FOOT ROT (INTERDIGITAL NECROBACILLOSIS) FOOT ROT (INTERDIGITAL NECROBACILLOSIS)

Causes

Footrotiscausedbyvariousbacteria,themostcommonofwhichis Fusobacteriumnecrophorum.

Whileitusuallyoccursassporadicindividualcases,outbreakscanoccur Allagesofcattlearesusceptible

Infectedfeetarethesourceofinfection,butthebacteriacansurviveinthesoil Bacteriainfectfeetthroughabrasionsordamagetotheskinbetweenthetoes Wet,humidweathercausingmuddygroundandwet,dirtybedding,rough ground,andhighstockingdensityincreasetheriskofdisease.

FOOT ROT IS THE MOST COMMON CAUSE OF LAMENESS IN BEEF HERDS, AND THE 2ND MOST TREATED DISEASE IN WEANED CALVES AND ADULT CATTLE.

Clinical Signs

Animals are usually severely lame in one limb, putting very little weight on the leg

The foot is swollen between and above the claws at the coronary band. The skin between the claws may have a crack covered in dead tissue, and the foot will have a foul odor.

Animals may have a mild fever (39-40°C).

Affected bulls may show temporary infertility and cows may have a temporary drop in milk production.

If left untreated, the infection may spread to the joints and tendon sheaths

PROMPT TREATMENT OF FOOT ROT CAN RESULT IN A POSITIVE RESPONSE!

Treatment

Immediate treatment after the onset of swelling and lameness typically results in an excellent response In outbreaks, footbaths with copper sulfate and/or feed medication with tetracyclines may be effective in controlling the disease For those cattle with secondary joint infections or chronic foot rot, consider culling or humane euthanasia

Always consult your veterinarian about treatment strategies.

Preventative Management

Foot Rot can be prevented by reducing the risk of foot injuries (e g , fixing corrals, eliminating garbage in pastures), ensuring even footing in cattle handling areas, and keeping bedding areas, pens, and barns clean and dry Consult your veterinarian for advice on prevention, treatment, and control, including the use of footbaths.

Vaccination

Foot Rot (i.e., Fusobacterium necrophorum) is considered a risk-based vaccine.

A commercial vaccine is available in Canada, but the vaccine’s effectiveness has not been well established in controlled field trials Discuss with your veterinarian whether to use the vaccine and its potential cost benefit in your herd.

Causes

Histophilosis is caused by the bacteria, Histophilus somni (previously called Hemophilus somnus).

This bacteria can be found in the upper respiratory and reproductive tracts of healthy cattle. The bacteria is shed in nasal and vaginal secretions and urine. It can evade normal immune mechanisms that normally kill bacteria

HISTOPHILUS SOMNI BACTERIA ARE A SIGNIFICANT CAUSE OF RESPIRATORY DISEASE IN PRE-WEANED CALVES AND A SIGNIFICANT CAUSE OF MORTALITY IN FEEDLOT CALVES.

Clinical Signs

Histophilosismayappearwithvarioussymptoms,suchas:

Pneumonia:depression,offfeed,nasaldischarge,coughing,fever Laryngitis(Wheezer):snorewhenbreathingin

Earinfections:eardroop,headtilt,dischargefromear

Heartdiseaseandpleuritis:depressed,frothatmouth,mouthbreathing, orsuddendeath

Nervousdisease:depressedandknuckleonbackfeetinearlystages; typicallyfounddowninpen;maystargazeorareunabletogetup,with involuntarycircularmovementofeyes

Jointinfections:lame,swellingsoverlargejoints(e.g.,stifle,hock); usuallyaffectingmultiplejoints;mayalsohaverespiratorysigns

Abortions:possiblebutnotcommon

HISTOPHILUS SOMNI ARE CONSIDERED RISK-BASED VACCINES. DISCUSS WITH YOUR VETERINARIAN ABOUT WHETHER YOUR HERD SHOULD BE VACCINATED AGAINST THIS DISEASE.

Treatment

Usuallytreatedwithantimicrobialsandifgivenearly,animals mayrespond.Heartdiseaseisnoteasytodiagnoseuntilafter irreversibleheartdamagehasoccurred

Alwaysconsultyourveterinarianabouttreatment strategies.

Preventative Management

Reduce stress on cattle. Ensure good biosecurity. Use antimicrobials for metaphylaxis only when necessary. Prudent antimicrobial use is necessary to reduce antimicrobial resistance against H somni in in-coming feeder cattle, so antimicrobials will be effective in these animals, which are at greatest risk of this serious fatal disease In a Histophilosis outbreak, contact your veterinarian on how to control and reduce disease losses

Vaccination

Histophilussomniisconsideredarisk-based vaccine.

Afewkilledwholecellvaccinesareavailable commerciallyinCanada.However,thereislittle evidencefromcontrolledfieldtrialstoshowthat existingvaccineseffectivelyreducethemultipleforms ofHistophilosisincommercialbeefherds

Discusswithyourveterinarianwhethertouse existingvaccinesandtheirpotent yourherd.