2. HORSES: Strangles (Streptococcus equi subsp. equi)

Question 1

caused by

Answer 1

Streptococcus equi subsp. equi

Question 2

characterized by

Answer 2

infection of upper respiratory tract

Question 3

agent

Answer 3

-Streptococcus equi subsp. equi

-Gram +

-Beeta-hemolytic

Question 4

survives in environment

Answer 4

less than 2 month

Question 5

host range

Answer 5

horses, donkeys and mules

Question 6

distribution

Answer 6

worldwide

Question 7

more severe in

Answer 7

young horses

Question 8

majority exposed horses develop immunity

Answer 8

lasts for same or more than 5 years

Question 9

morbidity

Answer 9

-high

> higher in young horses: foals and weanlings

Question 10

mortality

Answer 10

-low

> case fatality with Tx: 1-2 %; without 9%

Question 11

transmission: excretion

Answer 11

-nasal and abscess discharge

> shedding begin 2-3 days after onset of fever, lasts for 2-6 weeks after cessation of CS

Question 12

how transmitted

Answer 12

-direct contact

-fomites

Question 13

transmission route via

Answer 13

mouth or nose

Question 14

up to 10% of affected animals become

Answer 14

carriers

Question 15

IP

Answer 15

3-14 days

Question 16

first clinical sign

Answer 16

1. fever

Question 17

other clinical signs

Answer 17

-anorexia, listlessness

-nasal discharge (serous>mucopurulent)

-LYMPHOADENOPATHY

-dysphagia

-dyspnea, stridor

-hyperemic nasal and ocular mucosa

-inconsistent cough

> other signs depend on specific tissue involvement (e.g. neurologic signs)

Question 18

why die

Answer 18

due pneumonia

Question 19

complications in 20-30% of cases

Answer 19

-e.g. chondroid formation within GUTTURAL POUCH, metastatic abscessation

-increase case-fatality rate (less 40%)

Question 20

Post mortem

Answer 20

-suppuration in internal organs- liver, spleen, lungs, pleura, peritoneum

> Chondroids in guttural pouch after CHRONIC Strangles infection

Question 21

DDx

Answer 21

-Abscessation caused by other infectious agents

-Foreign body

-Neoplasia

-Salivary gland disease

Question 22

diagnostic: material

Answer 22

-nasal swab

-nasal washes

-guttural pouch lavages

-aspirated pus

Question 23

diagnosis: in the lab

Answer 23

-culture

-PCR

-serology: ELISA
>does not distinguish between vaccine and infection response!

Question 24

treatment

Answer 24

-ABs (penicillin)

> supportive care; NSAIDs

> Long-term ABs if internal abscesses

Question 25

disease

Answer 25

highly contagious disease of horses

Question 26

in case of an outbreak

Answer 26

-Restrict movement

-Separate horses to affected, exposed and non-exposed groups

-Recovered and exposed horses should be evaluated for shedding before release from quarantine

-Compost manure and waste feed from infectious horses at an isolated location

-Contaminated pastures and paddocks should be rested for at least 4 weeks

Question 27

prevention

Answer 27

-New arrivals should be isolated for 3 weeks and screened for S. equi

-Strict hygiene practices

-Vaccination – new vaccine developed in Sweden

Question 28

vaccination

Answer 28

YES, new developed in Sweden