----start medsurg.lec.03.18.98---- medsurg 3/18 saunders cardiac radiology Radiographic patterns of pulmonary disease: we did interstitial, we still have to do alveolar and bronchial and mixed before moving on. vascular will be covered with the cardiac stuff. common diseases associated with alveolar pattern: 4 common ones bronchopneumonia - inflammation extending from bronchus. includes aspiration pneumonia pulmonary edema - when severe. when mild, produces interstitial pattern atelectasis - alveolar collapse. many ddx here. bronchial obstruction, lobe torsion, etc. hemorrhage - usually starts as interstitial - when severe, alveolar fluid accumulation in alveoli or collapse are the two processes producing alveolar pattern. air is removed from alveolus producing this pattern. air is either displaced by fluid or cellular debris - lung volume stays constant. or, atelectasis occurs - resulting in loss of lung lobe volume and possibly a mediastinal shift. slide: alveolar pattern has about 4 abnormalities. 1: lungs appear very opaque, near soft tissue opacity. with interstitial pattern, there is just a diffuse haziness to the lung. the alveolar pattern is much more white, more opaque. therefore, due to this soft tissue opacity which is due to fluid or collapse,there are three other abnormalities. 1: air bronchograms - the bronchi show up as lucent, branching structures, because they contain air. 2. you don't see the pulmonary vessels adjacent to the bronchi. they should travel in pairs next to the bronchi. now the lung opacity is equal to the vessel opacity and the vessels are obscured. 3. you also lose the cardiac sillhouette, the diaphragmatic border, any other soft tissue structure. "sillhouette sign". in order to get a loss of the sillhouettes, the diseased lung must be up against the soft tissue structure. slide: say the lung is like a sponge. here we have a radiograph of a sponge with a straw in it. one straw is air filled,one is fluid filled. the airfilled sponge background allows us to see the water straw well, but not the air straw that well. the waterfilled sponge obscures the water straw but the air straw shows up really well. consider the air straw as a bronchus and the water straw as a vessel. slide: alveolar pattern cranial to heart. nice air bronchogram. absence of pulmonary vein. we see this on the left lateral radiograph. the right lateral radiograph is normal. therefore, there is probably something in the right lung, which is the up lung when you take a left lateral radiograph. the VD shows the alveolar disease in the right cranial and right middle lung lobe. we see soft tissue opacity, loss of cardiac sillhouette, maybe an air bronchogram. we often see bronchopneumonia, pulmonary edema, and pulmonary hemorrhages like this when they are in the up lung on a lateral radiograph. this is why we take 3 views. Bronchial pattern - harder to see. now the abnormality is associated with airway disease. characteristics on radiographs are thickened walls, irregular airways, and "ring sign." most common cause is a chronic bronchitis resulting in increased soft tissue opacity developing around the bronchi -this takes time. acute bronchitis doesn't show up - not enough inflammation yet. can be due to inhaled pathogen, allergen, toxin. results in inflammatory reaction in bronchus. the "ring" or "donut" sign is a puffiness around the bronchus. there may be an inflammatory infiltrate, secretions in lumen, bronchial wall thickening, fibrosis. main thing is thickening around the bronchus - tends to be kind of diffuse since the etiologic agent is inhaled, not local to one lobe. also may see "tram lines" of parallel lines running along longitudinal length of bronchus - more rare. key things - it's diffuse, may see tram lines or ring sign. because zone of opacity is around bronchus, t here is a decrease in sharpness of vessels bordering the bronchus. slide: cat with aelurostrongylus. the lungs are diffusely opaque, all lobes are involved. the opacity isn't homogeneous. it's more blotchy or motheaten. some areas are more opaque than other areas. pulmonary vessels are not well visualized. slide: VD view - here is where you tend to see the ring/donut sign. we see a fluffy heterogeneous opacity throughout the lungs, again. we also do see smoe donut signs - round opacities with central lucency. you usually need a bright light to see this. if there were no central lucency to the opacity, you'd think of a nodular interstitial pattern. slide: another abnormality seen in cats with bronchial pattern is hyperinflation - seen in cats with feline asthma, feline allergic bronchitis - due to thickening of bronchial walls there is no problem inhaling and expanding lungs, but trying to exhale is difficult because small bronchioles collapse. we see a big distance b/w heart and diaphragm, flattened diaphragm, and the lumbophrenic angle is open. often seen in cats with bronchopulmonary infiltrates. on VD view, we see the same thing. note that lungs look a bit better due to hyperinflation - less opaque because of hyperinflation. but there still are opacities with central lucencies. this is a hard pattern to pick up because you have to bright light the radiograph. Mixed pulmonary pattern: a mixed pattern is some admixture of the three main patterns - alveolar interstitial or bronchial. interstitial alveolar is most common mixed pattern. you might have hemorrhage or edema in the interstitium starting to flow into the alveoli, producing a mixed pattern. so you start with mild edema with interstitial pattern, then it gets worse and you have a more mixed pattern, and finally the alveoli fill up producing an alveolar pattern whch obscures the interstitial pattern. on your ddx list for both alveolar pattern and interstitial pattern: edema, pneumonia, hemorrhage, granuloma, tumor, atelectasis slide: neurogenic pulmonary edema - this dog had a seizure, got hit on the head, or bit a live wire. pulmonary edema develops in caudodorsal lung lobe region with this type of edema. the lung is very opaque, and we see air bronchograms. there are some linear lucent tracks. we can see the vessels cranially but not caudally near the air bronchograms. we can't see the aorta. this is an alveolar pattern in the caudodorsal lung lobe caused by severe edema. this will generally resolve and look more mixed slide: mixed interstitial alveolar pattern - less opacity, still a couple of air bronchograms, can see some linear soft tissue structures though, can see heart better. slide: a few days later - an interstitial pattern - slight haziness - near normal. or even normal. :) slide: dog that suffered smoke inhalation - some opacity over sternum in dependent portion of lung lobes. smoke causes membrane damage, pulmonary edema and sometimes hemorrhage. here there are no air bronchograms. very focal. slide: a few hours later it is more severe - increased opacity, larger area, with an air bronchogram within it. slide: 2 days later - more opacity over a broaderarea, still seeing air bronchograms slide: 5 days later - resolved. so, alveolar patterns in ventral portions of lung lobes - usually bronchopneumonia or aspiration pneumonia. whenever you see alveolar patterns in a dependent/ventral area of lungs, that's probably what it is. in other areas of lung lobes, think pulmonary edema or hemorrhage or atelectasis (look for mediastinal shift). the point is - clinical signs lead radiographic changes. radiographic changes lag behind clinical signs. rads here look worst after worst of clinical signs are resolved. CARDIAC radiography the handout is voluminous and overwhelming. information in the handout is there twice. the important stuff you get over and over. first part of the handout is normal, and the second part has differentials for the various abnormalities. the back of the handout has other stuff. all the acquired diseases and radiographic signs are listed for both acquired and congenital diseases. please know that you only have to know what we cover in class, not the whole handout, for exam purposes. one problem with evaluating the heart is that we deal with multiple species and multiple sizes of the same species like dogs being a chihuahua or a great dane...sizes of structures varies. you must consider the size of the thorax. always take rads in inspiration to maximize contrast. gross observations of cardiac size can be made. when you're inexperienced you need a checklist of things to go over. on a lateral radiograph, first look at position of trachea. trachea parallel to spine is a sign of heart enlargement. two ways to look at cardiac size/shape - subjectively and objectively tried and true subjective measurements - you have to mentally or with a ruler mark two dimensions - the long axis or length of the heart, from the base (ventral to trachea, cranial to carina) to the apex, parallel to the cranial and caudal borders of the heart. usually you can see the apex of the heart, though on this slide it is obscured by fat. also the short axis or width - run that line perpendicular to the long axis through the widest portion of the heart. so you get two lines. the width of the heart should be 2.5 to 3.5 intercostal spaces, where an intercostal space goes from caudal border of one rib to the caudal border of the next rib. a deep chested dog will have narrower hearts, little dogs have more globular hearts, etc. these are subjective measurements - you look at the heart and make an assessment. the length of the heart should be about 2/3 the height of the thorax. that's what allows trachea to deviate from spine. objective measurement where you try to come up with a number... you make same two measurements, length and width. then, you start at the cranial edge of T4 and lay your measurements down individually and count how many vertebral bodies the length is, and how many the width is. say your length is 5.8 vertebral bodies and your width is 4.6 - add them up, you get 10.4, and the normal range is 8.5 to 10.5, so this dog is normal. this is good if you're inexperienced, for toy breeds, or when you have serial radiographs and you want to see if it is getting better or worse with treatment. slide: radiograph of the heart those measurements were taken from. note: you can't add the axes measurements before you put them up against the spine, or you start getting down where there are shorter vertebrae. normal shapes and stuff - fortunately your two measurements have basically divided the heart into four quadrants for us, which correspond to the four chambers. on a lateral radiograph, the caudal part is the left side, and the cranial part is the right side. the only difference in outline of heart vs chamber is that the right side of the heart has a border made of the right auricle. the apex to base line roughly divides the heart in half, but the right side of the heart is really about 3/5 and the left side is about 2/5 (?? i'm not sure that got transcribed right. he confused me) cranial and caudal vena cavae feed into right atrium. note that RA is fairly central, and that the right auricle forms the cranial border of the heart. blood then goes through tricuspid into RV, then through pulmonic valve into main pulmonary artery which doesn't show up on rads, then into L and R branches of the PA, dorsal and ventral to the carina. we also don't see the cranial vena cava, or the azygous. left side of heart - caudal 2/5 of heart - accepts oxygenated blood from the lungs via the pulmonary veins, into LA (dorsal caudal quadrant) through mitral valve into LV, through aortic valve, through aortic arch, through the branches we can't see, and into descending aorta which we can see. we don't see the aortic arch or the root of the aorta. we know the mitral valve is right near where the caudal vena cava goes by, though. ---break---- where can you find these diagrams he's showing us in the slides? the ones with the chambers superimposed on the radiographs may be in older Ettinger cardiology text. The bible of thoracic radiography for dogs/cats is Suter's text. See references list on p 6 of the handout. other possibilities include the teaching files in the radiology department - radiographs which contain signalment, history, and final diagnoses. also a CD ROM of radiographic anatomy. but, he won't be using radiographs on the exam although he considered it. VD view - for cardiology cases, if they are coming from cardiology or we suspect a cardio problem, we actually do a DV instead because: 1. it is less stressful for a dog to be on the sternum instead of the back, 2. the heart is in a more normal anatomic position (when dog is on his back, apex flips from side to side more. apex should be midline to slightly left of midline), 3. the heart is closer to the cassette and therefore closer to normal size 4. you see the caudal pulmonary arteries and veins better because you inflate the dorsal lung lobes more. in a VD or DV view, you always put the rad on the viewbox so that left is to your right. aorta comes down on left, vena cava comes down on right. the fundus of the stomach is caudal to the left crus of the diaphragm. this is how you tell which side is which. heart can change in position a bit within the thorax. you want the animal positioned symmetrically, the sternum and spine should be superimposed. also look at symmetry of heart within thorax. make sure the apex hasnt worked its way over to the right or something because that changes the whole orientation and you may think there is an abnormality that isn't there. the easiest way to figure out where the chambers are is to think of it as a clock with the apex being 6 o clock. the cranial mediastinum and the cardiac sillhouette blend together. at about in between 11 and 1 o clock is the aortic arch, but we don't really see it - then b/w 1 and 2 o clock is the main pulmonary artery looping up and over - any bulge in the heart border b/w 1 and 2 is probably due to enlargement of the PA. the LA is central, beneath the mainstem bronchy. the L auricle is at about 2 to 3 o clock. a bulge here is an auricle enlargement. 3-6 LV, 6-9 RV, 9-11 RA. again - you can't see the aortic arch, it blends with cranial mediastinum. you see the descending aorta, though. The RV, from 6-9 oclock - main PA goes across at about 2 oclock - you only see a bulge there. he's going over cool radiographs with lines drawn on them. rapid run through of VD view: (or DV) on DV, the caudal pulmonary arteries are further from cassette and surrounded by aerated lung. there is a little phrase that the veins are ventral and central to the arteries. that means that on a lateral, you have artery bronchus vein, and on the DV they are central. so on DV/VD the artery is lateral to bronchus and vein is central (medial) to bronchus. you compare the arteries and veins to each other - should be about the same size. also, in DV view, compare them to the 9th rib - shouldn't be any larger than that width. count back 9 ribs, find artery, bronchus, and vein, and see where they intersect that rib, they should be no larger than the width of that rib. back way up to lateral view- here we pay more attention to cranial pulmonary vessels. we take a left lateral so are more likely to see right cranial artery and vein. we look at the triad - linear soft tissue opacity, lucency of bronchus, and then another soft tissue opacity - so it's artery, bronchus, vein.easy to see in up lung - cranial to heart, ventral to trachea. on the lateral, you measure compared to the width of the proximal 3rd of the 3rd rib or proximal 4th of the 4th rib - normal is about 1/2 the width of the rib to the whole width of the rib (published data is from 1/4 to 1 1/4) slide: first case. lat chest rad. 6 yr old rottie with hx cough, exercise intolerance. lungs are abnormal - heart subjectively looks an ok size. lungs have focal patchy opacities, kind of fluffy. are the sides of the heart in the right proportions? looks like about 2/3 right heart, 1/3 left heart - so there seems to be some right heart enlargement, which causes a change in the 3/5 to 2/5 rule. also, there is increased contact b/w heart and sternum although that is questionable as far as diagnostic use goes. may just be due to orientation. pulmonary artery is definitely enlarged - much bigger than the vein,and also much larger than the rib it shouldn't be larger than. the ddx for PA enlargement around here is heartworm. think about it - enlarged right heart, PA enlargement to right cranial lung lobe, and other enlarged pulmonary arteries. that's what all these other opacities are. signs of RH enlargment: carina looks too far caudal increased sternal contact w/heart derangement of 3/5 2/5 rule PA enlargement DV view, same dog - there is a bulge at the main PA b/w 1 and 2 oclock, and the proximal left PA has a huge diameter. w/HW, the PAs get large, torturous, and no longer taper. the caudal arteries show changes before the cranial ones do. the shape of the heart on this radiograph is a "reverse D" shape, due to R sided enlargement and a bulge in the main PA area (2 oclock) slide: closeup of a dog with HW disease - the PA coming back on the dog's right is pretty big. the pulmonary vein is hard to see. the PA to the right caudal lobe is obviously bigger than the width of the 9th rib. few diseases cause this - generally just HW or thromboembolic disease. your first 3 or 4 ddx for this vascular pattern are HW disease. slide: another dog w/HW - bulging right heart, increased sternal contact due to RV enlargement and main PA enlargement. long axis divides heart into abnormal ratio reverse D - flat left side due to PA protrusion, rounded bulging appearance to right side. dye in pulmonary artery - the main pulmonary artery is humongous, there are enlarged torturous branches. next: PDA - patent ductus arteriosus - the number 1 congenital heart disease in dogs. the dog shows up in your office as a young dog which is why we see open growth plates on this radiograph (vertebral physes close at about 6 mos) - this 5 mo old puppy has a very large heart so you think congenital disease. usually in dogs a L-R PDA is what it is. here we see a big heart, trachea parallel to spine. the cranial border of the heart is pretty clear, but the caudal border is kind of obscured by pulmonary vessels. the heart is grossly enlarged - generalized cardiomegaly or both right and left sided enlargement. another sign here that the L side is enlarged is that we see a big, bulging LA, elevating the mainstem bronchi. how do you know what exactly this is? dogs with PDA have enlarged pulmonary arteries and veins. both enlarged. the artery is kind of hard to see. the vein is there and it is definitely enlarged. in young dogs when you are trying to dx congenital heart disease, vessel size is crucial - if enlarged, you have too much blood going through lungs. if small, not enough blood is goign through the lung. here we have big arteries and veins, too much blood going into lungs - a left to right shunt. the patent ductus is normally present during fetal life as we know, normally bypassing the lung in the fetus so blood goes through main PA to aorta. when it is patent after birth, blood shunts from aorta into low pressure PA. small pulmonary vessels in a puppy would make you think of right to left shunts, where blood bypasses the lungs - tetralogy of fallot. DV view - heart is huge, vessels huge. angiogram used to be used for dx before echocardiography. the contrast goes into the aorta, through descending aorta, brachiocephalic and subclavian. catheter is in subclavian. in normal dog would have to circulate before whole body to get to PA - but here, it gets into the PA right away - there is a shunt - and you can see the patent ductus b/w the aorta and main PA. slide: doberman - large heart - good example of right heart enlargement and tremendous left heart enlargement. big bulge in left atrial area. this shows up as big soft tissue structure in left atrial area lifting mainstem bronchus and creating a flattened caudal border to the heart. normally should be convex. this heart is overall enlarged,trachea is elevated, RV and LA are huge. key to left atrial enlargement is elevation of mainstem bronchi, which start to get pinched, compressed - dog may cough. this dog probably has mitral insufficiency (most common acquired canine heart dz) - as valve fails, blood falls back into LA which enlarges. LH failure can then cause secondary RH enlargement. in dobermans, consider dilated cardiomyopathy - large breed dog, generalized heart enlargment - slide: diagram - shows changes in border of heart - pulmonary veins feeding into left atrium at the "caudal waist" of the heart, where there is a bit of a notch b/w atrium and vein. when atrium bulges, it flattens this area by fillign it out. also bulges dorsally, lifting mainstem bronchi. left atrial enlargement usually due to mitral insufficiency. when left atrium enlarges, left auricle enlargements. at 2 to 3 oclock on DV is left auricle hanging down (LA is in the middle) and so that bulges also. slide: tracheobronchial lymphadenopathy causes ventral deviation of mainstem bronchi, left atrial enlargement lifts the mainstem bronchi. another cause for generalized cardiomegaly (besides left and right heart enlargement) is fluid in the pericardial sac, pericardial effusion - produces a globular heart shape, or basketball shaped. slide: huge globular round heart taking up most of the chest. pericardial effusions may produce cardiac tamponade - compressed right ventricle, right heart failure, and ascites - this dog has a lot of fluid in the abdomen. we call these dogs "ticks" because they have huge bellies and tiny everything else. CKC spaniels get mitral insufficiency at very young age. dog with cardiomyopathy - also pulmonary disease - there's an alveolar pattern with air bronchograms in the caudal dorsal area. cardiac enlargement does not equal heart failure. cardiomegaly is a sign that the heart is trying to compensate. radiographic signs of heart failure are outside of heart. left heart failure produces severe cardiogenic pulmonary edema in the perihilar region around the carina, and pulmonary venous distension. this is because left heart can't handle blood returning. right heart failure signs are ascites, hepatomegaly, enlarged caudal vena cava, and pleural effusion. -don't worry about cats on the exam ---break---- Dr. Harvey pharyngeal and nasal disease Nasal Disease: today we'll cover pp 45 -51 of booklet 1. slide: diagram of nose in midsaggital section think about what goes on in the nose. it's a black box. there is no simple way in, and the contents are destroyed if you try to get in, because there are very fine bones and detailed conchae - different from humans. so we go in there at our peril, limiting our diagnostic and surgical options. slide: lacerations on dog muzzle with blood coming out of nares. it's not uncommon for cats to fall from a height and fracture their faces, or for dogs to be hit by cars. feline high rise syndrome includes nasal injury. (in europe they call it spring flying time for cats) blunt injury to muzzle is what happened to this dog. significant thing isn't what we see on the outside, but what's inside..obstruction? aspiration of blood? hemorrhage? you need to do a full physical exam - there may be blood loss, aspiration, etc. you may have no idea how much bleeding is going on from the outside. first you take pulse, check mm color, etc. animal may or may not be stable. generally we don't do much except back off and let mother nature fix the nose. often the owner is upset, animal is upset b/c owner is upset, animal is hypertensive - so you should separate them so animal can calm down, as hypertension may aggravate hemorrhage. if hemorrhage is severe you must treat it. also have to try to prevent further bloodloss - you can do this by ligating carotid arteries - vertebral arteries will provide enough circulation to the rest of the head. don't do this in people,though. you can do it in dogs and cats though. nasal trauma, acute effects: epistaxis, blood loss, aspiration more important is chronic nasal disease- many conditions result in discharge from nasal cavity or in sneezing, snorting, loss of appetite due to loss of sense of smell. chronic nasal d/c is common in dogs and cats. we have to put it in perspective and see which animals need diagnostic workups or should be left alone. slide: unlateral crusty tan d/c on right nares of dog. no obvious change to the nose itself under the d/c. dried d/c chronic nasal d/c in dogs - major causes: neoplasia - poor prognosis, expensive tx fungal rhinitis - difficult to manage, can be severe idiopathic - miscellaneous - those last two cover everythingg else. diagnostic methods available to us require access to the animal and sometimes anesthesia: history PE culture fungal serology history is important - age and breed not usually helpful because breeds that get nasal neoplasia are the same ones that get fungal disease. very young dogs not likely to have tumors but it can happen. fungal disease can occur in any age. discharge characterization is rarely helpful facial swelling is helpful - if there is a tumor pushing tissues apart you may see bulging, or if there is obstruction to mucous drainage, due to injury or other reason, there may be bulging. most swelling are neoplastic but not all of them are. planum nasale ulceration and temporal muscle atrophy are helpful- both point to nasal fungal disease. if both are present in the same dog in the absence of swelling it's probably fungal. in your PE make sure to look inside the mouth for swellings too, and use retropulsion on the eyes. useful clinical signs - swelling of face, ulcerated planum nasale, temporal muscle atrophy. ulceration is unusual in neoplastic cases. severe atrophy of masticatory muscles occurs with nasal fungal disease and we don't know why. usually bilateral even if active dz is unilateral. bacterial culture is a waste of time and money with chronic nasal disease.the nose is the vacuum cleaner and the tongue is the dishrag. you should expect gross contamination in the nasal and oral cavities. dogs with no nasal disease had all kinds of bugs growing in their noses in one study - staph, pseudomonas,etc. when do you want to pursue diagnosis? often you have to anesthetize the animal. nasal radiographs: anesthesia is essential, and the occlusal view is most helpful. when do you accept the risk and expense of this? if high risk of neoplasia, eg middle aged/old dog with bloody d/c - consider neoplasia, consider rads. if there has been chronic conservative tx with poor response, consider rads. any nasal d/c will likely improve a little bit with antimicrobial treatment, but that's just secondary to vacuum cleaner effect. looking at nasal rads, you want an anesthetized dog in excellent position tumors: 50% show increased density only, 50% show bone lysis fungus: 50% show increased density only, 50% show increased lucency so overall, 50% show only increased density and need further workup. when there is a lot of destruction and replacement with more dense tissue, think tumor. when there is destruction and increased lucency, think fungus. sometimes you get really lucky and see a radioopaque foreign body while patient is under anesthesia you can look up the nose. now, in dog/cat you can only see about 10% of total mucosal surface because it is so complex -you see a series of longitudinal turbinates - sometimes you can get through meatus into nasopharynx. you see highly vascular, smooth epithelium covering chonchae. a mass occupying what should be air space is seen in this slide - granuloma or tumor. need biopsy wad of fungus - hyphal matt - looks like wad of blue cheese - toxins in fungus erode away the tissue and this is why you see lucency on the rads. while animal is anesthetised you should biopsy if you have the equipment. don't bother looking in with an otoscope - you won't see anything. you need a fiberoptic rhinoscope. you can measure how far you need to go in using the radiograph, stick in your instrument, and grab. alternatively, you can get bigger pieces using a red rubber ear syringe, filling it with water, placing it against the external nares, pinching the nose closed around it, and forcing the water in as hard as you can. you're trying to use the water to force in and break a piece of tissue off.then you gather the sample from the pharynx out through the mouth. this can yield a fingernail sized piece of tissue. there is always inflammation around some area of nasal disease due to contamination - if you are too gentle you will just get some of that inflammatory tissue. sometimes we have to surgically open the nasal cavity to get a biopsy. sometimes you will flush out a foxtail or something. that's lucky. foreign body disease is an uncommon cause of chronic nasal disease in dog/cat. should be in differential but isn't likely. has good prognosis. nasal neoplasia is more common. slide: nasal adenocarcinoma that has filled nasal cavity by pushing away conchae and is bursting through external shape of the nose. clinical signs were snorting and nasal d/c only. nasal malignancy is locally aggressive and invasive with a low metastatic ra e. often adenocarcinomas. in other sites these tumors freuqently metastasize but the nasal tumors tend not to, until very late in the game. treatment - surgery alone - poor px. surgery and radiation - 45% survival at 18-24 mos. high likelihood of recurrence. with radiation only - insufficient data. slide: skull from dog with nasal fungal dz (usually aspergillosis - >70% are aspergillosis, most of the rest are penicilliosis, both of which are ubiquitous). aspergillus is a common bread mold. we breathe it in all the time. why in some animals is there a predilection for developing aspergillosis? more common in collies and other long nosed dogs. why? who knows. we think it starts with some local injury, perhaps caused by a sneeze, and a spore of aspergillus gets in, starts to grow, makes exotoxins, causes necrosis, etc. wide age range. typically, purulent d/c but can be bloody. temporal muscle atrophy, masseter atrophy, no swelling. there is a way of dxing nasal fungal dz as long as it is aspergillus - using a serological exam, an elisa test. can use this to rule out aspergillosis, but there is not a test for penicillium. fungal culture isn't useful. in dogs with no nasal disease, aspergillus and penicillium grew out in 27% and 13% of cultured dogs. so there isn't any point to doing a culture. use rads (radiolucent areas), rhinoscopy (visualization), serology, and clinical signs. tx: enilconazole tx - requires tubes in frontal sinuses. you need strong antifungals in contact with the fungus. the systemic antifungals are only about 50% effective. local drugs directly in the nasal cavity are better. enilconazole is a european drug available only by special dispensation at a few places in the states. also clometrazole, used under general anesthesia for a few hours. the enilconazole for 7-14 days at 20 mg/kg on both sides yields a 90% response rate. pretty good results. when you do surgery in the nose, you muck things up, and you then have abnormal clearance of material that is deposited in the nose. so it isn't uncommon for dogs to have serous nasal d/c if they have abnormal nasal anatomy. non-nasal causes of nasal d/c dental disease is a cause of chronic nasal d/c - roots of teeth and bone around them form floor of nasal cavity. if you have severe periodontal or root canal disease which has extended into bone, there can be an oronasal fistula, and chronic nasal disease. common in toy dogs. easy to fix. distemper, other systemic illnesses. usually you don't miss this, because dog has other signs of disease. nose is a mucocutaneous junction so you have to consider autoimmune diseases too. check out other mucocutaneous junctions - lips, anus, prepuce,vulva - and skin in general. so, you rule in or out all these things, and you end up with chronic idiopathic/active rhinitis cases. any nasal injury can result in abnormal healing and sequestration of bone or something and sometimes you never figure out the primary cause but you have chronic nasal d/c. this will be 10-40% of the dogs with chronic nasal disease. we treat a number of dogs with nasal surgery - dog does most of its heat loss by panting and it needs its nose to do this. most temperature control occurs involving a gland in the nasal cavity which secretes based on temperature. so if you remove everything in the nose, you remove that, and you have a dog at increased risk of heat stroke. you have to ensure you won't keep the dog in a hot car or anything. cats - have many of these same diseases, but there are some extras and some differences. lateral rads of a feline skull show smaller,finer bones. the cribiform plate and other bones are much, much finer. surgeons must be especially careful not to damage fine structures. also cats have large sphenoidal sinus, proportionately larger than dog. major things we see: neoplasia nasal/pharyngeal polyp (rare in dog) chronic rhinitis/sinusitis fungal dz trauma feline nasal neoplasia includes the adenocarcinoma seen in dogs, which is more destructive in cats since bones are thinner, and also lymphosarcoma, which in cats is treated by chemotherapy. it grows slower and produces less tissue loss. nasal pharyngeal polyps are odd - you pull back the soft palate and see this thing sitting in nasopharynx - usually a stalk going through auditory tube is what holds it there. there's no analagous thing in dog. the eosinophilic granuloma complex of cats is also unique to the cat. if you have a young/middle aged snuffling cat, radiograph it and you may find a polyp. sometimes the polyp fills the whole nasal cavity and sticks through the nares! more common in europe. here the nasopharyngeal polyps are more common - you can pull them out but they may grow back. slide: typical nasal fungal dz in cat is cryptococcus. often there is external swelling of muzzle. may mimic tumor. if bilateral, soft, and copious nasal d/c, stain the d/c with ink, and it may be cryptococcus and may respond well to systemic antifungals dx in cat: rule out neoplasia, polyp, and fungal dz with smears, rads, biopsy (not culture). then, you have leftover cases of chronic snufflers or chronic rhinitis/sinusitis, which is a diagnosis of elimination - unknown cause, often presumed early URI or trauma caused damage in the nose. treatment may be conservative or surgical. typically we treat conservatively unless it gets so severe that animal won't eat/drink. if you have a nose full of d/c and can't smell, you might not eat, esp if you are a cat. most commonly tx includes an antimicrobial drug of some kind. often you get an initial response and then a relapse. if you go through several cycles you may need to surgically clean out the nose. ---end----