Leptospirosis

The incidence of human Leptospirosis in New Zealand is amongst the highest in the world. Increasing awareness and regulation of health and safety on farms, means that you are responsible for managing the risk of human Leptospirosis infection on your farm.

The bacteria that cause Leptospirosis are shed in the urine of many animals, including dairy cattle. It then is transferred to humans through the mouth, nose, eyes and cuts or abrasions in the skin. The bacteria can survive for a long time in a wet environment.

Working with dairy cows puts you, your family and workers at risk. As well as anyone has contact with cow urine on a regular basis. There are plenty of opportunities for any one of them to become infected with Leptospirosis.
Despite widespread vaccination, there are still a significant number of farms with adult dairy cattle shedding the bacteria in their urine. The most likely reason for this is that calves are not vaccinated early enough. Vaccinations need to occur before the calf is exposed to any Leptospirosis bacteria. Sheep and beef and deer are mostly not vaccinated and provide a source of Leptospirosis for young calves.
Preventing Leptospirosis and managing the on farm risk of Leptospirosis has three key areas:


1. Vaccination of Cattle: Vaccination prevents urinary shedding of the Leptospirosis bacteria. The vaccines are very effective providing they are given at the correct time.
We recommend:

  • Calves are vaccinated when the youngest calf is three months old, November or December.
  • A booster vaccine is given four to six weeks later, December or January. They should also be vaccinated for BVD at this time.
  • R2 heifers/herd will also require an annual booster.
  • Heifer/herd are vaccinated at the same time as the calves receive their second vaccine, January or February.

2. Education of Staff: It is your responsibility to make sure that all staff are aware of the risk of Leptospirosis, how they might become infected, and the measures they should take to decrease the risk of becoming infected.


3. Reducing the Contamination of Leptospirosis Bacteria: Waterways and effluent ponds need to be fenced. Adequate drainage at the shed, on races and around feed storage is important. Rats need to be controlled. Many of the human cases of Leptospirosis seen in dairy farm workers are caused by a strain of Leptospirosis (L Ballum) that is shed in the urine of rats.


If you have questions regarding the timing of vaccinations on your farm, or if you have any questions about Leptospirosis risk management, please give your local clinic a call and speak with one of our vets.
We can make a plan for Leptospirosis vaccination that suits your farm.

 

iStock 91540695 WebReplacement Pic

 

 
VetEnt disease landing page 6

About VetEnt Group

Enjoy local service backed by nationwide support from NZ's largest vet group with over 75 vets nationwide, giving you more depth of expertise from shared knowledge and technical expertise.
 

Meet your local vet

Meet the team

Match
Name:
Clinic:
Speciality:
Search For
Name

 

I highly recommend VetEnt. They have been there with me for the past 5 years as my business has grown.  They are both proactive and leaders in their field. They are reliable and always go beyond the call of duty with their service

Make an Appointment

For urgent appointments within the next 24 hours, please phone the clinic directly.

Cattle Tick

 

A blood sucking external parasite Haemaphysalis longicornis which favours cattle but they are not completely host specific and can infest deer, sheep, goats, humans, horses, rabbits, hares and domestic pets.

There are many different species of tick in the world, but H longicornis, is the only one found in New Zealand. It is called a three host tick, with each of its growing stages- larvae, nymph, and adult feeding off separate hosts, not necessarily of the same species.

The adult female tick, which when fully engorged with blood can grow to approximately 9mm long by 7mm wide, lays hundreds of eggs from which the larvae will hatch on nearby vegetation. The larvae attach to a suitable host and feed before falling to the pasture where they develop to a nymph stage. Nymphs will also attach to a host to feed before detaching and developing into an adult. The time taken for the completion of the life cycle varies considerably from days to months depending on factors such as temperature and the host’s immunity developed from previous exposure.

The larvae and nymphal stages of the life cycle position themselves at the tips of long grass or vegetation and attach to the skin of grazing animals or hosts walking through the paddocks.

Ticks are obvious on clinical observation. Ticks are commonly found on the head, ears and lower body extremities.

The Impact

Ticks cause damage to hides and loss of production, anaemia and death when they are present in large numbers.

  • Ticks feed by puncturing the skin of a host with their mouthparts. These puncture sites and any damage that may result can reduce the quality and value of velvet antler during growth in the spring can be a problem in some years.
  • Nymph (larval) ticks can be a major problem on newborn fawns, and young grazing lambs prior to weaning causing anaemia with deaths from blood loss in severe cases.

Management & Control

There is a range of shower and spray treatments available for cattle and sheep. There is also a pour-on product registered for cattle and deer and an insecticide impregnated ear tag available for use in deer.

Ticks are practically impossible to eradicate but there are a few methods to reduce tick infestation of animals from pasture.

Contact your nearest VetEnt clinic to learn more about how to manage in your cattle tick on your property.

 
 
cattle ticks on deer
cattle tick  nymphs   cattle ticks engorged adults

 

Worms in Cattle

Managing cattle worms at the farm level is a complex issue.  It requires a sound understanding of the worm life cycle and the interactions between the worm, host and environment. 

Symptoms of the Disease/Condition

There are two broad types of worms that can affect cattle:

  • Gut worms (gastrointestinal)- three most important are: Ostertagia ostertagi, Trichostrongylus axei, Cooperia oncophora. Ostertagia and T.axei live in the 4th stomach (abomasum) and Cooperia lives in the small intestine.
  • Lungworm:Dictyocaulus viviparous- lives in the lungs and windpipe causing parasitic bronchitis. Very little is known about lungworm in cattle in New Zealand and the mainly pasture based systems which we run cattle in NZ probably accounts for why it is less of a problem compared to overseas where cattle are kept indoors for some or all of the year and lungworm is regarded a serious parasite.

The Impact

The effects of parasitism are likely to be most severe and of greatest long term significance in the first year of life. These young animals have little or no acquired resistance to worms, have minimal reserves to draw on and should be making maximal skeletal and muscular growth if their lifetime production is not to be impaired.

There is little published work on the effects of worms in cattle in the second and later years of life. The Ostertagia worm can “hibernate” in the young animal and emerge later on resulting in clinical disease in the older animal.(Type 2 Ostertagiosis)

Mature cattle that have endured a drought can suffer weight loss if exposed to substantial numbers of larvae on pasture.

The significance of gut worms in young cattle is mainly determined by the level of exposure to infection.  If the levels are high, clinical disease will result:

o loss of appetite
o listless appearance
o intermittent, profuse, watery diarrhoea
o rapid weight loss and emaciation

However the subclinical effects are probably more important economically – reduction in feed intake results in poor weight gain.

Level of nutrition also affects the ability of the cattle to cope with the effects of parasites and resist their establishment.

 
 
vet worm
 vet worm    vet worm

There have been numerous drenching trials in New Zealand that have demonstrated the scale of potential losses from parasitism by gut worms. They average about 15kg liveweight (treated cattle end up 15kg heavier than untreated) but range up to 55kg liveweight and 33% mortalities.

For dairy beef, at $2.00/kg LWT the potential loss of sale income caused by parasitism in yearling cattle could be worth $30.00 per animal at saleplus the cost of any deaths associated with high worm burdons.

Undergrown dairy heifers due to high worm burdons can affect their lifetime milk production. Also, heifers not reaching their target liveweights for mating have a reduced in-calf rate, but more importantly may not get in calf fortheir second lactation. Replacement heifers may have lower mating performance because of lower mating weights.

The other impact of worms is the inevitable risk of drench resistance.

Faecal egg counting as a tool to diagnose worm burdens in cattle is less reliable than in sheep and goats. The development of immunity to worms (particularly Ostertagia) by young cattle and the expression of that immunity by suppressing egg production of active gut worms makes the use of FEC in cattle older than 5-6 months unreliable.

Blood testing for gut damage (measuring pepsinogen concentration in the blood) may be a useful diagnostic test in cattle with large Ostertagia burdens.

Management and Control

There is a wide range of anthelmintics and a wide range of different ways they can be administered in cattle.

Contact your nearest VetEnt clinic to learn more about how to manage worms in your cattle.

Back to Dairy Menu >>

 
 calf scour    
 

Calf Diarrhoea (Scours)

Calf scours will result in the need for intensive treatments. Losses can be significant, and recovered animals can have reduced lifetime production.

 


Bacteria, viruses, protozoa and nutritional factors can all cause scours in new born calves.
These include:

  • Rotavirus - A viral disease causing severe scours with infection levels up to 100%, and high death rates in some cases. The virus can be transmitted from cows to their calves at birth, and with a short incubation period, calves as young as 1 – 4 days can be affected.
  • Coronavirus - A viral disease affecting calves at 5 – 20 days of age, with infection rates of 15 -20%.
  • E. coli - A bacterial disease with two distinct syndromes:
    - Enterotoxigenic Colibacillosis affecting calves up to 4 days of age
    - Enterohaemorrhagic Colibacillosis affecting calves greater than 6 weeks of age.
  • Salmonella - A bacterial disease affecting calves of any age. Salmonella is characterized by blood-stained faeces, medium to high infection levels and deaths. Salmonella can be transmitted directly to humans.
  • Cryptosporidiosis - A protozoal disease characterized by high infection rates and deaths. Cryptosporidiosis affects calves as young as four days old, but can be present up to 4 weeks or older.
  • Coccidiosis - A protozoal disease affecting calves 3 – 4 weeks of age and possibly up to post-weaning.
  • Nutritional - Non-infectious scours caused by nutritional factors, such as poor quality milk replacers, or sudden changes in diet.

 

calf scour Replacement Pic

Diagnosis is Important

Because there are many causes of neonatal scours, with potentially different treatments, it is important that we confirm the diagnosis as soon as possible after you notice diarrhoea.
A veterinary visit is recommended early in the outbreak. Apart from examination of the calves and faecal collection, this is also an opportunity to take blood samples to measure the adequacy of colostrum feeding, and to discuss facilities and management.

Symptoms, Treatment & Prevention

Symptoms vary from mild diarrhoea to severe watery diarrhoea with blood present. 

Calves may be depressed, dehydrated, unable to suckle and in severe cases will become recumbent. You may also notice bloated stomachs and teeth grinding (which indicates gut pain).
Once calves are unable to stand they will require veterinary intervention.

Treatment of neonatal diarrhoea involves adequate fluid, electrolyte and energy replacement for sufficient periods to allow the animal to recover. Fluids can be given orally if the calves are standing, but if they lie down and become excessively dehydrated intravenous fluids will be required to be given by a vet. The way you feed electrolytes and milk is important, and you should discuss this with your vet.
In most cases calves will recover well, but some may require antibiotic treatments in addition to fluids. If Cryptosporidiosis or Coccidiosis is diagnosed specific antiprotozoal drugs may be required. There are other supportive products available which should be discussed with your vet.
Preventing calf scours involves an integrated approach which includes cow vaccination prior to calving, excellent colostrum and milk management, calf pen and feeding utensil hygiene, low risk bedding, lower stocking rates, and minimizing draughts.

Neonatal diarrhoea has significant costs resulting from treatments, deaths and reduced live weight gains. Following recovery from diarrhoea, calves will require extra milk and concentrates to achieve weaning weights, and will have reduced live weight gains from weaning to mating which will have an effect on first service conception rates.

Calves affected by neonatal diarrhoea are usually below live weight targets for life which affects their life time milk production.
An animal 9% below live weight target at first calving may show the following reductions in production and reproduction

  • 10Kg less milk solids @ $6.50 / Kg = $65.00
  • 2% reduction in 6 week in-calf rate = $10.00
  • 5% increase in empty rate = $50.00
  • Total $125.00 for each stunted heifer.

 

 

 
VetEnt disease landing page 6

About VetEnt Group

Enjoy local service backed by nationwide support from NZ's largest vet group with over 75 vets nationwide, giving you more depth of expertise from shared knowledge and technical expertise.
 

Meet your local vet

Meet the team

Match
Name:
Clinic:
Speciality:
Search For
Name

 

I highly recommend VetEnt. They have been there with me for the past 5 years as my business has grown.  They are both proactive and leaders in their field. They are reliable and always go beyond the call of duty with their service

Make an Appointment

For urgent appointments within the next 24 hours, please phone the clinic directly.

 
Theileria

Theileriosis is a tick-borne disease caused by an intracellular blood parasite that in NZ is carried by the cattle tick Haemaphysalis longicornis.  Although it may cause tick irritation and local reactions in all species, it is currently believed that H. longicornis only transmits theileriosis to cattle.

Signs of Theileriosis are those associated with anaemia and include: pale membranes, depression, lethargy, lack of appetite, exercise intolerance, (lagging behind the mob) downer cows that do not respond to treatment and in some instances cattle may collapse and die if stressed or forced to move or run.  

Pregnant cows may abort and still births are common. In dairy cows a drop in milk production will occur and somatic cell counts may rise.

Theileria Theleria Image1 Replacement Pic
Theleria Image2
 

Treatment Options

Unfortunately our treatment options are currently limited in NZ and are mainly restricted to symptomatic and supportive care.

  • Minimise stress, handling and transport of affected animals.
  • Engemycin, at 20-25ml/cow/day has shown to show improvement in some cases, whether it affects the parasite itself, or helps with concurrent issues. If no improvement is seen in 2-3 days it is recommended that treatment is stopped as the stress of injections and movement may worsen the anaemia/clinical signs.
  • Blood transfusions – are an option for valuable, anaemic animals.
  • Buparavaquone – this is the preferred international treatment of choice, however is very limited in availability.
  • Always consult with your veterinarian and remember to observe the prescribed withholding periods before marketing products of treated animals.

Control & Prevention Options

In areas where Theileria is commonly found (endemic areas) most adult cattle are found to be immune. In Northland, Theileriosis has been noted frequently in the last year, and stock in areas like this should be closely inspected.

Calves should be examined closely when they are 6-12 weeks old as this is the time when temperatures are increasing and ticks will be starting to attach to stock.

Introduced cattle should be examined closely when they arrive on farm, and are starting to settle in over the next few weeks – as this is commonly when stressors are maximal and clinical disease may present.

In districts where Theileria is normally not present, but cattle from Theileria infected areas have been introduced (such as cattle been grazed away or cattle bought in from endemic areas), check home cattle regularly between two and six months after the introductions. If signs of disease are noted, seek veterinary advice as treatment when animals are mildly affected has been most successful.

Avoid importing animals from known affected properties, however where the health status of bought-in stock is unknown, treatment with a registered tick treatment such as Bayticol may be advisable prior to introduction. When using insecticides, always consult with your veterinarian and remember to observe the prescribed withholding periods before marketing products of treated animals.


Cattle may require treatment every two to three weeks for a few months during summer and autumn, but it must be noted that over-use of tick products can cause resistance within the tick population. Therefore it is important to remember that tick treatments should not be the only method of tick control – each stage of the life cycle of the tick is only on the body for a short period of time. Rotational grazing practices may also help control ticks; the use of sheep or deer may act as ‘vacuum cleaners’ to remove ticks from pasture before the introduction of cattle.

Theileria can also spread by way of blood transmission – ie use of a needle or ear taggers on an infected animal being then used on an unfected animal, or even biting flies. It is therefore very important to disinfect equipment between cattle to help prevent the spread and control flies in sheds and facilities.

 
VetEnt disease landing page 6

About VetEnt Group

Enjoy local service backed by nationwide support from NZ's largest vet group with over 75 vets nationwide, giving you more depth of expertise from shared knowledge and technical expertise.
 

Meet your local vet

Meet the team

Match
Name:
Clinic:
Speciality:
Search For
Name

 

I highly recommend VetEnt. They have been there with me for the past 5 years as my business has grown.  They are both proactive and leaders in their field. They are reliable and always go beyond the call of duty with their service

Make an Appointment

For urgent appointments within the next 24 hours, please phone the clinic directly.

Make an Appointment

For emergencies or urgent appointments within the next 24 hours, please phone the clinic directly.