Understanding the disease that makes animals cry
Sometimes disease case descriptions that land on my desk can be hilarious.
You see, the farmer reports what she observes, translating it according to her understanding. And my non-medical operations coordinator has firm instructions to record the cases exactly as reported.
This is to ensure the details are captured as seen by the farmer to avoid any loss of important information.
A few days ago, I came out of surgery and Emily, my operations coordinator, informed me a farmer from Kiambu had reported her cows and goats were crying. They were producing copious tears and then some would lose their eyesight. They had been treated many times with injections but the problem had persisted. “Can I call Veronica for you to confirm what she means by animals crying?” Emily asked. She obviously was not comfortable with the crying allegation.
I told Emily I understood Veronica meant production of a lot of tears and not the emotional act of crying. I followed the directions given and arrived at Veronica’s farm on the outskirts of Kiambu town half an hour later.
“Thank you doctor for coming. Call me Vero,” Veronica told me as I prepared to examine her animals.
The farm was a zero-grazing unit for both goats and cows of mixed breeds and it was evident Vero’s intention was milk production from both animals. She told me she kept the mixed breeds because she had been informed they eat less than the pure breeds and they produced a fairly good amount of milk. I concurred with the farmer, but added a caveat, “Mixed animals are in low demand and fetch poor prices even when their production is good.”
About half of Vero’s goats and cattle were heavily tearing in one or both eyes and they kept the affected eyes closed or were frequently blinking. Signs of pain such as tightly shutting the eyes, lowering the heads and sad appearance of the face were visible in many of the sick animals.
In some cases, the eyes were also swollen. Five cows, which Vero said were the initial cases, had very red eyes that discharged yellowish pus. They were eating poorly, had lost weight and reduced milk production.
Vero told me the disease had been ongoing for about 10 days. She had brought in three new cows and two goats about seven days before the outbreak. An animal health service provider in the locality had referred Vero to me after the treatment he had given failed to work.
From the presentation of the disease and the case history Vero narrated, it was obvious the animals had an attack of pinkeye, otherwise known medically as Infectious keratoconjunctivities.
I changed the medicines the previous service provider had used and offered a combination of antibiotic eye ointment and intramuscular injections on all the sick animals.
I also identified some cases that were in the early stages of the disease and treated them as well. I explained to Vero I would repeat the treatment for three consecutive days.
Pinkeye is a common disease in both goats and cattle and may affect up to 80 per cent of animals in the herd. The disease spreads fairly quickly in the herd once the first case appears. The occurrence on Vero’s farm is the typical manifestation of pinkeye. If untreated, it may progress to large ulcers in the cornea, pus in the eye and even lead to rupture of the eye ball. Left untreated, about 10 per cent of the animals may recover naturally but the rest progress to partial or complete blindness.
The disease in cattle is caused by a bacteria called Moraxella bovis while in goats it is caused by organisms called Clamydia and the bacteria Mycoplasma conjunctivae. The multiplicity of causative agents means that the success of treatment depends on laboratory isolation of the disease-causing organisms or the use of a combination of drugs known to kill all the varieties of causative agents. There is no vaccine for the prevention of pinkeye.
Pinkeye spreads rapidly in the herd through contact of sick animals with healthy ones or is spread by people and flies. A person who sees a cow tearing may examine the animal to see if there is injury in the eye and then touch another animal’s eye and spread the disease. Flies are attracted to eye secretions on which they feed and then transmit the disease agents to other animals.
Some animals carry the pinkeye organisms in their nose and vagina without exhibiting any signs of disease. When flies feed on secretions from the two organs, they pick up the disease organisms and transfer them to the eyes of the same or different animals where they cause the active disease. That is why pinkeye may break out in a herd even when no animals have been introduced from outside.
Pinkeye is best prevented through good hygiene, by cleaning and disinfecting the animal houses, good disposal of manure and other waste and good fly control, both on the animal and their dwellings. The animals may be regularly treated with pyrethroid insecticides which stay on the skin for extended periods of time and kill flies as they land on the animal.
Fly control chemicals and traps can also be strategically placed in the animal houses. Care must, however, be taken not to expose the livestock to the chemicals. New animals should be sourced from herds free of pinkeye disease and be kept isolated from the resident herd for at least three weeks once they arrive on the farm.
I gave Vero’s sheep and goats a three-day treatment and they responded well. However, due to the damage that had occurred in the eyes of some of the animals, it will take several weeks before they fully recovered. Pinkeye is best treated as soon as it is detected.