Sheep Respiratory Disease – Coughing Lambs Flashcards
What are some of the problems of in ovine respiratory disease:
A) Clinical signs?
B) Causal agents?
C) Necropsy?
D) Cost?
A) Clinical signs are not pathognomonic (may not be able to diagnose just by listening to the chest)
B) Causal agents may be difficult to identify
C) Necropsy findings may be confusing
D) Costs may quickly escalate
It is a Saturday morning in early November.
A farmer phones you to ask you to put out 10 bottles of oxytetracycline for some store lambs….
“I got about 200 lambs in the shed – they’ve been in for 5 weeks …..
…..now they’re all coughing..
….there’s been one or two dead ones…
…..I’d been hoping to send some fat each week but none have seemed ready to go…….
…I’m just going to jab them all & that should put them right – don’t you think?”
What would you most like to do?
It is always valuable to visit the farm (to hand out antibiotics you need to visit!!)
It is a Saturday morning in early November.
A farmer phones you to ask you to put out 10 bottles of oxytetracycline for some store lambs….
“I got about 200 lambs in the shed – they’ve been in for 5 weeks …..
…..now they’re all coughing..
….there’s been one or two dead ones…
…..I’d been hoping to send some fat each week but none have seemed ready to go…….
…I’m just going to jab them all & that should put them right – don’t you think?”
What would be top of your list of differentials in this case ?
- Pasteurellosis - Mannheimia haemolytica (Pasturella is a vgaue term and can no mean either this or the one below)
- Pasteurellosis - Bibersteinia trehalosi
- Atypical pneumonia
- Viral pneumonia (e.g. parainfluenza)
- Lungworm
- Mycotic pneumonia (fungal)
Pasturella is presumed and there may or may not be some virus or mycoplasma as with an atypical pneumonia
What are the causative agents of pasturellosis?
Mannheimia haemolytica
Bibersteinia trehalosi
Where is Mannheimia haemolytica found in normal sheep? (2)
Nasopharynx and tonsils
What does Mannheimia haemolytica cause in:
A) Older sheep?
B)Lambs <12 weeks?
A) Pneumonia
B) Septicaemia
What does Bibersteinia trehalosi cause in lambs 6-9 months?
Septicaemia
What are the clinical sign of ovine respiratory disease? (8)
Cough, Inappetance,
Oculonasal discharge,
Pyrexia, Toxaemia,
Hyperpnoea, Tachypnoea, Dyspnoea
What is the difference in clinical presentation of mycoplasma involvement cf with pasturella? (3)
Fewer acute signs, persistent soft dry cough with poor growth rates
Name Risk factors for outbreaks of M haemolytica pneumonia (5)
- Concurrent infections with other respiratory pathogens
- Environmental conditions (esp housing – nb stocking density, humidity, ventilation, temperature fluctuations). Can use a smoke bomb to look at the ventiliation
- Extreme weather (rain, wind, changes)
- Stress – mixing of sheep, handling, transport
- Movement from poor pasture to aftermaths or housing with change of diet - especially if there is not enough forage. In bad weather or a storm the environmental and stress can cause pasturella
What is this?
Normal Lungs on PM
Salmon pink
Flesh colour
What disease does this show and what can be seen? (4)
Mannheima haemolytica
- Petechial haemorrhages over pleura & pericardium
- Lungs purple-red, swollen & heavy (sink in water (cf congestion; where it will no sink in water but will be red on congested side))
esp cranio-ventral consolidation
- Straw yellow pleural exudate with fibrin clots (some green gelatinous- this is a very bad case)
- Tracheobronchial lining is red-purple & pink froth in airways
What disease is this? What can be seen on PM? (4)
Bibersteinia trehalosi
- subcutaneous petechiation & coalescing haemorrhages in thoracic regions
- Necrosis & ulceration of mucosa in pharynx, stomachs & oesophagus
- enlarged purple pharyngeal lymph nodes & lung consolidation
- Pin point foci of hepatic necrosis (less common)
Where is it normal to find Bibersteinia trehalosi in sheep?
Tonsils
What should you always do in a sheep which dies suddenly and what are you looking for?
Open the oesophagus for Bibersteinia trehalosi
What disease is this and what can be seen?
Mycoplasma ovipneumoniae
Dark red to grey RAISED areas on apical & cardiac lobes
Quite solid
What is this?
Immunohistochemistry
M ovipenumoniae antigen in bronchiole is coloured brown
