As we head into the drier months of the year, you might start to see more pinkeye on farm. Pinkeye is a common and contagious disease caused by a few different bacteria. It can result in ulceration of the eyeball which can lead to loss of the eye. It generally requires damage to the external surface of the eyeball before an infection can take hold; this is commonly caused by the eyeball scratching on dry grass, hay, or dust but even UV damage can be enough to cause it. Once the eyeball is damaged, the offending bacteria are easily spread around by flies and facial contact. Both the bacteria and the immune system ‘melt’ the surface of the eye, and a large ulcer quickly forms. It usually has a pus-filled centre with angry pink inflammation around it (see photo).
Treatment is with antibiotic eye ointment, but severe cases may need a bit more help. Anti-inflammatories(eg Ketomax or Metacam) are always helpful too. If the wound is so large that the eyeball is at risk of rupture, it is a simple surgery for the vet to come out and stitch the eyelids closed to protect the eye while it heals.
There is a vaccine for prevention of pinkeye, called Piliguard, but once an outbreak is occurring, it is often too late to vaccinate. Making sure that you are not overstocked and removing affected animals from the mob is the best way to prevent pinkeye or to reduce the severity of an outbreak.
A similar-looking disease is the damage caused by a foreign object to the eye; often grass seeds at this time of year. You will need to properly restrain the animal to have a good look in its eye and remove the grass seed. A bit of eye ointment and a shot of anti-inflammatories (eg Ketomax or Metacam) doesn’t hurt either.
Cancers of the 3rd eyelid and eye tissues are very common in dairy cattle. They occur due to UV damage and progressively grow and get worse. Cattle won’t be able to be transported if the growth/tumour is too large (over 2cm) or if it is leaking blood or fluid, so it’s best to remove them early.
When the growth is restricted to just the third eyelid, it is a simple procedure for a vet to come out and remove the cancer. When the cancer has grown into the other tissues surrounding the eye, the eye might be able to be removed entirely.
Otherwise, slaughter on-farm may be the only option. Recurrence of removed eye cancers is unfortunately fairly common. If you are unsure about whether an animal is fit for transport, ring your local Vetora clinic to get a vet out to have a look.