Health Management of Beef cattle and Small stock in winter

Worms and fluke are parasites of hot wet weather and over winter in the host animals without always causing damage.

Control is based on treating stock with a long acting flukicide such as Fluconix which also controls wireworm and an anthelmintic such as Intermectin as we enter cooler autumn months. Thereafter it is not necessary to deworm stock until warmer temperatures occur from September onwards. Check faeces for worm infestation at the FIVET diagnostic lab if you are unsure when to treat at the beginning and/or end of winter months. Fluke become active in spring as daytime temperatures rise and a single treatment with Fluconix will effectively reduce liver fluke challenge early in summer. Ideally treat stock for fluke three times during summer starting from the beginning, mid and end of summer.

Ticks may overwinter off the hosts depending on the tick species.

It is important for stock owners to understand the life cycle of ticks and recognise the stage and species of ticks infesting cattle and small stock as a basis for deciding when to treat for tick infestation.

The blue tick which is easy to recognise by their blue grey colour is a one host tick and newly hatched larvae feed and moult on the cattle for about 3 weeks until the fully engorged adult female blue tick drops off to lay her eggs on the ground. All farmers know this tick species which transmits redwater and gallsickness mostly during wet summer months. The blue tick often appears in June/July and may infest cattle into the spring and farmers need to watch for this. The tick is easy to recognise on cattle and small

stock infesting the back, sides, dewlap, neck and upper legs. Larvae are very small and farmers must look carefully for these parasites when deciding when to dip.

A very useful tip is to avoid dipping calves to control blue tick for up to 4-6 months of age during these cooler months as 4-5 month old calves are resistant to redwater

and gallsickness and allowing them to be exposed during this period will induce a resistance to these two tick transmitted diseases.

Brown ear ticks are well known to farmers. The life cycle is year long with larvae and nymphs active in winter and adults active in summer around January, February and March. The adults can cause severe damage to the ears, head, neck and areas under the tail leading to skin damage and screw worm infestation. The adult tick also transmits theileriosis causing high mortality in cattle. Tactical dipping during the winter months does reduce larval and nymphal numbers thereby reducing challenge by adult brown ear tick thereby reducing the risk of theileriosis. Be aware that calves are very susceptible to theileriosis and ALL ages of cattle must be free of adult brown ear ticks during the critical hot wet months.

Bont ticks are easy to recognise and have very robust mouth parts and are coppery, orange in colour. They have a life cycle similar to brown ear ticks but immature bont tick larvae feed preferentially on hares and Guinea fowl which can be a source of heartwater to stock. The adult bont tick infests cattle, small stock and wild animals and very importantly transmits heartwater to ruminants. Adult and nymphal Bont tick feed on the feet, legs, under the tail and neck and can be easily missed when checking for infestation. The mouth parts can cause skin damage and lameness due to skin abscesses. Look for Bont ticks in between the hooves when animals show lameness. Adults are active in hot wet months as with brown ear ticks. Be aware that adult bont ticks do not occur in treeless open grassland which is a way of controlling heartwater on a farm.

Vaccines are a key method of preventing disease in stock but be aware of essential do's and don't's Vaccines MUST be kept in the fridge at 2-7 degrees C. Thawing due to powercuts etc destroys vaccines. Read instructions carefully before starting to vaccinate stock. Do not vaccinate just before or just after transporting, dipping, castration and dehorning to save time and effort. Stress neutralises vaccination.

Be warned.

Winter Vaccination programme for cattle and small stock. Some key points Some vaccines must be administered in winter well before the onset of wet weather which heralds the

arrival of flies, mosquitoes and midges. In cattle these diseases include lumpy skin disease (LSD), Rift valley fever (RVF) and Three day stiff sickness (Ephemeral fever). Do not wait to vaccinate when rains begin. Order and book your vaccines with FIVET in winter, well before the summer months as vaccines may not be available when urgently required. Be warned that LSD and RVF can cause massive abortions and udder damage respectively which can bankrupt a farming operation. Bulls can be rendered unable to serve cows for weeks and sometimes months after contracting Three day stiff sickness. It is notable that although anthrax can infect livestock anytime of the year most outbreaks of disease have occurred in the early winter period as water levels in dams subside. Vaccinate against anthrax well before the winter months especially in the lowveld of Zimbabwe.

Sheep require vaccination against Blue tongue (BT) out of breeding season and well before wet weather.

Do not be afraid of vaccinating in winter 3 months before breeding as the vaccine can last for up to 2 years.