Bovine Top 20 Diseases - Part 3 Flashcards
what is the classic case presentation of a cow with a selenium deficiency?
stiffness, tetany, cows under 1 year old with acute recumbency, stiff gait, & heart failure & adult cows - with retained placentas, anestrus, & cystic ovaries
what is the classic case presentation of a cow with a magnesium deficiency?
adult cows, recently fresh, multiparous cow with recumbency, hyperesthesia, stiffness, hypertonicity, & sudden death
how is selenium deficiency diagnosed in a cow?
blood selenium levels < 0.05ppm & increased serum CK/AST/LDH
how is magnesium deficiency diagnosed in a cow?
serum magnesium < 1.5mg/dl
how is selenium deficiency in a cow treated?
give selenium, supportive care with slings, vitamin e, oxygen, & diuretics if heart failure
how is magnesium deficiency in a cow treated?
give magnesium & calcium after sedation with diazepam or else you can cause a fatal seizure
what is the prognosis for selenium deficiency in a cow? what about magnesium deficiency?
selenium - fair to good & magnesium - guarded to poor
magnesium deficiency is more common in what cows?
lactating cows on lush/potassium rich pastures with recent environmental changes
T/F: treatment for selenium deficiency doesn’t make necrotic muscles recover but just prevents further damage
TRUE
how is mastitis divided into categories in cows?
acute (high mortality), chronic (low mortality), contagious, environmental, & infectious
what is the classic case presentation of acute mastitis in cows?
serous to serosanguinous milk, diarrhea, obtunded, tachycardic, & febrile
what is the classic case presentation of chronic mastitis in cows?
swollen, firm, hot udder, discolored/flaky/watery milk, & few systemic signs
what are the most common bacterial etiologies that cause mastitis in cows?
strep, staph, & coliform bacterias
how is mastitis diagnosed in an individual cow?
udder palpates abnormally hard/abscessed, california mastitis test with a high somatic cell count, & milk culture
how is mastitis diagnosed on a herd level?
run a somatic cell count (> 750,000 indicates mastitis)
T/F: when treating mastitis, there are different treatments indicated for dry cows vs lactating cows, so withdrawal times need to be watched
TRUE
how do you make sure intramammary antibiotics for mastitis are used correctly for dry vs lactating cows?
the antibiotics will have different colored tips
what is the prognosis of mastitis caused by streptococci? what about staphylococcus?
strep - excellent, staph - variable
what is the difference between route of infection for environmental pathogens & infectious pathogens causing mastitis?
environmental - infects udder between milkings, infectious - infects udder during milking
what is stage I of milk fever? what is stage II of milk fever?
stage I - hyperexcitability, ataxia, & aggressive down cow, stage II - listless, fully down, & hypothermic cow
what are signs of a positive response to treatment of a stage II milk fever cow?
mascle fasciculations, belching, restlessness, urination, heart slows, & pulse strength improves
how is milk fever diagnosed?
clinical presentation - down, weak cow that has recently calved or is about to calve is usually diagnostic, total blood calcium < 8.0mg/dl, & ionized blood calcium < 4.5mg/dl
what treatment is used for stage I milk fever?
oral calcium salts
what treatment is used for stage II milk fever?
IV calcium in water, stop infusion if the pulse gets weak or the cow begins to pant
what treatment is used for refractory milk fever?
float cow in water tank if refractory
what is the prognosis for milk fever?
good to excellent if there are no concurrent disorders
what diets predispose a cow to milk fever?
diets high in potassium & low in anionic ions
what part of the diet influences the incidence of milk fever in dry cows?
pre-partum dry cow rations
what cows are most often affected by milk fever?
multiparous mature dairy or beef cow
what is the classic case presentation of enzootic calf pneumonia?
thin, weaned calf with a good appetite, tachypnea, cough, & crackles/wheezes heard on lung auscultation with harsh sounds & no cranioventral sounds
what is the classic case presentation of shipping fever?
any age cow recently shipped or stressed with tachypnea, soft cough, sepsis, & crackles/wheezes on lung auscultation with harsh sounds & no cranioventral sounds
what are common bacterial isolates from enzootic calf pneumonia?
pasteurella multocida type a, mannheimia haemolytica, & mycoplasma bovis
what are common bacterial isolates from shipping fever?
most often mannheimia haemolytica, but can have pasteurella multocida or histophilus somni
how is bovine respiratory disease complex (enzootic calf pneumonia/shipping fever) diagnosed?
tracheal aspirate, pharyngeal swab, culture/cytology, ultrasound/rads of thorax, & pleurocentesis
how is bovine respiratory disease complex treated?
appropriate legal use of antibiotics & anti-inflammatories
T/F: there is a worse prognosis for bovine respiratory disease complex if there is a concurrent BVD infection
TRUE
what prevention is used for bovine respiratory disease complex?
vaccinations against BVD, clostridial diseases, parainfluenza-3, & pasteurella multocida
T/F: most calves affected with enzootic pneumonia or shipping fever recover but will have a delayed time to maturity
TRUE
what clinical signs are seen with the clostridial condition black disease?
icterus
what clinical signs are seen with the clostridial condition black leg?
swollen limb with crepitus & lameness
what clinical signs are seen with the clostridial condition bacillary hemoglobinuria?
red water, icterus, hemoglobinuria, concurrent liver flukes
what clinical signs are seen with the clostridial condition gas gangrene?
malodorous wound with crepitus
what clinical signs are seen with the clostridial condition enterotoxemia?
bloat, colic
what clinical signs are seen with the clostridial condition malignant edema?
necrotic fasciitis, lameness
what clinical signs are seen with the clostridial condition hemorrhagic bowel syndrome?
multiparous dairy cow in peak production with blackberry jam feces & colic
what clinical signs are seen with the clostridial condition botulism?
recumbency, weak tongue, tails, eyelids, jaw, & anus
what clinical signs are seen with the clostridial condition tetanus?
stiffness, bilateral prolapsed nictitans, recent metritis, or wound
what is the etiology of black disease?
c. novyi type b
what is the etiology of black leg?
c. chauvoei
what is the etiology of bacillary hemoglobinuria?
c. haemolyticum
what is the etiology of gas gangrene?
many but especially c. perfringens
what is the etiology of enterotoxemia?
c. perfringens type d
what is the etiology of malignant edema?
c. septicum
what is the etiology of hemorrhagic bowel syndrome?
c. perfringens type a with b-2 toxin
what is the etiology of botulism?
c. botulinum
what is the etiology of tetanus?
c. tetani
how are clostridial conditions diagnosed?
aspiration or tissue collection for anaerobic culture, toxin analysis, PCR, or fluorescent antibody testing
what is the prognosis for clostridial diseases in cattle?
poor to grave due to rapid disease progression (inversely related to survival rate)
T/F: clostridium species are common contaminants of ruminant digestive tracts & soil
TRUE
what is required for clostridial growth?
necrotic tissue!!! they are anaerobes!!!
how are clostridial diseases prevented in cattle?
vaccinations using the 6 way clostridial bacterin/toxoid
how are clostridial disease treated?
when applicable - wound debridement, local antitoxin injection, & systemic antimicrobials
