Diseases Of Young Stock

Diseases Of Young Stock
Leptospirosis:
WHAT
A bacterial disease with many different species and strains that will affect different animals.
EFFECT
The disease can be spread to humans and other animals when leptospires are shed in the affected animal’s urine into the surrounding environment. These leptospires then enter the body through mucous membranes of the nose, eyes, mouth or reproductive tract, or breaks in the skin.
Infection in young stock can cause conditions such as acute septicaemia, red water which is blood in the urine, anaemia and jaundice which all affect productivity.
PREVENTION
Vaccines are available which provide protection against disease, preventing kidney colonization and urinary shedding, thereby providing protection for people in contract with animals.
Recent research has highlighted the need to ensure calves are protected by vaccinations from a young age. Consult your veterinarian on best practice vaccination program in your herd.
Clostridial Diseases:
WHAT
Clostridial are widespread in the environment and form highly resistant spores that survive in the environment for very long periods. They are also present in the gastrointestinal tract and as spores in tissues of healthy animals.
EFFECT
Often a disease that strike cattle suddenly, usually resulting in death, before any clinical signs are seen.
Contributing factors such as injury or wounds or diet changes, overeating and lush feed allow the clostridia bacteria to multiply and cause disease.
Signs of disease vary and include sudden death, high fever, localized stiffness, muscle spasms, dark red coloured urine, acute lameness and swelling.
Clostridial diseases progress so quickly that it is usually impossible to treat successfully.
PREVENTION
Prevention by vaccination is an economical and effective strategy for preventing disease. Various combinations of clostridal vaccines are available which protect against multiple types of clostridial bacteria. Ultravac 5 in 1 vaccine is a cheap and reliable vaccination which will benefit all stock. These vaccines require a primary course of 2 doses separated by 4-6 weeks and then annual boosters to maintain protection.
Bovine Viral Diarrhoea (BVD):
WHAT
A viral disease of cattle that can have devastating affects on production and reproduction and sometimes causes diarrhoea. Infection is widespread and occurs in both dairy and beef herds throughout New Zealand.
EFFECT
BVD has a large effect on the reproduction and fertility of a dairy herd but its effect on young stock health is due to immune-suppression i.e. the animal is less able to fight off other diseases and hence becomes overwhelmed, affecting production and may even cause death.
Young stock that are grazed off the property and mixed with other stock are particularly at risk.
PREVENTION
Vaccination to protect young stock can begin from 4 months of age. A sensitiser and a booster 4 weeks apart are required and then an annual booster should be given 4 weeks pre-mating.
Yersiniosis:
WHAT
A contagious bacterial infection of the gut, which causes extensive damage to gut lining. Weaned calves and yearlings are most at risk and often succumb to this disease when their immune system is already compromised. Yersinia is most often seen in conjunction with parasitism.
Spread by infected faeces contaminating pasture, supplement feeds and drinking water.
EFFECT
Affected animals often scour and lose weight very quickly. Left untreated, infected animals often become weak and even die.
Most commonly affects a small number of weaners and yearlings within a mob. These often show as an ill-thrifty, poor-doing group, with rough coats, dehydration and poor appetites.
PREVENTION
Important to differentiate Yersinia from other causes of scouring, ill-thrift and condition loss and/ or death. Treatment includes specific antibiotics, so establishing a diagnosis is critical.

Facial Eczema:
WHAT
Fungal spores produces by fungus Pithomyces chatarum growing on pasture produce a toxin which when ingested buy grazing stock damages the liver and bile ducts.
The fungus produces spores when grass minimum temperatures are above 12°C for two or three nights and humidity is high (usually January to May).
EFFECT
The resulting liver damage results in poor growth and if severe death can occur.
The damaged liver cannot rid the body of wastes and a breakdown product of chlorophyll builds up in the body causing sensitivity to sunlight and inflammation of the skin.
PREVENTION
Control options include oral zinc (in water and/or drench), fungicidal spraying of pastures and intraruminal zinc boluses.
Pinkeye:
WHAT
Cattle pinkeye can be causes by a number of viruses and mixed bacterial infections. The main infectious agent involved in pinkeye is the bacteria Moraxella bovis, which is carried in the nasal and eye secretions of carrier animals.
M.bovis attaches to the surface of the eye and damages it by producing toxins which erode the cornea, causing ulceration and severe inflammation.
EFFECT
Predisposing factors for the development of disease include: flies, ultraviolet light, long grass, dust, overcrowding and poor immunity due to other disease or poor nutrition.
Treatment options include: eye ointment, powders, sprays, antibiotic injections and/or surgery.
PREVENTION / TREATMENT
Prevention involves management changes such as fly control, segregation and early treatment of infected stock, avoidance of dust and long stalk pasture.
Vitamin B1 or Thiamine deficiency:
WHAT
Vitamin B1 deficiency is a relatively common nervous disease in young cattle. It usually occurs in individual animals but can occur in outbreaks.
Calves at 4-9months of age are mostly affected but occasionally the disease is diagnosed in adult cattle.
EFFECT
In the early stages calves will show poor appetite and staggery gaits. They walk with their heads erect and ‘Star Gaze’ and appear blind. Untreated cases can progress to complete blindness with head pressing, recumbency, muscle tremors, progressing to convulsion and death within 2-3 days.
Causes include sudden dietary change (often a change from poor, stalky pasture to a diet of good lush pasture), high meal intakes causing excessive rumen breakdown of Vit B1 and high sulphur diets (often due to suphur fertilizer applications).
TREATMENT
Treatment requires repeated injections of Vitamin B1 administered 2-3 times daily for a number of days. Recovery may be slow in animals treated in the later stages of the disease.
Coccidiosis:
WHAT
Protozoa such as Eimeria or Cryptosporidium can invade the cells that line the gut, causing damage. Coccidiosis usually occurs in calves between 3 and 8 months of age.
Most cattle are infected with low numbers of coccidia, but clinical disease occurs if they are subject to heavy infestations or if the animal’s resistance is lowered by stress, poor nutrition or other disease.
EFFECT
Clinical signs range from mild to severe diarrhoea which is often blood-stained with mucous. The calves often strain after defaecating.
PREVENTION / TREATMENT
To achieve effective control of coccidiosis, good management and hygiene are vital. This includes: separating infected calves, reducing stock density, regularly shifting feed and water troughs, preventing faecal contamination of feed and water troughs and cleaning and disinfecting buildings.
Prevention can be achieved by feeding meal containing coccidiostats. Treatment is with a drug called toltrazuril which kills the coccidian.
Internal Parasites:
WHAT
Worms are picked up from the pasture. Heavy worm burdens can cause obvious clinical signs such as scouring, and ill thrift. Less severe burdens will still have an impact on growth rates- you may not be aware this is happening. Worms also cause a drop in appetite, so calves eat less when they actually need more.
Young stock are particularly susceptible to gastrointestinal worms.
EFFECT
It is not until 18-20months of age that a high degree of immunity develops against the three major worm species.
PREVENTION / TREATMENT
Young animals should be drenched regularly with an effective anthelmintic and good parasite management practices should be followed on-farm.
If calves ‘look like they need a drench’ you have left the calves too long between drenches and the damage is done.
“Never mix drench with milk or orally drench after milk feeding. Never drench calves by putting drench into the calfeteria. These practices are high-risk for causing drench toxicity. Young stock will not require drenching in most circumstances until they are will weaned and over 100kg.”
For further information please talk to your vet, or contact your local Anexa FVC clinic.


Date Added: Tuesday, 30th June 2015


Back...