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Livestock disease - Agriculture Form 3

Suggested Learning Activities

1.Visit neighbouring farms and find out the main diseases that affect livestock and how the local farmers control them.
2.Carry out appropriate feeding practice as a control measures of disease. 3.Collect information on general symptoms of each disease observed and the type of animal they attack.

Background information.

Before learners begin this lesson they should have covered causes of livestock diseases and various methods of disease control. Examples of disease control include:

  • Vaccination,
  • Proper housing,
  • Vector control,
  • Use of prophylactic drugs,
  • Proper feeding.

Causes of livestock diseases.

Livestock diseases are mainly caused by pathogens namely bacteria, protozoa and viruses. Apart from pathogens, livestock diseases can also be caused by nutritional disorders, physical injuries, parasites, poisons and genetic disorders.

Methods of disease control

Generaly disease in livestock can be controlled through practicing farm hygiene, vaccination, good feeding and vector control.
Specific methods of livestock disease control include good feeding, fencing, proper disposal of dead animals, implementing quarantine by the government, isolation of the sick animals and timely treatment should be offered when the animals are attacked by disease.


1.Anaemia: -Lack of adequate blood in the body of livestock. 2.Blood serum: -A clear liquid which separates from blood when it is allowed to clot. 3.Bursa: -A pouch or sac especially the sac enclosing tendons (and ligaments)where they are attached to bones. 4.Coccidiostat: - A drug or substance used to prevent the multiplication of coccidia. 5.Emaciated: -Reduced in flesh,thin,starved looking. 6.Immunity: - Property by which organisms resist infection by the production of antibodies. 7.Intravenous: -Within or into a vein. 8.Lachrymation: -Secretion and discharge of tears. 9.Lactation: -Milk production in livestock. 10.Lesion: -Any pathological or traumatic abnormality in a tissue. 11.Orchitis: -Inflammation of the testes. 12.Pathogen: -A disease producing micro-organism. 13.Prophylactic: -Pertaining to the prevention of diseases. 14.Rigor mortis: -Stiffness of the body muscles in carcasse. 15.Rumen: -The first and largest of the four stomachs of a ruminant. 16.Quarantine: -Restriction of livestock movement by the government especially in the event of disease outbreak. 17.Species: -A category used in the taxonomic classification of living organisms which is subordinate to a genus. 18.Staring coat: -A symptom in which the hairs of the coat instead of lying flat and being smooth and shinny, are standing up with the ends clear of each other and are dull. 19.Traumatic: -Pertaining to injury,especially to injuries of mechanical rather than disease origin. 20.Vaccine: -A suspension of killed or attenuated micro-organisms,or of products derived from them,which an injection stimulate the production of antibodies against the disease which the micro-organisms cause. 21.Vector: -A carrier especially the arthropod which carries an infective agent from one host to another. 22.Zoonotic: -A disease which is transmissible between animals and man.

Topic objectives

By the end of this topic, you should be able to;

  • Describe causes and vectors of main livestock diseases.
  • State the incubation period .
  • Describe the signs and control measures of each disease.
  • State the predisposing factors where applicable.
  • Demonstrate a caring attitude towards livestock.

Livestock Health III (Diseases)


A livestock disease is any alteration in the state of the body of the animal or its organs which interferes with the proper performance of its functions. One cause of low production in livestock is infection by various diseases. Farmers must therefore have knowledge of common diseases that affect livestock.

Protozoan Diseases

Protozoa are unicellular organisms capable of causing diseases in livestock. Common examples of protozoan diseases include Trypanosomiasis, Anaplasmosis and East Coast Fever.

Other diseases caused by protozoa include;

  • Coccidiosis
  • Nagana.

East Coast Fever.

East Coast Fever is caused by protozoa known as

Theileria parva

which is transmitted by brown ear tick. It mainly attacks cattle and has incubation period of 15 days .East Coast is mainly characterized by the swelling of lymph nodes especially those around the base of the ears, shoulders and stifle joints. High fever, profuse salivation, a lot of tears coming out of the eyes. Coughing and difficulty in breathing are also common among infected animals.

Control measures of East Coast Fever

Control of East Coast Fever requires rigid control of the vector tick. All animals moving from non-enzootic to enzootic areas, and particularly non-zebu cattle should be totally prevented from being infested by ticks. East Coast Fever can be control through treating infected animals using appropriate drugs and through effective control of ticks


Coccidiosis is caused by Coccidia of Eimeria species.It affects mainly poultry, calves, kindlings, kids and lamb. Major symptoms of coccidiosis include rough plumage, drooped wings, dysentery and dullness in infected animals. Coccidiosis has an incubation period of 7 days to 4 weeks.


Trypanosomiasis affects cattle, pigs, sheep and goats. It is caused by protozoa Trypanosoma species transmitted by tsetseflies .Incubation period of trypanosomiasis is 1-3 weeks.

  • High fever
  • Dullness and loss of appetite.
  • Lachrymation.
  • Swollen lymph nodes.
  • Loss of hair at tail end and reduction in milk production.
  • Anaemia and Rough coat.


Anaplasmosis is caused by a protozoa Anaplasma marginale transmitted by Blue tick(Boophilus decolaratus). Anaplasmosis has an incubation period of 3-4 weeks and can be transmitted through contaminated surgical instruments and hypodermic needle. Anaplasmosis is characterized by anaemia, constipation, high fever and low production of milk in lactating cows.

Bacterial Diseases

These are diseases caused by bacteria. Examples include mastitis, contagious abortion, foot rot and anthrax. Examples of other bacterial diseases affecting livestock are scours, blackquarter and pneumonia. It mainly attacks cattle, sheep, goats and pigs.


This is an infectious disease of the mammary gland which can be acute or chronic. Mastitis is characterized by inflammation of the udder,presence of pus in milk, death of infected quarter and during suckling, the animal kicks due to pain.

Predisposing factors of Mastitis

Predisposing Factors are those factors that lead to an animal attracting a disease. In mastitis they include age, stage of lactation period, type of udder attachment and poor sanitation. Among the important predisposing factors of mastitis is the poor milking technique, which may result in mechanical injury of the teats and weakening of the sphincter muscles of the teat. This leads to mastitis attack since the pathogens can easily enter through the wounds.

Control measures of Mastitis

Effective control of mastitis requires strict cleanliness within the dairy shed. Detecting mastitis using a strip cup and immediate treatment of wounds especially on the udder are known to stop the spread of the disease. Other control measures against mastitis include using the right milking techniques, teat dipping, improved farm hygiene and prevention of wounds on the teats.

Foot rot.

Foot rot is an infectious and contagious disease which affects all cloven hoofed animals for example cattle, goats and sheep.It is caused by bacteria of the

Fusiformis family.

In sheep attacked by foot rot disease,the foot becomes swollen,limp while walking and rotten smell coming out of the hooves.In most cases,the sheep is found lying or kneeling when grazing.

Control measures of Foot rot.

Control of foot rot can be effectively achieved through provision of a clean environment, foot examination and trimming, wound treatment and grazing sheep in dry pasture fields. Apart from hoof trimming, foot rot can be controlled through farm hygiene, use of footbath, wound treatment and isolation of sick animals.

Fowl Typhoid.

Fowl Typhoid

is caused by

Salmonella gallinarum

and it attacks domestic birds eg chicken, turkey and Ducks. Fowl Typhoid is characterized by depression, dullness, greenish yellow diarrhoea, anaemia and drooping wings in birds.

It can be controlled through proper disposal of carcass, regular vaccination, improving hygiene in poultry house and obtaining chicks from reliable sources. Infected birds can be treated using sulphur drugs mixed in water or in mash.

Contagious abortion

Contagious abortion is characterized by spontaneous abortion, retained placenta, low libido and orchitis in bulls. A yellowish brown, slimy, odourless discharge from vulva may occur after abortion. Contagious abortion is caused by

Brucella abortus

in cattle,

Brucella suis

in pigs and

Brucella malitensis

in goats and sheep.

Control measures of contagious abortion

Contagious abortion can be controlled through Artificial insemination,culling,proper disposal of carcase and vaccination.When contolling contagious abortion,the attendant should avoid contact with the aborted foetus.Blood test should be done in breeding animals to detect infected ones and hygiene must be maintained in livestock houses.

Bacterial scours.

Bacterial scours attacks calves, piglets ,lambs and kids. It normally attacks young animals in their first week of life. Unhygienic condtions and poor feeding do expose the young animals to bacterial scours. Symptoms of bacterial scours include white or yellowish diarrhea, pungent smell of faeces, high fever, loss of appetite and sunken eyes. Restlessness and presence of undigested milk and mucus with blood spots in faeces are noticed in infected livestock.

Control measures of Bacterial scours

Bacterial scours can be controlled through maintaining farm hygiene, ensuring dry floor in livestock houses, and disinfecting calving pens. Replace the feeding of milk with warm water mixed with glucose for the first 3 days as soon as the first symptoms are observed. Ensure raised floor in calf houses and have separate attendants for the infected calves in order to avoid spread of bacterial scours. Infected calves should be promptly treated with appropriate antibiotics.

Black Quarter/black leg.

This is an infectious disease which affects all ruminants animals, aged between 8-18 months old cattle, sheep after shearing and goats. Black Quarter is caused by a bacteria known as

Clostridium chauvei


Chauvei septicum

which is spore forming. It is found permanently living in the soil and it is difficult to eradicate once prevalent in a place.

Symptoms of blackquarter

Black quarter is characterised by high fever, lameness, swelling of the affected body parts, loss of appetite and dullness in infected livestock. It can be controlled through vaccination, proper disposal of the carcase treating infected animals with antibiotics. Heavy and faster breathing is common among infected animals. Also common is grinding of teeth, blood oozing from nose and anus of the carcase, muscles of dead animals appearing dark when cut, the sick animals stopping chewing the cud. Bloody froth having smell of rancid butter and crankling of the swollen parts are common symptoms in blackquarter.


Anthracis found in the faeces of the infected animals .Anthrax is associated with the swelling of the underside of the body and high fever. There are blood stains in faeces and milk and swelling in the throat especially of pigs. Carcase lacks rigor mortis and produces tar- like watery blood through the orifices. Spread of the anthrax can be prevented through proper disposal of carcase, Quarantine and vaccination.


Pneumonia is cased by bacteria

Mycoplasma mycoides.

It affects young animals mainly calves, kids, lambs, piglets and poultry. Factors which predispose pneumonia include poor ventilation, overcrowding, young age and effects of diarrhoea and other illnesses. Pneumonia is characterized by dullness, loss of appetite, rough hair coat, rapid breathing, emaciation. nasal discharge of mucus and reluctance to move in livestock. Abnormal lung sounds, coughing when chest is pressed and fluctuating body temperature are common in infected livestock. Ensure farm hygiene, isolation of infected animals, provision of warmth in livestock houses and treatment using appropriate antibiotics to control pneumonia in livestock production.

Viral diseases

These are diseases caused by viruses. They include rinderpest, foot and mouth disease, Newcastle, fowl pox, Gumboro and African Swine Fever.Viral diseases are caused by viruses. Common examples among livestock are Gumboro, Foot and mouth disease and Newcastle.

A diagram of a cock infected by fowl pox showing lesions on the comb.

Newcastle diseases

Newcastle diseases is highly is contagious and infectious disease. It mainly affects poultry at ages of three months and one year and has incubation period of 5-7 days. Affected birds show difficulty in breathing, lack appetite, are dull and have beaks which remain wide open and strained necks. Major symptoms of Newcastle in poultry include nasal discharge which forces the birds to shake their heads ,eyes closed all the time ,staggering motion, and production of watery greenish diarrhoea. production of soft shelled eggs and drooping wings are noticed in birds that are infected by Newcastle. To control Newcastle farmers are advised to kill all infected and incontact birds. Poultry house should be cleaned and disinfected before bringing in new flock. Vaccination and quarantine have been effective in controlling Newcastle.

Fowl pox

This is an infectious disease of poultry. Animals affected include chicken, turkeys, pigeons and other birds. It is caused by a virus known as

Avian fox

which has an incubation period of 3- 14 days. Presence of wounds and biting insects can expose the birds to fowl pox disease. In birds affected by fowl pox there are lesions on combs, and wattles. In severe cases birds lose appetite, become dull and their eyes and nose discharge watery fluid. Fowl pox can be effectively controlled through vaccination and mass slaughter of infected and incontact birds.

Gumboro disease

Gumboro attacks chicken ,turkey pegions and ducks. It is caused by Birna virus and has incubation period of 2-3days.In birds infected by Gumboro there is swelling of the vent ,decrease in egg production, respiratory distress and loss of appetite. Affected birds by Gumboro show low water intake, severe immune suppression and high mortality rate especially in hot weather and humid conditions. It can be controlled through vaccination and proper feeding involving vitamins especially Vit. B12.

African Swine Fever.

African Swine Fever is a highly contagious, infectious and fatal disease of domestic pigs. It is transmitted through direct contact with infected farm structures and reservoir. It is caused by

Irido virus

and has incubation period of 5-15 days. Symptoms of African Swine Fever include high fever, lack of appetite, general body weakness, coughing and nasal discharge. African Swine Fever can be controlled through vaccination, quarantine, proper disposal of infected pigs and double fencing to keep off wild animals. There should be no consumption of pork from pandemic areas to avoid spread of the disease to man.


Rinderpest is highly infectious and a contagious disease. It is a viral disease which mainly affects cloven hoofed animals eg cattle, sheep, goats and pigs. Livestock attacked by rinderpest are characterized by high fever, eyes appearing watery, discharge in mouth and nose, grinding of teeth, diarrhoea and are emaciated. The incubation period of rinderpest is 3-15days.It can be controlled through vaccination every 6months.Quarantine and mass slaughter of affected and incontact animals are also effective measures against rinderpest.

Nutritional Diseases

These are diseases as a result of poor feeding in livestock .They include milk fever and bloat. Nutritional diseases are non infectious and may affect various
Farm animals for example lactating cows.

Milk fever.

Milk fever is caused by low calcium levels in blood. It mainly occurs in high producing cows. Milk fever mainly attacks cows that have recently calved and are high milk producers. Goats and pigs in similar conditions may be affected. This is because these animals lose more calcium through milk secretion than they are getting from the diet.

Symptoms of milk fever.

Major symptoms of milk fever include dullness, muscular twitching, animal lying down on one side, lung fever and complete loss of appetite. Animals suffering from milk fever can be treated using an intravenous injection of soluble calcium salt in form of calcium borogluconate. Farmers should implement partial milking for the first 10 days.

Milk fever treatment

A lactating cow suffering from milk fever showing muscular twitching and the animal falling down and becoming unconscious.


Bloat is the accumulation of gases as a result of food fermentation in the rumen. It mainly attacks ruminants eg cattle, sheep and goats. In livestock affected by bloat, the left side of the abdomen is extensively distended due to gases which can be felt by pressing with the hand. Accumulation of gases in ruminant animals can be caused mainly by obstruction of the oesophagus due to bulky food particles and indigestion.

Bloat can easily be controlled using trocar and canula; feeding livestock with lush pastures which have been wilted and administering appropriate chemicals for example Epsom salt.

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