---start---- medsurg 4/30 williams more cow stuff ddx for atypical interstitial pneumonia in cattle hypersensitivity (farmer's lung, etc) fog fever BRSV parasitic (dictyocaulus, ascaris) plant toxins (fusarium mold on sweet potato, stinkwood, purple mint) irritants (smog, nitrogen dioxide, zn oxide, chlorin and hydrogen sulfide) experimentally induced syndromes systemic anaphylaxs bordetella pertussis -- miscellaneous pneumonias minor importance these are individual animal presentations, not herd outbreaks these require lots of history, PE most have poor px 1. most avoidable - iatrogenic pharyngeal abscesses. the pill gun is big, the pills are big, can hurt the pharynx. tx w/supportive care, abx. if you suspect this, ask if farmer uses multiple pill guns. 2. necrotic laryngitis - signs of upper respiratory obstruction in calves 2-6 mos of age or in feedlots 2ry to viral infexn. also fetid breath, respiratory stridor, and lesions in back of mouth. usually involves fusobacterium which really smells bad. necrotic plaques in larynx, trachea. foul smelling exudative covering. low grade fever possible. onset may be somewhat insidious. in dairy animals, these are often calves kept in a damp barn, often in winter, often fed poor stemmy hay that traumatizes laryngeal area. also called calf diphtheria b/c forms diphtheritic membrane in trachea. improved management really cuts down on this. if this is severe, can inhale sloughing diphtheritic membrane and obstruct parts of lung. caught early, can tx w/penicillin. 3. metastatic pneumonia - very uncommon. sporadic individual cases in individuals with no prior pneumonias. most often in neonatal calves secondary to E.coli septicemia, associated with bad umbilicus, septic arthritis, or FPT. often presents as acute death. no AV consolidation - just embolic shower, toxic event. 4. caudal vena cava thrombosis syndrome - fairly sudden onset, or short term hx of resp distress. dyspnea, increased RR, soft cough, wheezing later; epistaxis or hemoptysis, variable at first; sudden death is also possible. area full of blood. or may present as progressive anemia, melena due to coughing up and swallowing blood. how do they get it? can be secondary to rumen acidosis in feedlot cattle =- most common. liver abscesses may form and rupture causing an embolic shower to lungs, creating new abscesses that rupture or erode into an artery. speed at which they bleed out depends on affected vessels. various bacteria may be involved - fusobacterium, actinomyces, staphs or streps. or coliform. source could also be mastitis, metritis, other septic process in cow. in dairy cow, usually seen in aniamls over a year, in feedlots occurs quickly after starting on feed. on PE, if you find any epistaxis, suspect this. the bad thing is we do not have much to do about it. prognosis is very poor. this is more of a "don't stress the cow" situation. ddx: ARDS, lungworms, other acute bronchopneumonia lung abscesses look disgusting, signs highly variable very poor px. 5. allergic rhinitis aka summer snuffles is a lot more common in .nz and .au most often jerseys, guernseys. begins at 2-6 mos. progressive. seasonal in pastured cattle. allergy to pollen or mold. IgE type hypersensitivity (Type I). swelling of nasal mucosa, granuloma formation, can calcify. readily visible easy to tell from IBR. alert, no fever, third eyelid may be thickened, sneezes and nasal pruritis with sudden onset of dyspnea is common. the cows run around trying to scratch the nose - ddx nervous ketosis, fungal granuloma, FB, resp diseases. progressive each season. 6. aspiration pneumonia - this cow was down with milk fever at calving and inhaled some nasty rumen contents into her lungs and 4 wks later necropsy revealed a big area of walled off abcess. yuck. surface of lung is thick, white, not thin, pink. adhesions to pleural cavity present. very inflammatory. this cow was very stoic, only a little pain evident. in same cow - injection site abscess occured from injection of erythromycin. this cow was on erythromycin for 10 days - very irritating. lung abscess is very walled off. -- quick review of the and then we have a case on the exam, on exams like the national board, they overemphasize subtle differentiations b/w viral agents, so you need to keep that in mind. ok. they also make a very big deal of vaccination protocols and the like. important things from summary charts are to know what is common - IBR and PI3 are very common. PI3 pretty much in shipping fever complex, otherwise mild. major role is setting up for bacterial invasion. also keep in mind that 90% of cows are seropositive so you need to look at 4 fold increase in titer to dx PI3 involvement in disease. for both, intranasal vaccination gives rapid onset local immunity but very short lived. these are useful in the face of an outbreak and prior to shipping. the MLV is most durable level of immunity but may be abortigenic so be careful. IBR and BVD have caused abortion. not a high rate, but enough. BRSV, one of the most important things about it is it is frequently latent. IBR also frequently latent. BRSV is of most interest due to ARDS and atypical interstitial pneumonia which can occur, which occur infrequently but are classic for this and devastating to a herd. also salivation, subq emphysema and open mouth breathing. difficult to isolate, serology not that useful. dx on clinical impression. also both passive immunity from dam in colostrum and serum Ab from vaccination may or may not be protective, and may make things worse. in human disease, HRSV, we have found that vaccination may exacerbate immune components of the disease. may also happen in cattle. poor response in therapy to BRSV b/c once damage is done it is hard to overcome. think emphysema. also bottlejaw. BVDV important mainly in other regards, can potentiate secondary bacterial infs. for bacteria: remember p. hemolytica is the worse one, more aggressive and pathogenic than p. multocida. p. hemolytica Ia is usually responsible for trainwreck outbreaks. fever, purple mms, painful rapid breathing. nasal swabs useless b/c normal flora of nasal tract. culture from lower resp tract is significant. p.multocida - chronic, less aggressive. more typically seen in calves, esp dairy calf pneumonias. also may be part of shipping fever. moist cough. h. somnus - #2 bug for acute fibrinous bronchopneumonia. ubiquitous, difficult to dx, hard to culture. pos culture or ab not diagnostic actinomyces - chronic bronchopneumonia, sporadic. vaccination for these things - bacterins do not work, some toxoids do, but mainly we tx with abx, long term, high doses. actinomyces - may use rifampin to penetrate abscess, and penicillin to tx. -- CCT case: you are the newest member of a four person mixed practice in northern MO. cold friday night mid-november, you get a call about sick calves. 160 beef cow herd. you go to see recently weaned calves. feed intake increased till wednesday then two died. after that he found many breathing fast, runny nose, pinkeye. no tx yet. you get there at about 8:30 am. on the way to the calf pen what do you ask him? what vaccines have you given? clostridial vaccine and pinkey vaccine, and brucella for heifers how many are sick today? about half of them when did you notice the sick ones? yesterday (don't ask about treating) (don't ask about weight, don't ask how many there are, don't ask what breed they are) what are you feeding? dry grass pasture, grass hay, ground corn, pellets how often? hand fed twice daily how much? hay free choice. they were eating 9# daily, now 4# daily where do they drink? do not ask this what is water source? do not ask have any cows aborted? don't ask how long have they bee in this pen? don't ask any diarrhea or lameness in herd this year? don't ask were the calves uncoordinated at birth? don't ask did they have good weaning wt? don't ask have you dewormed them? don't ask. have you changed rations? don't ask how many died? just two, yesterday any new calves lately? don't ask any starlings around? don't ask section B: 15 of the sickest calves are separated out. what do you do now? -observe sick calf pen - many calves show serous nasal d/c eye d/c, increased RR, hypersalivation. some open mouth breathing, frothing of saliva, submandibular edema -take rectal temp - 104-108 -examine submandibular areas - some have edema -palpate skin of sick calves (nah, don't ask. but two have sq emphysema) -auscult lungs of sick calves - increased bronchovesicular sounds with intermittent widespread fine crackles. decreased cranioventral sounds in a few. -look at feces - vary from diarrhea to pelleted -evaluate the rest of calves by driving through pasture? yes. calves are scattered, half are grazing, eating at bunk, or lying down chewing their cuds. -examine eyes - corneas and conjunctiva appear normal -examine nasal mms - normal (so, not pasteurella) -examine vaginas - no, don't -necropsy dead ones - both have diffuse pneumonia, with subpleural and interstitial edema and emphysema. lungs red, meaty, bullae are scattered through lungs. cranioventral lobes consolidated -look at buccal surfaces, eye reflexes - these score neutral, don't bother -don't remove and examine brains, don't look at muscle tissue section C: lab tests what procedures will you now request? -buffy coat viral isolation? no. (BVD) -nasal swabs for viral isolation, elisa? yes. get results next thursday (IBR) -serum for paired sera? no (good idea, but takes weeks) -fecal? no -lung histopath? yes! will get results thursday -fluorescent ab on lung? yes, results come monday -bacterial culture of lung? yes, get results in 72 hrs -muscle samples, anaerobic culture? NO -submit brain for culture? no section D: you complete investigation of herd problem and have tentative dx. what do you do now? -treat sick calves parenterally with therapeutic levels of oxytet and evaluate responses - best idea. -withold concentrates and handfeed? no points lost but not needed. handfeeding does help id new cases -tx herd with ivermectin? no, you will lose points. -tx with thiamine? no, calves do not respond and you lose points. -change diet to 50% roughage and add thiamine - no. points lost. cows do not get better. -tx with procaine pen and dihydrostrep daily for 5 days - no section E: choose the lab tests to check to confirm your dx not fecals nasal swabs negative histopath - hyperplasia of type II alveolar pneumocytes. exudative bronchopneumonia with cranioventral distribution, interstitial edema, etc IFA: BRSV identified in both bacterial culture: p.hemolytica in both what do you do to prevent recurrence? -deworming plan? no -preweaning vaccination for IBR? no -avoid pasturing calves on this pasture in fall? no -suggest different clostridial vaccine? no -formulate postweaning ration with increased protein? no -vaccinate all calves at 6 mos and preweaning with BRSV vaccine? YES ---break---- Rubin ophthalmology we'll start today with a lecture dealing mostly with small animals; dr beech, dr riley will do large animal eye stuff. as with other specialties, this one has its own language which you will have to learn. we're going to go over the common ocular abnormalities on a positional basis, startin with orbit, lids, back to eye, retina. there is a lot of surgical stuff that he has no interest in our learning the minutiae of; just know general pricinples. the first thing we'll discuss is diseases of the orbit. one of the most dramatic problems is a traumatic injury to the orbit that occurs mainly in dogs and is called "proptosis" proptosis is an ocular emergency (one of the few) and you need to get client and animal in. first, you have to calm the client down. the eye is pushed completely out of the orbit with proptosis ("i'll keep an eye out for you" comes from this, ha ha). some of the things that you have to do is calm the client, get first aid started. when eye is out of the orbit, no tear film is covering it. there is an immediate tendency for absolute dessication of the eye. there is also emotional trauma to the owner. so have the client hide the eye from the client - best by draping it with some sort of moist towel to reduce evaporation - keep eye wet, hidden; get it in. when animal presents to you, first you have to evaluate the animal by doing a complete PE. if this animal was clobbered then there must be some head trauma. if you are going to anesthetize the animal to replace the globe into orbit, it's not a good idea to have it die from neuro dz under anesthesia. if there is neuro damage, assess and treat that first. write off the eye. if you do not do that., you are really practicing poorly. 2nd thing to notice is what kind of animal is it. you know the head types of the animals you deal with - you know there are brachycephalics and dolicocephalics and mesocephalics. in a dolicocephalic dog like small collie, the amount of force that must be applied to the orbit to throw the eye out is maximal, requires a lot of force to get small eye out of deepset orbit. for a peke, pug, eyes already half out, requires minimal force to dislodge the eye. at VHUP it wasn't unusual to have a recalcitrant pug or peke grabbed by a student with enough force to create this situation.. what happens to the eye? 1. dessication 2. lids clamp down over the posterior portion of the eye [slide - lids come down over the globe, immediately compressing venous return from globe; net result is fluid volume in eye increases - not enough pressure to cut off arterial supply] 3. eye increases in size - if you try to put it back in, it is too big, bigger than what you started with. this slide shows eye proptosed about 30 min - black, dessicated, rather messy. in 95% of cases, you can replace an eye like this a nd have a cosmetically acceptable result. if the eye is out too long, the fluid accumulation in the eye will make it impossible (almost) to immediately replace. after about 2 hrs, it is very large. there is a lot of reddening, congestion of conjunctiva, cornea is opaque, eye is dessicated - could still replace and have a reasonable result, so do not give up. logically you can figure out what to do. if lids are clamping down, and palpebral fissue is too small to accomodate eye, by enlarging palpebral fissue you can put eye back through lids. cut under anesthesia after PE the lateral canthus of the eye. use scissors. cut anywhere from 5-15 mm, whatever is required to put eye back through. you have to also consider what happened immediately after the trauma - there is edema of orbital tissue, maybe some hemorrhage. orbit will be shallower. so once you get globe past lids, maybe it won't go all the way into orbital fossa, because of the edema. he's impressed by my typing. ok, here's the cut lateral canthus,a lateral canthotomy. now the effort is made to forcibly push globe back into orbit. with it being shallow, if you can't keep iglobe in there it will pop out again. so you need an assistant to help you replace the globe in the orbit. try to push it in, then quick like a bunny close the lids so it doesn't pop out again. Ok, with reasonable rapidity. so the sutures are preplaced. not tied. because the case came in reasonably early and inflammation in orbit is just starting, anticipate that orbital contents will increase more over the next couple of days as things progress. if you aren't careful about placing the sutures, pressure of globe against lid in the next few days will be great, will cause lid sutures to break, saw their way through the lids, or if tied tightly enough they will rub on cornea and damage it so you have to prevent that. when you place the sutures you put a tension relieving device like button, tubing, on the lids, top and bottom, so sutures pull against that instead of skin. in addition if you can, the 3rd eyelid, also will allow you to use it as a bandage, a pressure relieving device - you can put a suture in it, pull it up, and close lids over that. sometimes this step due to eye position or breed, has to be skipped, but it is good to try. so, later on, it looks all nice and tidy with either a rubber band factory or button factory or embryonic IV tubing factory in this animal. all of those are necessary to prevent 2ry complications. placing sutures correctly is important. if they go all the way through the lid, as eye comes forward, they will saw through. do not use through and through sutures. try to put the sutures so that you have apposition of lid margin and lid margin, through the lid margin. these will allow you to minimize secondary corneal damage. questions? this is simple stuff unfortuanately, most of these animals, except pekes/pugs; there will be as a result of trauma or inflammation, damage to the optic nerve - do not ever prognose return of vision. there may be optic nerve transection, or severe damage. if you are capable of looking in, you may see the nerve pressing forward, maybe some blood around it due to traumatic optic neuritis. in addition, the choroid swells, and a reasonable amout of transudate occurs, so there will be some secondary retinal detachment. that too will minimize, or will affect, the amount of vision retained in posttraumatic state. third, there is likely to be anterior uveitis as well. that also can cause complications. you have to be careful with the prognosis, therefore, even if you do a good job of replacing things. if you go back to the surgical technique, if you are really lucky, or if you are a gambler, or both, you can leavea small opening at the medial canthus on top of nicitating membrane, as a port for introducing topical meds. if you do not want to do that, you can skip that step and use systemic meds to try to keep the animal going. at the end of your replacment, you have a closed lid, an overlying nicitating membrane, a swwollen orbit, a damaged eye and things are just beginning. so, at the end, and b/c you know this was traumatic, not infectious, you want to minimize the forthcoming damage due to continuing inflammation - so you will try to that end to give a repository steroid in the retrobulbar area - not too much - can't add that much volume. 1/10 mL of 40 mg/cc methylprednisolone. be careful not to put that in the eyeball either - go behind the eye, to area of optic nerve where damage has occured. just above the zygomatic arch and posterior to orbital ligament - feel the bony prominence at your lateral canthus, the soft spot - take the needle containing the steroid and project it toward the lateral canthus of the other eye and you can place the meds retrobulbarly without damaging anything. if you fear this, use a curved needle and try to go through the lid, around the globe. if you left a treatment port, treat the traumatic inflammation by dilating the pupil with something like atropine and give topical antibiotics to disinfect. so now, you have the eye in, you've got it held there, you have inflammation being handled, you feel pretty good, pretty cocky, you have to decide when to remove sutures. this will minimize your cockiness. you have to have th eclient return at multiple intervals so you can palpate the area, and determine when pressure on lids is minimal. then you can remove sutures stepwise over a few days or all at once. if you remove sutures too soon, proptosis isn't there but the animal still has exophthalmos, a protrusion, and secondary damage will occur - the animal can probably close th eye partway, but a central zone may be completely exposed, cornea can be dessicated. depending on how you feel, owner can give frequent applications of artificial tears or you can replace sutures - either choice ok. another thing you notice often is muscle damage to extraocular muscles that support the globe. this damage involves restriction of movement medially - eye points outward or up and outward - some people suggest rupture of medial rectus muscle but no one proved this. repair not proven to help. if you see this abnormal position of the globe and wait 6 wks, it will probably straighten out to a more acceptable position on its own. until then, it's just like that. a few weeks later looking at the same animal we see some residual corneal damage, much less inflammation, globe is still pointing outward and a bit upward. this will straighten out though. this now blind eye will be cosmetically acceptable in a couple of mos without any intervention from you. more typical presentation of the eye after the sutures come out - this eye is pointing way up - he knows where he's going and can see where he's been - well, can't see out of that eye, but anyway, conjunctiva are exposed, there is some irritation, abnormal position - but will get better. some corneal damage from exposure exists. generally the animal is in reasonably good shape. questions? anyone in small animal practice will have to handle this condition, unless he wants to refer them all to an emergency clinic which is unreasonable for the dog. what if you leave the sutures in too long? you can't. if you err, err on leaving them too long. tell the client "sorry, gotta wait another week." won't hurt anything. since the dog won't be able to use the eye to see with, would it be better to remove the eye? no question, sometimes you would. in fact, though, the removal is as painful as the replacement - but if you feel there are mitigating circumstances that will prevent a good result, remove the eye. some of them do retain vision when replaced. opthalmologists do not like losing eyes - it's like losing clients. usually client is happier if you try to save the eye. they do not like having eyes remove. they visualize a milieu in which a large hole with nothing there and goop oozing out and stuff like that and that is wrong but that's what they think, so they fight the decision to remove the eye. you can override that, but they want you to make the effort to put it back. when you initially moisten towel to cover eye, do you use water or saline? yes. you use anything that is wet. the eye is exposed, dirty - grossly contaminated. doesn't matter, you'll wash it off later - especially if you use philadelphia water. one warning - in your enthusiasm to try to get globe back, and to bring it down to manageable size, you should not under any circumstances breach the integrity of the eye. do not incise it with needle or knife. do not do this. it will be under pressure and when you breach the wall, there will be some aqueous in your face and all the things in the eye will rush to the site of puncture. if you feel you must reduce volume of globe, you can use a topical osmotic agent to suck fluid out of the cornea/anterior chamber. most available one as a home remedy is karo syrup - highly concentrated sugar, big osmotic draw. (i used this on a turtle with paraphemosis once...) so we're ok? everyone can fix a proptosed eye? ok, for the lady, woman, whatever, that asked about why bother to replace the eye, we'll satisfy her by talking about what happens if you lose the fight to put the eye back. then you take it out. there are several ways, depending on what reason you are removing it for. if because of proptosis, then you can take it out, and leave all the surrounding supporting tissue in. that bulk will prevent the lids from sinking in and looking bad. if you are taking it out for a tumor of the conjunctiva and cornea like SCC in cattle or horse, then you must remove globe, conjunctiva and lids. if you are taking it out b/c it is too big and you want to put in a false eye, then remove eye contents and put implant in. process of removing the eye alone is called enucleation. removing the eye and contents of orbit is called exenteration. if you diagnose a meningiosarcoma of the optic nerve that you can't remove and save the eye, you would do exenteration - leave only bare bone. use this for infectious or neoplastic process. a bloody mess, this is. with enucleation there are two approaches - subconjunctival (removal of globe only, leaving conjunctiva, muscles, fascia) and en bloc enucleation (take out globe, conjunctiva, leave muscles and stuff) depending on which you do, en bloc or subconjunctival depends on condition. en bloc is ok all the time, can't hurt - but subconjunctival allows you to do subconjunctival grafts. know both. en bloc is used for cattle with SCC sometimes, can be done in the field. quick and dirty. good results. in the en bloc procedure, what is done is initially some method is used to close the lids, clamps, sutures, whatever - have motherinlaw hold them together if you like. then an incision is made around the lids into subconjunctival CT, so now lids are pulled out, you have avoided cutting into the conjunctiva and are going in back of them. then you dissect along the globe with scissors all the attachments to the globe, constantly pulling forward so the conjunctiva is stretched out and you do not breach it (esp if tumor present!). when you have dissected off all the muscles and CT, a curved instrument is placed in to grab the optic nerve (major blood vessels too), that's clamped and cut, eye is out, close in a couple of layers, and you ahve a blank wall where once there was an eye. you have removed the lids too. the tough thing is the initial incision is in a really vascular area, lids bleed profusely, and you are doing things through a wall of blood. exenteration, that's an en bloc done sloppily. you take out the tissue behind the eye as well. also bloodier. but no point removing tissue you do not have to, when doing an en bloc. the tissue left in will minimize the pit that you have postoperatively. some surgeons will actually implant a silicone ball in the orbit as a conformer so there is a normal contour under completely closed lids. subconjunctival: instead of starting on lid margin, you start at the limbus and dissect at the limbus 360 degrees around the globe, leaving conjunctiva in place. see muscle attachments as you go, name them as you go :) and cut them, then use that same instrument to clamp and then cut optic nerve - put in ligature - close conjunctiva, trim lid, suture. this is cleaner and more satisfying. takes a little more, and if you can dissect and mobilize conjunctiva nicely you will be able to move it down to cornea and suture it to cornea to treat corneal ulcers (huh? we removed the eye!). you have to remove lacrimal gland and nicitating membrane which also contains a gland - if not, you get secretions in the closed orbit, and a big swelling that looks like a seroma develops and you have to go back in . this is an uncommon complication. ---end----