Surveys of anthelmintic use on deer farms coupled with known information about parasites
in weaner deer suggest that for effective parasite control the following recommendations
- Available products are effective
- Initial treatment needs to be at weaning or if weaning is delayed then it’s better
to commence early ie before weaning rather than delay commencing the programme.
- Regular treatments are necessary from approximately weaning to late winter/spring.
- The interval between treatments is difficult to assess but as a rule of thumb
- Pour-ons should be given at 6-8 weekly intervals. The actual timing will depend
on product, stocking rates, pasture contamination, climate conditions
- Oral drench treatments should probably be given at no greater than 4-weekly intervals
- Treatment intervals should not be extended beyond those recommended as to do so
will lead to poor parasite control and poor growth weights.
- Adult drenching recommendations are not clearly defined, much more trial work is
Stags in their second winter appear to be at risk to subclinical parasitism
- Monitoring of deer groups by faecal egg and lungworm larvae counts will provide
information on an individual farm and lead to better drenching recommendations for
- The pepsinogen blood test is currently being used as a monitoring test but only
limited information is available
Life Cycle of Dictyocaulus viviparus in Red Deer
A. First-stage larvae passed in faeces
B. Infective larvae penetrate intestinal mucosa and migrate via lymphatic and blood
circulation to lungs
C. Development to fifth stage and maturation to adulthood in lungs
D. Adult worms inhabit bronchial tree and lay eggs
E. Eggs coughed up and swallowed; hatch to L1 larvae in faeces
F. Infective larvae consumed with herbage
Ostertagia - Type
Apteragia qua drispiculata
These are true deer parasites
*probably the most widespread and representative of the Ostertagia types found.
**probably more common in South Island
Cattle/Sheep parasites which appear to be a well adopted to deer.
True deer parasite.
True deer parasite.
May be found in deer. Possibly opportunists available through mixed grazing with
sheep and cattle.
Parasite Control in Deer
Increasingly various researchers are finding that control of parasites in deer requires
a similar approach as in other animals, otherwise productivity is affected and parasite
control is incomplete.
The objectives of parasite control are:
- Removal of exisiting parastie burden
- Reduce reinfection challenge to the animal
- Reduction in the level of pasture contamination
- Essentially the effect of parasitism can be viewed as clinical prarsitism (the effects
can be seen) or subclinical parasitism (the efects are not seen but they can be
The most serious and important parasites in young growing deer are lungworm. They
cause clinical and subclinical losses.
Gut parasites are of increased concern in farmed deer and these parasites can cause
clinical problems in deer. Gut parasites may be an important "routine" cause of