Large Animal Sx - Integument 3

drraythe's version from 2015-11-24 20:14


Question Answer
what kinda weather is CH associated with?warm weather
if you are unsure of if the granulation tissue you are seeing on your patient might be due to CH, how might you know from your practical knowlege?it will be Granulation tissue that does not respond to routine treatment
what is the exudate like with CH?very SMALL CORES of exudate
what are two general places CH likes to be on an animal?(1) Associated with wounds (2) usually likes In thin skinned areas, such as Prepuce, penis, medial canthus of the eye
what is the etiology behind CUTANEOUS habronemiasis?Allergic reaction to the aberrant larvae of the Habronema species
what are the three species of habronema and where do they like to be as adults?(1) Habronema musca - adults live on the stomach mucosa (2) Habronema microstoma - adults live on the stomach mucosa (3) Drashia megastoma - adults live in granulomas in the stomach wall (this is the one that's super hard to get rid of)
4 main things you need to do to manage CH?(1) Remove the larvae (2) Topical medication (3) Control and or remove the excessive granulation tissue (4) Control the allergic response
what is the types of medication you use to tx CH- parenteral/ topical?(1) Parenteral: Ivermectin - at the usual anthelmintic dose (200 mcg/kg) (2) TOPICAL: An antibacterial ointment with added ivermectin, a corticosteroid and DMSO
with habronemiasis you might need to control the allergic response to get the cutaneous rxn under control- what might you have to do to do this?Sometimes necessary to use parenteral corticosteroids
what is the life cycle of habronema?Adults are in the stomach --> eggs pass in the feces--> House or stable flies ingest the eggs (Flies are intermediate hosts) --> Habronema larvae emerge from the fly and are deposited around the mouth of the horse--> Larvae find their way to the oral mucosa and then to the stomach--> adults mature and their eggs are passed in the feces
CUTANEOUS habronemiasis happens in what situation? details?This is where the life cycle is ABERRANT! Fly feeds on wound exudate or in thin skinned areas--> Habronema larvae are deposited in these area (instead of around the mouth to be ingested)--> Larvae in these areas cause an allergic response and excessive granulation tissue
3 ways to interrupt the life cycle of the habronema?(1) Control flies (remove manure, install spray systems, screened in stalls) (2) Repel flies (Repellants applied to horses) (3) Remove adults from the stomach (Habronema musca and habronema microstoma are sensitive to most all routinely used equine anthelmentics. Drashia megastoma is more difficult to remove but it is sensitive to the avermectins...Deworming with one of the avermectin anthelmentics is affective against all Habronema species)

wounds involving periosteum and bone, coronary band, tendon sheath, wounds caused by encircling material, complicated by a foreign body

Question Answer
Bone sequestrum occurs as a result of... (3)(1) Trauma causing periosteal damage (2) Open wounds causing drying of the periosteum (3) Application of caustics to periosteum or bone
Osteomyelitis Commonly develops as a result of... (2)(1) Poor drainage of wounds that involve bone (2) Hematogenous infection (most common in foals)
Periosteal proliferation Commonly develops as a result of what?Continued irritation from either physical or infectious causes
CQ: (T/F) A bone sequestrum can routinely be managed by giving antibiotics until the sequestrum is absorbed.F (need to remove the sequestrum)
how do you go about medically managing wounds which involve bone?Radiograph (if necessary) to determine possible fractures. Protect with bandages until granulation tissue covers the bone. Establish good drainage. Use systemic antibiotics as necessary. Don't use caustics or healing powders on exposed bone. When bone is properly protected and there is good drainage, there is less chance for a sequestrum, osteomyelitis or periosteal proliferation
what are three common complications of a wound with periosteum or bone exposure?bone sequestrum, osteomyelitis, periosteal proliferation
Surgical management of wounds involving bone can be what two things?(1) Fracture repair (2) Exploration and removal of bone fragments
if there is a bone sequestrum, how should you manage it?If present a sequestrum should usually be removed so that normal healing can progress! (Occasionally a small sequestrum will be absorbed and healing will progress without surgical removal)
what is the technique for surgically removing a sequestrum?radiographic ID, Parenteral antibiotics, General anesthesia. Consider the use of an Esmarch bandage (rubber bandage which you use to wrap distal to prox and squeeze all the blood out of an area and help with hge). Sx prep. Incision into bone, ID the sequestrum (Because of the amount of new bone growth, intra operative radiographs are some times indicated). Remove sequestrum and abnormal surrounding bone--> Collect tissue for culture and sensitivity (Allows one to determine if the parenteral antibiotics that have been administered are effective and to change if indicated). Consider the use of a positive suction drain. Routine closure. Remove the drain when it quits draining (usually 48 hours)
what should you discuss with your owner about injury to the coronary band?Healing of the coronary band is difficult to predict--> Discuss with the client the fact that abnormal hoof development might be the result of this type of wound
when should you debride a coronary band injury, and why?wait several days before debriding- This Allows more accurate determination of the devitalized tissue
Removal of less than a _(length)_ segment of the coronary band usually results in regeneration of a normal coronary band 1 inch
what is required for optimum healing of the coronary band injury?A snug pressure bandage is required for optimum healing
how DO you bandage a coronary band injury? what DON'T you do/what isnt effective?A snug pressure bandage is required for optimum healing! A non stick pad and two or three gauze sponges over the wound under tightly applied elasticon tape is recommended (It is best, if the constricting bandage applies pressure from the injured area to the hoof on the opposite side of the limb ( that the constricting bandage does not encircle the coronary band). A normal leg wrap does not apply adequate pressure!!!
what type of tx s CONTRAINDICATED for coronary band injuries?Caustic drugs are contraindicated
how can OWNERS indirectly contribute to the problem of a tendon sheath puncture?Small puncture wounds of the tendon sheath are considerable problem since owners many times don't realize the severity and delay treatment. Take every opportunity to explain to owners the severity of puncture wounds of joints and tendons sheaths
If you saw this radiograph (pic shows areas involved in green) what injury might you think this is from, and why? puncture of the tendon sheath allows a lot of spreading of infection through the sheath
how do you perform a surgical primary closure on a puncture of a tendon sheath?Surgical preparation. Flush with liberal quantities of sterile saline. Close under suture if the wound meets the necessary criteria (under 10 hours old and sufficient tissue to close without tension). Consider placing a drain in the tendon sheath. Give Parenteral antibiotics, and Consider regional limb perfusion. Also Consider continual infusion (with a medication system) into the tendon sheath
how do you perform a DELAYED closure of a tendon puncture injury?If the wound is more than 10 hours old and there is adequate tissue to close without undue tension, do delayed closure. Do Surgical preparation and thorough flushing, then Maintain under sterile bandage for three days with adequate antibiotic therapy. Then, Close as in primary closure. Continue on parenteral antibiotics and a suction drain and/or regional limb perfusion
when would it be appropraite to consider medically managing a tenon sheath puncture wound? (3)(1) Small puncture wounds that have recently occurred (2) Open sheath without adequate tissue to close surgically (3) Established infection in a closed tendon sheath
if the tendon sheath injury is a Small puncture wound that has recently occurred, how can you manage it?can medically manage in this situation, keep Maintained on adequate levels of antibiotics. Consider regional limb perfusion
if the tendon sheath injury is an Open sheath without adequate tissue to close surgically, how do you manage it? what is prog like for wounds like this?MEDICALLY manage Until the wound closes by contraction and epithelialization. Do this by maintaining drainage, Maintaining under sterile bandage, Provide adequate parenteral antibiotic therapy, Periodic flushing and cleaning. Fair prognosis if adequate drainage is maintained
If the tendon sheath injury is Established infection in a closed tendon sheath (example - the great digital sheath) how do you manage it? (prog of this technique?)Best managed by establishing liberal drainage! Anesthesia - regional or general. 5 cm vertical incision on the palmar or plantar aspect of the first phalanx to open the great digital sheath. Then Insert forceps through the incision to the dorsal lateral aspect of the sheath (proximal to the fetlock joint) make a skin incision over the tips of the forceps. Repeat the procedure inserting the forceps to the dorsal medial aspect of the sheath. Then, With the tips of the forceps in the lateral and medial position grasp a penrose drain and pull it down through the tendon sheath. Maintain the area under bandage with parenteral antibiotics for four or five days and then under sterile bandage until the tendon sheath closes. This technique usually results in at least a pasture sound animal
most common objects involved in encircling material?Wire, rubber bands, twine are most commonly involved
how does an encircling material become buried in the flesh?If the material is tight, the leg swells, the skin sloughs and the material becomes buried
If you see a wound like this, what should you consider? conisder that the material encircling the wound might still be there! Remove and do normal wound management
in which two situations should a wound be ESPECIALLY be thoroughly explored?(1) Wounds on the anterior surface of the body should always be thoroughly explored (2) All wounds that don't heal as expected should be explored
what is the most effective way to explore a wound?The bare, thoroughly scrubbed finger is most effective. Also, Ultrasound (if available) is very helpful. Radiographs Help in the identification of a foreign body, and help To rule out bone involvement and the development of a sequestrum
what can you do to check if you have removed all of the affected tissue/ foreign body (esp if it is wood) ?Infusion of sterile methylene blue into the tract to stain all of the involved tissue and wood foreign body (which is the most common) is very helpful (In some cases it is indicated to remove all stained tissue)
most common FB of wounds?wood!
best dx tool for dx of FB?U/S

Abscess, indolent wounds

Question Answer
the two main etiologies for an abscess?(1) Localization of a hematogenous infection (2) Secondary to a poorly draining wound
explain how an abscess develops in the bodyBacteria localize--> White blood cells migrate--> Purulent exudate is formed by living and dead white blood cells, bacteria and cellular debris
how can you dx if sthing is an abscess?Classic signs of inflammation are present! Redness, heat, swelling, pain and function loss. Confirmation by test puncture, and/or ultrasound
WHEN is it appropriate to tx an abscess? how will you know when?Wait until the abscess matures! Initially will be hard and firm, then With time it will become fluctuant (then it is ready to tx)
describe how to manage/tx an abscesswait for abscess to be mature (more on this in diff card) Clip shave and scrub--> Ultrasound is of value in determining the extent and the most ventral aspect. Perform test puncture. Analgesia or local anesthesia. Incise to provide adequate ventral drainage, Use drains if ventral drainage is compromised. Use of caustics to destroy the abscess wall may be indicated in cattle (usually not indicated in other livestock, dogs or cats)
when would you want to use caustics to destroy abscess wall? when would you NOT?Use of caustics to destroy the abscess wall may be indicated in cattle (usually not indicated in other livestock, dogs or cats)
what are indolent wounds?These are wounds that reach a stage of healing and then don't get worse but they don't heal
4 possible etiological causes of indolent wounds?(1) Animal in a poor nutritional state (2) Epithelial fatigue (3) Chronic infection (4) Over exuberant attempts to control granulation tissue
what is happening in "epithelial fatugue" and what problem can this lead to?Occurs in large wounds where the epithelium has to proliferate a considerable distance. This can lead to indolent wounds.
what are examples of agents which might be used to control exuberant granulation tissue? what can happen if you go overboard with these?Steroids, caustic agents, DMS0....can lead to indolent wounds
how do you manage an indolent wound?(1) Correct underlying problem (2) Stimulate epithelialization
how do you stimulate epithelialization in order to help treat an indolent wound?Surgically undermine the wound edges, then Stimulating the wound edge with a mild irritant such as Scarlet red. You can also insert pinch grafts, and use occlusive dressings
what can packing a drained abscess with idodine soaked packing do?might cause slough of abscess- we want this- bc after slough and heals, minimal response as a aftermath....bc if just drain that, there will be a sizeable lesion there tho.