Peter called and said his favourite cow was unable to open its eyes, which were also shedding tears.
He explained that both eyes had long and wide streaks of wetness all the way down to the ramus of the mandibles. The ramus is the prominent projecting back part of the lower jaw bone.
He explained the problem had persisted for two weeks, having started as frequent blinking with some tears but progressed to complete closure of the eye. I told him the issue needed my visit and physical examination. He had wanted me to prescribe some eye medicine that he could apply and further argued that if I prescribed the medicine, he would apply it and call me if it did not work.
I explained to the farmer that it was already bad enough that he had waited for two weeks before reporting the illness. Second, it was not possible for me to ask him to tell me how the eyeballs looked because the lids were not opening.
There are many causes of the situation the cow was in. It could have been a bacterial infection that made the eyes sensitive to light and hence forced the animal to keep them tightly shut. It could also be that the animal had parasitic worms in the eyes that caused inflammation and swelling of the eyelids. Though foreign body injuries could also cause the same problem, it was an unlikely possibility because both eyes were affected.
I arrived on the farm and examined the animal. Outright, I could tell the cow was in great pain. It preferred to seclude itself in a dark corner of the shed with its head lowered. Definitely, the eyes were sensitive to sunlight even though they were tightly shut.
There were no flies in the cow pen, for which I congratulated the farmer. He had effectively controlled flies using a combination of cleanliness and hygiene as well as fly catchers.
Peter said he thought cows in cowsheds without flies were protected from eye infections. I told him since his animals sometimes grazed in the compound; they could still get some flies in the pastures. Further, dust and physical injuries are also causes of eye injury and infection. I would get to know the cause of the problem after thorough examination.
I noticed the eyelids were very swollen and inverted. The eye lashes were causing injuries to both eyes. Further, eyelashes trap dust which carries infectious agents. The dust would add to the types of bacteria infecting the eye.
Additional examination revealed the eyelids in both eyes had thickened because the infection had penetrated into the tissues. There were many channels that discharged whitish, greenish and yellowish pus when I pressed. The eyeballs were heavily infected. The cornea was thickened and destroyed. There was no chance of the poor cow ever seeing again.
I first cleaned the eyes with dilute iodine solution then expressed the pus in the swollen eyelids. Further, I gave the animal an anti-inflammatory and pain-killer injection. Finally, I gave a long-acting antibiotic injection and eye drops. Peter would administer the eye drops twice daily in both eyes for five days and report progress.
I explained to Peter that it was cruel and poor animal welfare to keep an animal untreated until it lost eyesight. First, there is the pain that the animal suffers followed by permanent disability. It is important that we remember humans domesticated animals from the wild and the move denied them their self-coping mechanisms. We must always know that it is our responsibility to ensure good animal welfare at all times for animals under our care.
At the point I found the cow, it was impossible for me to determine which bacteria could have caused the infection. But from the history of tearing, sensitivity to light and reddening of the eye, I suspected it was a case of pink eye disease complicated with opportunistic bacterial infection.
The most common cause of pink eye disease in cattle is a bacterial species called Moraxella bovis. Infected animals start with tearing, then progresses to light sensitivity and finally reddening of the eye and pus discharge. Some animals may recover without treatment but most require treatment. In some cases, the infection progresses to the brain through the optic nerve and the animal dies due to brain damage.
If left untreated, pink eye disease may be complicated by infection from other bacteria that find it easy to infect the eye due to its weakening by the initial disease. The appearance of different colours of pus in Peter’s cow indicated there were at least three different types of bacteria causing the infection.
The cow was responding well to treatment by the time of writing this article but would require repeat treatment. It is good for farmers to note that delayed treatment often results in loss of organ function, increased cost of treatment, reduced production or even death of the animal.