Directorate Communication


National Department of Agriculture


 

TICK-BORNE DISEASES
IN RUMINANTS

Jenny Turton

        
What are tick-borne diseases?


Important tick-borne diseases in ruminants

  • Heartwater in cattle, goats and sheep

  

  • Redwater in cattle

  • Gallsickness in cattle


Which tick species transmit the different diseases?

  • Heartwater: bont ticks


Male


 Female

  • Redwater: blue ticks


Male


Female

  • Gallsickness: blue ticks, others also important (such as red-legged tick)

Male red-legged tick

 

Gallsickness can also be spread from one animal to another by biting flies and by blood on instruments and needles (eg during vaccinations, injections, dehorning and castration)


Where do the different tick-borne diseases occur?

• The diseases occur wherever there are ticks


Distribution of heartwater


Distribution of gallsickness


Distribution of redwater

African redwater--dark area
Asiatic redwater and African redwater--lighter area

 


How important are tick-borne diseases?

• Tick-borne diseases can cause heavy losses of animals

• They can prevent the introduction of high-producing animals to upgrade or replace local stock

Which animals are most at risk from tick-borne diseases, and when is disease most likely?

  • Exotic (European) breeds (tropical breeds like the Nguni and Brahman tend to be more resistant)

 

  • Older animals
  • Goats and sheep are more at risk
    from heartwater than cattle
  • Animals moved from disease-free areas to disease areas
  • Animals born in winter (not exposed to parasites when young)

 

  • Disease is most likely after good rains, because then there are more ticks

          


Signs in sick and dead animals

Heartwater

Sick animals

·         Nervous signs

- Nervous signs are more obvious in cattle than in sheep and goats

- Trouble with walking

- High stepping walking

- Unusual behaviour like walking into fences, circling, falling down, chewing movements (can look like rabies)

- Slight tapping of the forehead with a finger causes blinking

- Convulsions, with pedalling movements

·         Death
                                

Dead animals


Redwater

Sick animals

  • There are two types of redwater, namely Asiatic redwater and African redwater
  • Asiatic redwater is the more serious disease, although African redwater is probably more important as it is more widely spread. The signs are the same, although nervous signs also occur with Asiatic redwater
  • Fever (40-41,5  degrees C)
  • Pale to yellow eyes and gums
  • Red-coloured urine
  • With Asiatic redwater there could be nervous signs, with difficulty in walking and convulsions (can look like heartwater)
  • Death
  • Calves are resistant for the first 6 to 9 months of life

 

Dead animals


Gallsickness

Sick animals

  • May have a fever
  • Pale to yellow eyes and gums
  • Trouble with walking
  • Heavy breathing
  • Constipation (from rumen movements stopping)
  • Death
  • Calves are resistant for the first 6 to 9 months of life

 

Dead animals


How can you know if your animals have these diseases?

You can suspect these diseases by:

• Clinical signs in sick animals
• Appearance of dead animals

Your veterinarian or animal health technician will confirm this by looking for parasites in:

• Blood smears for redwater and gallsickness
• Brain smears for heartwater and Asiatic redwater

What other diseases can tick-borne diseases be confused with?


The only way to be sure of the disease
is to have it confirmed by tests
on the sick or dead animal


How can tick-borne diseases be treated?

Heartwater

Redwater

Gallsickness


How can tick-borne diseases be prevented or controlled?


 


For further information about the control,
recognition and treatment of these diseases,
contact your animal health technician or
state veterinarian

or

Animal Health for Developing Farmers
at the ARC-Onderstepoort Veterinary Institute
Private Bag X05, Onderstepoort 0110
 



1999

Compiled by Directorate Communication, National Department of Agriculture
in cooperation with
ARC-Onderstepoort Veterinary Institute

Printed and published by National Department of Agriculture
and obtainable from Resource Centre, Directorate Communication
Private Bag X144, Pretoria 0001, South Africa