Sunday, June 8, 2014

pre-weaned lambs and worms

Right now many of the spring lambs are at the point where weaning will be occurring, if it hasn't already. as cool spring grasses begin to slow in growth, pastures can be over-grazed and this can lead to increased parasite pressure, especially from the barberpole worm (h.contortus). while they may become dormant in prolonged drought and heat, the younger animals particularly are susceptible and can easily help these parasites multiply.

When sampling fecals to check on the need to deworm, include samples from some of this years lambs and treat them if indicated. It will help them wean off better, make better use of the creep feed that may be provided and get them to target weights for those breeding early ewes to lamb as yearlings.

Treat smart as well. Using Safeguard or Valbazen(the benzimidazole class), often it is recommended to double the dose, and also hold sheep off feed prior briefly; this will help increase the effective concentration of dewormer in the gut. Don't use give dewormer as an injectable(such as ivomec - drench form is fine)in small ruminants - the long tail of declining concentration when given that way can lead to resistance developing more rapidly. And if you haven't used Ivomec - don't go immediately to Cydectin drench(moxidectin). If you develop resistance to that drug, you'll also have created resistance to Ivomec too - instead, keep using Ivomec until you find it isn't working. Save Cydectin for when you need to treat a resistant population.

Do you see this? Here is a very anemic animal, evident in the pale conjunctiva

Besides other clinical signs(bottle jaw/anemia, ill-thrift and weight loss, lagging behind flock)how best to find if your dewormer isn't working? Test fecals before and after. Treat the animals that need it and not everybody on a random calendar date. Treatment of parasites in small ruminants is a complex equation often. Questions of timing, testing, and how to treat? Ask your flock veterinarian on these and other questions, such as how to handle new arrivals to keep those resistant worms off your pastures. You will not only boost the performance of your animals but keep the dewormers working by avoiding or minimizing resistance.

And hope for timely rains this summer - to keep these pastures growing along with the sheep and lambs on them.