Tetanus (Lockjaw)
- limb stiffness, stilted gait
- as disease advances, animal will stiffen completely and not be able to open jaw
- convulsions, often triggered by sudden noises
- 3rd eyelid membrane may be visible
- breathing difficult
- death occurs in 3-4 days
Cause/Transmission
- bacteria in soil (Clostridium tetani) enters body through wound and produces a toxin which damages nervous system
- bacteria grows in absence of oxygen, therefore deep puncture wounds are problematic
- most often seen in lambs after castration or docking (elastrator bands and contaminated knives)
Treatment
- usually too late by the time animal shows obvious signs
- clean damaged area and any dead material
- if animal has not been previously vaccinated, dose with tetanus antitoxin and tetanus toxoid (vaccine)
Prevention
- vaccinate ewes using an 8-way (Clostridial and tetanus toxoid) prior to lambing
- use clean equipment for castration and docking, house lambs in sanitary conditions
- don’t use elastrator bands on farms with previous cases of tetanus
Listeriosis (Circling Disease)
(also see abortion diseases)
(also see abortion diseases)
- most often seen in feedlot lambs, but also possible in animals of any age
- depression, off feed, fever
- one side of the body is affected (face paralysis, droopy ear, lip and eyelid)
- animal walks in a circle
- convulsions, death
- diagnostic lab can identify bacteria and examine brain for abscesses
Cause/Transmission
- bacteria (Listeria monocytogenes) forms abscesses in brain
- contracted from infected sheep through cuts
- spoiled feed (particularly silage) often implicated
Treatment
- antibiotic treatment rarely successful
Prevention
- provide good quality feed
- properly dispose of deadstock
- keep pregnant ewes away from sick lamb area
Polio Encephalomalacia
- seen most often in feeder lambs
- non-infectious (no fever)
- may see blindness, staggering, head pressing, progressing to convulsions, coma, and death
Cause/Transmission
- not known for certain, but thought to be a deficiency of thiamine (vitamin B1), due to microbes in the rumen depleting thiamine supplies (can be provided in diet but not available to the animal)
- high mineral content in water may be a contributing factor
- deficiency will eventually give rise to neurological disorder
Treatment
- this is an emergency situation, (contact vet) but if the animal is treated quickly the prognosis is good
- intravenous thiamine injections
- separate animal during recovery
Prevention
- consider adding brewer’s yeast to grain rations
- avoid feeding mouldy hay
- provide adequate water and water analysis
Scrapie
- relatively rare, but reportable disease
- long incubation time, animal may be infected at birth but no signs until sheep is 2yrs or older
- typically extensive loss of wool due to rubbing
- uncoordinated, muscle temour, twitching, grinding teeth, convulsions
- some sheep die quickly with few signs, most die within six months of first signs
- diagnosis only confirmed by lab exam of the brain after death
Cause/Transmission
- prion disease (abnormal protein in body which builds up in nervous tissue)
- transmitted to lambs and older sheep that come in contact with placenta and birth fluids of an infected animal
Treatment
- no treatment
- reportable by law, contact your vet immediately if you suspect your flock may be infected
Prevention
- careful screening of breeding stock sources
- voluntary federal scrapie program is in development to identify flocks at risk of infection, may involve liveanimal test and/or testing for genetically resistant animals
Rabies
- restlessness, twitching lips, excessive drooling (note: not all drooling animals will have rabies, often may be an obstruction in the throat or mouth, however, always wear gloves if you may come in contact with salvia)
- animals may act either excessively docile (depressed form) or aggressive butting against wall or fence etc.
- males may show sexual behaviour
- animal is progressively paralyzed and generally dies within six days
Cause/Transmission
- viral disease which attacks the central nervous system
- usually contracted from the bite of an infected animal (dog, fox, skunk etc.)
Treatment
- none
- reportable disease, contact your veterinarian immediately
Prevention
- no vaccine for sheep
- vaccinate farm dogs annually
- control populations of potential carriers (foxes, skunks etc.)
