resp notes sheep, goats, and swine Flashcards
1
Q
Oestrus ovis
- what is this?
- signs? issues?
A
- Oestrus ovis adult flies deposit first-stage larvae that migrate through and develop in the nasal cavity of sheep and goats.
- These can result in sneezing. They occasionally become imprisoned in nasal passages or sinuses as they outgrow their escape routes.
2
Q
pneumonic pasteurellosis (sheep and goats)
- agents
- risk factors
A
- Mannheimia haemolytica, Bibersteinia trehalosi, Histophilus somni, and Pasteurella multocida cause similar diseases as in cattle.
- Predisposing causes include viral and mycoplasmal infections.
2
Q
enzootic nasal tumor (sheep and goats)
- etiology
- transmission
- clinical signs
A
- Nasal adenomas caused by a retrovirus named Enzootic nasal tumour virus
- Because the disease is contagious, multiple cases may occur within a flock
- Clinical signs are stertor, sneezing, or failure to thrive
- obstructive mass, can deform face
3
Q
septicemic pasteurellosis (sheep and goats)
- agents
- presentation
A
- Mannheimia haemolytica and Bibersteinia trehalosi > important causes of septicemia in lambs
- Affected lambs are usually found dead, with widespread petechial hemorrhages in lung, muscle, lymph nodes, and serosal surfaces
<><><><> - In young lambs, Mannheimia haemolytica typically causes concurrent bronchopneumonia and septicemia with petechial hemorrhages and/or fibrinous exudates in body cavities
<><><><> - In weaned lambs (older lambs), Bibersteinia trehalosi typically causes widespread petechial hemorrhages from septicemia, but usually without pneumonia
> digestive tract entry?
4
Q
viral pneumonia in sheep and goats - agent
A
Respiratory syncytial viruses cause disease similar to BRSV
5
Q
lentiviral pneumonia in sheep and goats
- what are these?
- diseases?
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- transmission
- presentation
- age
- lesions
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- difference between these diseases?
A
- Lentiviruses are a subfamily of retroviruses
- cause maedi-visna in sheep (also known as ovine progressive pneumonia) and caprine arthritis-encephalitis in goats
<><><><> - Maedi visna virus is transmitted to lambs by ingestion of infected colostrum, but disease manifests only in adulthood
- “Maedi” (dyspnea), “Visna” (wasting, for neurologic form, which is now rare)
- adult sheep usually more than 2 years old
- causing chronic inexorably progressive weight loss and dyspnea
- interstitial pneumonia: the lungs are diffusely pale, heavy, wet, and fail to collapse
- Bronchial lymph nodes are enlarged
- may be polyarthritis and/or mastitis
<><><><> - Caprine arthritis encephalitis (CAE)
- polyarthritis, mastitis, and/or respiratory disease
- respiratory disease is characterized by progressive cachexia and terminal dyspnea, and interstitial pneumonia is grossly similar to that described for maedi
<><><><><>
Note this difference: maedi-visna is a disease of adult sheep, whereas CAE may affect old goats or young kids.
6
Q
Ovine pulmonary adenocarcinoma
- cause?
- progression?
A
- form of lung cancer caused by “jaagsiekte sheep retrovirus”
- primary neoplasm often metastasizes within the lung but not typically to other organs
- rare in canada
7
Q
Muellerius capillaris
- what is it?
- significance?
- lesions?
- worm appearance?
A
- nematode
- common in sheep, but usually of little clinical significance
- most commonly causes clinical disease in goats
- The gross lesions are red to gray nodules in the dorsocaudal lung
- worms are not grossly visible but microscopic examination reveals numerous worms
> (In this way, Muellerius is comparable to Aleurostrongylus in cats)
8
Q
caseous lymphadenitis
- pathogen
- lesions
A
- Corynebacterium pseudotuberculosis
- Abscesses develop in lymph nodes, lung, and other tissues, and often have a characteristic laminated appearance on cut section
9
Q
inclusion body rhinitis in pigs
- pathogen
- clinical signs
- histo
A
- Porcine cytomegalovirus (Suid herpesvirus-2)
- high morbidity but low mortality in baby pigs
- sneezing and nasal discharge
- may also cause stillbirths or abortion of mummified fetuses, and might play a role in the “post-weaning failure-to-thrive syndrome”
- pathognomonic histologic lesions of epithelial enlargement (cytomegaly) and intranuclear inclusions
10
Q
atrophic rhinitis in pigs
- agent
- pathogenesis
- clinical signs
- lesions
A
- specific toxin-producing strains of Pasteurella multocida type D
- risk factors: infection with Bordetella bronchiseptica, and ammonia and dusts in the environment
<><> - Pasteurella multocida cytotoxin elicits resorption and atrophy of turbinate bone by osteoclasts
- Clinical signs are sneezing, coughing, and nasal deformity
- Secondary bacterial pneumonia
<><><><>
atrophy of the scroll-like nasal turbinates
11
Q
Actinobacillus pleuropneumoniae
- type of pathogen
- disease
- mechanism
- clinical signs
- lesions
- similar pathogen?
A
- primary bacterial pathogen
- it can cause fatal pneumonia “Contagious pleuropneumonia” without other predisposing causes
- produces toxins that cause lysis of neutrophils and macrophages
<><><><>
The clinical severity varies: death without premonitory signs; or an acute onset of anorexia, dyspnea, fever, and bloody nasal discharge; or milder signs of coughing and mild respiratory distress.
<><><><> - severe lobar fibrinous bronchopneumonia with fibrinous pleuritis, usually affecting the caudal lung lobes
- Note that this disease is the exception to the rule that the lesions of bronchopneumonia are cranioventral
<><><><> - Actinobacillus suis causes lung lesions that are identical to APP, or can cause septicemia with multifocal lesions in lung and other tissues.
12
Q
opportunist causes of bacterial bronchopneumonia in swine
- risk factors? relationship to PRDC?
- lesions?
A
- Pasteurella multocida
- Bordetella bronchiseptica
- Streptococcus suis
- Glaesserella (Haemophilus) parasuis
<><><><> - bacterial infection is often secondary to impaired respiratory following infection with Mycoplasma hyopneumoniae, swine influenza, PRRS virus, circovirus, and/or poor ventilation, temperature fluctuations, or stress
- This mix of causes is referred to as the “Porcine respiratory disease complex”
<><><><> - cranioventral lesions that are firm and red- purple, with or without fibrin on the pleura.
13
Q
mycoplasma hyopneumoniae
- prevalence
- clinical signs
- lesions
- sequelae?
- pathogenesis
A
- common infection
- Most infections are subclinical, or induce a cough that spreads slowly through the herd
- lung lesions are cranioventral, with a “fish flesh” texture that is less firm than a bronchopneumonia, and pink-tan-grey discolouration.
<><><><> - M. hyopneumoniae infection predisposes to bacterial bronchopneumonia, and PRRS
<><><><> - M. hyopneumoniae adheres to cilia, impairing ciliary function and permitting other bacteria to colonize the lung.
- M. hyopneumoniae also activates lung macrophages, which helps replication of PRRS virus and worsens this viral disease
14
Q
swine influenza
- strains
- clinical presentation
- human concerns
- lesions, histo
A
- H1N1 is the classical strain, and H3N2 H1N2 are more recent in North America
- The strains are only partially cross-protective, so vaccines must be representative of field strains
<><><><> - rapid spread of severe coughing throughout the herd, affecting all age groups, with high morbidity but low mortality
- some herds instead develop endemic pneumonia with fatalities due to secondary bacterial bronchopneumonia
<><><><> - Swine-to-human transmission is documented but rare for most strains
- concern that swine may act as “mixing vessels” whereby co-infection of a pig with a highly pathogenic avian influenza virus and a mammalian influenza virus might permit swapping of genetic material that allows the high-virulence avian virus to infect other mammals
<><><><> - cranioventral pattern of rubbery firmness and red discoloration, similar to that seen in cattle with BRSV and dogs with distemper
- Histologically, there is necrosis of bronchiolar epithelium with neutrophil infiltration, and there may be proliferation of type II pneumocytes in alveoli
