Animal Health


The Mackinnon Project has considerable experience dealing with animal health issues in sheep and cattle. We provide a full diagnostic service for animal health, supported by the pathology services of the University of Melbourne's Veterinary Faculty.

For more background to disease control click here.

Some information on important diseases of sheep and cattle is provided below.

Sheep diseases

  • Internal parasites
  • Footrot
  • Lice
  • Blowfly strike
  • Fleece Rot
  • Weaner ill-thrift and mortality
  • OJD (Ovine Johnes Disease)
  • Vaccination against clostridial disesases
  • 'Smart Grazing' For Weaner Worm Control

Cattle diseases

  • Intestinal parasites in cattle
  • Bovine Viral Diarrhoea ('pestivirus')
  • Bloat in cattle

Background to disease control

Key management decisions, such as time of lambing, flock structure, stocking rate and time of shearing can have an important influence on the probability of disease occurring, or the likelihood of preventive measures being effective.

For example, at similar winter stocking rates, worm control in a self-replacing Merino flock that lambs in autumn or winter in southern Australia is much more difficult than for a flock that lambs in spring. Similarly, disease problems related to under-nutrition, such as Pregnancy Toxaemia of sheep are more problematic in autumn and winter lambing flocks.

Services – Disease diagnosis and control programs

The Mackinnon Project provides a full diagnostic veterinary service for sheep and beef cattle. This service has an almost unrivalled capacity in southern Australia, and includes:

  • Knowledge - senior Mackinnon veterinary consultants with over 50 years combined experience in the sheep and beef cattle industries
  • The ability to put advice on Animal Health into a whole farm context and develop cost-effective control programs
  • Testing capacity - access to post-mortem facilities, senior Pathologists and the full testing capabilities of the University of Melbourne Veterinary School & other testing laboratories
  • Research capability - the ability to conduct controlled trials to identify new and emerging disease issues in the grazing industries

Cost of disease

Disease conditions are rarely the most important determinant of farm profitability and Farm benchmarking studies, such as the Victorian DPI's Farm Monitor Project, show that animal health costs are only a small proportion of total variable (enterprise) costs on an average wool farm - typically just over $1 per dse (dry sheep equivalent), or about 10% of total costs.

However, disease can have a significant negative impact due to reduced production, cost of control programs and deaths (an indicator of failed control programs) in both Sheep and Cattle.


A study published in April 2006 by Meat and Livestock Australia (MLA) found that Internal parasites (worms), Flystrike, Lice, post-weaning mortality, bacterial enteritis and Footrot were the most significant animal health issues for Australian sheep producers in the high winter rainfall zones. The costs of these diseases are summarised in the following table:

Table 1. Highest cost diseases for sheep*


National cost


Cost per head in high

winter rainfall area

Internal parasites









Post-weaning mortality



Bacterial enteritis









Perennial Ryegrass



Phalaris toxicity



a - $1.03/ head for body strike & $1.38/ head for breech strike
b - assuming weaners in 50% of flocks are at risk
c - in infected flocks the first year after infection is introduced
d - an infected fine wool merino flock using OJD vaccine
e - estimated cost for episodes involving 2% or 5% sheep affected

* From Sackett et al (2006). MLA report AHW.087 - Assessing the economic cost of endemic disease on the profitability of Australian beef cattle and sheep producers

Beef cattle

Significant disease conditions in southern Australia include Bloat, Worms (gastro-intestinal parasites), Pinkeye, Grass tetany, & Pestivirus infection.

An estimate of total and per head costs for herds at high and low risk of suffering these conditions is given in Table 2 below.

Table 2. Highest cost diseases for beef cattle in southern Australia*


National cost


Cost per head


High risk


Low risk






Internal parasites










Grass tetany





* From Sackett et al (2006). MLA report AHW.087 - Assessing the economic cost of endemic disease on the profitability of Australian beef cattle and sheep producers