CS: Cough

Question 1

What is ivermectin effective against? (horse parasites)

Answer 1

• Large strongyles (redworms),
• adults and 4th larval (arterial) stages of Strongylus vulgaris,
• adults and tissue larval stages of S. edentatus
• adults of S. equinus.

Question 2

What does scanty growth of E.coli from the tracheal aspirate suggest?

Answer 2

Not significant - although not a normal ‘commensal’ of the RT, this is not wholly abnormal as it is present in the GIT.

Question 3

What does a BALV with a high cellularity (36% neutrophils suggest)?

Answer 3

Should be <15% so high.

Question 4

How are RAO and IAD diferentiated?

Answer 4

Typically done on signalmnet - IAD in younger horses, RAO seems to have a genetic component unlike IAD.

BALV results:
RAO: neutrophils >15%
IAD, neutrophils, eosinophils or mast cells present.

Question 5

How should RAO be treated? 4

Answer 5

• Environment changes (reduce dust)
• Reversal of bronchoconstriction (oral or inhaled clenbuterol)
• Decrease pulmonary inflammation (oral prednisolone, a steroid, best given inhaled but can also be given IV but greater risk of side effects)
• Decrease pulmonary mucus accumulation

Question 6

Why does clenbuterol have a lower efficacy if you use with steroids such as prednisolone?

Answer 6

receptor downregulation

Question 7

How quickly does clenbuterol work?

Answer 7

within 5 minutes (but always administer any other drugs, eg. steroids, after)

Question 8

What other management changes can be made for RAO?

Answer 8

• Soak the hay prior to feeding
• Avoid round bale hay ( major cause of RAO)
• Complete commercial feeds eliminate the need for roughage.
• Hay cubes and hay silage
• Stable should not be in the same building as an indoor arena.
• Hay should not be stored overhead.
• Perhaps turn out to pasture more (day and night)
• Addition of good ventilation to the stable

Question 9

T/F: NSAID, antihistamines, and leukotriene-receptor antagonists have all failed to demonstrate therapeutic benefit in RAO.

Answer 9

True

Question 10

Side effects - clenbuterol

Answer 10

Sweating (due to action on the beta-2-receptors to relieve bronchoconstriction but these receptors are also present in skin.
Tachycardia (beta-2-receptors also present in heart)

Question 11

Side effect - systemic steroid

Answer 11

Laminitis (if you have a horse at risk of laminitis associated with systemic steroids you may consider inhaled steroids from the outset but expensive).

Question 12

T/F: there is a risk of iatrogenic cushings in horses given inhaled or systemic steroids

Answer 12

True - make sure to wean them off so there is no sudden drop but there is no protocol for this.

Question 13

What do elevated fibrinogen and SAA suggest on biochemistry results?

Answer 13

Both APPs so suggests an inflammatory problem. You can’t differentiate between septic and non-septic causes of inflammation on this basis.

Question 14

Which 2 ABs are the most protected for human health?

Answer 14

Cephalosporins and Fluoroquinolones

Question 15

What should you do if you have a bacterial pneumonia, run a culture and sensitivity test and find that the only agent that treats both bacteria that are implicated is a cephalosporin or fluoroquinolone.

Answer 15

Don’t use either as 1st line treatment. Instead use ABs that target the different implicated bacteria separately.

Question 16

What is the main side effect of gentamycin (AB) in horses?

Answer 16

nephrotoxicity

Question 17

What is the MIC for ABs for most equine pathogens?

Answer 17

4

Question 18

T/F: it is not uncommon for horses with an infection to be treated and then have an inflammatory lower airway disease.

Answer 18

True

Question 19

Treatment - bacterial pneumonia that has cleared followed by LRT inflammation.

Answer 19

Rest, environmental management, mucolytics, bronchodilators, (neutroceuticals). Steroids – own more indicated (infection cleared). Use inhaled bronchodilator and steroids because the inflammation problem is local.

Question 20

What do these results suggest ( High globulinaemia, high APPs, total WBC high )?

Answer 20

infectious cause

Question 21

Treatments - EIV - 3

Answer 21

• Rest, isolate (prevent other horses becoming infected).
• NSAIDs – the horse is sad! Flunixin, phenylbutazone (not for this horse, but it tales it out of the food chain, doesn’t mean you can’t, but it would take an income source away from this owner), meloxicam.
• ABs – prophylactic – not indicated because although dull, not eating and unhappy, it is only a small proportion of horses that will acquire a secondary infection so don’t blanket treat in the interest of AB resistance.

Question 22

What if a horse with EIV was rested during its recovery?

Answer 22

The recovery would be impacted if the horse wasn’t rested (virus kills epithelium of respiratory tract). It will maintained an inflamed state for longer –> increases risk of post-viral inflammatory state.