Unit 2 - Small Ruminant Pizzle Rot to Enterotoxemia Flashcards
What is water belly?
Urolithiasis
What causes urolithiasis?
High phosphorus in the diet
What should the Ca:P ratio be in small ruminants?
2:1
How do you prevent urolithiasis?
Balance rations, feed ammonium chloride, provide free choice salt, and ample fresh clean water
What is pizzle rot?
Ulcerative posthitis
What causes pizzle rot?
excessive protein in the diet and the presence of Corynebacterium renale
What does C. renale do?
It breaks down urea in urine to ammonia which irritates the mucous membranes of the prepuce
What lesions are associated with pizzle rot?
Erosions, ulcers, necrosis, crust formation, and constriction/phimosis resulting in the inability to urinate
How is Ulcerative posthitis prevented?
Reduce protein in the diet
Remove wool or hair from the preputial area
How is ulcerative posthitis treated?
Topical treatment of the lesions and surgical drainage of the lesions
What causes Bluetongue?
Orbivirus (many different serotypes)
What species can harbor orbivirus?
Deer and cattle
What transmits Bluetongue?
Culicoides (midges)
It can also be transmitted via semen and from the dam to the fetus
In what season does Bluetongue typically occur?
Mid-summer or later months
T/F: Suckling lambs are protected from Bluetongue by their colostral immunity in endemic areas
True
What small ruminant population gets severe disease from Bluetongue?
Feeder lambs
What does Bluetongue cause in pregnant ewes?
It may cause abortion at 4-8 weeks of gestation, hydrancephaly, or congenital deformities
What clinical signs does Bluetongue in feeder lambs?
High fever for 6-10 days
Hyperemic or cyanotic mucous membranes of the mouth, skin of the face and feet
Vascular damage
Erosions on mucous membranes of the mouth after 48 hours of fever
Profound depression, anorexia, and weight loss
Edema
Lameness or stiffness
What causes epizootic hemorrhagic disease of deer?
Orbivirus
How is Bluetongue diagnosed?
Clinical signs, several serologic tests, and virus isolation
How is Bluetongue prevented and controlled?
Vaccination (MLV)
What population of small ruminants should not be vaccinated against Bluetongue?
Pregnant ewes
When should vaccination against Bluetongue be done?
after shearing because it can cause wool break
What is one of the ‘big five’ causes of sheep abortions? When does it (the abortion) happen?
Listeriosis in the last trimester
What other clinical manifestations does Listeriosis cause in small ruminants?
Circling disease
Septicemic
How does the circling disease caused by Listeriosis present?
Unilateral facial paralysis
Roughage hanging out the side of the mouth
Will move back to same position if moved
Where is Listeriosis found?
Plant material and soil
Silage with a pH greater than 5
High ash content
Other forms of spoiled roughage
How is Listeriosis diagnosed?
Abortion - culture/histopath
CNS - CS/culture/histopath
Septicemic - culture
How is listeriosis prevented?
Prevent contamination of feed
What differential diagnosis should be considered with listeriosis?
Polioencephalomalacia
What can cause polioencephalomalacia?
High grain diets, high sulfur diets, corn, sugar beet, and sugarcane by-products
How is polioencephalomalacia treated?
Injectable thiamine
What is the most likely cause of focal symmetrical encephalomalacia?
Clostridium perfringens type D
Most focal symmetrical encephalomalacia outbreaks occur in conjunction with what?
Enterotoxemia in lambs
What are the differential diagnoses for focal symmetrical encephalomalacia?
Brain abscesses, tetanus, strychnine, hypomagnesemia, and rabies
When should ewes be immunized against tetanus?
at least 2-weeks prepartum
How many times should lambs be vaccinated against tetanus and with what?
2x with CDT (C. perfringens type C and D and C. tetani)
What are the reasons for tail docking?
Fly strike and for looks
What happens if tails are too short after tail docking?
Nerve damage predisposes to rectal prolapse
Where should a lambs tail be docked?
At the distal end of the caudal tail fold
What are some reasons for/against castration?
Ethnic markets - some prefer intact males
Commercial - lower price for intact males
Growth rate - slows when they reach sexual maturity during breeding season
Safety
How do ruminants with strychnine poisoning present?
Animals are hyperexcitable and rapidly develop spastic convulsions and die in a few hours
What is hypomagnesemia also known as in small ruminants?
Grass tetany or grass staggers
What clinical signs does hypomagnesemia cause?
Muscular spasms, convulsions, respiratory distress, collapse, and death
How is hypomagnesemia treated?
With Mg salts
What is the primary agent in small ruminant contagious foot rot? Other agents?
Primary: Dichelobacter nodosus
Other - Fusobacterium necrophorum, Trueperella pyogenes
In what season is ovine foot rot transmitted?
Wet/warm season - 50-70 degrees F
How is ovine foot rot treated in the US?
Parenteral abx or culling
How is ovine foot rot prevented in the US?
Routine hoof trimming and footbaths (zinc sulfate)
Describe the Australian Eradication Program for footrot.
Control disease as much as possible during wet and warm season
Do not treat during dry season/season of no transmission
After 10-12 weeks, inspect every hoof and cull affected sheep
Repeat inspection and culling every 4 weeks
Surveillance - cull any lame sheep
T/F: Contagious pustular dermaitis, soremouth, Orf, and Ecthyma are all different diseases caused by the same virus; Parapoxvirus
False - They are all the same thing caused by 6 different strains of parapoxvirus
T/F: Orf is readily transmitted to lambs and can transmit to the teats of the ewes from lambs,
True
T/F: Orf is zoonotic.
True
How is Orf vaccinated against?
Vaccination by scarification - take the vaccine and scratch the animal with it
Make sure all Orf lambs are infected (before/after) weaning.
after
What is the etiologic agent of caseous lymphadenitis?
Corynebacterium pseudotuberculosis subsp. ovis
What are the two routes of infection of caseous lymphadenitis?
Traumatic introduction
Inhalation and invasion through damaged buccal mucosa
What lesions are associated with caseous lymphadenitis?
Abscessation of the lymphoid tissue, lungs, liver, kidneys, and other sites
How is caseous lymphadenitis prevented?
Sanitation
Minimize wounds and disinfect when they occur
Immunize
Chlortetracycline in the feed
How is caseous lymphadenitis treated?
Antibiotics - not really effective
Surgical removal
T/F: Injecting formaldehyde into superficial abscesses is FDA approved
No
A feeder lamb found dead without prior clinical signs is considered to have died from _________ until proven otherwise.
enterotoxemia
What population of small ruminants is enterotoxemia common in?
Almost always feeder lambs being fed high levels of concentrates - they are the best doing lambs typically
What causes Enterotoxemia?
C. perfringens type D
What toxin causes enterotoxemia?
Epsilon toxin
What does epsilon toxin act on?
Vascular endothelium
What does enterotoxemia cause (general)?
Edema and occasionally hemorrhage in affected tissues - brain is most sensitive
What clinical signs are associated with enterotoxemia?
Usually found dead
If alive - CNS signs predominate, stargazing, opisthotonos, circling, depression, stumbling, convulsions, recumbency, and rapid death
What lesions does enterotoxemia cause?
Focal symmetrical encephalomalacia Pulmonary edema Serous effusions Hemorrhages of the meninges, small intestine, endocardial, and subendocardial around the mitral valve May have a colitis
How is enterotoxemia prevented?
Vaccinate with CDT 2x prior to placing on full feed
Good feedbunk management
Creep feeding
Feeding Iasalocid
How is enterotoxemia treated?
There really is no treatment once clinical signs appear
