An understanding of the enemy and how he functions makes him far less dangerous. Learn about ticks to protect your livestock.
THE BROWN EAR TICK (Rhiphicephalus appendiculatus)
The third Rhipicephalus tick is widespread and occurs in the DRC, Tanzania, the Highlands of Malawi, Zambia, Zimbabwe and Eastern Botswana. It vectors parasites that cause East Coast fever, corridor disease, gall sickness and Nairobi sheep disease. The tick itself may cause toxicosis through a mechanism that shunts toxins into the tissues of the host.
Bulls may be carriers of the parasite that causes East Coast fever and corridor disease and show no symptoms (asymptomatic).
Anaplasmosis (gall sickness)– vectored by the African blue tick, the Asiatic blue tick and the brown ear tick
Livestock born and raised in areas where the disease is endemic are usually infected when young and become naturally immune. African indigenous breeds have better resistance than European breeds to the tropical and sub-tropical tick-borne diseases.
The symptoms of gall sickness are; high fever (temperatures 40°C, 41°C), loss of appetite, pale gums and eye membranes, breathing with difficulty and constipation due to the rumen not functioning.
There is one good thing about gall sickness – if you start the treatment early you can save the animal’s life.
If the stockman checks his herd every day and has a reasonable pair of eyes and some common sense he will see when an animal first gets sick. The tick-borne diseases are not forgiving of slackness; ‘we didn’t see the animal it was in the long grass’, or a lack of diligence; ‘we knew the animal was sick but we decided to wait until tomorrow before starting treatment’ or a lack of common sense; ‘we saw she was sick but we decided to walk her back to the home kraal 3km away through the heat of the day’.
One can save animals but not like this.
Animals nine months or younger can tolerate infection but this changes with age and mature animals can succumb to anaplasmosis, especially when stressors are high at events like calving. This is something to watch out for.
Be aware that biting flies and needles can also transmit anaplasmosis. If you live in an endemic region, it is best to use a fresh needle for each animal.
Prevention is better than cure and dipping with a good acaracide (anti-tick pesticide) is a cheaper and easier option than dealing with diseases or animal mortalities. Small herds of between 10 and 20 animals can be dipped in the crush with the dip in a hand-held sprayer or by using a pour-on treatment.
Practice strategic tick control so that animals can build up some immunity.
If you can’t get a vet to help and you suspect gall sickness, keep the animal quiet, make water and food available and don’t walk it for any distance.
Good vaccines are available for animals older than nine months.
Tetracycline drugs are a frontline treatment for gall sickness. The key is to inject the sick animal/s early. Farmers will more often use a single dose of long-acting oxytetracycline injected into the neck muscle. According to the Merck vet manual it is possible to eliminate the carrier status of the animal if two long-acting injections of oxytetracyclines are given one week apart. When administering the intra-muscular injection, make sure that the drug is properly dispersed and does not pool.
Because it is difficult to diagnose which parasite is the guilty one, a combination of tetracyclines and imidocarb is often recommended by vets.
At the risk of stating the obvious, the drug companies clearly know more about their drugs than farmers do and it is really important to follow the directions on the package insert, or to take direct advice from your vet.
Equally obvious, for practical reasons, farmers must be able to administer life-saving drugs in the absence of vets.
No authority without responsibility – so use drugs wisely. Your livelihood and the livelihoods of other stock farmers depends on it.