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Calves are susceptible to some common infections.

It’s important to identify warning signs of illness and know how to control and prevent infectious diseases should they arise. If in doubt, consult your veterinarian.

Symptoms Causes
Lame/reluctant to stand Injury, joint problem
Sunken eyes Dehydration
Swollen navel Naval infection, hernia
Scours Nutritional: Faeces pale in colour, can be yellow and softer than normal
Infectious: Dull calf, high temperature, faeces foul smelling and may contain mucous or blood
Coughing, rapid respiration or shivering Respiratory infection from poor ventilation or infectious agents. Cold or wet conditions, feeding cold milk or a draughty calf shed
Bloat Cold milk feeding – milk in the rumen, over-drinking or gorging on a meal, young fresh grass
Salivation Mouth, tongue and cheek lesions, injured jaw, ulcers, and abscesses
Grinding teeth Abdominal pain, scours, lack of fibre, boredom
Pizzle suckling Low volume feeding, unsatisfied sucking instinct, lack of water
Hair loss Often after a bout of severe scours, excessive cold and wet (mud)


The most common cause of scouring is nutritional scours, which happens when there is a change in diet, or the diet is inappropriate for that age group of calves.

Calves with nutritional scours are often still bright, and their faeces are not smelly or bloody. Nutritional scours can be prevented by ensuring dietary changes are slow and that feeds are suitable for that age of animal. Most nutritional scours resolve without specific treatment within a few days, but electrolytes (such as Novolyte) can help prevent dehydration.

Scours can also be caused by viruses, bacteria, protozoa, or parasites. Infection occurs orally when calves are exploring their new environment. Many of these infectious organisms can be found at low levels in the faeces of healthy adult cows which means calves will be exposed from birth, reinforcing the importance of good colostrum management.

Prevention of contagious scours requires good colostrum management, well designed calf sheds with freely draining bedding, meticulous hygiene with milk preparation and feeding equipment, and a rapid response should a calf become sick.

Having a hospital pen where sick calves can be isolated until they are let outside can be an effective component in preventing further spread of disease. Make sure to interact with the sick calves last and thoroughly disinfect equipment before using it with healthy calves. Testing of faecal material by your local vet can be a useful method to identify the cause of scours and appropriate animal health interventions to reduce further disease spread.

Vaccination of pregnant cows against common diarrhoea causing pathogens will boost antibody levels in their colostrum, but this only helps if calves are getting their first feed of colostrum in a timely manner.

Navel ill

Before a calf’s navel dries up it is effectively another opening into their body that can allow bacteria a way in.

The wet weather typical over the calving period doesn’t help, as it results in slower drying and higher levels of contamination. This is why dipping navels in iodine right down to the skin at the base of the navel helps reduce disease; these products contain iodine to kill bacteria and alcohol to help dry the tissue.

If a navel does get infected, the body doesn’t have any physical barriers to prevent the infection going deeper and the calf becoming systemically unwell. This can lead to liver or lung abscesses or swelling and infection of joints.

It is recommended to dip the navels of newborn calves at the time of collection before putting them into the transport trailer to reduce the risk of infection. 

Daily checking of navels (palpation) by feel for at least the first 4 days when the calves are in the nursery pens and fed colostrum is recommended to enable early detection of swelling or infection and early animal health interventions to reduce severity of disease.

Respiratory disease

Respiratory disease of calves is less common in New Zealand than in some other countries, and it is one of the reasons you see calves overseas reared in individual hutches. In this country respiratory disease tends to be sporadic, often with only one calf affected at a time. Prevention is by ensuring calf housing is warm and dry and free from drafts, but with enough airflow that ammonia doesn’t build up. Affected calves usually need antibiotics and are at real risk of having long term damage to their lungs.

Intestinal parasites

Adult cattle are reasonably resistant to intestinal parasites, but it takes about 18 months for that resistance to build up, and so young stock are commonly drenched semi regularly up until they enter the milking herd. In theory a calf can start shedding worms three weeks after first going out onto pasture, and for total worm control it is recommended to drench every four weeks. Because young stock are the main shedders of worm eggs onto pasture, if calves are grazed in the same paddocks year after year those paddocks can have very high levels of eggs on pasture. The speed and severity of parasite burdens is somewhat dependent on dose and exposure, so calves grazing pasture that has been ‘cleaned up’ by cross-grazing with adult cattle or sheep will need less drenching. Talk to your local vet about which anthelmintic are recommended for your young stock.

Infectious agents

Frequent, bloody, foul-smelling scouring is almost certainly something serious and will require vet assistance and/or laboratory testing for an accurate diagnosis. If this is the case, we would recommend contacting your local vet as soon as possible.

Infectious Agent Possible Symptoms Risks Treatment Others Affected
  • Acute scouring
  • High temperature (39-40◦C)
  • Low colostrum intake
  • High mortality – fast acting
  • Contagious – depends on strain
  • Rehydration
  • Antibiotics
  • Humans
  • Pets
  • Acute, foul-smelling, watery scouring
  • High temperature (39-40 C)
  • High mortality if not treated quickly
  • Highly contagious
  • Rehydration
  • Vaccination of cows pre-calving
  • None
  • Acute scouring
  • Often associated with Cryptosporidiosis or Rotavirus
  • Low mortality
  • Rehydration
  • None
  • Acute, foul-smelling, watery scours
  • Scours usually of short duration
  • First 3 weeks of life
  • Medium contagiousness
  • Rehydration
  • Improve water supply
  • Humans
  • Pets
  • Acute, foul-smelling, watery scouring
  • High temperature (39-40 C)
  • High and rapid mortality
  • Highly contagious 
  • Poor recovery – if any
  • Rehydration
  • Antibiotics
  • Antipyretics
  • Vaccination
  • Humans
  • Pets
COCCIDIOSIS (associated with weaning off meal)
  • Scouring with mucous and blood present
  • Presence of blood around the anus
  • Normal temperature
  • Occurs from 3 weeks of age
  • Non-fatal
  • Inhibits growth
  • Transmitted through faeces of other bovine stock and contaminated water
  • Rehydration
  • Feed sources medicated with a coccidiostat
  • Possibly antibiotics
  • None
  • Acute, pale, watery scouring for 3 days
  • High temperature (39-40 C) 
  • More commonly occurs in the first 10 days
  • Can occur in conjunction with Rotavirus
  • Rehydration
  • Maintain energy
  • Humans
  • Pets

Rehydration during scours

Calves suffering from scours lose fluids and salts and don’t absorb the sugars they need for energy. 

This can cause alarming weight loss and dehydration. Therefore, lost fluids and salts must be replaced as soon possible to maintain calf energy.

  • A good quality oral electrolyte (such as Novolyte) at therapeutic levels during the diarrhoea and recovery period is the most efficient way to ensure optimum calf health
  • Oral electrolytes are lower in energy than milk, so milk feeding should be continued during the scouring period
Symptoms % Dehydration
Diarrhoea only 5% even if only scouring for one day
Eyes slightly sunken, skin losing elasticity, calf staggers on its feet, but still suckling 7%
Eyes sunken, skin slow to flatten if pinched, gums sticky, calf depressed 9% - additional intravenous fluids need to be administered by a vet
Eyes very sunken, skin won’t flatten out if pinched, calf cannot stand 12% - additional intravenous fluids need to be administered by a vet<

Calf rehydration

It’s important to feed both milk and electrolytes during rehydration. Ideally feed 2L of milk followed by 2L of electrolytes. These feeds should be 4 hours apart as the electrolytes can interfere with milk digestion.

Key points:

  • Use high-quality electrolytes (such as Novolyte) to ensure a balanced intake of salts and energy
  • Electrolytes can be offered via a teat feeder, trough, bucket or tube feeder
  • Warm feeding (38°C) is recommended to increase voluntarily drinking