Head & Integument Diseases Flashcards
You are called in to a farm because a large number of the heifers in the herd look like this. What is your no 1 differential? What will you tell the producer? How will you get rid of this?
dermatophytosis or “ringworm” caused by trychophyton verrucosum
this is zoonotic, so be careful when touching these animals! any species can get it!
these animals spontaneously recover in a few months so we dont necessarily need to do anything at all. Topicals can be used but efficacy is questionable, and systemics such as Na Iodide IV are NOT recommended
risk factors for dermatophytosis in cattle?
young animals, indoor housing, post weaning, poor nutrition can make lesions worse
your friend calls you because his little baby jersey cow has dry grey to white crusty slightly raised and alopecic lesions. The cow is not itchy though. differential?
dermatophytosis
what is a main differential for ringworm and how can you tell which is which?
manges
ringworm is not itchy tho, and mange is VERY itchy
how do you diagnose ringworm?
usually not done, but skin scrapings or fungal culture, use KOH wet mount
a producer sends you this picture and says DOC WTF IS WRONG WITH BESSIE? What are your differentials? how will you diagnose and treat BESSIE???
papillomatosis (warts) caused by BHV-2
other differentials: early dermatophytosis, cutaneous lymphosarcoma
diagnosis can be made just by looking at her. Can do skin biopsies but this is rarely done.
lesions spontaneously regress and will go away on their own so we dont need to do anything. Could crush or pinch lesions to stimulate immune system or surgically excise lesions
risk factors for papillomatosis in cattle?
young cows (BHV-2), old cows more likely BHV -1
particularily young cows that are all in close contact with each other
how do warts form?
virus enters basal keratinocytes and causes hyperproliferation of the epidermis and dermis to create a papilloma/fibropapilloma
describe the lesion of papillomatosis
grey-white hairless, dry raised pedunculated (ew) masses on any epithelial surface
regarding bessie with the warts from a previous question, what is one relatively simple treatment you could offer? there are other cows housed with bessie, some of which are dairy cows. What will you tell the owner?
there is an autogenous vaccine that can cause regression of lesions within a few weeks but this only works for BHV-2
this virus can spread from cow to cow and if there are cows bring milked it could get into the milk! If it gets onto the teats the milking machines could hurt the cow and cause more problems so maybe milk those cows last. But in general, clean ya dang equipment!
this is Dorothy. All of Dorothy’s sisters look like this too. differentials for her? how will you diagnose?
infectious bovine keratoconjunctivitis (IBK) caused by moraxella bovis, moraxella bovoculi, or mycoplasma bovoculi.
others: traumatic conjunctivits (would only be 1 or 2 cows, not large group affected), infectious bovine rhinotracheitis (IBR, usually only eye edema), or malignant cataral fever (would only be uveitis)
diagnose: rarely done, but can fo fluorescin stain or a culture
what time of year is IBK most often seen?
summer time–>thought to have something to do with flies as possible transmission? Flies dont carry the bacteria, but they can cause cows to huddle together more which helps infection spread
what one thing is a major risk factor for IBK?
corneal trauma such as UV expsure, dust, irritants, virus
clinical signs of IBK?
lacrimation, squinting, photophobia
corneal ulcers and edema, pain, anterior uveitis
vascularization, corneal infiltrates and necrosis, granulation, and possible rupture
how are you going to treat Dorothy and her sisters all with IBK?
use systemic antibiotics on the ENTIRE herd such as OXYTETRACYCLINE or TULATHROMYCIN (draxxin). tula lasts longer but is more $$$$. can also use florfenicol
subconjunctival infection (labor costs and not as effective): PENICILLIN
dorothy’s owners are worried about her prognosis. what do you tell them? remember, she has IBK
prognosis is good, usually self limiting, may leave a scar
a producer named Steve calls you and asks for advice as to how he can prevent IBK in his herd. He’s had many problems with it this summer. What do you tell him?
try to control “bunching” of cattle so it spreads less
can also use long lasting insecticides in Ear tags. put on just before fly season and removed in autumn
tell him vaccines aren’t very effective and to not waste his money on it
this is Snowy. top differential for this and risk factors for the disease?
Ocular SCC
genetics, white faces (esp around eye), older cattle, environmental (UV)
what are the 4 stages of SCC/cancer eye
plaque–>keratoma–>papilloma–>SCC
can you send a cow to market that has SCC?
if spread to regional LNs (usually to parotid first) or it starts to invade peri-ocular tissue, the cow cannot be sent to market and the entire carcass is condemned, but if not, just the head is condemned
what are some differential diagnoses for SCC in cows? best way to differentiate these from SCC?
IBK (the eyelids will remain in tact, only consider this if it is a very severe case)
lymphosarcoma from BLV–>will have exophthalmos/protruding eyeball
trauma (only if seen from distance)
What is the prognosis for Snowy (SCC)?
in stages 1-3, up to 80% can spontaneously regress
in stage 4, they rarely regress. metastasis more likely if eyelids and/or 3rd eyelid are affected
surgical treatment options for SCC?
superficial keratectomy
3rd eyelid excision
Enucleation (if peri-ocular tissues involved)
what’s the best way to prevent SCC?
dont breed animals that get it, and select for pigment around the eye, try to detect it early!
