Approach to Conditions of the Equine Hoof PDF

Approach to Conditions of the Equine Hoof Dr Alissa Cooper BSc BVetMed PGCertVedEd FHEA MRCVS Lecturer in Equine Clinical Practice a.m.cooper@surrey....

Approach to Conditions of the Equine Hoof Dr Alissa Cooper BSc BVetMed PGCertVedEd FHEA MRCVS Lecturer in Equine Clinical Practice [email protected] Acknowledgement: Holly Lenaghan Wednesday, 08 November 2023 1  Learning Objectives Develop awareness of the common conditions affecting the equine hoof Sub-solar abscess Identify the common clinical presentations Understand the aetiology & anatomical considerations Describe and demonstrate appropriate treatment options Solar Penetrations Outline the diagnostic approach to solar penetrations Understand the potential severity of penetrations Laminitis Understand the diagnostic approach and prognostic indicators Outline the first-line treatment for acute laminitis Wednesday, 08 November 2023 2  Reading List Essential Reading Pascoe’s Principles & Practice of Equine Dermatology. D.C.Knottenbelt Chapter 17 – Injuries and diseases of the hoof Diagnosing and treatment of penetrating injuries of the hoof in horses O’Neill & O.Meara 2010 In Practice 32; 484-490 Wednesday, 08 November 2023 3  Approach to Hoof Problems Initial presentation Lameness Heat in foot Crack visible or obvious clinical sign Foul smell (Thrush) Increased digital pulses Further Examination →Hoof testers to localise pain →Pare out foot and examine all elements Identify problem - Visual identification - Radiographs - MRI 5 Common Conditions of the Hoof Conditions of the equine hoof generally occur due to; NEGLECT / POOR TRIMMING ENVIRONMENT TRAUMA Horseworld.co.uk Thehorse.com Horsesidevetguide.com 6 Wednesday, 08 November 2023 7 Hoof Cracks Toe, Quarter, Heel or Sole Cracks Severity depends on depth of crack “Grass” Cracks From ground up, usually due to poor foot conformation “Sand” Cracks Extending from Coronary band distally, due to lesions at the coronary band Pascoe’s Principles & Practice of Equine Dermatology - Chapter 17 8  Hoof Cracks Treatment Identify and treat the underlying cause – Foot balance – Good quality nutrition – Improve horn quality Biotin (15-20mg/day) Moisturising products Hoof hardeners Stabilise the crack – Clean and debride (dremmel) – Farrier clips / wire – Fill with synthetic resin – Good shoeing 9 Thrush What is it? Exudative bacterial dermatitis in the sulci frog Caused by poor hygiene, poor foot care, overgrown feet Fusobacterium necrophorum Diagnosis Appearance and SMELL Treatment Debridement of necrotic frog Improved hygiene Topical treatments – povidine/iodine, formalin, H2O2 Antimicrobials if deep/sensitive structures affected Prognosis Very good Pascoe’s Principles & Practice of Equine Dermatology - Chapter 17 10 Trauma 11 Trauma FOOT CAST Support Sterility Protection Pain Relief 12 SUB–SOLAR ABSCESS ‘Pus in the foot’ 13 14  Sub-Solar Abscess ‘Pus in the foot’ The most common cause of lameness in horses Ascending bacterial infection into the chorium (solar dermis) Lesions in the white line “Nail bind” Penetration injuries Risk Factors Poor foot conformation Seedy Toe Wet, muddy conditions Seen both in shod & unshod horses Chronic Laminitis / PPID 15  Sub-Solar Abscess Diagnosis Acute & severe unilateral lameness Increased digital pulsation to affected hoof – “Bounding pulses” Heat in the hoof +/- distal limb swelling Repeatable and marked pain response on application of hoof testers TheGlassHorse Differential Diagnosis Solar Bruising, Pedal bone fracture, Laminitis (rare to be unilateral) 16 Sub-Solar Abscess TREATMENT AIM TO ENCOURAGE DRAINAGE Remove Shoe Pare and clean the sole ‘Explore’ any discoloured tracts or defects in the white line (Sedation +/- nerve block infrequently required) POULTICE To soften hoof prior to curetting To maintain drainage after abscess open Poultice should be changed 1-2 times daily 17 Sub-Solar Abscess TREATMENT Provide pain relief 24-48 hours NSAID therapy o Phenylbutazone 4.4 mg/kg IV or PO BID Antibiotics are not indicated for un-complicated abscess Tetanus Prophylaxis Check tetanus vaccination status If in doubt → Administer tetanus antitoxin 18  Sub-Solar Abscess Chronic Abscess Purulent Abscess Might rupture at coronary band or heel Deeper/sensitive structure involved bulb Will require further diagnostics – Radiography Still aim to encourage drainage distally Likely to need more extensive surgery May require repeat flushing Antimicrobial therapy indicated 20 Solar Penetrations 21  Solar Penetrations – First Principles If nail/wire is still in place Leave it in situ - support leg Obtained radiographs if possible If nail/wire already removed by owner Try to identify tract and carefully pare sole to expose chorium (solar dermis) Clean, lavage and dress the lesion BEWARE delay in onset of lameness Further investigations ASAP if any suspicion of complications; Probe/Contrast Radiography/MRI 22  Solar Penetrations Potential Sequelae Damage to Pedal bone Pedal osteitis → Sequestrum formation Damage to Soft tissue structures Insertion of Deep digital flexor tendon Impar Ligament Synovial Infection TheGlassHorse Navicular bursa Distal interphalangeal joint 56% survival from hospital 36% return to normal athletic function Digital tendon sheath Number of complications + Time to treatment Prognosis 23 Solar Penetrations (O Meara & O Neill, 2010) 24  Solar Penetrations – Treatment Simple, uncomplicated penetration; As per solar abscess – pare and poultice Antibiotics only if clear evidence of infection Judicious use of analgesia / NSAIDs Penetrations with synovial penetration; Broad-spectrum antimicrobial therapy Procaine Penicillin, 22mg/kg IM BID (or IV QID) Gentamicin, 6.6mg/kg IV SID SURGICAL INTERVENTION – Arthroscopic lavage of synovial cavity TETANUS PROPHYLAXIS 25 Neoplasia - Keratoma 26 Neoplasia - Keratoma 27  LAMINITIS Review 2nd Year Lecture “Condition of the Equine Hoof” Foundations of Disease 3 29 Laminitis 30 Clinical categories of Laminitis Multifactorial disease process, with common end-point of laminar degeneration 1. Endocrinopathic Insulin dysregulation (Equine Metabolic Disease) Equine Pituitary Pars Intermedia Dysfunction (PPID) Iatrogenic – steroid induced 80% of cases of laminitis have underlying endocrinopathic disorders 2. Inflammatory Systemic Disease – sepsis, colitis, endometritis Feeding accidents e.g Grain overload Retained Foetal Membranes 3. Traumatic Excess weight bearing on one limb (contralateral limb laminitis) 31  Clinical Signs of Laminitis Acute onset lameness Shifting weight Rocking back onto heels Reluctance to walk Short, choppy gait ‘Bounding’ digital pulses Heat through dorsal hoof wall Pain on over toe on hoof testers 32  Laminitis - Diagnostics Diagnosis based on clinical signs and history Radiography is an important modality to assess Severity Progression Prognosis Response to treatment Be aware of time since onset when taking radiographs 33 Diagnostics - Radiography Dorsal Angle of Rotation Should be 15%) ‘Sinking’ of P3 into hoof capsule CE Distance >15mm 18° Prolapse of P3 through sole Mediolateral Rotation Chronicity Undiagnosed / Untreated underlying condition 38  Laminitis - Principles of Treatment 1. Support the pedal bone – Prevent / Restrict displacement Strict Rest during the acute phase o Exercise will make laminitis worse Support the foot o Soft deep bed – sand or shavings o +/- Remove shoes o Sole and frog supports supports 39 Sole Support 40 Treatment of Laminitis - Only practical and useful in a hospital setting treating inflammatory laminitis 41 Treatment of Laminitis 2. Suppress inflammation and provide pain relief Non-steroidal anti-inflammatory therapy o Phenylbutazone 4.4mg/kg IV/PO for 24-48 hrs 2.2mg/kg PO BID after 48 hrs Additional pain relief (multimodal): o Paracetamol – Not licensed o Gabapentin – Not licensed o Opioid analgesia in severe cases 3. Acepromazine? o Vasodilator – improve blood flow in feet o Anxiolytic – calm horse 42 Treatment of Laminitis 4. Dietary Restriction o Low quality or soaked hay (12 hours) o Stop any concentrate feeds o Balancer should be given (Vitamin & mineral supplement) 43 Treatment of Laminitis 5. Diagnose and treat the underlying condition Pituitary Pars Intermedia Dysfunction (PPID) Endogenous ACTH concentration TRH-stimulation test Treat → Pergolide Insulin Dysregulation Resting hyperinsulinaemia In feed glucose test Treat → Diet & Exercise(once recovered from laminitis) +/- Metformin Ertugliflozin/Canagliflozin? – sodium-glucose cotransporter 2 inhibitors (SGLT2i) 44 Treatment of Laminitis 6. Remedial Farriery Once displaced (rotated or sunken), the pedal bone cannot be replaced Essential to engage with a good farrier (remedial farrier) who can Rebalance the hoof to encourage weight bearing Provide longer term frog/sole support Reduce breakover Work with the hoof over 6-8 months and encourage new hoof growth to align with the position of the pedal bone 45 Treatment of Laminitis 6. Remedial Farriery 46  Treatment of Laminitis 6. Remedial Farriery imprintshoes.co.uk Heart Bar Clogs 47  Laminitis - Treatment Remedial farriery – Corrective trimming / shoeing – Proprietary shoes eg Imprint shoes – Wooden shoes – +/- impression material/wedge pad AAEP 2007 Convention Further reading 1 The Laminitis Site – Home The Laminitis Trust – www.laminitis.org ECEIM consensus statement on equine metabolic syndrome - Durham - 2019 - Journal of Veterinary Internal Medicine - Wiley Online Library Effects of metformin hydrochloride on blood glucose and insulin responses to oral dextrose in horses - PubMed (nih.gov) Further reading 2 A comparison of seven methods for continuous therapeutic cooling of the equine digit - PubMed (nih.gov) www.researchgate.net/publication/6120052_Induc tion_of_laminitis_by_prolonged_hyperinsulinaemi a_in_normal_ponies A "modified Obel" method for the severity scoring of (endocrinopathic) equine laminitis - PubMed (nih.gov) Diagnosis and treatment of penetrating injuries of the hoof in horses - O'Neill - 2010 - In Practice - Wiley Online Library  Laminitis – Further reading 2 Laminitis – Imprint Equine Foot Care (imprintshoes.co.uk) The proper application of the wooden shoe: An overview (oclc.org) Clinical application of the wooden shoe to complement surgical management of laminitis and other foot‐related disease in the horse: A report of three cases - Torrent‐Crosa - 2023 - Equine Veterinary Education - Wiley Online Library Preliminary observations on the use of ertugliflozin in the management of hyperinsulinaemia and laminitis in 51 horses: A case series - Sundra - 2023 - Equine QUESTIONS?