Autumn Animal Health Update

Toxic Weeds 

With the fantastic recent rainfall seen across the north coast, pastures have bounced back remarkably well. However, with the good has also come the not so good. We have seen the rapid growth of many weeds across the region and the toxicities that go with them. Lantana, smartweed and bracken toxicities are examples of what we have seen across the region recently.

Cases of nitrate toxicity and oxalate poisoning have also been reported around the state. Some weeds, such as pigweed (portulaca), have the potential to cause nitrate toxicity in cattle., especially after the stock has been yarded or trucked and released into an area growing pigweed.  Oxalates in plants can bind with calcium and form crystals in the kidneys, causing severe kidney damage.  Plants such as seteria, amaranth and pigweed can contain high levels of oxalate. Remember, hungry stock are most at risk.

Insects and Parasites

Rainfall in the region has led to explosive populations of mosquitos, flies, midges and other biting insects. Not only is this a nuisance to people but can potentially have detrimental effects on livestock. With increased insect activity, there is a greater risk of disease spread.

Despite the recent explosion in mosquito numbers, we have not yet seen the spread of Bovine Ephemeral Fever (3-day sickness). However, anyone still considering vaccination should do so as soon as possible before cases start to occur.  Three Day Sickness causes fever,  lameness, stiffness and recumbency in cattle. While many cattle may recover in “three days” there are some that remain affected for much longer and deaths, as a result, do occasionally occur. Stock at highest risk is those that are late pregnant, lactating and heavily weighted animals such as cows and bulls.

Along with mosquitoes, buffalo fly numbers are high across the region. These biting flies cause intense irritation and a significant drop in production. There are several control options available.

We have started to see an increase in internal parasite burdens.  Sheep, goat and alpaca are highly susceptible to barbers pole worm, and burdens can increase very quickly in conditions like we are currently experiencing.

Vibriosis 

As reproductive efficiency is one of the most important economic factors in beef breeding enterprises and with the current high cattle prices, producers should be doing everything possible to maximise productivity in their herds. Losses due to vibriosis can have a significant impact on productivity. We have seen quite a few herds with vibriosis lately. Vibriosis is a bacterial venereal disease of cattle; bulls can carry the infection and spread it at mating. In infected herds, we see poor in calf rates at pregnancy testing, especially in heifers and young cows. The disease can be prevented by vaccination with Vibrovax, which should be considered a must for all bulls.

Pink Eye

Pinkeye is a bacterial infection of the eye which can be spread by flies. Many herds are affected by pinkeye (aka blight) at the moment. Bright sunlight and physical irritation to the eye by long grass will predispose cattle to pinkeye. Discuss treatment options with your vet, and fly control is an integral part of prevention.