Infectious lower respiratory disease

Question 1

what are the common three clinical signs of infectious disease?

Answer 1

groups effected
pyrexia
dull/inappetence

Question 2

what clinical pathology can be done to aid diagnosis of infectious disease?

Answer 2

haematology - white cell count, acute phase proteins

Question 3

what are the main positive acute phase proteins?

Answer 3

serum amyloid A
fibrinogen

Question 4

which acute phase protein increases the quickest in response to infection?

Answer 4

serum amyloid A

Question 5

what is the main issue with testing for antibodies for an infection?

Answer 5

have to allow time for them to increase

Question 6

what is the morbidity and mortality of equine influenza?

Answer 6

high morbidity and low mortality

Question 7

what are the subtypes of equine influenza based on?

Answer 7

surface glycoproteins (H and N)

Question 8

what are the surface glycoproteins of equine influenza?

Answer 8

haemagglutinin
neuraminidase

Question 9

what is the main strain of equine influenza?

Answer 9

H3N8

Question 10

why aren’t vaccines effective against equine influenza?

Answer 10

display antigenic drift (always developing)

Question 11

how does equine influenza effect the ciliated epithelium of the trachea?

Answer 11

strips it of cilia, so the respiratory tract loses the ability to defend itself

Question 12

what is the incubation period of equine influenza?

Answer 12

1-5 days

Question 13

what are the clinical signs of equine influenza?

Answer 13

fever (up to 41°C)
cough (dry/moist)
oedema/hyperaemia of trachea
nasal discharge (serous/mucopurulent)
lethargy/inappetence

Question 14

what type of cough is seen with equine influenza?

Answer 14

dry that turns into a moist cough

Question 15

what type of nasal discharge is seen with equine influenza?

Answer 15

serous that turns into a mucopurulent

Question 16

how long does it take for a horse to recover from equine influenza?

Answer 16

1-3 weeks (unless secondary infection)

Question 17

what initially happens to the white cell in equine influenza cases?

Answer 17

lymphopaenia (neutropaenia)

Question 18

what happens to white cells after the initial lymphopaenia in equine influenza?

Answer 18

monocytosis
neutrophilia

Question 19

what happens to fibrinogen levels in equine influenza?

Answer 19

hyperfibrinogenaemia

Question 20

how is equine influenza diagnosed?

Answer 20

looking at rising antibody titre over 2-4 weeks (should quadruple)

Question 21

why does care need to be taken when measuring antibody titre to diagnose equine influenza?

Answer 21

if they are vaccinated it can effect the results

Question 22

when is the best time to swab the respiratory tract for equine influenza?

Answer 22

2-5 days after infected (highest level of shedding)

Question 23

how is equine influenza treated?

Answer 23

supportive - hydration, NSAIDs…
antibiotics if secondary infection present

Question 24

how long should a horse with equine influenza be rested for?

Answer 24

1 week off work for every day they are pyrexic

Question 25

how is equine influenza spread?

Answer 25

respiratory route, especially via direct contact

Question 26

how long can equine influenza survive in the environment?

Answer 26

36 hours (easily killed by disinfectant)

Question 27

why can't we prevent horses diagnosed with equine influenza from moving off the yard?

Answer 27

the disease isn't notifiable

Question 28

how long can horses excrete equine influenza for after they become infected?

Answer 28

up to 8 days

Question 29

how is equine influenza managed?

Answer 29

isolate and monitor pyrexia disinfect and separate all equipment

Question 30

how many foals are exposed to equine herpesvirus 1 and 4?

Answer 30

most exposed and seroconvert

Question 31

when is equine herpesvirus 1 and 4 shed?

Answer 31

at times of stress (is a latent infection)

Question 32

what forms of disease does equine herpesvirus 1 cause?

Answer 32

respiratory abortion neurological

Question 33

where is equine herpesvirus 1 and 4 found latently?

Answer 33

trigeminal ganglia and lymph nodes

Question 34

how severe is the respiratory disease caused by equine herpesvirus 1 and 4?

Answer 34

mild

Question 35

what are some examples of mild respiratory disease?

Answer 35

adenovirus, rhinovirus, herpes virus...

Question 36

what are the features on haematology of acute respiratory virus infections?

Answer 36

decreased neutrophils and lymphocytes

Question 37

what are the features on haematology of mild viral infections? (after the acute lymphopaenia)

Answer 37

lymphocytes increase (lymphocytes go higher than neutrophils - reverse differential)

Question 38

what is Rhodococcus equi also known as?

Answer 38

rattles

Question 39

what horses is Rhodococcus equi seen in?

Answer 39

3 weeks to 6 month old foals

Question 40

what bacteria is Rhodococcus equi similar to in human?

Answer 40

Tuberculosis

Question 41

what does Rhodococcus equi cause?

Answer 41

pyogranulomatous pneumonia

Question 42

how is Rhodococcus equi treated?

Answer 42

long cause of antibiotics (hard to get rid of)

Question 43

what antibiotics are usually used to treat Rhodococcus equi?

Answer 43

macrolide or rifampin

Question 44

why is Rhodococcus equi so hard to treat?

Answer 44

lives intracellularly within macrophages causing pyogranulomatous lesion that are difficult for antibiotics to penetrate

Question 45

what is Streptococcus equi var equi also known as?

Answer 45

Strangles

Question 46

why is Streptococcus equi var equi called strangles?

Answer 46

causes a massive swelling of submandibular lymph node causing strangling of horse

Question 47

how is strangles spread?

Answer 47

through direct nose/mouth contact and fomites

Question 48

where do strangles carriers harbour the infection?

Answer 48

guttural pouch

Question 49

why is isolating strangles useful?

Answer 49

it is an obligate pathogen that isn't part of normal flora so you know it is a significant finding

Question 50

what is the incubation period of strangles?

Answer 50

3-14 days

Question 51

what are the early clinical signs of strangles?

Answer 51

depression/fever mucoid nasal discharge cough anorexia/difficulty swallowing mild pharyngeal swelling

Question 52

in relation to shedding, when do the first clinical signs of strangles present?

Answer 52

2-3 days before shedding (pyrexic before they start shedding)

Question 53

what are some clinical signs of strangles after the initial signs?

Answer 53

purulent nasal discharge lymph node enlargement

Question 54

what is the most common site for lymph node enlargement associated with strangles?

Answer 54

submandibular and retropharyngeal

Question 55

where does strangles spread to if the retropharyngeal lymph node access ruptures?

Answer 55

guttural pouch

Question 56

what happens if strangles enters the guttural pouch due to rupture of retropharyngeal lymph nodes?

Answer 56

chronic guttural pouch empyema leading to chondroids

Question 57

what are some possible complications of strangles?

Answer 57

cellulitis and local tissues damage pneumonia and abscessation immune mediated myositis/myocarditis purpura haemorrhagica bastard strangles

Question 58

what is purpura haemorrhagica in regards to strangles?

Answer 58

type III hypersensitivity caused by a strangles and antibody complex implanting onto a capillary bed and being attacked by the immune system and damaging the vessel wall

Question 59

what is a type III hypersensitivity?

Answer 59

an antibody-antigen complex

Question 60

what is bastard strangles?

Answer 60

strangles causing abscesses in lymph nodes not in the head

Question 61

how is strangles diagnosed?

Answer 61

clinical signs nasopharyngeal swabs/lavage guttural pour wash rising antibody titres

Question 62

how can you confirm a horse is free from strangles?

Answer 62

3 negative nasal swabs (3 successive weeks) 1 guttural pouch washes

Question 63

how is strangles treated?

Answer 63

symptomatic (NSAIDs...) soft, wet feed hot pack abscess flush abscesses (antibiotics)

Question 64

should antibiotics be given to strangles cases?

Answer 64

not if there is developing abscesses in lymph nodes as it delays the maturation of abscesses and prolongs the disease

Question 65

what is the best antibiotic for strangles?

Answer 65

penecillin

Question 66

what is the best way to prevent strangles?

Answer 66

quarantine new animals for 3 weeks

Question 67

is there a vaccine for strangles?

Answer 67

yes - modified live

Question 68

what is inflammatory airway disease?

Answer 68

mold/moderate equine asthma