AgWatch


Wet Weather – Good Or Bad?

DR. TERESA L. STECKLER 

SIMPSON, ILL.
   During the first week of July around 10 inches of rain have fallen at the Dixon Springs Ag Center! I do know other areas have received even more rain. The consistent rains have left behind saturated pastures. While the pastures look green and growing, the ample rain can possibly cause health issues for livestock.
   Risks of foot rot and pinkeye are higher among livestock grazing flooded or muddy pastures as both bacterial infections thrive in wet conditions.     Therefore, it is very important for livestock producers to carefully monitor their animals’ health.
   Livestock hooves soften if animals are pastured on wet ground or housed in damp pens for extended time. Softer hooves are more susceptible to cuts, tears, or abrasions creating an opening for organisms that cause foot rot. To minimize foot rot, move the cattle to higher ground but avoid hard or gravel surfaces until their hooves have dried out to reduce the likelihood of cuts, tears, or abrasions.
   A tell-tale sign of hoof problems is lameness.  Livestock producers should bring lame animals up and examine the animals’ hooves. Cattle with foot rot typically have a swollen foot with the toes, or “claws,” spread out more than usual. Additional signs of foot rot include foul-smelling odors, heat and inflammation at the coronary band where the hoof adjoins the pastern are signs of the disease. Producers should trim the hoof to remove damaged or dead tissue and then treat the affected foot with one of the following: antibacterial sprays, footbaths, or footsoaks.
   Since the copious rains have fallen, several herds have been affected by pinkeye. Pinkeye can affect cattle of all ages, but calves are especially susceptible. One of the problems associated with this disease is weight losses of as much as one half pound per day in calves with pinkeye. On average calves diagnosed with pinkeye weigh 19.6 pounds less than healthy calves. Moreover, calves left with scars on the cornea are known as “blue eyed” and subject to discounts in the markets.
   Pinkeye can render an animal completely blind, thus affecting its eating habits and ability to sustain normal health. Studies estimate that pinkeye costs $150 million nationwide because of decreased weight gain, limited milk production and treatment costs.
   The primary infectious bacteria is Moraxella bovis. The surface of the bacteria is covered by hair-like structures known as pili, which attach or adhere to the conjunctiva or the cornea. Adhesion prevents the bacteria from being washed away by tears and blinking. The disease is highly contagious and causes inflammation of the cornea and the mucous membrane lining the inner surface of the eyelids and covering the front part of the eyeball.
   Early signs include excessive tearing, squinting, avoiding sunlight and pain. On examination in the chute, you might notice an ulcer in the affected eye. M. bovis bacteria are shed in the tears or discharges from the eye of infected cattle. Carrier animals, shedding M. bovis, can remain infected for over a year, and can provide the source of the infection from year to year.
   Thus, while the rain is a blessing for forage production, the wet weather typically increases the incidence of face flies that irritate eyes and help spread the disease. Another factor that increases the susceptibility of the calf to M. bovis is irritation of the eye by dust or plant material from mature, unmowed pastures.
   In addition to the wet weather potentially increasing the incidence of foot rot and pinkeye, keep in mind that the wet weather also creates conditions favorable for internal parasites to infect animals on pasture. 
   Liver flukes, which can cause significant economic losses in cattle, are more common in wet weather. Barber pole worm, large stomach worm, wire worm, medium or brown stomach worm and small stomach worm are aided by wet weather. Scours, anemia and unthriftiness are common signs of a heavy internal parasite infestation.
   “Bottle jaw” – swelling under the jaw caused by fluid escaping from the blood vessels, is a serious indicator of barber pole worm infestation in calves. However, many dewormers used against barber pole worm are becoming ineffective.
   Also wet weather creates conditions ripe for ticks. Treat ticks with dips, sprays, pour-ons or ear tags. Tick bites can cause swelling, redness and localized infections. Ticks are also the primary transmitter of anaplasmosis, which causes severe anemia. Older cattle are more susceptible to the more severe forms of the disease than are calves or heifers. Infected cows may exhibit rapid weight loss, off-feed, incoordination, breathlessness and brown urine. Fevers up to 106 oF may occur, and pregnant cows may abort.  
   Whether you are sure or unsure of the diagnosis, call your herd health veterinarian for consultation and advice on the best treatment and dosage indicated. ∆
   DR. TERESA L. STECKLER: Extension Specialist, Animal Systems/Beef, Dixon Springs Agricultural Center, University of Illinois
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