Registered Name Equivac-S Strangles Vaccine
Composition Sterile, cell free extract of Streptococcus equi adsorbed on an aluminium adjuvant which increases the level and duration of immunity. Contains no living organisms.
Actions Following administration of a primary 3 dose course, circulating antibodies reach their maximum level about 2 weeks after the last dose.
Indications Control of strangles due to Streptococcus equi in horses. (For control only; no value in the treatment of strangles.)
Precautions Other diseases may be confused with strangles. It must be emphasised that Equivac S is of value only in the control of infection due to Streptococcus equi.
The objective in carrying out a regular program of vaccination is to maintain a high level of antibodies to strangles in the blood of all horses in a herd or group to prevent the onset of an outbreak of strangles. Field experience has confirmed that control of the disease can be achieved by this means. Nevertheless, breakdowns do occur, usually under conditions where vaccinated animals are exposed to an outbreak of the disease and the challenge to immunity is great. It is not claimed that Equivac S is an absolute preventive.
See product literature for further details.
There may be settling of the adjuvant after storage but material is easily resuspended by inversion of the syringe.
Safety directions. Repeated exposure may cause allergic disorders. Wash hands after use.
Disposal. Dispose of syringes and needles by immediately placing into a designated and appropriately labelled sharps container.
Withholding Periods Nil.
Adverse Reactions Experimental work showed that the vaccine was virtually nonreactive and that signs of local irritation rarely occur in normal horses. In general, this has been confirmed by normal usage in the field. However, occasional reports have been received of local reactions to vaccination and on rare occasions systemic signs have been observed. This appears to occur when horses have been sensitised to Streptococcus equi by exposure to infection or when they are incubating the disease. Horses showing an abnormally severe reaction following vaccination should not receive further doses of vaccine for 12 months.
Local reactions are more evident if the vaccine is injected subcutaneously. Provided the injection has been carried out aseptically, any swelling which occurs at the site of inoculation should disappear in a few days.
Dosage and Administration Give by intramuscular injection in the centre of the side of the neck; clip the hair and disinfect the skin prior to injection.
Vaccination programs. Give previously unvaccinated horses and foals a course of three 1 mL doses with an interval of not less than two weeks between each dose.
Give all horses annual 1 mL booster doses, as artificial immunity has been shown to wane significantly towards the end of the year of vaccination.
Obtain increased protection by administering booster doses more frequently; consider 6 monthly revaccination in circumstances of high infection risk.
It is strongly recommended that all horses should be included in a regular program of vaccination.
Give foals a primary (3 dose) course commencing as soon as possible after the age of 3 months; maintain antibody response with regular booster doses.
It is particularly important to give booster doses prior to periods of greater risk of infection, e.g. the breeding season. Pregnant mares may be vaccinated up to two weeks before foaling.
In the event of an outbreak of strangles, segregate horses into three groups. Treat those affected by the disease, but do not vaccinate. Vaccinate horses with no known contact with the disease immediately. Observe horses known to have been in contact for seven to ten days and vaccinate only if afebrile and show no clinical signs of the disease.