Diseases of small ruminant respiratory system Flashcards
history
events, herd management strategies
specifics of disease/problem
results from other animals
facilities
remove examination
stance
BCS
Normal 10-33
inspiratory (obstruction/upper airway) vs expiratory (lower airway) dyspnea
direct examination
start at front
nasal d/c, facial symmetry, airflow characteristics, LN enlargement
layrngeal stridor
loud inspiratory noise heard wtih or without a stethoscope over the trachea
indicates recued diameter of larnyx
snore or stertor
deep guttural sounds on inspiratory from vibration of pharyngeal mucosa
thorax exam
small lung fields
auscultation and percussion
friction rub
dry grating sounds resulting from inflamed parietal and visceral pleura rubbing together
What are miscellaneous sounds that can be heard in the thorax?
gut sounds
rustling of skin and hair
crepitant sounds from SQ emphysema
Thoracic percussion findings
detects lesions to a depth of about 7 cm
consolidated lesions need to be about the size of a human fist to be detectable
indicates: pneumonic lesions, abscesses, tumors, enlarged nodes, thicken pleura
may elicit pain and avoidance in animals with pleuritis
cardiac auscultation
muffled–>pneumomediastinum, thoracic abscesses, diaphragmatic hernia, thoracic neoplasia
jugular distension or pulsation, peripheral edema–>HF
CBC
bacteria inf–>neutrophils>lymphocytes, absolute neutrophilia, toxic change, hyperfibrinogenemia, dysproteinemia
eosinophilia can occur in lungworm inf
TTW and BAL
septic inflammation-increased number of neutrophils, degenerate changes and intracellular bacteria
eos suggest allergic or parasitic dz
neoplastic cells rare
radiographs
space occupying masses, reticular FB, bronchopneumonia, emphysema, pneumothorax and pleuritis
When is U/S useful?
may identify early pulmonary lesions in animals with no overt clinical signs
lung bx
usually reserved for chronic intractable lung dz
to investigate unusual rad findingsor specific lesions found with imaging
complications: epistaxis, hemoptysis, pneumothorax, SQ emphysema-occurs within 24 hours
thoracocentesis
sample of pleural fluid for cytological analysis and C&S
may be followed by drainage of remaining effusion to reduce respiratory compromise and to aid recovery from pleuropneumonia
Ruminants do not accumulate large amounts of pleural effusion, effusion is thick and fibrinous
Nasal bots etiology
Oestrus ovis
Nasal bots epidemiology
all sexes, breeds and ages of sheep
goats-less common
in warm areas, adult and larvae persist in environment
in temperate zones, larvae over winter in sheep’s sinus
Nasal bots: pathogenesis
Adults: annoyance-disrupt feeding and reduce BCS, deposit larvae in and around nostril (spring through autumn)
larvae: migrate to dorsal turbinates and sinuses and develop for weeks to months; MM infection, rhinitis and sinusitis, CNS lesions, Secondary bacterial inf, then migrate back to nostrils, expelled and pupate on ground
nasal bots: clin sxs
avoidance rxn in fly seaons
rhinitis & sinusitis causes nasal d/c, sneezing and head shaking
morbidity-80%, mortality 0
nasal bots: tx
usually not necessary
for severe cases or to prevent over-wintering of larvae
larvacidal anthelmintic (ivermectin)
nasal bots: control
pine tar on nostril
what are the majority of neoplasms in sheep?
adenopapillomas, adenomas, adenocarcinomas (contagious retrovirus)
SCC reported
no breed/sex predilection
usually occurs in yearlings to adults
Nasal adenocarcinoma: pathogenesis
uni or bilateral
benign, locally expansive
olfactory region of ethmoid turbinates
probably from Bowman’s gland
death usually within 90 d of recognition from asphyxia
Nasal neoplasia: clin sxs
inspiratory dyspnea
stridor
exercise intolerance
mouth breathing
serous, mucoid or MP nasal d/c
tachpnea
decreased airflow
head shaking/sneezing
exophthalmos, facial asymmetry
nasal neoplasia: dx & tx
endoscopy +/- bx
surgical management
Larygneal chondritis
acute obstructive respiratory condition
Texels and Southdowns
severe dyspnea and laryngeal stridor
fatal if untreated
larygneal occlusion occurs due to chronic suppurative lesions usually assoc with Arcanobacterium pyogenes within laryngeal cartilages
affects rams, ewes, lambs
Laryngeal chondritis cause
grass awns
trauma
hereditary predisposition
congenital cavitations of cartilages
laryngeal chondritis tx
tracheostomy
abx
anti-inflammatories
largyneal chondritis prognosis
guarded unless caught and treated very early
choanal atresia
congenital defect in new world camelids
caused by a membranous or osseous separation of nasal and pharyngeal cavities at the level of the choanae
open mouth breathing in crias
predisposes them to fatal aspiration pneumonia
similar to human CHARGE syndrome and results from genetic defect
don’t surgically correct breeding animals
Pasteurellosis
one of the most common causes of sudden death and of pneumonia in sheep & goats
high mortality and great economic loss
Causal organisms for bacterial pneumonia
- Mannheimia haemolytic*
- Pasteurella trehaolsi*
- Pasteurella mutlocida*
respiratory viruses (PI-3, AV, RSV) or Mycoplasma infections can lead to secondary bacterial infections
virulence factors of M. haemolytic and P. trehalosi
endotoxin
leukotoxin
capsular polysaccharide
three manifestations of Pasteurellosis
caused by M. haemolytica: septicemia & rapid death in young lambs; pneumonia in older lambs & adults, late spring, early summer, but also in store and fattening lambs in fall and winter
caused by P. trehalosi: Septicemia & rapid death in fattening and store lambs (6-9 mo) in fall and winter
clinical signs of Pasteurellosis
found dead
other separated from flock, pyrexia, respiratory effort, +/- coughing
morbidity: 10%
usually some predisposing factor: movement, handling, driving, change in weather, concurrent inf
consider clostridial dz as DDx
Tx and control of pasteurellosis
isolate affected sheep
treat affects and in contacts with abx (oxytetracycline)
consider treating with abx prior to stressful event if hx in flock
reduce stress factors
consider vax: passive protection in lambs for 3-4 weeks, recommend to vax early, ASAP after birth and 4 weeks later
non progressive atypical pneumonia
closely resembles pneumonia in fattening pig and housed calf
problem in housed or densely stocked fattening or store lamb (3-12 mo)
associated wtih PI-3, Mycoplasma ovipneumoniae, RSV, adenovirus
particularly common following mixing of lambs
non progressive atypical pneumonia clinical signs
chronic cough
ocular and nasal d/c
usually afebrile
occ acute pneumonic lamb-off-feed, listless, respiratory distress
reduced weight gain
dx of non-progressive atypical pneumonia
clinical signs
environment
necropsy
control of non-progressive atypical pneumonia
supply more fresh air
reduce numbers under one roof and in a group
divide groups by age, size and origin
abx tx during risk periods
consider Pasteurella vax
Mycoplasma Pneumonia of Goats
not contagious among adults caused by several spp of Mycoplasma
what other conditions are associated with mycoplasma pneumonia
polyarthritis
mastitis
conjunctivitis
keratitis
MAKePS syndrome
Mycoplasma mycoides ssp mycoides LC
emerged as serious cause of mortality amongst goat kids and does
3 syndromes: peracute illness with high fevers and death within 12-24 hr; CNS syndrome with opisthotonus and death with 24-72 hr, acute to subacute syndrome with high fever, multiple hot swollen joints and pneumonia
dx of mycoplasma pneumonia
isolation of organism from milk, joint fluid, blood, urine or tissue
tx of mycoplasma pneumonia
Tylosin or tetracycline may be rarely successful
artritis becomes chronic
prevention of mycoplasma pneumonia
based on maintainig herds free of inf
isolate newcomers and culture milk before mixing with herd
give heat treated milk/colostrum to newborns
cull kids with swollen joints
improve milking hygiene to reduce transmission
monthly cultures of bulk tanks
treat affected and in contacts with abx
consider treating with abx prior to stressful event if hx in herd
ear mites have been proposed to possibly disseminate the inf
contagious caprine pleuropneumonia
reportable disease
highly fatal dz of goats in Africa, Middle East and Western Asia
Mycoplasma capricolum ssp capripneumoniae
highly contagious
introduced by asymptomatic carrier or goat that is in incubation stage (6-10d)
rapid spread by inhalation
100% morbidity, 60-100% mortality
clinical sxs of contagious caprine pleuropneumonia
fever
cough
labored breathing
recumbent
contagious caprine pleuropneumonia diagnosis
Serology
latex slide agglutination assay
contagious caprine pleuropneumonia tx
tylosin or oxytetracycline is highly successful
contagious caprine pleuropneumonia prevention
prevnet introduction of carrier goats (quarantine 2 weeks) and vax
Dictyocaulus filaria
found in trachea and bronchi
time from ingestion to larvae in feces 4 weeks
heaviest pasture inf with larvae from sept to nov
larvae can overwinter to infect next seasons lambs
mainly young animal affected
pneumonia typically caudo-dorsal distribution
Dictyocaulus filaria clinical sxs
dyspnea
coughing
tachypnea
loss of weight
infection may predispose to secondary bacterial infection
Dictyocaulus filaria dx
fecal exam for L1 larvae by Baermann technique
Dictyocaulus filaria tx and control
benzimidazoles, levamisole, avermectins
move to fresh pasture
Muellerius capillaris
most common lung worm of sheep and goats
more pathogenic in goats
indirect life cycle
Muellerius capillaris: clinical signs
dyspnea
coughing
tachypnea
loss of weight
infection may predispose to secondary bacterial infections
Muellerius capillaris: dx
fecal exam for L1 larvae by Baermann technique
nodular lesions in lung
Muellerius capillaris: tx and control
can be difficult
Fenbendazole, Albendazole, oxfendazole, ivermectin
avoid wet pasture
tx before start of grazing season
Caeous lymphadenitis (CLA)
bacterial inf char by abscessation of LNs and internal organs.
Chronic, recurring dz
reduced weight gain, repro efficiency and wool & milk pdn
Causes of CLA
Corynebacterium pseudotuberculosis
inf occurs through superficial skin wounds that are contaminated with material from ruptured abscesses from other sheep
able to penetrate unbroken skin & MM
environmental contamination: rupture superficial and lung abscesses, contaminated dipping vats, shearing, handling and feeding equipment
bacteria can survive for months in hay, shavings and soil
tx of CLA
abx tx limited
drain abscess and thorough clean with abx topically
surgical resection
high rate of recurrence
prevention of CLA
young lambs should be raised isolated from infected older animals
older animals and those with abscesses should be sheared last
disinfect equipment
skin wounds treated topically and sutured
vax-reduces incidence and prevalence of dz
new animals tested
eradictation of CLA
current status of flock determined by serology
all positive animals-culled and maintain closed flock
Sheep pulmonary adenomatosis (SPA)
rare
morbidity 2%, mortality 100%
contagious adenomatous tumor of sheep lungs
caused by betaretrovirus (JSRV), foundin lung fluids, tumor and lymphoid tissue of affected sheed
incubation period up to 3 years
affects mature sheep 2-4 yo
clinical sx of SPA
severe progressive respiratory distress
without coughing
no fever, no loss of appetite
auscultation sounds: “bubbly porridge”
weight loss
Wheelbarrow test-large volumes of clear fluid flows from the nostrils-infectious
terminal stage-fulminating pasteurellosis
dx of SPA
clinical signs-wheelbarrow test
no serological test yet
necropsy-bronchalveolar carcinoma
pasteurellosis may mask presence of SPA
Ovine progressive Pneumonia (OPP or Maedi-visna)
lentiviruses
char by pneumonia, arthiritis, meningitis, mastitis
usually infects lambs
long incubation peroid
Clinical sxs of OPP
non-responsive pneumonia
dyspnea
weakness
emaciation
progressive hindquarter paresis
OPP causes
lentivirus
transmission: mainly through colostrum from dam to offspring, passed through respiratory secretions
OPP tx
no tx is curative
palliative only
cull infected animals
OPP prevention
prevent exposure of healthy sheep
isolate infected adult sheep
remove lambs of infected ewes before nursing occurs
test purchased animals
OPP eradication
blood test to determine current flock status
cull infected sheep
complete eradication-cull all positive animals, maintain a closed flock or test all incoming animals before arrival, only keep replacement ewe lambs from negative females
caprine arthritis encephalitis
lenivirus
infects monocyte-macrophage cell lines
localized to synovium, mammary gland, CNS and lung
lifelong inf
may be asymptomatic for years
transmission: via milk to nursing kids
2 major presentation for Caprine Arthritis encephalitis
1) leukoencephalomyelitis 2-6 months of age, rear leg paresis, ascending to paralysis, mild interstitial pneumonia
2) chronic hyperplastic polysynovitis-adults-more common, most does also have mammary gland involvement
dx of carpine arthritis encephalitis
AGID-using OPP virus as ag
ELISA
PCR for milk, blood and tissues
most goats become seropositive 4-16 weeks after inf
tx and px of caprine arthritis encephalitis
tx: none
px: variable, stress appears to affect the development of clinical dz
Prevention and control of carpine arthritis encephalitis
prevent of milk transmission
isolation from seropositive goats
serologic monitoring
remove kid at birth and feed heat pasteurized colostrum/milk
serologic testing of kids, remove positives
breed to CAEV negative bucks
camelid respiratory dz
little known about camelid respiratory dz
normal flora not reported
pneumonia is often a presumptive dx
very good at hiding clinical sxs
The snots
upper respiratory tract dz of camelids
nasal d/c for 3-7 d-most resolve without complications
both sexes all age groups
viral cause suspected
alpaca fever
Associated wtih Streptococcus equi subsp zooepidemicus
acute, subacute, or chronic forms
subacute: high fever and anoxeria
systemic inf:involves lungs or serosal surfaces, thoracic/abdominal cavities
death may occur in 4-8 days of the onset
