Page 711 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

686 CHAPTER 3

VetBooks.ir Table 3.2 Recipe to make 50 ml penicillin gel for ammonium disinfectants, 1% bleach, 70% ethanol,
iodine-based disinfectants and phenolics are effec-
guttural pouch infusion
tive disinfectants. It should be emphasised, how-
• Add 2 g of gelatin to 40 ml sterile water ever, that disinfectants become easily inactivated by
• Heat or microwave to dissolve the gelatin organic debris, and cleaning of grossly contaminated
• Cool gelatin to 45–50°C environments or surfaces with water and detergent
• Add 10 ml sterile water to 10,000,000 units sodium penicillin G should precede disinfection.
A live attenuated intramucosal vaccine has been
• Combine penicillin solution and cooled gelatin available in Europe since January 2005. In the USA
• Dispense into syringes and leave overnight at 4°C to set and Australia, bacterin, M protein and live attenu-
Note: the mixture must be warmed to body temperature before infusion. ated intranasal vaccines are available.
From: Verheyen K, Newton JR, Talbot NC et al. (2000) Elimination of The Horserace Betting Levy Board in the UK
guttural pouch infection and inflammation in asymptomatic carriers has established guidelines on strangles (http://www.
of Streptococcus equi. Equine Vet J 32:527–532. hblb.org.uk and follow the links).

gel into the pouch can be effective at elimination Prognosis
of guttural pouch colonisation in S. equi carriers The prognosis is variable. For mild disease (atypical
(Table 3.2), provided that all chondroids have been strangles) the prognosis is good. For the more severe
removed and the pouch flushed clear of any accumu- disease (classical strangles) the prognosis depends
lated pus before treatment is infused. In some carri- on whether complications develop. The majority
ers it can be a true challenge to get the inflammation of horses recover once abscesses have resolved, but
and infection in the guttural pouch under control. up to 10% of cases develop complications that delay
It is also important to note that some clinicians have recovery or may be fatal.
reservations about the use of the instilled gels.
Prevention relies on management measures. New FURTHER READING
arrivals should be kept quarantined and tested for Aceto HW, Schaer BD (2008) Biosecurity for equine
exposure to S. equi using the duplex iELISA, with hospitals: protecting the patient and the hospital. In:
any seropositive horses tested for S. equi carriage by The Equine Hospital Manual, 1st edn. (eds K Corley,
qPCR testing of guttural pouch lavages combined J Stephen) Wiley-Blackwell, Chichester, pp. 180–200.
with a nasopharyngeal swab, before admission to Boyle AG, Timoney JF, Newton JR, Hines MT, Waller AS,
the stables. Ideally, horses should have two serology Buchanan BR (2018) Streptococcus equi infections
samples performed, the first on entry to quarantine in horses: guidelines for treatment, control, and
and the second 10–14 days later, to ensure that horses prevention of strangles-revised consensus statement.
exposed just before entry to quarantine are identi- J Vet Int Med 32(2):633–647.
fied. New cases should be isolated, investigated and Caveney L, Jones B, Ellis K (2012) (eds) Veterinary Infection
treated promptly. Yards with endemic infection Prevention and Control, 1st edn. Wiley-Blackwell,
Chichester.
should screen all horses for carriage using the duplex Maxwell LK (2017) Antiherpetic drugs in equine
iELISA test to identify horses that have been exposed medicine. Vet Clin North Am Equine Pract 33(1):9–125.
and require screening to identify carriers by gut- Sellon D, Long M (2013) (eds) Equine Infectious Diseases,
tural pouch lavage combined with a nasopharyngeal 2nd edn. Elsevier, St. Louis.
swab, or multiple nasopharyngeal swabs. Quaternary www.oie.int.