Individual & Flock Approach to Ovine Pneumonia

Question 1

what are some common reasons adult sheep die

Answer 1

Mastitis

Acute fluke

OPA

Pasteurella bronchopneumonia

Chronic pulmonary abscesses

Question 2

what are common reasons lambs die

Answer 2

Gut worms

Coccidiosis

Pulpy kidney

Pasteurella septicemia

Pasteurella pneumonia

Other reasons besides pneumonia that are important in lambs

Question 3

what should BCS be at mating, mid preg and lambing for lowland ewes

Answer 3

mating: 3-3.5

mid preg: 2.5-3.0

lambing: 2.5-3

Question 4

what should BCS be at mating, mid preg and lambing for hill ewes

Answer 4

mating: 2.5-3.0

mid preg: 2.0-2.5

lambing: 2.0-2.5

Question 5

what are general causes of ill thrift

Answer 5

Poor nutrition

Parasitism (fluke or haemonchus in adults)

Chronic respiratory disease

Dental disease (molar & incisors)

On PM look at dentition

Gastrointestinal disease

Lameness

Skin disease

Others (mastitis, CLA, scrapie)

Question 6

what are common respiratory diseases

Answer 6

Chronic suppurative pneumonia (abscessation)

Jaagsiekte (ovine pulmonary adenocarcinoma OPA)

Maedi Visna virus

Laryngeal chondritis

Pneumonic pasteurellosis

Caseous lymphadenitis (CLA)

Question 7

what are other respiratory diseases to consider that are less common (6)

Answer 7

1. Atypical/chronic pneumonia/chronic non-progressive pneumonia
2. Lungworms: doesn’t generally kill sheep
3. Estrus ovis (anthelmintic use)
4. Enzootic nasal tumour
5. Inhalation pneumonia
6. Tuberculosis

Question 8

what are the causes of atypical/chronic pneumonia/chronic non progressive pneumonia

Answer 8

Mycoplasmia ovinpneumonia

Question 9

is Mycoplasmia ovinpneumonia commensal or not

Answer 9

yes

found in normal and diseased lungs

Question 10

what role does Mycoplasmia ovinpneumonia play in the health of the sheep

Answer 10

Most commonly a permissive disease to other diseases!

Question 11

what is the signalment of atypical/chronic pneumonia/chronic non-progressive pneumonia

Answer 11

Usually 4-7 month old lambs —> more prevalent in housed lambs (orphan)

Question 12

how does mycoplasma ovinpenumonia invade the lungs and what does it cause

Answer 12

Frequently found in nasal cavity, where it moves from ewe to lamb — then invades the bronchi

• No air exchange
• Pus
• Bronchial cuffing with immune cells

Ciliostasis

Question 13

how does mycoplasma ovinpneumonia lead to infection of other pathogens

Answer 13

Ciliostasis

Question 14

what are the clinical signs of atypical/chronic pneumonia/chronic non-progressive pneumonia

Answer 14

Mild

Reduced growth

Remember calf ‘cuffing pneumonia’

Question 15

how is atypical/chronic pneumonia/chronic non-progressive pneumonia treated

Answer 15

Generally self limiting

Most non-aminoglycoside antibiotics (even broad-spectrum penicillins)

Longer recovery than shipping fever —> a week

Question 16

how is atypical/chronic pneumonia/chronic non-progressive pneumonia prevented

Answer 16

Lower stocking densities

Avoid multiple stress events

Keep healthy sheep

Question 17

what are the causes of chronic suppurative pneumonia

Answer 17

inhalation of bacteria

Fusobacterium necrophorum

Trueperella pyogenes

Question 18

what does chronic suppurative pnuemonia cause

Answer 18

secondary bacterial infection of compromised lung tissue

hematogenous spread from septic focus

secondary to mannheimia hemolytica

Question 19

what are the clinical signs of chronic suppurative pneumonia

Answer 19

Weight loss (chronic ill thrift ewes)

Depression (depends on if the infection is walled off)

Tachypnea (compromised lung tissue)

Cough (variable, depends on whether abscess has burst)

Usually normal temperature

Smaller, slower growing lambs

Question 20

what hematogenous spread from septic focus can lead to chronic suppurative pneumonia

Answer 20

Mastitis

Metritis

Chronic lameness

Blood goes from systemic circulation into the lungs and the lungs filter it out

Question 21

why is chronic suppurative pneumonia difficult to diagnose

Answer 21

Auscultation (?)

Difficult to diagnose on clinical exam

Ultrasound may identify pleural abscess

Pleuritis, etc

Question 22

how is chronic suppurative pneumonia treated

Answer 22

Most antibiotics have some effect, however effectiveness will be improved with drugs concentrating in lungs/abscesses and having long persistence

• Macrolides
• Penstrep x2 normal dose for 14-21days (long term residues and meat withdrawal)

Most of the time you won’t succeed in treatment (unless its a valuable sheep don’t bother)

Question 23

how is chronic suppurative pneumonia prevented

Answer 23

Healthy sheep

Control the things one can and the sheep will be in a better place to control infections Pasteurella vaccination?

Question 24

what is jaagsiekte or ovine pulmonary virus

Answer 24

contagious lung tumour

Question 25

what causes jaagsiekte or ovine pulmonary virus

Answer 25

retrovirus jaagsiekte virus

Question 26

what is the incubation period of jaagsiekte or ovine pulmonary virus

Answer 26

3-4 year old sheep

Question 27

what are the clinical signs of jaagsiekte or ovine pulmonary virus

Answer 27

initial weight loss (appetite maintained) with exercise intolerance increasingly tachypneic crackles over lungfield

Question 28

what secondary bacterial infeciton does jaagsiekte or ovine pulmonary virus cause

Answer 28

mannheimia hemolytica

Question 29

how is jaagsiekte or ovine pulmonary virus diagnosed

Answer 29

“Wheelbarrow test” diagnostic — clear frothy fluid from nostrils No detectable immune response — no serological tests at present (PCR on BAL is a research technique) US: * Sharp demarcation from normal lung tissue * Lung that looks like liver is diagnostic * Secondary abscesses Post mortem confirmation of diagnosis

Question 30

how is jaagsiekte treated

Answer 30

Cull affected sheep and offspring

Question 31

why is jaagsiekte difficult to control

Answer 31

Difficult to control: Regularly inspect flock for weight loss/signs of respiratory disease Don’t buy it in (how do you tell?)

Question 32

what is shown here

Answer 32

jaagsiekte ## Footnote Consolidated lung Heavy, non compressive Not elastic Solid if cut into it Pus from secondary bacterial infection

Question 33

what is maedi

Answer 33

ovine progressive pneumonia ## Footnote Chronic respiratory disease caused by lentivirus (retrovirus) — closely related to caprine arthritis and encephalitis virus (CAEV)

Question 34

how are sheep infected with maedi

Answer 34

Sheep infected as lambs: Colostrum/milk

Question 35

what is the incubation period of maedi

Answer 35

clinical disease rare in animals \<3 years old

Question 36

what does maedi cause

Answer 36

Lymphocytic infiltration of lungs, udder (flaccid that doesn’t produce much milk), joints, nervous tissue (visna) If animal is seropositive doesn’t necessarily mean the animal will develop the disease but at risk of spreading it

Question 37

what are the clinical signs of maedi

Answer 37

Exercise intolerance Weight loss Progressive tachypnea/dyspnea or hyperpnea Indurative mastitis Arthritis (USA)

Question 38

how is maedi diagnosed

Answer 38

Detection of antibodies to Maedi Visna virus AGIDT or ELISA But there is a 6 month diagnostic gap (implications when exporting, importing, quarantine)

Question 39

what is the appearance of the lungs on PM with maedi

Answer 39

Firm Rubbery Heavy lungs Do not collapse (often concurrent Pasteurellosis or Jaagsiekte) Marks of ribs Concurrent secondary infection —\> abscessation, etc Light pink colour

Question 40

how is maedi controlled/prevented

Answer 40

Test & cull seropositive animals and offspring Artificial rearing of lambs Purchase replacements from accredited MVV-free flocks USA have a genetic test for susceptibility to disease SRUC Premium Health Scheme

Question 41

what might be the caustive agent of the lung pathology

Answer 41

post mortem maedi

Question 42

what is laryngeal chondritis

Answer 42

Abscessation of arytenoid cartilage in larynx — non-specific environmental bacteria

Question 43

when is laryngeal chondritis commonly seen

Answer 43

Terminal sire tups Higher prevalence in certain breeds: dished face breeds Texel Southdown

Question 44

what are the clinical signs of laryngeal chondritis

Answer 44

Progressive Severe inspiratory dyspnea Open mouth breathing Cyanosis Painful larynx — often die

Question 45

how is laryngeal chondritis treated

Answer 45

Early cases — corticosteroid (if in respiratory difficulties) and high dose broad spectrum antibiotic for 3-4 weeks Macrolides tracheotomy

Question 46

what is shown here

Answer 46

laryngeal chondritis

Question 47

what are other causes of respiratory signs to consider

Answer 47

lungworms nasal bots (oestrus ovis) pneumonic pasteurellosis enzootic nasal tumour inhalation pneumonia tuberculosis

Question 48

what is ovine lungworm

Answer 48

Normally non-pathogenic Controlled in young lambs with routine GI nematode treatments Adult sheep seem to develop a degree of immunity

Question 49

what species cause ovine lungworm

Answer 49

Dictyocaulus filaria Muellerius capillaris Protostrongylus sp

Question 50

what is the PPP of dictyocaulus filaria in sheep

Answer 50

5 weeks

Question 51

what is shown here

Answer 51

dictyocaulus filiaria

Question 52

what is the lifecycle of Muellerius capillaris & Protostrongylus sp

Answer 52

indirect snails and slugs

Question 53

what is shown here

Answer 53

Muellerius capillaris & Protostrongylus sp lungworm