Respiratory disease in cattle Flashcards
What does inspiratory stertor vs exaggerated resp effort suggest about location of infection
Inspiratory stertor –> URT
Increased resp effort –> LRT
Difference in type of cough with upper and lower resp issues
Harsh non-productive cough = URT
Moist cough = LRT
What do crackle lung sounds indicate
accumulation of fluid in airway
e.g in fog fever, pulmonary oedema
What are wheezing lung sounds
Musical, continuous sounds
Seen in chronic pneumonias, bacterial pneumonias, fibrosing alveolitis
- High pitch = small airways affected
-Low pitch = large airways affected
What does stertor sounds indication
Accumulation of secretions in extra-thoracic airway
What are pleural friction rub sounds
Rubbing sandpaper like sounds
Seen in advanced pasteurellosis pneumonia
What is stridor sound and what does it indicate
Wheezing on inspiration; suggests obstruction in upper airway e.g in calf diptheria, pharyngeal abscesses
When might we hear decreased or absent lung sounds
With pneumothorax, pleural effusions, diaphragmatic hernia
Some of the most common respiratory conditions in cows
Infectious bovine rhinotracheitis
Pasteurellosis (shipping fever)
Fog fever
Lungworm
Inhalation pneumonia
Chronic pulmonary disease
Pathogenesis of infectious bovine rhinotracheitis
From bovine herpes virus 1
- Can get latency; shedding during stress
Type of disease caused: respiratory (pyrexia, white plaques on nasal mucosa, coughing, milk drop, tracheobronchitis), conjunctival, bortion, infectious pustulovaginitis, enteritis, encephalomyelitis
= broad range
What may be the first sign of BHV-1 infections in dairy herd
Milk drop (due to respiratory form of disease)
Dealing with infectious bovine rhinotracheitis
Can vaccinate in face of outbreak
Treatment unrewarding; if secondary bacterial infections can treat that; NSAIDs may help
Cause of pasteurellosis Shipping fever
= Mannheimia haemolytica
(may have involvement of B trehalosi + P multocida)
= commensal BUT can cause infection after stress/viral infection
Seen in weaned beef cows following stress e.g moving
Clinical signs of pasteurellosis (shipping fever)
Moist painful cough, shallow breathing, pyrexia, depression, salivation, crackles on auscultation (fluid)
Post mortem findings in shipping fever pastuerellosis
= fibrinous bronchopneumonia; cranioventral
+ yellow pleural fluid
(can get bullous emphysema)
dEaling with shipping fever
Treat with long acting antibiotics, NSAIDs fluids, nursing
Prevent via good hygeine, ventilation, vaccination before risk periods?
Cause of Fog fever and typical group seen in
= HERD issue after moving onto rich pasture; usually adult suckler cows
Due to L-tryptophan in foggage being converted into 3-methyl indole by ruminal microbes
= TOXIC to type 1 pneumocytes
Pathogenesis of fog fever + PM findings
Pulmonary congestion and oedema; type 2 pneumocyte hyperplasia, interstitial emphysema, congestion and haemorrhage
ON PM: lungs grossly large, red and heavy
Clinical signs of fog fever
Rapid breathing progressing to air hunger mouth breathing
NO COUGHING
Frothing at mouth
Death within a few days usually
How could we treat a cow with fog fever
Remove whole herd from pasture
Give diuretics to clinical cases, + can give NSAIDs, clebuterol (as in asthma)
Cause of lungworm ‘husk’ and which cattle usually affected
Dictyocaulus viviparous
- Typically cattle in first grazing season in Autumn
BUT now that adults less immune due to routine anthelmintic use get more disease in adults
Clinical signs and diagnosis of lungworm
Harsh cough, increased resp effort and rate; can get emphysema
Diagnosis via Baermann sedimentation; can look at bulk milk ELISA; hearing crackles over dorso-caudal lung lobes
Treating lungworm in cattle
Most anthelmintics dine
Levamisole = immunomodulatory so avoids mass killing
Eprinomectin = 0 milk withdrawal time
+ can vaccinate
Bovine resp syncytial virus pathogenesis
Mainly calves affected
Invades lower airways, damaged mucocilliary transport, impairs immune cell function
+ can get Ab-Ag complexes which may explain biphasic disease with severe disease weeks later
Signs of Bovine RSV infection
Pyrexia, milk drop, depression, nasal discharge, dyspnoea
+ emphysema in severe cases