This article is part of a series of informative animal health articles. The series goes hand in hand with the #VideoVet video series – watch the video below.

Infectious diseases in livestock pose a major threat to animal health and welfare, and their effective control is crucial for safeguarding and securing national food supplies and alleviating rural poverty. Some devastating livestock diseases are endemic in certain parts of the world, and threats from old and new pathogens continue to emerge.

With changes to global climate, agricultural practices and nations’ demography, conditions are presented that are especially favourable for the spread of vector-borne diseases into new geographical areas. Zoonotic infections that can be transmitted either directly or indirectly between animals and humans are on the increase and pose significant additional threats to human health.

What are vector-borne diseases?

Vector-borne diseases are caused by parasites, viruses and bacteria that are transmitted by vectors. These vectors are living organisms that can transmit infectious pathogens between animals, among humans, or from animals to humans.

Many of these vectors are bloodsucking insects, which ingest disease-producing micro-organisms when they take a blood meal from the animal.

Types of vectors

There are mainly two types of vectors: Mechanical vectors that spread pathogens by carrying them on the outside of their bodies, and biological vectors carrying pathogens inside their bodies.

Mechanical vectors transmit pathogens by transporting them on their feet or
mouthparts. The common housefly, for example, collects these pathogens while sitting on manure and transmits them to animals or people when it comes into contact with these new hosts.

Biological vectors, on the other hand, are involved in the life cycle of parasites or viruses, which must pass through the vector in order to mature to a stage capable of being transmitted to human or animal hosts, when a vector ingests a blood meal. A good example of a biological vector is ticks.

Disease transmission

The following are some of the most notable vectors and the diseases they transmit:

  • Mosquitoes: Rift Valley fever.
  • Flies: Transmission of lumpy skin disease.
  • Ticks: Redwater and heartwater.

Status of vector-borne diseases

Vector-borne diseases play a crucial role in both animal and human health. These diseases lead to a decrease in animal production and can cause zoonotic diseases (e.g. anthrax). Although it does not cause disease in animals, Crimean-Congo haemorrhagic fever is a vector-borne disease in humans.

Vector control strategies

The most effective ways of controlling vector-borne diseases are by controlling the vectors and vaccination. The best way of accomplishing this is by adopting a holistic
approach, which involves both chemical and biological control measures. If you want to employ a sound holistic programme on your farm, it is essential to discuss the matter with your MSD Animal Health agent.

Chemical control of vectors

MSD Animal Health has several products for chemical vector control. This includes fly control products containing deltamethrin, and products containing both deltamethrin and amitraz for the control of flies and ticks.

Delete® All

Delete® All

Delete® All: Reg. No. G2837 (Act 36/1947). Namibia Reg. No. V01/18.3.9/664 NS0.

Contains: Amitraz 2,0 % m/v, deltamethrin 0,50 % m/v, piperonyl butoxide 2,0 % m/v.
Indications: Ready-to-use pour-on for cattle, sheep, goats and game. Residual action, nonsystemic action.

  • Controls ticks, stable flies, horn flies, cattle louse flies, and nuisance flies on cattle.
  • Kills lice (biting and sucking) and mange mites and protects against blackflies on cattle.
  • Controls ticks on game.

Dosage form: Easy pour-on application along backline.

Dosage rate for cattle: 1ml/10kg.

Sheep and goats: 1ml/5kg.

Pack size: 200ml, 1Lt, 5Lt & 20Lt.

For full details, read product insert or visit www.msd-animal-health.co.za. Read previous articles in the series here.

Contact your local MSD Animal Health agent or veterinarian for more information.