We have seen a few interesting cases this past few weeks of cattle and sheep eating plants that have proved toxic. Often a wet spell in the autumn encourages grazing animals to seek out some more fibrous plants; or weather conditions encourage the proliferation of unwanted plants and moulds/fungi (mycotoxins).
We have had reports of Ergot poisoning this year and I have heard people talking about having to clean grain that is contaminated with Ergot. Ergot contains the Claviceps mycotoxin which causes severe constriction of blood vessels, commonly causing gangrene of the extremities; ear tips and hooves typically can slough. Ergot has the appearance similar to rat droppings in grain, typically rye, barley, wheat and oats but it can also occur in grass seed heads. Those of you who are home mixing should be mindful not to include any contaminated grain.
We have seen an outbreak of Perennial Rye Grass Toxicity or Staggers in growing lambs. This is the first case I have ever seen; conditions have allowed the growth of Epichloë festucae that produces an alkaloid mycotoxin responsible for the condition. Signs include muscle tremors and fasciculations, ataxia, a stiff or spastic gait, weakness, recumbency, heat stress, dehydration, and collapse. Signs became apparent only when the lambs were moved or stressed. Removal from the affected pasture gave a virtual total recovery in a week.
We also saw an outbreak of Photosensitisation (severe sunburn) in store lambs that were grazing some SFI pasture with a mix that contained buckwheat. The pasture was past its best for grazing, that meant the buckwheat was probably more palatable than normal. Buckwheat contains fagopyrin, a toxic compound that reacts with UV light from sunlight causing skin cell membrane damage. White lambs/cattle are particularly affected as black skin pigment is protective from UV light. Cases of photosensitivity in cattle can be quite remarkable and visual where only the white skin is affected. Other plants that can cause this primary toxicity are St John’s Wort and Cow Parsley. We can see a secondary photosensitisation due to liver damage where the substance phylloethyrin (ingested in normal plants) that is usually metabolised by the liver accumulates in the skin and causes cell damage.
In all cases of photosensitivity, it is important to remove the animals from UV light and provide supportive therapy. Primary cases can improve once the poisonous plant has passed through the gut, secondary cases are less responsive as liver damage is slow to repair.
A new Dog flea and tick treatment has been launched; Bravecto injection lasts for a whole year, giving you peace of mind and no need to remember to re-treat. Since the Bravecto oral was launched quite a few years ago it has been our go to product with excellent reviews. The injection will need to be administered by us and can be done at the same time as the annual booster vaccine for convenience.
We are holding a Sheep Lameness meeting on the 6th November 7pm for 7.30pm start at the surgery. Please call to reserve your place, refreshments will be provided.