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Rodents And Their Impact On Livestock

By Katie Murray

Rodents are inevitably present on most farms, and with the use of buildings, such as barns the use of animal feeds and water, they provide perfect conditions for an infestation to occur.

In fact in some areas, more than 90% of farms are infested with rats and/or mice.

Infestations cause serious damage to buildings, building insulation, equipment, and electrical cords from gnawing and burrowing.

- Damage to electrical cords can cause fires: It is estimated that 50% of farm fires are related to rodent problems. Rats and mice are the known carriers of 45

diseases. They consume, contaminate, and damage feeds

and water with feces and urine, which plays a part in the spread of diseases.

Therefore, rodent infestation causes various huge economical losses for farmers.

Caused by the bacteria erysipelothrix rhusiopathiae. Carried by both rats and mice- spread by bites from the infected animal through

saliva and/or droppings and urine from contamination. Zoonotic disease. Swine are most commonly infected- “Diamond Skin Disease” - Subacute Form- lesions and ulcerations form on the skin in sort of a diamond shape, have a fever, decreased appetite, gilts/sows become infertile, abortions and dead piglets from sows. - Acute Septicemia Form- fever, raised diamond shaped bumps on skin, which turn from red to black due to dead tissue, reluctance to walk, abortions, stillbirths, mummified piglets, sudden death. - Chronic Arthritis Form- may or may not follow subacute/acute form- infects the joints producing joint infections leading to lameness and heart valves producing growths. Also spread by infected pigs through feces and nose-to-nose contact.

Treatment- Penicillin is the drug of choice and pigs will typically show improvement within 24hrs. Those pigs with the chronic form should be culled.

Erysipelas

Caused by the bacteria yersinia enterocolitica. Carried by both rats and mice- spread through the infected

animals’ feces. Zoonotic disease. The disease is a bacterial infection of the gut infecting mostly

young cattle- weaned calves and yearlings. Can also spread from calf to calf through feces on pasture,

where they can pick it up by grazing. Symptoms- infected cattle scour, dehydrate, have decreased

appetite, lose weight very quickly, develop a dull coat, and become ill-thrift. If left untreated death can occur.

Diagnosis- this disease can be confused with such diseases as worms, coccidiosis, or acidosis, so a fecal culture is useful in the determination for proper antibiotic treatment.

Treatment- specific antibiotics that kill the particular bacteria.

Yersiniosis

Caused by the protozoan parasite cryptosporidium parvum. Carried by both rats and mice- spread through the feces and

flesh of the infected animal. Zoonotic disease. Most livestock can contract the parasite, but young animals are

most susceptible, especially calves and lambs. Causes infection of the gastrointestinal tract from the ingestion

of oocytes that are found in the infected animal’s feces. Symptoms- diarrhea (typically green and watery), decreased

appetite, depression, weight loss, and dehydration. Diagnosis- observing the described symptoms, but a fecal

sample is also helpful as these symptoms are similar to other diseases.

Treatment- not typically used because animals will recover without it. However, electrolytes should be given to dehydrated animals.Cryptosporidio

sis

Caused by the parasite toxocara vitulorum. Carried by rats and mice- spread by the infected

animal’s feces. There are several types of toxocara, but toxocara

vitulorum is exclusively passed onto ruminants. Cattle can get it by ingesting pasture contaminated

with feces that contain the parasite’s eggs. Once inside the animal, these eggs can hatch in

the intestine and penetrate the intestinal wall to move to other tissues, such the liver, lungs, kidneys, lymph nodes, etc. It can also be passed to calves through colostrum in milk.

Toxocariasis

http://www.ah.novartis.com/fhp/en/rodent_control.shtml http://map.ais.ucla.edu/portal/site/UCLA/menuitem.789

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http://www.vetmed.wisc.edu/pbs/zoonoses/Erysipelas/erysipelasindex.html

http://www.thepigsite.com/diseaseinfo/41/erysipelas http://

www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/50902.htm

http://www.cambridgevets.co.nz/data/usr/37/Advisor%20Dec09.pdf

http://www.thevetcentre.co.nz/afawcs0149991/CATID=14/ID=97/SID=782027244/productdetails.html

http://www.thebeefsite.com/diseaseinfo/209/cryptosporidiosisResources