Meaning and Causes of Livestock Disease
A disease can be defined as any abnormality in the functions of the tissues, organs or system of the animal body. In other words, disease is any conditions in which these is a deviation from normal state of health or normal functioning of any or all the tissues and organs of the animal body. Animal diseases are generally caused by viruses, bacteria, fungi, protozoa and malnutrition.
DIFFERENCE BETWEEEN RESISITANCE AND SUSCEPTIBILITY TO DISEASES
The difference between resistance and susceptibility to disease is that an animals is said to be resistant to disease when it is not affected by an invading pathogenic disease-causing organism or pathogen while the animal is said to be susceptible to disease when it is not able to ward off the effect of the invading pathogenic organism, in which case it manifests disease symptoms.
ECONOMIC IMPORTANCE OF ANIMAL DISEASES
- The diseases bring about poor growth of animals.
- Disease lead to poor feed utilization by animals due to loss of appetite or anorexia
- Disease bring about low yield of products
- Diseases in animals produce low income for farmers due to reduced quantity and quality of products and death of the animals.
FACTORS WHICH DETERMINE THE DEGREE OF AN ANIMAL’S RESISTANCE TO A DISEASE
The factors which determine the degree of an animal’s resistance to disease are:
- Development to immunity
- Specie of animals
- Level of feeding
- Age of animal
- Physiological condition of the animal
CONDITIONS THAT MAY INACTIVATE A PATHOGEN
Conditions that may inactive or will not bring back to active life a pathogen are:
- Low temperature
- High temperature
- Sunlight and x-rays
- High pH medium
- Low Ph medium
- Dryness or low relative humidity
FACTORS THAT COULD PRE-DISPOSE ANIMALS TO DISEASE
Factors that could predispose animals to diseases include:
- Health Status of the Animal: Animals with poor health stand the risk of getting infected with disease faster than animals with good health.
- Nutrition: Animals which are poorly fed are easily infected with diseases that animals that are well-fed with balance diet.
- Sanitation: Poor or improper sanitation, including dirty environment could predispose animals to diseases.
- Management: Poor management of the animals such as non-administration of vaccines and drugs at appropriate doses and time could predispose animals to diseases.
- Breeds of Animals: Poor breeds of animals are in position to get infected with diseases than good breeds.
- Poor Housing: This pre-disposes farm animals to disease due to unfavourable climatic conditions like heavy rainfall, high temperature, etc. disease and parasitic infestation can also breakout due to poor housing.
- Unfavourable climatic conditions: Extremes of temperature, winds, rainfall, etc., do pre-dispose farm animals to diseases.
- Foot and Mouth Disease
Animals affected: They include cattle, sheep and goat.
Causal Organism: It is caused by a virus.
Symptoms: (i) Formation of blisters on the mucous membrane of the mouth and the skin; between and around the hoofs; (ii) inflammation of teats and udder; (iii) salivation; (iv) lameness and; (v) loss of weight
Method of transmission: (i) These are transmitted through infected materials like urine, faeces, milk; (ii) mechanical means by farmers.
Control: This includes isolation of infected animals and burning or burying contaminated materials. They should also be given regular vaccination.
- Rinder Pest Disease or Cattle Plague
Animals affected: these are cattle, sheep and goat.
Casual organism: it is caused by virus.
Symptoms: (i) high fever (ii) weakness (iii) difficult breathing (v) blood stained diarrhea (vi) high mortality (vii) loss of appetite and weight.
Method of Transmission: (i) Rinderpest is a contagious disease and is transmitted by: (i) contact; (ii) contaminated feed and water; (iii) contaminated faeces and urine.
Control: this can be done through: (i) regular vaccination; (ii) isolation of infected animals; (iii) restriction of infected animals movement within the farm.
- Newcastle disease
Animals affected are: domestic fowl, turkey, ducks, goose and guinea fowl.
Causal organism: Newcastle disease is caused by a virus
Symptoms: (i) Respirator symptoms include sneezing, coughing, nasal discharge and difficulty in breathing. (ii) Nervous symptoms include paralysis, muscular tremor, somersaulting and cycling movements. (iii) Digestive symptoms include: lack of appetite and diarrhea.
Method of Transmission: Newcastle disease through contaminated feed, water, breeds and litter.
Control: (i) vaccination (ii) proper sanitation (iii) disinfection of poultry building, (iv) burning and burying of infected birds.
Animal organism: It is caused by a bacterium called Bacillus anthraxis.
Symptoms: (i) High fever (ii) depression (iii) blood oozes from nose, mouth and anus of carcass (iv) lack of appetite (v) loss of weight (vi) Staggering and sudden death of animals.
Method of transmission: this can be through contaminated feed, water, equipment and infected animals.
Control: (i) Regular vaccination (ii) proper sanitation, (iii) isolation of infected animals.
- Brucellosis or Contagious Abortion
Animals affected: Pigs, cattle, sheep and goat
Causal organism: it is caused by a bacterium called brucella abortus or brucella spp.
Symptoms: (i) high fever (ii) diarrhea and dysentery (iii) posterior paralysis (iv) wobbling gait (v) pre-mature abortions (vi) still-birth (vii) retention of the after birth (placenta) (viii) infertility of male animal (ix) reduction in milk production and inflammation of scrotum (x) inflammation of uterus (womb).
Method of transmission: this can be through contaminated feed, water, infected animals, etc.
Control: (i) isolation of infected animals (ii) proper sanitation (iii) regular vaccination.
Animals affected: Cattle, poultry birds, pigs and sheep.
Causal organism: it is caused by bacterium call Mycobacterium tuberculosis
Symptoms: (i) difficult breathing (ii) constant coughing (iii) loss of weight and appetite (iv) emaciation (v) paled combs and wattles (vi) high mortality (vii) milk reduction (viii) soft and moist cough.
Method of transmission: (i) this is through inspiration of germs, contaminated water, feed, litters and dropping.
Control: (i) Regular vaccination (ii) slaughter infected animals (iii) proper sanitation (iv) isolation of infected animals.
Animals affected: Poultry birds, pigs and cattle.
Causal organism: it is caused by a fungus (Aspergillus fumigates)
Symptoms: (i) difficult breathing (ii) loss of appetite (iii) skin irritation (iv) respiratory disorder (v) high body temperature (vi) loss of weight (v) high body temperature (vi) loss of weight (emaciation) (vii) general unthriftiness of the animal.
Method of transmission: this can be through contaminated feed (mouldy feed), mouldy litter and contaminated incubator
Control: (i) regular disinfection of pens and equipment (ii) avoid the use of mouldy feed and litter (iii) practice good sanitation and hygiene (iv) spray with fungicides to prevent the growth of fungi spores.
Animals affected: These are pigs, sheep, goat, cattle, rabbit
Causal organism: it is caused by a fungus.
Symptoms: (i) lesions on the skin of farm animals (ii) skin irritation (iii) loss of appetite and weight
Method of transmission: This may be through infected animals, contact with infected brushes, feeders and drinkers.
Control: (i) disinfection of all pens and equipment (ii) infect parts of animals should be treated every two to six days with mixture of sulphur and Vaseline (iii) old scabby area can be scrapped off and iodine solution applied.
Animals affected: Resistant breeds of cattle are N’Dama, Muturu and keteku. While susceptible breeds are White Fulani, Red Bororo, Kuri Chad, Sokoto Gudali and Boran.
Causal organism: It is caused by a protozoan called trypanosome spp, e.g., trypanosome vivax, T.congolensis, T.gambiensi.
Symptoms: this include (i) rise in body temperature (ii) dullness in appearance (iii) anaemia (iv) sleepiness (v) nervous disorder leading to paralysis and death (vi) weakness (vii) loss of weight (viii) loss of appetite.
Method of transmission: The disease is spread by blood sucking tsetse fly (Glossina spp) which may such blood from an infected animal and transmit the pathogens to a healthy animal.
Control: (i) clearing of bush around the farm in order to remove the fly’s habitat. (ii) spraying with insecticides to kill vector (tsetse fly). (iii) Treatment of infected animals with drugs such as trypanosomide and antimosan. (iv) Eradication of wild species or animal carriers in and around the ranch or pasture. (v) Isolating affected animals. (vi) Biological control of insect vectors.
Animals affected: These are domestic fowl, turkey, duck, goose, rabbit, etc.
Causal organism: It is caused by the protozoa (Eimera spp).
Symptoms: (i) dropping wings (ii) loss of appetite (iii) blood stained diarrhea (iv) emaciation (v) high mortality (vi) dullness and unthriftiness (vii) loss of hair or acopecia (in rabbits) (viii) rough feathers (ix) huddling (crowding together).
Control: (i) practice proper sanitation. (ii) Avoid wet litters and feed. (iii) Changing of water sued and general disinfection (iv) use suitable drugs such as amprolium, nitrofurazone or sulphaquinoxaline in water.
- Red Water Fever (Piroplasmosis)
Animal affected: These are sheep, goat, cattle and pig.
Causal organism: It is caused by a protozoan called babesia spp.
Symptoms: (i) rise in body temperature (ii) loss of appetite (iii) diarrhea (iv) pale red colour of urine (v) emaciation and death.
Method of transmission: It is transmitted through the bite of infected animal by a vector called blue tick.
Control: (i) Spray with insecticides to kill the vector of disease (blue tick) (ii) Inject animal with drugs like trypan blue, babesan or acaprin.