Respiratory System part 3

Pneumonia is the disease of the ____________(organ) and is often secondary to _______________

Lung, a stressful event or a viral infection

which is the most common opportunistic bacterial invader?

streptococcus zooepidemicus

What are some signs of pneumonia

increased HR and RR, dyspnea, coughing, mucopurulent discharge, fever, inappetence, depression

How is pneumonia diagnosed

signs, TTW or BAL, CBC

How is pnemonia treated

systemic ATB based on C +s (start with Gentamicin and Penicillin)

what type of bacteria does Gentamicin attack

most Gram -

what type of bacteria does Penicillin attack

Gram +

Pleuropneumonia results in a large amount of fluid in the ____________ cavity

thoracic

what is Pleuropneumonia usually secondary to

bacterial pneumonia

what are some signs of Pleuropneumonia

depression, fever, stiff gait, shallow painful breathes, soft cough (hurts to cough)

What does it mean if a horse with Pleuropneumonia has fetid breath

indicates presence of anerobic bacteria

how is Pleuropneumonia diagnosed

thoracic ultrasonography (shows pleural effusion), thoracocentesis with C + S, CBC

how is Pleuropneumonia treated

should be managed aggressively (thoracic drainage, broad spectrum ATB, fluid therapy, NSAIDS)

what is the prognosis of Pleuropneumonia

best prog if treated within 1-2 days

What is the hallmark (pathognomonic) sign of strangles

swelling and abscessation of lymph nodes

the etiologic agent of strangles is __________

Streptococcus equi

T or F - The prolonged carrier state of strangles is rare, although some horses may remain carriers for months after clinical recovery

False- (While not every horse will become a long-term carrier, a significant proportion (around 10%) can remain carriers for months or even years after recovering from clinical signs of strangles, making a prolonged carrier state not uncommon)

what is the incubation period of strangles

3-14 days after exposure

Transmission of strangles is both by direct nose to nose contact or indirect via ____________

fomites, flies, water troughs

T or F- With strangles, abscesses become hard and painful before rupturing and draining

true

When does nasal shedding of strangles occur

2-3 days after onset of fever

What are some clinical signs of strangles

abscess formation in lymph nodes, 103° F fever, mucopurulent discharge

How is strangles diagnosed

signs, PCR, culture of nasal area or abscesses

What is bastard strangles?

when the bacteria spread from head and neck to other regions

Which sequella of strangles occurs in 1-2% of all horses and can include swelling of the head, ventral abdomen, and limb extremities

purpura hemorrhagica

T or F- there is poor immunity against strangles once a horse has had it and recovered

T, 75% develop solid enduring immunity after recovery

For how long should you consider a paddock occupied by a horse that has had strangles as contaminated

at least one month

what are 2 adverse reactions to the strangles vaccines

Purpura hemorrhagica and injection site swelling

what is the gold standard of testing before a horse is declared "clean" from strangles?

3 negative PCR tests about 7 days apart

what is the most common secondary bacterial invader of the respiratory tract

Streptococcus Zooepidemicus

How does Strep. Zoo enter the tissues of the lung

it invades after damage to the respiratory epithelium occurs

what is the most effective antibiotic for Step. zoo

Procain penicillin G

Which opportunistic bacteria affects foals 2-4 months of age

Rhodococcus equi (R. equi)

What are 2 basics predispositions of R. equi

overcrowding of foals and feces contaminated dust

T or F- respiratory signs occur very rapidly after infection with R. equi

False, slow progression of signs

On necropsy of a foal with R. equi, what will be found in the lungs

pyogranulomas (abscesses) in lungs

what are some signs of R. equi

intermittent coughing and mild mucopurulent nasal discharge, fever, depression, cyanosis, high RR

how is R. equi diagnosed

ultrasonography, radiography (shows large abscesses), tracheobronchial aspiration w/ culture and PCR test

what are 2 antibiotics used for R. equi that work synergistically (together)

Erythromycin + Rifampin

What stable managment practices should be implemented for TREATMENT of R. equi

confine in cool and clean enclosure, sprinklers in paddocks to reduce dust

What stable managment practices should be implemented to PREVENT R. equi

avoid overcrowding, remove feces, use clean paddocks for foals

what are the predisposing factors of influenza

close quarters, stess, low humidity, low temps

what is the incubation period for influenza

1-3 days

what times of year do horses seem to be most susceptible to influenza

late fall, winter, and spring

How does influenza spread

inhalation of viral particles produced by another coughing horse

what happens to the respiratory epithelium that is invaded by the influenza virus

the virus spreads on the mucous blanket and causes loss of cilia from tracheal and bronchial surfaces

What kind of cough is usually associated with influenza

explosive, harsh, dry, unproductive cough

What is the most common secondary bacterial invader to influenza

Strep. Zo

What are some clinical signs of influenza

harsh cough, fever, mucopurulent discharge (meaning secondary bacterial infection)

Is influenza initially a disease of the upper or lower airway

initially upper airway

how is equine influenza diagnosed

signs: rapid spread of disease with frequent, harsh coughing

Nasopharyngeal swab

how long should a horse with influenza be rested

minimum of 3 weeks after coughing has stopped and/or 1 week for every day of fever

when would you use antibiotics with a horse with influenza

if they also have a 2ndary bacterial infection

how long should newcomers to a farm be isolated

at least 2 weeks

how close to a competitive event is it safe to vaccinate horse from influenza

more than 2 weeks before a competitive event

what are some of the most common signs of a vaccine reaction

local edema, swelling, heat, or injection site pain

what does EHV-1 cause

abortion, stillbirths, neurological disease

how is EHV-1 trandmitted

aerosol droplets, fetal membranes, genital secretions

How long can EHV-1 live in the environment?

up to 14 days in bedding, much shorter time compared to strangles

how is EHV-1 transported to the uterus

virus might enter the WBCs and be carried by bloodstream to the uterus

what age horse is generally affected with the respiratory form of EHV-1

weanlings 4-8 months of age

Is the respiratory form of EHV-1 typically serious?

no. they will usu have an uneventful full recovery if there is not secondary bacterial infection

Are there any signs prior to abortion in horses with EHV-1?

NO

At what stage of gestation foes the mare usually abort with EHV-1

late gestation

what are some ways to prevent viral abortion of mares

avoid mare contact with weanlings, yearlings, or show horses; minimize stress, maximize immunity (vaccinate all horses or all ages)

what kind of disease results from EHV-4

major cause of acute respiratory disease

In what age group is EHV-4 most common

less than 2 years old

you should bootser the mare for the EHV viral respiratory disease ___________ (before or after) she foals

before

What is the common name for RAO

equine asthma or Heaves

what is the greatest source of dust and mold that cause an allergic response

hay

what results from airway inflammation and hyper-reactivity to stable dust/mold in horses with RAO

bronchiolitis, mucus plugging or bronchioles, airway smooth muscle contraction and hyper-responsiveness, and airway wall thickening

What are some early signs of RAO

mild nasal discharge, cough during and after exercise or while eating

what are some later signs of RAO

frequent coughing, exercise intolerance, dyspnea, heave line, weight loss

Is RAO typically found in older or younger horses

older

how is RAO diagnosed

auscultation (wheezes and crackles), endoscopy (mucus and pus in trachea), BAL (looking for inflammatory cells)

what is the number one treatment for a horse with RAO

remove them from the environment that is causing the problem.

IAD (inflammatory Airway Disease) is a problem of what kind of horse

young athletic horrses, especially if confined

what are some initiating factors of IAD

dust, transportation over long distances, strenuous exercise

what are some signs of IAD

decreased performance, coughing, mucus accumulation in airways

how is IAD diagnosed

signs, history, BAL (increase neutrophils)

how is IAD treated

Environmental management, appropriate ATB based on C + S, bronchodilators

what horses are affected by EIPH (exercise Induced Pulmonary Hemorrhage)

racehorses or horses that exercise strenuously

What are signs of EIPH

coughing, dyspnea, epistaxis is seen during or after strenuous exercise

How is EIPH diagnosed

signs, endoscopy (blood in ventral part of tracheobronchial tree after racing), BAL (macrophages containing hemosiderin)

how is EIPH treated

diuretics and nasal dilator strips

how do diuretics help EIPH

they decrease blood pressure which decreases capillary rupture