Most of the UK has had an usually dry Spring and we’ve received several calls from customers about summer sores appearing on horses mouths already.
Fern is a 7 year old Dales pony in good health and condition, who has always been very sensitive to flies. In August of 2024 she got a summer sore for the first time.
Summer sores are caused by the larvae of stomach worms, specifically Habronema species, being deposited on the skin by biting flies. The lavae survive where there is moisture and try to burrow into the skin tissue, resulting in a raw, swollen lesion.
Fern was on pasture that was not dung picked but had a fly rug on whenever she was turned out along with copious fly spray. In August 2024 she developed a sore on her bottom lip.
Fern was treated and the yard paddock management has since improved. While she is the picture of good health, sadly this Spring, Fern's owner spotted some summer sores on her hind legs while giving her a bath! We believe that they're not around her mouth this time as Fern has been wearing a grazing muzzle which allows limited access to flies.
TREATMENT
Fern was treated internally with an ivermectin wormer as well as some of the wormer being applied topically to the sore for 3 days initially.
Biteback Sweet Relief Silver Cream was used after that twice daily to help heal the sore.
This treatment was successful, however in severe cases steroids and antimicrobials may be prescribed alongside this by your vet to reduce inflammation and treat secondary infections.
Takeaways
- Once a horse has had it they are likely to be more susceptible to getting them again in the future, depending on weather and the fly activity
- While one horse’s infection doesn’t directly spread to another, the presence of flies and the overall risk of infection exists for all horses on that property.
- Those that are very sensitive to flies e.g have sweet itch or are hyper-sensitive to flies are mainly affected, especially darker horses with white socks.
- Adhering to strict fly control measures is the best way to prevent summer sores and the prevention of Cutaneous Habronemiasis disease.
- Regular (at least twice weekly) poo picking of pasture to remove the infected dung that contains the stomach worms and/or fly larvae.
- Stable horses during times of peak fly activity or use fly rugs, masks and repellent as appropriate for the horse/environment requirements.
- Remove and dispose of manure & soiled bedding and wet feed that can breed stable flies.