Eye infections in livestock

Livestock handlers with a pinkeye infected cow

It is important to differentiate between eye conditions in animals in order to execute the correct treatment. This Simental cow had an eye cancer which led to the removal of the whole infected eye.

 

Most farmers have raised concern over their animals getting eye infections after the rainy season.
Some of the conditions are just simple irritations of the eyes from minor injuries, to tearing of the eyes while others are worse cases with reddish eyes with pussy discharges.  
Most of these cases can be attributed to the high activities of flies common during this time.  In addition, when the dust in the kraal is too much, it is also implicated in carrying eye infections.
Let’s tackle the most common eye infections and how to deal with eye infections in animals especially in our livestock.
The most common eye infection that we deal with in livestock is a bacterial disease called pink-eye, which is scientifically referred to as Infectious bovine keratoconjunctivitis (IBD).  
This is a disease of animals caused mainly by a bacteria Moraxella bovis and other bacteria such as Listeria, Chlamydia and  Mycoplasma are also implicated. The animals are infected from other animals when they touch them, but flies commonly carry the infection faster between animals.
 The infection is specific to the type of animals where cattle only infect other cattle and goats infect only other goats.  Since pink-eye is a contagious disease that spread between animals, you will rarely find only one animal affected.
The common signs of pink-eye infection are;
•     Clear or teary discharge comes from the affected eye,   but later on become whitish/grey
•    The inside layer of the eye (mucous membrane or conjunctiva) become red. (This makes me wonder why they didn’t just call the disease “red-eye” instead of the common “pink-eye”). Conjunctivitis actually refers to the inflammation of this conjunctiva or the eye membrane.
•    The infection irritates the eye and the animal blinks a lot.
•    Affected animals also avoid sunlight and tend to stand with their heads cast down. In fact, animals feel pain when the eye is exposed to direct sunlight.
•    There is corneal opacity of the eye, meaning that in the middle of the eye you see a grey/whitish/yellowish kind of a spot which grows and covers most of the eye. Sometimes this spot turns red and swells
•    Most times the animal cannot see with the eye when the infection becomes worse. Actually, blindness is quite common in such cases.
•    In worse cases, the eye bulges out and sometimes get injured on the grass or shrubs when the animal is grazing or it can hurt when in close contact with other animals.
•    If the eye is not treated on time, it can sometime burst. It’s a sorry sight I’m telling you
Sheep and goats sometimes recover without treatment between 5-10days without treatment, but the cattle recovery period is longer up to a month. But it is better to treat affected animals and not wait for self-recovery. You never know when the infection will overload the immunity of the animal and causes blindness or the loss of an eye.  
There are a variety of treatments for eye infections and irritations ranging from eye drops, powder and ointments. However, for general treatment, it is important to always wipe affected eyes with a wet soft cloth around the eye to remove excessive dirt and to flush the eye out with clean water and treat it with an antibiotics. Most antibiotics preparations for eyes comes in practical prepackages that are easy to use for farmers but other treatments need prescriptions from veterinarians while others can only use under veterinary supervision.
At vet school the preferred antibiotic was penicillin mixed with streptomycin (Pendistrep®) + a bit of dexamethasone. All these drugs usually need a prescription from a vet. The best method of administering this mixture is what we call the sub-conjuctival injection. In this type of injection, you inject the antibiotic and dexamethasone mixture in the thin layer covering the inside of the eye with a small needle. It is a highly sensitive method of injection and is not recommended to anyone who doesn’t have the right. But it is worth learning how to do and next time asks your vet to show you how.
I’m not that much a fan of eye powders because you have to put it in the eye like 3 times a day and farmers rarely get to do that. But if you are sure you can handle your animal more than ones a day for 3 days consecutively to place powders, then go for it. But, what I rather advise farmers is to put eye treatment such as PRED FORTE® drops, Eye-C drops, Exocin® eye ointment or drops. In case of any doubt veterinary personnel will advise you on the best treatment for your animal.
I can testify that mastitis (udder infection) antibiotic ointment is effective in treating eye infections. These are those little tubes that squirt into the teats of an infected udder quarter. I hear of cases where farmers in the villages sometimes put drops of the usual injectable antibiotics straight in the eye when they don’t have the right eye treatments like powders, ointments and drops. To this I would advise them to rather dilute one part antibiotic and one part water and put a few drops in the eye. The antibiotics are a bit strong to be placed directly in the sensitive eyes. They might cause some burning, stinging, irritation, itching, redness, blurred vision, eyelid itching and eyelid swelling.
Traditionally we hear a lot of stories on how to treat eye conditions such as putting sugar in the affected eye, placing menthol sniff  and my utmost least favorite of grinding a piece of glass finely and place the glass powder in the eye. Of course farmers swear by these methods but I would say this should be used with caution because, eish- putting glass in the eye?
Even though it is important to rule other confusing (differential diagnosis) eye conditions that could be an irritation or when there are foreign bodies in the eyes or diseases such as infectious bovine rhinotracheitis (IBR) and malignant catarrhal fever, most eye infection treatment protocol is similar. However, for other eye conditions such as cancer (squamous cell carcinoma) the treatment requires veterinary intervention where the affected eye can even be removed.
Other precautions of handling animals affected with eye infections is to try keep them out of direct sunlight, control flies around animal housing/kraals.