Ruminant Dermatology Flashcards
What fly infestation is seen?
a. face fly
b. deer fly
c. horn fly
d. horse fly
e. stable fly
A
What fly is likely affecting this cow based on location?
a. face fly
b. deer fly
c. horn fly
d. horse fly
e. stable fly
C
What fly is likely affecting this cow based on location?
a. face fly
b. deer fly
c. horn fly
d. horse fly
e. stable fly
E
Where do face flies lay their eggs? What unique aspect affects control measures?
newly deposited manure - hatch within a day and complete their lifecycle within 14-21 days
strong fliers - can fly several miles to find a new meal/mate
What face fly commonly affects ruminants? Where are they most commonly found? What are they a vector for?
Musca autumnalis
feed on secretions of eyes, muzzle, and open wounds with spongy mouthparts
pinkeye
What is the main way of controlling face fly infestation?
insecticidal fly tags placed in ears a few weeks before peak fly season (July-Aug)
When are fly tags for controlling face flies removed? Why?
fall - decreases fly resistance due to low concentration of insecticide left at this point
Are fly takes used for controlling face flies placed in both ears? What breed commonly does not require any tags?
depends on susceptibility and prevalence.incidence of disease
Bos indicus - larger ears make tags not as useful
Other than fly tags what are other options for face fly control?
- dusting/dusting bags
- oilers, back rubbers
- whole animal sprays
- oral insecticides incorporated into mineral blocks or feed (Rabon, Methoprene (IGR), Dimilan)
- biological control with Pteromalid wasps that deposit their eggs within the pupa case of flies and larva feed on developing flies (not as effective in pasture situations)
How long do most insecticidal fly tags last?
variable - depends on fly resistance
What horn flies commonly affect cattle? Where do they lay their eggs?
Hematobia irritans - disease vector with sabre-like proboscis, which allows transfer of blood-borne disease
fresh manure (same control as face fly!) —> overwinter in puparium near or under manure pats
How do horn flies act?
adults stay on host continually, unless laying eggs —> good weather = sides and back, bad weather = ventrum
- swishing tail can spread flies to nearby cows in the herd
How much blood can horn flies take from their host? When are control measures performed?
500 flies = 7 mL blood loss/day (>200 flies on a cow starts affecting economics)
pour-on ivermectin products and tag when 200 flies are present per head —> recommended to start just as horn flies start appearing in the spring
What part of the environment is commonly affected by horn fly control measures? What alternative is preferred to avoid this?
dung beetles —> ivermectin kills
cydectin does not affect them
Why are multiple measures of fly control recommended for herds?
flies commonly become resistant to the pyrethroid/OP found in the ear tags
- pour-ons
- dusting
- fly traps
What is a stable fly? What are their preferred feeding sites?
Stomoxys calcitrans —> biting house fly with sabre-like mouthparts (transmits blood-borne disease)
lower extremities and flanks during the day - only on the host when feeding
How can stable flies be controlled? What are they linked with spreading?
- clean environment
- eliminate breeding sites
- UV zapper and other predatory systems
- insecticides (pour-ons, dust bags)
- feed additives
HIV
In what 5 ways can breeding areas of stable flies be controlled?
- remove manure and rotting vegetation
- clean up spilled silage and broken bales
- fix leaky water and pipes
- provide drainage around silage pits and pens
- remove decaying spilled grain
What kind of hosts do lice prefer? How do they complete their life cycle?
highly host specific - bovine lice will not feed on humans
takes 3-4 weeks and spends it entirely on the host —> eggs hatch in 8 days, so long-term treatment is not necessary
Once treated, when should cattle with lice be retreated? How does this compare with different types of lice?
14 days
- BITING lice feed on epithelial and cutaneous debris, so topical treatments are enough
- SUCKING lice feed on blood and tissue fluid, so systemic treatments are needed
What 3 sucking lice infect cattle? Where on the body do they tend to be found?
- Hematopinus eurysternus
- Linognathus vituli
- Solenoptes capillatus
neck, poll, nose, withers, tail = pruritic, alopecic, restlessness, anemia
What cattle are affected by lice? When is infection worse?
all ages
seasonal - worse in winter
What ectoparasite is likely affecting this calf?
sucking lice
- alopecia, likely itchy
What is the lifecycle of lice like? When is the best way to treat?
eggs laid on host hatch within 8 days —> larva develop for 18-21 days —> able to lay more eggs and begin life cycle again
treat once eggs are noticed and retreat within 2 weeks as larva develop
What biting lice most commonly infects cattle? Where are they found?
Damalinia bovis
neck, withers, and tailhead —> rough hair coat, patchy alopecia, excoriations, anemia
What treatment is recommended for lice infestation? How can it be prevented?
IVERMECTIN —> resistance not as common in lice, twice at 2 week intervals
- SQ
- pour-ons cover both type of lice
- powders/dust work OK
improve hygiene, nutrition, and environment, quarantine
How do goats present with lice infestations?
- will chew on themselves = twisted hair
- alopecia
- pruritis
How do swine lice compare to cattle lice?
much larger, easy to find nymphs on hair at the neck and ears
- Hematopinus suis
Swine lice:
- most common on neck and ears
- large!
Which of the following is true regarding bovine lice?
a. control consists of treating only clinical cases
b. identification the louse is important for vital treatment and control purposes
c. lice problems tend to be worse in colder weather
C
Which of the following is true regarding bovine flies?
a. face flies have sponge-like mouthparts and feed around the eyes and may spread pinkeye
b. horn flies are blood suckers that spend most of their time on the head and neck
c. parasitic wasps are highly effective non-chemical form of stable fly control
A
- horn flies are most commonly found on the back
What fly is primarily responsible for transmitting pinkeye?
face flies
Which flies are associated with each control measure?
- improve hygiene and clean up manure
- insecticidal pour-ons
- ear tags
- stable fly
- horn fly
- face fly
What 3 mites most commonly affect ruminants? Where are each found on the body?
- Chorioptes bovis - leg and tail
- Psoroptes natalensis - body
- Sarcoptes scabies - scabies, barn itch
What clinical signs are associated with Chorioptes bovis infection? What is its lifecycle like? When is infection worse?
pruritic and crusty lesions on feet, hind legs, udder, scrotum, tail, and perineum
can live a few days off of the host, not necessarily host-specific —> horses, sheep, goats
fall/winter - regresses in summer
How is Chorioptic mange diagnosed? Treated?
superficial skin scraping
OP or Ivermectins (residual Ivomec) for entire herd at 10-14 days intervals
What is an indication for dipping/spraying for ectoparasite control? When is this preferred?
control ticks (weekly), kill lice (2x with weekly intervals) and mites (weekly)
low withdrawal times for dairy (0 days) and meat (7 days) cattle
What is the most common location for Chorioptic mange lesions?
pruritic alopecia in the fossa around the tail
More severe Chorioptic mange:
starts affecting the thigh area
- dairy > beef due to closer living conditions
Very severe Chorioptic mange:
leg and tail extensively affected
- rarely reaches this level
How does chorioptic mange most commonly present in goats? How does this affect diagnosis?
extensive hyperkeratosis of lower rear legs
difficult to find ectoparasites on scrape of adults compared to kids
What clinical signs are associated with Psoroptic mange? Where in the US are infestations most common?
intense pruritis on shoulders and rump (body mange) —> can lead to anemia, lymphopenia, and neutropenia
western and central US
What is the most deadly mite infecting cattle?
Psoroptic mange —> can survive off hose >2 weeks, causes anemia, lymphopenia, and neutropenia
How is Sarcoptic mange transmitted? What 2 species most commonly infect cattle?
direct/indirect contact —> can survive short periods off the host, tend to be species-specific but can be transmitted to humans —> self-limiting with no re-exposure
- Sarcoptes scabiei var bovis
- Sarcoptes scabiei var suis
What age of cattle are most commonly affected by Sarcoptic mange? How does the lifecycle compare to other types of mange?
all ages, not as prominent in the young
- mites burrow deeper to lay eggs that hatch more rapidly within 2-3 days (many products work in this period of time!)
- total lifecycle = 10-17 days
What clinical sign is most commonly seen with Sarcoptic mange?
intense pruritis due to hypersensitivity to mite feces distributed over the face, neck, shoulders, and rump
How is Sarcoptic mange diagnosed?
- DEEP skin scrape
- remove encrusted lesions and place on black paper to observe adults
usually presumptive
How do most humans come into contact with Sarcoptic mange from farm animals?
cuddling pigs
What treatment is recommended for Sarcoptic mange? Eradicated?
treat entire herd with Avermectins —> long lasting Doramectin, Ivermectin (one-time SQ)
treat facilities with acaricide
What is the most common cause of tail sloughing in cattle?
feces packing on tail due to poor environmental conditions
