ALUMNI REUNION

By Christoph Mans, DVM and Kurt K. Sladky, MS, DVM, Diplo­mate ACZM

Intranasal admin­is­tra­tion of mida­zo­lam in a green-winged macaw.

Seda­tion of dogs and cats in vet­eri­nary prac­tice is daily rou­tine for a vari­ety of pro­ce­dures, such as radi­ographs and ultra­sonog­ra­phy, or other non-painful, but poten­tially stress­ful pro­ce­dures. How­ever, for avian patients, either man­ual restraint of con­scious birds or gen­eral anes­the­sia is typ­i­cally per­formed, in order to com­plete most clin­i­cal pro­ce­dures. Gen­eral anes­the­sia pre­dis­poses birds to car­dio­vas­cu­lar and res­pi­ra­tory depres­sion, and may cause aspi­ra­tion of gas­tric or crop con­tents. In con­trast, man­ual restraint in con­scious birds is sim­ple to per­form, but can have neg­a­tive con­se­quences, includ­ing stress to the bird and/or han­dler, neg­a­tive con­di­tion­ing to the clinic envi­ron­ment (e.g., the per­son restrain­ing or the towel used for restraint), and the pre­dis­po­si­tion of trauma to the han­dler and/or bird.  Sev­eral recent stud­ies demon­strated that man­ual restraint of birds causes increased body tem­per­a­ture and res­pi­ra­tory rate. In sick or very stressed bird, acute col­lapse and death sec­ondary to man­u­ally restraint have been reported. There­fore, sim­ple seda­tion tech­niques pro­vide a use­ful alter­na­tive for reduc­ing phys­i­o­logic stress in birds under­go­ing non-painful clin­i­cal procedures.

A rose-breasted cock­a­too, 5 min­utes after intranasal admin­is­tra­tion of mida­zo­lam, for seda­tion prior to phys­i­cal exam­i­na­tion and blood collection.

Recent research at the Uni­ver­sity of Wis­con­sin School of Vet­eri­nary Med­i­cine (SVM) revealed that intranasal admin­is­tra­tion of mida­zo­lam in Ama­zon par­rots results in rapid onset of mild to mod­er­ate seda­tion, which is com­pletely reversible with intranasal flumaze­nil. The time of onset to seda­tion is rapid, typ­i­cally within 3–5 min­utes, and the intranasal route is less painful to the bird than intra­mus­cu­lar or sub­cu­ta­neous admin­is­tra­tion. Dur­ing seda­tion and while under phys­i­cal restraint in a towel, the birds’ cloa­cal tem­per­a­tures and res­pi­ra­tory rates were sig­nif­i­cantly lower than those birds not admin­is­tered mida­zo­lam, and vocal­iza­tions and flight and defense behav­iors were reduced in mida­zo­lam treated birds. Alto­gether, admin­is­ter­ing intranasal mida­zo­lam pro­vided easy cap­ture and restraint for both han­dlers and birds. In addi­tion, clients per­ceive the intranasal route as non-invasive, com­pared to intra­mus­cu­lar injec­tion, which leads to bet­ter client com­pli­ance in cases in which seda­tion is recommended.

A green-winged macaw, sedated for a phys­i­cal exam­i­na­tion and beak over­growth cor­rec­tion. Only light man­ual restraint was nec­es­sary after intranasal seda­tion with mida­zo­lam. Vocal­iza­tion was absent dur­ing the entire period of restraint.

Com­monly used dosages of mida­zo­lam for seda­tion of healthy psittacine birds range from 1 to 2 mg/kg, admin­is­tered intranasally. For rever­sal, flumaze­nil can be admin­is­tered at a dosage of 0.05 to 0.1 mg/kg, intransally. In cases in which deeper seda­tion is needed, intranasal butor­phanol (1 to 2 mg/kg) can be admin­is­tered together with mida­zo­lam. When adding butor­phanol, mida­zo­lam dosages can be reduced, due to the syn­er­gis­tic effects of this bal­anced seda­tion pro­to­col. Since indi­vid­ual birds respond dif­fer­ently to the seda­tives admin­is­tered, we rec­om­mend start­ing with lower dosages, and increas­ing if the achieved state of seda­tion proves insuf­fi­cient for the planned procedure.

Intranasal seda­tion has been used in over 200 avian patients at the SVM for rou­tine well­ness exams, blood sam­ple col­lec­tion, restraint needed for radi­ographs and ultra­sound, and for groom­ing pro­ce­dures, such as nail and wing trim­ming. No neg­a­tive side effects have been observed in any of these patients. There­fore, intranasal seda­tion, using mida­zo­lam, with or with­out butor­phanol, is a sim­ple, safe, effec­tive, rapidly reversible, and read­ily avail­able option for seda­tion of avian patients in daily clin­i­cal practice.

Intranasal admin­is­tra­tion of mida­zo­lam in an Ama­zon parrot.

A Quaker para­keet pre­sented for a frac­tured left tibio­tar­sus, sedated with intranasal mida­zo­lam and butor­phanol. Deep seda­tion was achieved, which allowed for com­ple­tion of radi­ographic posi­tion­ing and splint appli­ca­tion, for which oth­er­wise gen­eral anes­the­sia would have been used. The ani­mal recov­ered within 5 min­utes, after admin­is­tra­tion of flumazenil.

A: Arthro­scopic image inside a dog shoul­der joint with an enlarged supraspina­tus ten­don (ST) push­ing on the bicep tendon(BT). B: MRI image of this same dog show­ing the enlarged supraspina­tus ten­don (blue arrows) push­ing on the bicep ten­don (white arrow). The bones of the shoul­der joint are black (H=humerus, Sc=scapula) C: MRI image of a nor­mal dog shoul­der. Upper arrows point to the supraspina­tus ten­don. Lower arrow iden­ti­fies the bicep tendon.

Dr. Sue Schae­fer, UW Vet­eri­nary Care ortho­pe­dic sur­geon, was very frus­trated with the tools avail­able to her for diag­nos­ing shoul­der prob­lems in dogs. So, she began her own research on the appli­ca­tion of MRI tech­nol­ogy to mus­cu­loskele­tal anatomy and to ortho­pe­dic prob­lems in dogs.

“Many of our clients come in and say they’ve had an MRI on their knee or on their shoul­der and they want the same thing done for their ani­mal because they under­stand that it is a very use­ful diag­nos­tic tool,” Schae­fer said. “But we didn’t have a base­line for being able to look at the dog shoul­der. I could do an MRI of a dog that has lame­ness in its fore­limb and has pain in its shoul­der, but I wouldn’t know what I was look­ing at.”

Since no one had writ­ten an anatomy guide to what a nor­mal dog shoul­der should look like under MRI, Schae­fer decided to do just that. She began her research sev­eral years ago by using MRI to com­pare nor­mal joints to abnor­mal joints and is now using this infor­ma­tion for what she calls the “Dog Shoul­der Atlas.”

“You have to have a base­line, you have to have a guide­book,” she said. “If we’re doing an MRI and we are try­ing to look for torn lig­a­ments or torn car­ti­lage we need to know what nor­mal looks like and we need to know where we would find it on the MRI—where in the
joint I should find one spe­cific ten­don and another lig­a­ment, where’s the nor­mal posi­tion, what’s the nor­mal size, those kinds of things.”

Schae­fer began her research by using cadaver joints from dogs who died from other unre­lated ill­nesses. She used these joints in her “nor­mal” group and eval­u­ated them with MRI to deter­mine “nor­mal.” From this, she cre­ated scans of dif­fer­ent sec­tions and dif­fer­ent views and angles of those sec­tions to put together her atlas of nor­mal joints.

“We were able to match the anatomy per­fectly with what we see on the MRI so I can now go back to the MRI and say ‘oh I know this is the bicep ten­don, I know that this is the supraspina­tus ten­don, I know this is the humerus, because here’s my guide’,” Schae­fer said. She would then com­pare the scans from her “nor­mal” group to actual patients in order to deter­mine the nature and loca­tion of the problem.

“This is really a foun­da­tion,” said Schae­fer. “We under­took a clin­i­cal trial per­form­ing MRIs on dogs in our clinic with shoul­der prob­lems. We then con­firmed [through] surgery that the MRI showed the same changes seen at surgery. We were able to demon­strate that MRI is a use­ful tool. Through clin­i­cal research we were able to val­i­date its appli­ca­tion to diag­nos­ing shoul­der injuries in dogs. We need to develop an atlas for all of the joints in the dog, but we’ve started with the shoul­der. I wanted to start here because it is a very chal­leng­ing joint.”
Now Dr. Schae­fer and oth­ers can use this atlas to bet­ter diag­nose patients who have shoul­der prob­lems and to pre­scribe the best treat­ment options. “The more we learn about the shoul­der, the more we under­stand how com­plex it is, the bet­ter we are at diag­nos­ing very spe­cific ten­don and lig­a­ment prob­lems. If we get bet­ter diag­nos­tic infor­ma­tion, then we can fig­ure out bet­ter ways to treat the ani­mals. It improves our therapeutics.” Schaefer isn’t fin­ished yet. Her next area of inter­est is the “Dog Hip Atlas!”

Dr. Sara Erick­son with some of the PNGIMR staff, work­ing in the research lab­o­ra­to­ries located near Madang, PNG.

When peo­ple say “your job will take you places,” they don’t usu­ally mean to a remote vil­lage of Papua New Guinea, sit­ting by someone’s bed­side in the night as they donate blood. But that’s just one of the places that Sara Erickson’s work has taken her, when she began her grad­u­ate research at the UW School of Vet­eri­nary Med­i­cine. Erick­son stud­ies lym­phatic filar­i­a­sis, a dis­ease caused by a par­a­sitic worm that is car­ried and passed on by mos­qui­toes. Erick­son com­pleted her PhD degree in August 2011.

“I’ve worked in mos­quito research for 11 years now,” said Erick­son, who still finds no short­age of fas­ci­nat­ing phe­nom­ena in the mos­quito world to keep her busy. The research for her PhD the­sis tar­geted the dif­fer­ent par­a­sitic worms respon­si­ble for lym­phatic filar­i­a­sis, the dis­fig­ur­ing dis­ease com­monly known as ele­phan­ti­a­sis. “Of course, we don’t have those in the States,” said Erick­son. “But I’ve always enjoyed traveling.”

That travel took Erick­son to Papua New Guinea, one of the most endemic regions for lym­phatic filar­i­a­sis. Although not fatal, the dis­ease is nonethe­less destruc­tive, with a dev­as­tat­ing mor­bid­ity rate. “See­ing the impact in endemic areas is really astound­ing,” Erick­son said. “Peo­ple can no longer live the same life.”

Erick­son and her advi­sor, Bruce Chris­tensen, designed research projects to inves­ti­gate the par­a­sites respon­si­ble for the dis­ease and the mos­qui­toes that trans­mit it. “We want to crit­i­cally define how good mos­qui­toes are at trans­fer­ring these dis­eases,” said Chris­tensen. “We try to look at mos­qui­toes in the real world, and how well they do or do not function.”

Accord­ing to Erick­son, this data is invalu­able to any plan to erad­i­cate the par­a­site. “Lym­phatic filar­i­a­sis is being tar­geted for elim­i­na­tion,” she said. But the drugs avail­able affect only one stage in the parasite’s life­cy­cle, mean­ing that it’s easy for them to resurge if the whole pop­u­la­tion isn’t elim­i­nated. An erad­i­ca­tion pro­gram must be care­fully timed based on accu­rate data. Cut­ting the pro­gram short risks a resur­gence, while run­ning it too long is eco­nom­i­cally impractical.

Armed with a grant from the NIH Fog­a­rty Inter­na­tional Cen­ter and an agree­ment with the Papua New Guinea Insti­tute of Med­ical Research (PNGIMR), Erick­son left for Madang, Papua New Guinea to set up her research pro­gram. Her first task was to find an endemic vil­lage that could be stud­ied in detail, and that proved harder than expected.

“That’s pretty easy to write in a grant. It’s just a few lines,” said Erick­son. “But it took about a month and a half.”

Dr. Erick­son with a research team test­ing vol­un­teers for infec­tion with lym­phatic filar­i­a­sis parasites.

Erickson’s research requires human blood sam­ples to test the cur­rent lev­els of infec­tion and track the parasite’s rate of spread. Not only is this logis­ti­cally com­pli­cated, as the par­a­site is only present in the blood­stream by night, but it also requires a rela­tion­ship with the local peo­ple. “It takes a long time to build that rela­tion­ship,” said Erick­son. She cred­its PNGIMR for the help she received in mak­ing these con­nec­tions possible.

Once that trust was estab­lished, Erick­son went into the vil­lage with the PNGIMR team to col­lect blood sam­ples, set­ting up cots to draw blood overnight in what they call “night bleeds.” “It’s an event then,” said Erick­son. “The chil­dren come out and fol­low us around.” In this fes­tive atmos­phere, they gather the blood they need to col­lect their data, return­ing to the lab the next day.

Papua New Guinea is within the Pacific Ring of Fire, which has many active vol­ca­noes and fre­quent earth­quakes, both of which were expe­ri­enced by Erick­son while per­form­ing field research.

Mov­ing from vil­lage to vil­lage, Erick­son expe­ri­enced the diverse cul­ture of Papua New Guinea. “These vil­lages are five min­utes apart, but their cul­tures can be very dif­fer­ent,” said Erick­son. “Every vil­lage has its own dialect.” Locals speak Malaysian Pid­gin, a unique langue with so many near-English words that Erick­son found she could under­stand it. “There’s no real lan­guage bar­rier,” said Erick­son. But, like all cul­tural dif­fer­ences, some aspects of the lan­guage took get­ting used to. “I was always called the ‘white meri,’” said Erick­son. “That’s their word for ‘woman.’”

After two trips over­seas, Erick­son learned more than you can put in a research paper. “Work­ing in Papua New Guinea, you never know what to expect on a given day,” said Erick­son. “You learn to accept it.”

Even with her the­sis work com­pleted in August 2011, Erick­son has no inten­tion of cut­ting her ties with Papua New Guinea. “We still have one and a half years left on the project,” said Erick­son. She looks for­ward to keep­ing up the ties she forged by her research. “You want to build sci­en­tific rela­tion­ships with peo­ple in other coun­tries,” said Erickson.

Erickson’s next move will build even more con­nec­tions as she is works on her post doc­toral research at the Wal­ter and Eliza Hall Insti­tute of Med­ical Research in Mel­bourne, Aus­tralia, where she will be their first mos­quito researcher.

By Chanda Miles, DVM and Christo­pher Sny­der, DVM, DAVDC

Lat­eral sur­vey skull radi­ograph reveal­ing one frac­ture of the right mandible (black arrow).

Diag­nos­tic imag­ing is a hall­mark of vet­eri­nary med­i­cine that aids in diag­no­sis, treat­ment and helps estab­lish prog­no­sis of the patient, espe­cially patients who sus­tain trauma. Often­times our vet­eri­nary patients suf­fer injuries in which the patient or the clin­i­cal signs do not fully rep­re­sent the true extent of the injury.  This is par­tic­u­larly true with cases of max­illo­fa­cial trauma where the only obvi­ous injury may be a frac­tured tooth or soft tis­sue abrasions.

His­tor­i­cally, the imag­ing modal­ity of choice to eval­u­ate max­illo­fa­cial trauma has been radi­og­ra­phy.  Skull radi­ographs are read­ily avail­able but can be very chal­leng­ing to eval­u­ate due to super­im­po­si­tion.  Mul­ti­ple views are typ­i­cally required to best com­pletely eval­u­ate the skull.  The pro­fes­sion has pre­vi­ously been lim­ited to con­ven­tional radi­og­ra­phy.  With appro­pri­ate tech­nique, sur­vey radi­og­ra­phy can reveal evi­dence of bony injury, but due to the extent of super­im­po­si­tion frac­tures can be dif­fi­cult to iden­tify.  Unknown bony and soft tis­sue injury can lead to incom­plete diag­no­sis, and lack of treat­ment, which can have severe long-term consequences.

In humans, imag­ing with com­puted tomog­ra­phy (CT) has long been the gold stan­dard for eval­u­at­ing max­illo­fa­cial trauma as it is far more sen­si­tive in detect­ing such pathol­ogy as max­illo­fa­cial, mandibu­lar, and tem­poro­mandibu­lar joint (TMJ) frac­tures.  CT in vet­eri­nary patients also pro­vides clear and con­cise imag­ing that allows the diag­nos­ti­cian to appro­pri­ately diag­nose and treat if nec­es­sary.  Not only can CT pro­vide supe­rior imag­ing in com­par­i­son to radi­og­ra­phy, but it has also become more read­ily avail­able to our patients as well as afford­able to our clients.  One study by Bar-Am eval­u­ated the sen­si­tiv­ity of skull radi­ographs com­pared to CT when deal­ing with max­illo­fa­cial injuries.  Radi­ographs ver­sus CT revealed a mean of 4.8 and 7.6 injuries in dogs and 3.8 and 7.7 for cats.

Gen­er­ally speak­ing, max­illo­fa­cial trauma, itself is not life threat­en­ing.   Once the patient is sta­ble enough for anes­the­sia, a CT scan can be per­formed.  If the CT scan is present in the build­ing, treat­ment can be insti­tuted imme­di­ately after the scan requir­ing one anes­thetic event, thus fur­ther decreas­ing risks asso­ci­ated with mul­ti­ple anes­thetic procedures.

CT image of tem­poro­mandibu­lar joints show­ing a com­min­uted frac­ture of the right condy­lar process (white arrow).

An exam­ple of where CT is supe­rior to radi­og­ra­phy can be seen with a patient that recently pre­sented to the UW Crit­i­cal Care Ser­vice after hav­ing sus­tained a seri­ous head injury (head was report­edly run over by a car).  The patient required sev­eral days of sup­port­ive care for trau­matic brain injury.  Skull films (see skull radi­ograph at top) among other imag­ing (chest radi­ographs) were per­formed as cur­sory diag­nos­tics.  The skull films revealed one iden­ti­fi­able facial frac­ture.  After sev­eral days the signs of brain injury improved and the patient was sta­ble for anes­the­sia and was trans­ferred to the Den­tistry & Oral Surgery ser­vice for a CT scan and treatment.

CT image show­ing mul­ti­ple frac­tures involv­ing the max­il­lary and pala­tine bones. 1) Depressed frag­ment of max­illa bone into the nasal cav­ity; 2 & 3) Frac­ture of both the right and left side of the pala­tine bone; 4) Frac­ture of left max­illa bone; 5) Devi­ated septum.

The CT scan revealed mul­ti­ple frac­tures involv­ing the mandible, and inci­sive, max­il­lary, pala­tine, frontal, ptery­goid and sphe­noid bones.  The patient also sus­tained condy­lar frac­tures involv­ing both TMJ’s (See fig­ures above and left).  While only a sin­gle view sur­vey radi­ograph was taken of this patient, the true extent of trauma was grossly underestimated.

Not all injuries asso­ci­ated with max­illo­fa­cial trauma require sur­gi­cal treat­ment.  Under­stand­ing the full extent of the injury and the pathol­ogy that exists is the first step in cor­rect treat­ment plan­ning.  By inven­to­ry­ing all injuries, an appro­pri­ate treat­ment plan can be for­mu­lated and an edu­cated, long-term prog­no­sis can be given to the client.  The client and vet­eri­nar­ian can appro­pri­ately mon­i­tor for heal­ing of injuries not requir­ing repair such as non-displaced facial frac­tures that may not require fix­a­tion or teeth that may have suf­fered a dis­rupted blood sup­ply. The ulti­mate goal is to pro­vide the patient with a life long com­fort­able, func­tional bite.