POLIO IN CATTLE AND SHEEP

POLIO IN CATTLE AND SHEEP

 

Recently I have been called out to a number of heifer which had some unusual symptoms and behavior. The cause was Polio, and I have seen in sheep on feed but not very often in range cattle.  This year I am getting reports all over Eddy County.  The correct name is Polioencephalomalacia, commonly called (PEM).  It occurs sporadically in cattle and sheep and deer.  It is characterized by sudden onset of blindness, and head-pressing and pathologically by acute cerebral edema.   Un- like human polio the cause of this disease is not completely understood but there is a strong indication that thiamin inadequacy is associated.  Some also suggest selenium deficiency.

 

There are a couple ideas as what causes for this condition.  One is that certain bacteria in the gut of the affected animal produce an enzyme which ties up the thymine and prevent it from being metabolized by the animal. The disease may occur in range cattle grazing on dry, short, grama grass pastures. There is circumstantial evidence that Kochia scorpia which is common in Eddy County as is dry, short grama grass.  The case the Dr. Uric and I looked a few years ago was fairly rare because it was a mature heifer.  But since then we have seen it in mature Bulls and cows.  The disease is also associated with Sulfur consumption, which is common in some of our water.  The clinical finding is similar no matter what the cause.  Sudden onset of blindness, muscle tremor, particularly of the head, champing of the jaws and frothy salivation, and head pressing as well as the animal can be hard to handle.  With the high incidence of rabies found in the skunk population in our area these symptoms start sounding similar to findings with rabies.  One of the differences is polio animals will have close to normal temperature.

Control is dependent on the producer.  First consult with your veterinarian and follow an approved vaccination program.  Select supplemental feed with a good thiamin or vitamin b complex on the label.  Dietary supplementation of thiamine at 3-10 mg/kg feed has been recommended for prevention, but the efficacy of this approach has not been carefully evaluated, and may be at a higher cost. In a recent study, scientists at New Mexico State University's Clayton Livestock Research Center found that steers gained more weight per pound of feed if they also were fed a ruminally protected form of the B vitamin known as choline, or RPC.  In a recent NMSU study, 160 feedlot steers were fed varying levels of the vitamin. "RPC is a granular material that can be mixed in with the animals' feed," said Glenn Duff, current superintendent at the research center.  Steers fed a small amount of the vitamin -- one quarter of a percent of their diet -- showed increased feed efficiency and weight gain. "These steers had an 11-percent increase in daily weight gain compared to steers that weren't fed RPC," Duff said. "Also, their feed-to-gain ratio was improved, so they only needed 5.6 pounds of feed to gain one pound versus the 6 pounds needed by steers with no RPC." The steers fed a small amount of the vitamin also overcame another obstacle -- they began the experiment weighing less than steers in the other groups. "But by the end of the trial, the low RPC steers had passed the other groups in weight gain," Duff said.  The efficacy of PRC for prevention of PEM is unknown at this time.   During a PEM outbreak, sufficient roughage should be provided. If the problem could be associated with high sulfur intake, all possible sources of sulfur, including water, should be analyzed and the total sulfur concentration of the consumed dry matter estimated. Dietary ingredients or water with high sulfur concentration should be avoided; if this is not possible, then more gradual introduction to the new conditions can improve the chances of successful adaptation.   Because of the high rabies out break it is important for human health that a Veterinarian be call if livestock have some of these abnormal conditions.