Animal Health, Disease and Parasites
Health is more than absence of disease
A healthy animal is alert, has good appetite, normal temperature, pulse and respiration, clean eyes and nose, and a glossy coat. Learn the normal ranges: cattle about 38–39 °C, sheep and goats 38.5–40 °C, pigs 38.5–39.5 °C, poultry 40–42 °C. Recording these values lets you detect problems early.
Causes of disease
Classify by agent: bacteria, viruses, fungi, protozoa, internal parasites (roundworms, flukes, tapeworms), external parasites (ticks, mites, lice, fleas) and non-infectious causes (nutrition, poison, injury, genetics). Know the difference between infectious (spread between animals) and contagious (spread readily), and between a sign (what you observe) and a symptom (what the animal feels).
Disease control tools
Vaccination, quarantine, culling, disinfection, vector control, good nutrition and stress reduction. Understand the terms incubation period, carrier, reservoir, zoonosis and notifiable disease. For parasites, know the direct life cycle versus the indirect cycle requiring an intermediate host, and the meaning of anthelmintic resistance.
Common traps
- Confusing foot-and-mouth disease with foot rot; the former is viral and notifiable.
- Assuming all diarrhoea is infectious - nutrition and stress also cause it.
- Forgetting that dipping or deworming without pasture management fails to break the cycle.
- Mixing up vaccine (prevention) with antibiotic (treatment of bacterial infection only).
Worked rule of thumb
When you see scouring in a group, check the pattern first: if all ages are affected at once, suspect feed or water; if only the young are affected, suspect infectious agents or management stress. This single observation narrows the diagnosis quickly.
Record keeping
Note date, animal ID, signs seen, treatment given, withdrawal period and outcome. Without records, resistance and disease patterns stay invisible.