REPORTS ON BLUEGRASS LAMINITIS SYMPOSIUM 2004

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Lee Foster
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1 REPORTS ON BLUEGRASS LAMINITIS SYMPOSIUM 2004 Editr's Nte: Fr several years the New Zealand Equine Research Fundatin in cnjunctin with the Pye Fundatin have ffered schlarships t a veterinarian and a farrier t attend the Bluegrass Laminitis Sympsium and t spend a shrt time with clleagues in the USA t study cnditins f the hrses' ft. The fllwing reprts are frm Andre Fisher the successful farrier applicant and Warren Mitchell, the successful veterinary applicant in FARRIER'S REPORT - by A J Fisher * I wuld like t begin by thanking the Pye Fundatin and the Equine Research Fundatin fr the pprtunity t travel t the United States f America t attend the Laminitis Sympsium. While there I tk the pprtunity t stay an extra ten days t spend bserving and wrking in Dctr Ric Redden's clinic. This was f great benefit as 1 gained a much better understanding f the things discussed at the Sympsium as 1 was able t see everything put int practice. This was helped greatly by Dctr Redden and his teams amazing hspitality end infectius enthusiasm. At the Sympsium I tk the pprtunity t attend the extra sessin n Radigraphy. As a farrier it is imprtant t be able t identify the main structures f the lwer limb n x-ray s that 1 can understand a given diagnsis frm the veterinarian. It is als imprtant as a farrier t be able t explain exactly what 1 need t be able t acquire frm the x-rays in rder t accurately apply a given sheing technique. In rder t accurately fit a therapeutic style she a farrier must knw the dimensins, angles and psitin f the internal structures f the ft as in a laminitis case fr example it is impssible t knw these things just frm external bservatins. The mst imprtant things t a farrier n x-ray are: * Farrier, 100 Thmpsn St, Leamingtn, Cambridge 1

2 These measurements are imprtant when determining the type f she, hw much elevatin, psitining f the she and knwing hw much ft there is t wrk with. It is imprtant t have reference pints such as the drsal wall and pint f frgg marked. Dimensins are crucial as it is impssible t accurately measure sle depth r wall thickness if the x-ray image is larger than the ft r is nt perpendicular t the ft. Fllw up radigraphs shuld als be taken when fitting therapeutic shes t determine whether r nt the desired result has been achieved. There is n pint leaving a she n if it has nt achieved its intended purpse, this will prbably be mre detrimental t the ft. Vengrams als give a much clearer picture f the cnditin f the internal structures f the ft as in mst cases f laminitis r serius trauma it is the bld supply and the imprvement f it that is a majr factr in the success f any treatment. X-ray may als be used t determine the extent f sft tissue damage. Abnrmal sft tissue parameters are a precursr t hf capsule abnrmalities. In rder t btain the desired infrmatin frm radigraphs a disciplined, methdical apprach must be taken t establish a clear picture f the internal structures and their relatin t each ther. When reading x-rays it is imprtant t knw the 'range f nrmality', the palmar angle fr example may range frm 0" t 20 depending n the breed f hrse and the type f ft. Ultra sund can als be used effectively t establish sft tissue parameters within the hf capsule. Particularly when there are n significant radigraphic findings in cases such as a hrse displaying typical symptms f cnditins such as navicular syndrme. The deep digital flexr tendn, impa ligament and cllateral ligaments f the navicular bne and the attachments f them alng with the bne surfaces may be examined within the ft via the frg crnet and digital cushin. Thickening f the tendns and ligaments, evlutin fractures, stelysis and sitentin f synvial fluid can be identified in these structures. When using ultra sund it is imprtant t cmpare the injured structure t the symmetrical structure f the same limb and t the equivalent structure f the ppsite limb. All structures shuld be examined bth lngitudinally and traversely. Treatment f injuries with traditinal methds such as ease f break ver, elevatin, width and supprt fr the injured structure may be enhanced by a better understanding f the lcatin and extent f the injury. Dr Redden's 'rck'n'rll she' is an adaptin f the rail she design t restre nrmal mechanical functin t the structures f the pasturn. An abnrmal palmar angle has a direct effect n the alignment f P2 which reduces all the structures ability t cpe with lading efficiently which will result in injury t ne r mre f these structures. One cmmn abnrmality is lng te lw heel syndrme. When x-rayed a palmer angle that is less than wuld be cnsidered nrmal fr the given case will be evident. In the thrughbred this may range frm negative palmer angle t arund 5. T manage this type f ft the rlled and crushed heel must be brught back t slid hrn and t restre balance t the ft but this will in mst cases exaggerate the abnrmal palmer angle. A simple elevated she may be used t crrect the pasturn alignment but in mst cases the cncussin upn impact is exaggerated by this style f she causing further damage t 2

3 the heels. The rck 'n' rll she allws the ft t land in a nrmal fashin, heel t te then rll frward unlading the heel. When at rest the hrse is able t rck frward n the she t restre a nrmal palmer angle and pasturn alignment while easing the pressure n the heel enhancing circulatin which will result in the prductin f quality hrn and sle. The rck 'n' rll technique may be applied t any style f she t enhance the treatment f mst cnditins. High Lw syndrme r mismatched feet, is a cmmn ccurrence especially in thrughbreds. It is cmmn practice fr aesthetic r cmmercial reasns t try t bring bth feet int symmetry. Hwever it is imprtant t identify the difference in the internal structures that are the reasn fr the differences in the size and shape f the hf capsules. Many similarities can be drawn between an upright r club ft and a laminitic ft, fr example, exaggerated r faster heel grwth, cntracted heels and retracted frg. Upright r club feet shuld be treated as individual entities. Palmar angles and the size and shape f the pedal bnes f bth feet are 3

4 different, therefre the pasturn angles, drsal wall angles and the shape f the hf capsules will als be different. Lacerum r platelet rich plasma is being used by Dr Redden in cases f severe trauma r injury t induce heeling f wunds. This utilises grwth factr technlgy that was riginally develped in human medicine. Lacerun prmtes rapid prductin f granulatin tissue which will the stabilise. Dr Redden fund it particularly useful in cases f severe puncture wunds and in ne particular case that invlved the remval f peace f necrtic pedal bne he believed the heeling time was dramatically reduced. Transprtatin f hrses suffering acute laminitis r trauma t the ft can be detrimental as the stresses invlved can further aggravate an already unstable ft. Hwever it is smetimes necessary t mve these hrses in rder t prperly treat them. T d this Dr Redden has develped a casting technique t supprt the ft and lwer limb while in transit. This technique can als be used in cases where wall resectins are dne r the hf capsule has sluffed r is remved. Surgical pins are placed thrugh the cannn bne in rder t take all lad bearing ff P3. Dr Redden has used his technique fr up t seven mnths while re grwing the hf capsule. Careful attentin must be paid t the pins as they are the main lad bearing structures. 4

5 In any laminitis r severe trauma case the treatment can be very invlved and require many specialised skills. Therefre and rganised team apprach invlving a veterinarian, farrier, wner and the hrse is essential. A full understanding f the cnditins, financial restrictins, carse and duratin f treatment and pssible utcmes is als essential fr all parties. There is n pint embarking n a $500 diagnstic prgramme n a $200 budget. There is n substitute fr experience and the pinins f clleagues shuld nt be discunted withut thught. Cmmunicatin is vital, fr example a farrier cannt fit a heart bar she accurately with nly instructins ver the phne, he/she must be included in the diagnstic prcess. The farriers knwledge f the limitatins f a given ft, fr example whether she can be nailed n r nt is an imprtant part f the prcess f deciding a carse f actin. Smetimes such cases present as quite daunting tasks, when apprached in a psitive, disciplined manner we can 'Make it happen'. 5

6 2. VETERINARIANS REPORT - by W Mitchell β In January 2004 I attended the 17 th Bluegrass Laminitis Sympsium held in Luisville, Kentucky. This annual event brings tgether veterinarians and farriers frm all ver the wrld. On rute t the cnference I spent a day at UC Davis, the Califrnian veterinary cllege. The large animal teaching hspital has a very full caselad prviding state f the art treatments. The equine medicine sectin cntained an impressive array f diagnstic equipment; digital radigraphy, ultrasund, cmputer assisted tmgraphy (CAT scans), scintigraphic imaging and magnetic resnant imaging. The Davis Equine unit sees a lt f referral clic patients. The mst cmmn cmplaint being intestinal bstructin caused by enterliths. Enterliths are smth laminated rcks cnsisting f ammnium magnesium and phsphate salts. Suspect bstructive clics rutinely have abdminal radigraphs taken lking fr enterliths. The high prevalence f enterliths in the hrse ppulatin in Nrthern Califrnia is thught t be due t the mineral make up f the sil and a high alfalfa cntent diet. The Bluegrass Laminitis Sympsium is rganized by Dr Ric Redden, an innvative farrier and veterinarian, whm is very passinate abut equine pdiatry. The first presentatin was by Dr Redden entitled "Hw t make it happen" - evaluatin, strategy, planning and executin. Equine pdiatry wrk requires a farrier and a veterinarian bth cmmitted t wrk in unisn t slve a prblem. Seldm d we a find simple primary diagnses with the ft, mst prblems are multifaceted and each area invlved must be dealt with mechanically r surgically. The gal being fr ft prblems is t simply enhance the healing envirnment; Mther Nature des the rest. The imprtance f the visual examinatin was stressed lking at the ft frm all angles, nticing bdy psture and cnfrmatin - each ft will give yu either subtle r strng messages cncerning the unhealthy areas. Obtaining meaningful infrmatin abut the ft remains a challenge fr veterinarians and farriers. The key is t use a disciplined methdical apprach that is designed t disclse the varius nrmal sft tissue parameters, nrmal bne anatmy and nrmal hf capsule anatmy as well as the inter relatinship f each cmpnent. When examining a ft r radigraph lk fr all nrmal areas first. What is left ver, pints t the prblem. β Matamata Veterinary Services, Matamata 6

7 A paper entitled the descriptive and functinal anatmy f the equine ft was presented by Dr J Denix frm France. The anatmy f the interphalangeal jint was reviewed. During lcmtin the interphalangeal jints underg a variety f cmbined mvements in the sagittal frntal and transverse planes, especially n uneven surfaces r during turns. Each mvement induces specific stresses n the articular surfaces and ligaments. Frm his research he cncluded that the distal interphalangeal (cffin) jint is: One f the mst affected jints in the hrse.' The mst influenced by hf placement and rientatin. The mst directly manipulated by hf trimming and sheing. Medial r lateral hf wall imbalance induces cllatermtin and sliding n ne side and rtatin n the ppsite directin f the bnes in the cffin jint. Ligament and deep digital flexr tendn injuries are ften cnsidered in the differential diagnsis f ft prblems in which there have been n radigraphic abnrmalities detected. In Dr Devix's study the tw cllateral ligaments (CL) f the affected DIPJ were examined ultrasngraphically (utilizing drsal and cllateral appraches t the crnet with lngitudinal and transverse sectins made by 7.5 r 10 mhz linear prbes) and then cmpared t the CL f the ppsite nrmal limb. In all cases the injured ligament appeared thickened and hypechgenic cmpared t the ppsite sund ne n the same limb and the hmlgues ne n the nrmal limb. Bne changes at the insertin sites were als clearly seen with ultrasngraphy. These included enthesephyte prductin, stelysis and avulsin fractures. On radigraphs mst f the affected limbs presented with enthesephytes n the secnd r third phalanx. Synvial fluid distensin f the DIPJ drsal and r palmar recesses was als dcumented Ultrasngraphically in mst hrses in the study. Cllateral ligament injuries treatment ptins: Acute Cases Jint immbilizatin. Casting. Chrnic Cases Crrective sheing Rlling te. Wide she n side f injured ligament. At least fur mnths rest. Grwth Factr Technlgy Dr Dave Jlly gave a presentatin n wund healing and hf repair using a newly develped equine prduct called Lacerum. Lacerum cntains platelets islated frm mares plasma, which when activated with thrmbin induce release f grwth factrs. 7

8 This technlgy using platelet rich plasma gel has been used in human medicine fr sme time fr treatment f chrnic ulcers and pressure sres. A series f case studies were presented shwing a variety f severe wunds t the bdy and limbs that were refractry t traditinal treatment, which respnded and healed thrugh the use f Lacerum. In an experimental study 2.5 cm 2 full thickness wunds were created belw the knee and hck in Thrughbred hrses, ne grup received platelet rich plasma n the wunds; the ther grup was left untreated. The platelet rich plasma (PRP) gel treated wunds at day 79 cntained abundant dense cllagen bundles rientated parallel t each ther and t the verlying epithelium, where as the cntrl tissues cntained fewer cllagen fibres that were rientated randmly. Wunds treated with PRP gel induced accelerated epithelial differentiatin and prduced tissue with rganized interlcking cllagen bundles. Quarter Cracks and Lacerum Often quarter crack wunds are insulted with bnding prducts, which are ht, caustic prevent water mvement. In a study f quarter cracks which were cut dwn t the sensitive laminae examinatin shwed they cntinued t dehydrate and pen up fr an additinal 12 t 14 days. The aim in quarter crack repair is t prduce grwth f healthy tissue. Lacerum applied, t these cracks under a tefal pad and adherent bandage did prmte healthy crnary band hf grwth. Using grwth factr treatment it is pssible t return t a functinal hf in sixty days. It was interesting t hear a series f case reprts by Dr Redden abut his experiences using Lacerum in treating high scale ft damage, severe puncture wunds and third phalanx sequestrum, with sme very encuraging results. Treatment Prtcls fr Chrnic Laminitic Ft and Club Ft Gene Ovnicek RMF Hf distrtin in chrnic laminitis has similar characteristics as a clubft hence hf management is similar. 8

9 1. Trim the heels t the live, functinal sle frm the frg apex caudally. 2. Leave ample hf wall length frward f the frg apex t ensure sle clearance. 3. Optimal breakver may need t be caudal r directly belw the tip f the third phalanx initially, t help reduce rapid heel grwth. Cmplicatins ccur when heels are trimmed cntinually and aggressively int the functinal sles and the tes are left lng. 1. Increased tensin n the Deep Digital Flexr Tendn (DDFT) will cause the heel t re grw and the walls t flare. 2. The heels will cntract. 3. The hrse will nt land heel first. 4. The hrse may develp pedal steitis. 5. Lng-term aggressive trimming may cause laminitis. Recgnizing and Treating, Heel and Navicular Pain Befre They Becme Irreversible Thrugh studying feral and dmestic hrses feet researchers have discvered that the widest part f the ft ffers the mst reliable reference t the drsal distal edge f the third phalanx. Research has shwn the hf capsule can migrate frward f the widest part f the ft. This lng te shrt heel hf distrtin in early phases causes: Hrses t stumble Land te first Decline in perfrmance. Lng perids f this hf distrtin can cause: Navicular syndrme Cffin jint pain Ring bne Pedal steitis DDFT prblems. Alignment f the distal phalanges is the cmmn gal f farriers. Using the widest part f the ft fr balance is mre reliable than using the frg apex as this can be stretched frward in distrted feet. With breakver placed slightly anterir t the tip f the third phalanx and caudal frg cntact made, substantial imprvement is seen in the psitin f the navicular bne and cffin jint. Hrses that land te first usually have a lnger than nrmal te which causes a delay in breakver and are inclined t mmentarily sublux the distal end f the secnd phalanx caudally and cause undue strain n the navicular bne and impar ligament. 9

10 Repeated activity f lading the navicular bne imprperly by creating strain seems t cause interruptin f bld flow t the navicular bne.. It is believed that substance P receptrs' that assist in regulating bld flw thrugh that regin are destryed. Relieving strain in this area at the time f breakver and at the time f grund cntact is extremely imprtant in preventing and treating lwer limb pathlgy: What t lk fr: Recgnise hw a hrse lands. Lk at the bttm f the ft and see if the distance frm the widest part f the ft is greater t the te than frm the heel. Early treatment by mving the- pint f breakver back with mst likely save the hrse frm future lameness issues. Sme hrses als need extra heel supprt (rcking rail shes). The flat r thin sled ft will change t a mre upright ft if the heels are nt ver trimmed and the breakver is placed belw r just slightly frward f the tip f the third phalanx. Digital Vengrams Recently, the use f vengrams f the ft has been advcated fr assessment f the laminitic ft. The technique is described in Equine Veterinary Educatin (2001) 1:3 (3) In shrt, vengraphy invlves placing a turniquet arund the fetlck and injecting mnipaque dye int the palmar digital vein, the ft is then immediately radigraphed. It is then bvius what part f the ft has r has nt gt perfusin and where the bld supply is cmprmised. This infrmatin helps: 1. Give a prgnsis (in extreme cases a lack f bld supply will mean a hpeless prgnsis). 2. Helps farrier and veterinarian determine where t fcus their treatment t imprve bld supply eg. mechanical sheing, hf wall resectin, crnary grving. 3. Identify pedal bne utside vascular beds in sequestrum and space ccupying lesins keratmas. 4. Serial vengrams can prvide infrmatin abut respnse t treatment i.e. imprvement in bld supply may precede clinical imprvement. If there is 'n imprvement in the bld supply after six weeks, a pr prgnsis is given. 5. Dr Redden suggested there might be therapeutic value in vengraphy thrugh mechanical dilatin f vessels in the ft. Ft Radigraphy Sft tissue pathlgy is present t sme degree in every ft sre hrse; evaluatin f sft tissue structures can be perfrmed radigraphically. Radigraphs f the feet shw many pints, which assist the farrier, veterinarian and wner in deciding the best treatment. 10

11 Infrmatin Frm Radigraphs Include: Sle Depth Measured frm the apex f the third phalanx in the healthy ft this shuld be at least 15 mm. Less than this is clinically significant. Drsal Hrn Lamellar Zne (H-L) Measure tw lcatins just belw extensr prcess and distal tip f the third phalanx. Bth measurements shuld be the same; nrmal is mm. Third phalanx rtatin when distal measurement is greater than prximal measurement. Third phalanx sinker withut rtatin f third phalanx, H-L measurements 25mm r greater with bulging f crnary band. Crnary Extensr Prcess Distance (C-E) It is the vertical distance between the mst prximal extent f the uter hf wall (immediately belw the crnary band) and the tp f the extensr prcess f third phalanx. T measure this yu need a radipaque marker frm crnary band dwn the drsal hf wall. Palmar Angle The angle between the bttm f the pedal bne and the sle. Prvides infrmatin n structural integrity f sft tissues in the heel and is indicative f mechanical effect f any she attached t the ft. Healthy feet have a psitive palmar angle,,the wings f third phalanx being higher than the apex. A palmar angle f apprximately 5 is cnsidered nrmal. High palmar angles are fund with club r laminitic feet. A negative palmar angle ccurs when the wings f third phalanx are lwer than the apex.this indicates substantial lss f heel bulb area and a small digital cushin. 11

The depth f digital cushin can be estimated by placing yur thumb in the depressin between the heel bulbs and the index finger f the same hand in the centre f the frg.

12 The depth f digital cushin can be estimated by placing yur thumb in the depressin between the heel bulbs and the index finger f the same hand in the centre f the frg. In a medium hrse with healthy heels this measurement, will be arund 8 cm. If the distance were well shrt f this yu wuld expect t see sft tissue cmprmise radigraphically. After the cnference I spent a very interesting day at Dr Redden's pdiatry centre in Versailles, bserving veterinarians and farriers frm the clinic wrking in tandem n a variety f ft prblems. Dr Redden is cntinually experimenting with new prcedures and treatments fr severe limb injuries with sme amazing results. The mst spectacular that I saw was a hrse mving freely in a paddck wearing a prsthetic hind limb that had been fitted six years ag. The pdiatry centre deals with referrals frm thrughut Nrth America. My final tw days in Versailles, Kentucky, was spent at a large private equine practice Hagyard Davisn and McGee. ' The clinic has a staff f arund frty equine veterinarians wrking with state f the art medical, surgical and reprductive facilities. The latest equipment additin being a hyperbaric xygen chamber. The principle is t maintain hrses in a pressurized cabin where they breathe 100% xygen at three atmspheres f pressure, which has been demnstrated t imprve xygenatin f the tissues. This technique is particularly useful t treat areas such as bnes and tendns in which the bld supply and hence the xygen supply is lesser than in ther parts f the bdy. It is als used t imprve xygenatin f tissues that may have been impaired by disease, injuries r infectin. Benefits f this type f therapy have been scientifically dcumented in humans and include: An increase in new bld vessels in affected areas u Decreased edema Decreased inflammatry respnse Antibacterial affect against anaerbic bacteria Prductin f new cells in bnes and cnnective tissues, which hasten recveries f injuries t such tissues. I wuld like t thank the Pye Fundatin and the New Zealand Equine Research Fundatin fr their generus supprt f this schlarship. 12

5.1. What do we need to know before we start planning a canine rabies control programme?

5.1. What do we need to know before we start planning a canine rabies control programme? 5.1. What d we need t knw befre we start planning a canine rabies cntrl prgramme? Yu need t knw abut: The epidemilgy f rabies in yur area The reservir species in yur area Hw rabies is transmitted. This