – sticky black material in trachea = IBR, lung pathology = BRD, bronchitis and adult worms in bronchi = lungworm

·    Baemann – lungworm

·    Antigen testing – BRD

·    SICCT or blood test – mycobacterium bovis

·    Blood sample for ELISA (antibodies) - IBR

Treatment

·    Supportive (keep warm, deep bedding), ISOLATE

·    IBR – vaccinate to prevent, improve management and biosecurity

·    MCF – no treatment – euthanise

·    Mycoplasma bovis – IV oxytetracycline 3d (cat D, good penetration of respiratory tract, broad spec, effective against mycoplasma)

·    Lungworm – ivermectin, vaccinate calves before turning out to prevent, and delay turnout to avoid lungworm challenge

Prevention

·    Reduce stocking density ® reduce environmental pressure and stress

·    Keep in groups of similar ages

·    Cleanliness important – regular bedding change, drainage, sweeping

·    Fresh air and ventilation – avoid heat or cold stress

·    Vaccination – for IBR, PI3, RSV, lungworm

Causes

·    IBR

·    MCF

·    BRD

·    TB

·    Mycoplasma bovis = otitis media (ear droop, head tilt), joint inflammation, abortion, mastitis

o  Transmission: aerosols through coughing, milk, respiratory secretions

·    Contagious bovine pleuropneumonia = pyrexia, incr. resp rate/effort, polyarthritis in calves

o  Mycoplasma mycoides, transmission via aerosol

·    Fog fever = respiratory distress WITHOUT coughing or pyrexia

o  After moving from sparse to lush, high protein pasture, seen in autumn, L tryptophan ingested, and converted into 3-methylindole (pneumotoxic)

·    Lungworm = coughing at rest, dyspnoea, outstretched head/neck

o  Dictyocaulus viviparus: incr. risk if wet summers, heavy stocking

·    Mannheimia haemolytica = shipping fever in young stock

o  Occurs post-weaning after periods of stress, e.g. transport, mixing with other animals