October 5, 2023

Summer Creepy Crawlies for Lifestylers

By Dr David McDonnell, Managing Director of Tauranga Vets

Have they six legs or eight? Well, that’s an important question for the minds eye of a veterinarian to work out what Arthropod class we are dealing with.

We get asked to identify various external parasites seen on the skin of poultry, goats, sheep, cattle, horses, deer and alpaca. It is easier for us to determine from seeing the adults that have emerged – the eggs, larvae or nymphs lesser so.

Insects have three body parts (head, thorax and abdomen) and six legs. Examples are flies, lice, and keds. They are relatively easy to kill with insecticides and preventative measures. Because lice and keds are obligate parasites – meaning they need a host to survive, an annual herd/flock treatment of an insecticide in the Winter when their numbers increase usually suffices. Sometimes, we see lousy animals at this time of year when nutrition and environmental conditions abound signifies some other underlying disease. Crutching, dagging, shearing for the Summer and good internal parasite control (dagginess) will reduce the attractiveness for flies to ‘strike’ sheep. Ensuring dumps of compost, household rubbish etc do not act as a breeding area for flies helps with environmental control. The hot humid conditions of late have seen an earlier rise of ‘strike’ in Katikati surrounds.

Arachnids have four pairs of jointed legs. Examples are ticks, mites and spiders. They are a lot more difficult to control. The cattle tick is New Zealand’s only tick and affects many species of lifestyle animals. It has three stages and three hosts and is a lot harder to control as it spends its time off the host. The final stage adult is prevalent in November-December. Particularly in Deer, Cattle and Sheep – also in horses. Control is a little more difficult with insecticides as not all products have a registered claim for ticks. Mites burrow deeper into the skin and may be in localised areas, such as the scrotum in sheep. The Red Poultry mite however feeds on blood and is dormant in the coop cracks and perches but comes out at night when the birds are resting. Whereas another poultry mite stays all the time on the bird-particularly around the vent area.

A keen eye, assisted by a magnifying glass will help identify what external parasite you may be dealing with – six legs or eight?

If you have any questions or concerns regarding parasites, contact us on 0800 838 7267.