Quick Review Flashcards
Most common cause of severe oral pain?
Deep periodontal food pocketing such as occurs with diastemata. Oral pain may result in small boluses of masticated food falling fro mouth during chewing.
Most common dental disorder?
laceration of cheeks and tongue by sharp dental overgrowths that develop on the lateral edges of the maxillary and medial edges of the mandibular cheek teeth.
Clinical signs of dental isease?
quidding, Painful dental related lesions may cause bitting problems, resistance to the bit, abnormal head carriage, head shaking during work. Signs of CT infection - painful facial swellings, sinus tracts, unilateral swellings of mandible or rostral aspect of maxillary bones. Unilateral nasal discharge persistent and purulent, may be due too dental sinusitis.
What is usually the cause of a foul smelling odour in the mouth?
Anaerobic infection of the periodontal tissues, such as seen with diastemata.
What is the difference between overjet and overbite?
Overjet - when upper incisors protrude rostrally i relation too the lower incisors. Overbite is when the upper incisors also lie directly in front of the lower i ncisors.
What do overbite/overjet commonly cause?
Overgrowths of 106 & 206 and 311 & 411.
Absence of wear on central upper incisors - develop a convex occlusal surface - a smile.
What will horses with prognathism (undershot jaw) develop?
A concave upper incisor occlusal surface. and lower 06 and upper 11 growths.
What will retained deciduous incisors lead to?
If retained for a prolonged period they will cause permanent incisor to be displaced further caudally and may even cause permanent wear changes in the incisor arcade.
Why should supernumerary incisors be left alone?
Have very long reserve crowns that are usually intimately associated with the reserve crowns and roots of the normal permanent incisors. Cause Little clinical problems unless grossly displaced.
what should all incisor fracture cases receive?
tetanus antitoxin and prolonged antibiotic therapy eg Trimethorpim or sulfadiazine. First aid treatment - debridement of exposed pulp with a needle and application of a hard setting calcium hydroxide past into pulp canal.
What cause equine odontooclastic tooth resorption and hypercementosis result in?
Painful disorder - periodontitis, with resorptive or proliferative changes of all the calcified dental tissues.
What is slant mouth associated with?
A unilateral abnormality of the CT that has caused a pronounced unilateral chewing action which causes uneven wear of the incisors. Or more commonly - developmental abnormalities of the facial bone, hard palpate or premaxillary bones.
Why do canine teeth commonly get calculus?
They do not anatomically oppose each other. Often extensive calculus on lower canines. Localised periodontal disease and ulcers of lips.
What signs may a horse show with retained deciduous teeth?
When very loose - may cause oral pain, quidding, playing with the bit and loss of appetite for a couple of days.
how should the occlusal surface of the cheek teeth normally sit?
occlusal surface of all 6 CT are normally compressed tightly together and the CT row functions as a single grinding unit. This is achieved by the action of the angled first Ct and the last two CT, compressing the occlusal aspect of all 6 CT together.
What are diastema?
Abnormal spaces between teeth. often 2-5mm wide. narrower at occlusal aspect. Food becomes impacted into these abnormal spaces and leads to progressively deeper food impaction and gingival recession followed by deeper secondary periodontal disease -
What clinical signs may be seen with diastemata?
quidding when fed hay/haylate and improve at grass. Secondary sinusitis can also occur. In longer cases - will extend along the sides of affected teeth and can even extend deep into mandible or maxillary sinuses
What is the treatment for diastemata?
Foood should be removed
In younger horses the spaces may close with further eruption
Feed only finely chopped forage eg grass or alfalfa
abnormal transverse overgrowths may develop on the teeth opposite diastemata - which may widen the diastemata and selectively force food into them. remove these. If marked - widening of the diastemata. Filling with plastic materials i less severe cases.
Describe how acquired dental disease occurs in the horse.
domestication - fed large quantities of concentrates and eating much less forage. Chewing with a more vertical than lateral mandibular action. Not enough lateral movement - predisposes horses to develop enamel overgrowths of the CT. The maxillary CT rows are further apart than the adibular parts. Absence of complete occlusal contact between upper and lower CT is a furteher predisposition to the development of enamel growths or points. Sharp points will eventually merge into a steeply angulated occlusal surface termed shearmouth. A mechanical obstruction may now additionally obstruct the normal side to side jaw movements and mastication will be even less effective. Some cases develop an uneven or undulating occlusal surface termed wavemouth. Deep periodontal disease can lead to tooth loss - so the opposing tooth will erupt more rapidly , leading to dental irregularity termed stepmouth.
What are the clinical signs of advanced dental overgrowths?
May not be able to fully clear their mouth of food. Swellings may occur due to accumulation of fibrous food wedges between the lateral aspects of the CT and the cheecks. in the presence of oral pain some horses may also chew very slowly, making soft slurping sounds when chewing forages. some affected horses may permanently use one side of their mouth for chewing rather than using alternative sides or they may hold their head in an abnormal position during chewing. May readily eat mashes or grass but are reluctant to eat hay. Halitosis may be present if widespread periodontal disease or advanced caries. Bitting problems also
How should acquired dental disease be treated?
Treatment includes removal of major overgrowths using manual or power tools followed by rasping of treated teeth to smooth out any sharp edges. As unopposed CT may erupt abnormally fast, there is a large likelihood if a cheek tooth overgrowth is reduced to the level f the remaining ct, the pulp will be exposed. Very lose teeth can be extracted orally using Ct extractors in standing sedated horses. all loose teeth do not have to be extracted especially in older horses.
What is senile excavation caused by?
Absence of the enamel folds due to wearing out of the infundibular enamel and of the peripheral enamel infolding that normally prevents such excessive wear of the dentine. Smooth mouth is the absence of enamel on the occlusal surface of the CT.
How should you rasp mandibular CT
Long straight handled rast on caudal CT.
Cut in a rostral direction - on the pull.
Rostral - short handled straight rasp. Solid carbide blade used to cut on the caudal direction - on the push.
How do you rasp maxillary CT?
Lateral aspect of the CT row is convex- difficult to rasp lateral overgrowths using straight handled.
Use an anlged head or offset head to rasp 6s and 7s. Maintain initially at an angle of 45 degrees during maxillary CT rasping, with this angled varied latearlly to round of buccal edges of the teeth. a long angled rasp can be used to rasp 8s and 10s.
What is the cause of most fractures of the CT ? what happens to these fractures.
Most CT fractures occur in the absence of known trauma. these usually affect the maxillary CT and the most common pattern is a lateral slab fracture through the two lateral pulp cavities. the fracture space becomes filled with food, thus laterally displacing the smaller portion which may cause buccal lacerations. removal of the smaller loose fragments with forceps will usually resolve the problem in the short term but infection of the apex will later occur in a minority of CT.
What is the cause of midline fractures of the maxillary cT?
Due to advanced infundibular caries. Deep seated infections of the alveolus and sinus frequently accompany these fractures in younger horses. complete extraction of the affected tooth and sinus lavage are required if sinusitis is present.
What are ameloblastomas?
Non calcified epithelial tumours derived from the epithelium that forms enamel.
How do Periapical infections of the CT occur?
Haematogenous or lymphatic borne infections. (inflammation of pulp due to dental impaction may predispose).
In upper CT - may be due to food accumulation and fermentation in cemental defects in the infundibulum (caries) leading to infection of the pulp or saggital fractures.
Periapical abscessation of the lower CT commonly involves rostral ct in 1-2 years of eruption and may occur when there are eruption cysts in the early stages, infection usually remains confined to the apex, adjacent to the sinus tract and all the pulp cavities remain vital - antibiotics may suffice.
What are the clinical signs of Periapical infections of the CT?
In young horses - cannot drain into oral cavity, but will affect supporting bones and drain from the apical aspect of the tooth. mandibular infections accompanied by unilateral mandibular swellings and external draining tracts.
Infections of upper 6s and 7s will often develop focal swellings of the rostral maxilla. Infections of the caudal 4 maxillary CT generally results in a secondary sinusitis with the presence of a chronic malodorous unilateral nasal discharge.
Apical infections that arise as an extension of deep periodontal disease from abnormal spaces surrounding the CT including supernumerary teeth, diastemata, developmental and acquired dental displacemets - will drai into the mouth.
How can you confirm that a tooth needs to be extracted?
Intra oral examination with mouth gag
Radiographic evaluation of the dental apices (latero oblique projections)
Scintigraphy or CT may provide conclusive evidence of apical infection
If external sinus tract - obtain radiographs with a metallic probe in situ to define the infected area of the tooth. This procedure will also provide surgical landmarks, if the infected tooth is to be extracted by repulsion.
When should a tooth be extracted?
If a CT is infected. antibiotic therapy, maxillary sinus lavage - failure to respond to these - further clinical exam and definitive evidence of dental infection - then extraction.
What are the different methods of extraction?
Repulsion - high level of damage to alveolar and supporting bones.
Lateral buccotomy technique - incision through skin and subcut tissues into alveolus under GA.
Oral extraction
Endodontics - treat CT infections by root canal therapy.
What are the causes of oral dysphagia?
oral pain by quidding - dysmastication rather than inability to swallow.
Fractures of mandible or premaxillary fractures.
Disorders of the tongue due to paralysis of the 12th cranial nerve, or generalised neuro disorders such as botulism.
Sharp wooden or metallic foreign bodies lodging in the tongue or oropharynx.
Tumours of the oral cavity such as SCC.
What are the causes of pharyngeal dysphagia?
Congenital neonatal neuromuscular pharyngeal dysfunction cleft palate guttoral pouch mycosis strangles infection botulism heavy metal poisoning nasopharyngeal foreign bodies nasopharyngeal tumours Guttoral pouch disease.
What are the signs of pharyngeal dysphagia?
Masticated food flowing down both nasal cavities after eating and coughing due to aspiration of food material and saliva.
What is the cause of guttoral pouch mycosis?
Aspergillus fumigatus. It can invade roof of the guttural pouch causing destructive changes and secondary bacterial infection.
What are the signs of guttoral pouch mycosis?
depends on which erve affected; Cranial sympathetic - horners syndrome 7th - facial paralysis 9th -, 10th, 11th - pharyngeal paralysis 12th - toongue paralysis Internal carotid, internal maxillary artery, vein, external maxillary artery - Massive haemorrhage. (baloon or embolising coil needed).
What is the treatment of guttoral pouch mycosis?
Local anti mycotic treatment with Natamycin or enilconazole sprayed onto the roof of the pouch using self retaining or trans endoscopic catheters 2-3 times daily.
What is chondroids?
A sequel to strangles, with abscessation and drainage of the Retropharyngeal lymph nodes into the guttoral pouches, which have poor natural drainage. extensive swellings of the guttoral pouches can interfere with upper airway or swallowing, occasionally leading to stridor or dysphagia. chondroid formation occurs with more chronic cases. Chronic low grade purulent discharge - usually unilateral.
How are chondroids diagnosed/treated?
Endoscopically - collapse of the nasopharyngeal roof may be seen along with a purulent exudate draining from the affected pouches 7 pus, or chodroids. feed from the ground. lavage of pouches with dilute antiseptics. transendoscopic removal of chondroids or surgical drainage. using ventral approach.
What is guttoral pouch tympany?
A neuromuscular defect or abnormal tissue fold at the nasopharyngeal ostium acts as a one way valve allowing air into but not out of guttoral pouches.
How is guttoral pouch tympany diagnosed and treated?
Radiography will show an enlarged air filled pouch and a ventral fluid line. A Foley catheter can be placed and distort the ostium into open position - or transendoscopic laser treatment. good prognosis.
What signs would point you towards a diagnosis of botulism in a cdysphagia case?
Endoscopy will confirm the presence of pharyngeal dysphagia without any detectable underlying lesion. closer examination may also reveal weakness of the hindlimbs and a flaccid tail.
Wha are the signs of choke?
Distress, salivation, dysphagia, nasal discharge containing a food.
What iis choke commonly caused by and what will occur?
Sugar beet pulp or pelleted food. obstructs a variable distance of oesophageal lumen - large amounts of sugar bet pulp or dry unsoaked sugar beet pulp. Dehydratin, hypochloraemia will occur.
How is diagnosis of choke made?
Unable to pass nasogastric tube, confirm endoscopically and by ultrasound and palpation.
How is choke managed?
Take off all bedding & starve. most cases will get better spontaneously or respond to treatment with spasmolytics and sedatives. conservative treatment is safe for up to 24 hours. if not cleared by then - iv corretion of hydration and gentle lavage f oesophagus by stomach tube in sedated horse with head lowered. Penicillin/metronidazole should be administered to help prevent aspiration pneumonia as som degree of aspiration is inevitable.
Why does pyloric stenosis ocur and how is it treated?
Congenital in foals up to 4 months or acquired secondary to gastroduodenal ulceration > fibrosis > stricture. contrast radiographs show delayed outflow. treatment - pyloromyotomy or bypass pylorus with gastrojejunostomy.
Can the stomach, jejunum ileum ileocaecal junction or duodenum be exteriorised during surgery?
stomach - no uodenum - attached to right body wall - no Jejunum - long mesojeunum - YES Ileum - no Ileocaecal junction - no
What may cause ileal or jejunal impaction?
Certain diets eg Bermuda grass hay or with severe ascarid infestation in young horses possibly related to tapeworm. treatment is decompression. good prognosis.
Which neoplasia of the intestine is most common? How can this be managed?
Lymphosarcoma.
Thickening of intestinal wall > complete/partial obstruction. weight loss. Resect affected portion. Often multifocal. poor prognosis.
How does pedunculated lipoma cause strangulating obstruction of the small intestine?
Most common cause. mature/obese animals. lipoma often suspended n a single fibrous band attached to the mesentery > encircles a bowel segment > strangulates intestinal vasculature.
How does a small intestinal volvulus cause strangulating obstruction?
Rotation of all/some of the jejunum about its attachment in the doorsal abdomen at the cranial mesenteric arterial root. often severe pain and poor prognosis due to amount of gut affected. may be secondary to other lesions causing distension.
How does intussuception cause a strangulating lesion?
Invagination of proximal intussusceptum into distal intussucipiens > simple obstruction initially then strangulating as more gut entrapped and arterial supply is drawn in. May involve any segment of bowel but jejuno-jejunal intussusceptions more common in foals. Ileo caecal associated with tapeworm infestation.
What is a thromboemolic colic the result of?
Mesenteric vascular thrombi - result of the migration of strongylus vulgaris larvae > vascular infarction of a segment of SI which can be extensive. these lesions - formerly the most common cause of SI colics have become rarer since the widespread use of avermectins.
What are the different parts where the SI can become entrapped and cause a strangulating obstruction?
Epiploic foramen - caudal vena cava, caudate liver lobe, pancreas, hepatic portal vein. Gut entrapped cranial to liver > may be no abnormal rectal findings.
Inguinal /scrotal - swollen inguinal region. Palpate per rectum.
Herniation through a mesenteric rent - broodmare after parturition.
Gastrosplenic ligament - rare
Umbilical hernia
Diaphragmatic hernia - congenital or major trauma
Can the caecum be exterioorised?
only apex and part of body exteriorisable at laparotomy.
Why might caecal impaction occur? what is the treatment for this?
primary impaction or secondary to motility disorer, common in hospitalised patients .g after GA or repeated sedation. Surgery needed if no response to medical treatment because caecum is prone to spontaneously rupture. Surgery - evacuation & caecal bypass because condition often recurs.
what order does the colon go in? which part is most likely to displace?
Caecum > RVC> LVC > LDC > RDC > Transverse colon > small colon.
Left colons - highly mobile, displacements and torsions occur commonly
How does left dorsal displacement of the colon occur ? (aka nephrosplenic entrapment)
colon becomes entrapped between dorsal aspect of spleen and nephro splenic ligament adjacent to the left kidney. total or partial obstruction and variable pain. surgery to reduce displacement - prognosis generally good.
How does a right dorsal displacement occur? what is the prognosis with this?
The left colons migrate around the body of the caecum (clockwise or anticlockwise). if no volvulus - good (70-80%).
How does colon torsion occur?
Often around caeco colic junction > whole colon involved. can be 180 degrees to 360 degrees (strnagulating). Rapid deterioration due to massive endotoxaemia. - surgical correction and colonic resection needed. guarded prognosis.
Where do enteroliths tend to obstruct?
Mineralised enteroliths tend to obstruct narrow transverse colon. Treatment - surgical removal of the enteroliths via an enterotomy carries a good prognosis.
What is the prognosis with a rectal prolapse? how can these be treated?
graded 1-4. grades 3&4 - guarded prognosis because the mesorectum tears. If mild - clean and resect affected mucosa & replace, provided the seromuscular layer is intact. Prolapse >25-30cm - probable mesocolon rupture > more aggressive surgery needed - refer.
Describe the different grades of rectal tears?
Usually occur during rectal palpation. graded 1 - depending on depth. grade one - mucosa only, grade 2- muscularis only, grade 3- mucosa and muscularis and grade 4- all layers. grade 4 results in abdominal contamination with faeces.
How can rectal tears be treated?
Sedate, give epidural or larve volume of local anaesthetic per rectum,c areful evacuation and packing of the rectum to prevent further contamination, broad spectrum antibiotics non steroidal anti inflammatories then referral/surgery in the cases of severe lesions. grade 3 &4 carry guarded prognosis.
Discuss the complications of colic surgery
Repeat episodes of colic - especially in first year post surgery.
Continuing endotoxaemia/dehydration.
Ileus - (20% prevalence) may result from inflammation (peritonitis, handling at sugery, systemic effects of endotoxaemia), distension, or denervation (grass sickness). Ileus causes further distension and pain & dehydration if SI or impaction if LI affected. diagnosis - rectal or abdominal ultrasound > distended SI loops with little movement, nasogastric intubation > reflux.
Incisional drainage/infections/hernations.(10-40% prevalence). Prediposes horses to incisional herniation at a later date.
Adhesions - usually weeks after surgery - fibrinous then fibrous adhesions may cause intestinal obstruction, strangulation etc and recurrence of colic. prevention is by careful tissue handling, use of anti adhesion therapy eg heparin, peritoneal lavage, carboxymethylcellulose.
Describe the open castration technique
Careful examinatio for scrotal herniatioon. if present - closed castration must be performed. Horses sometimes castrated standing using IV sedation and analgesia along with local anaesthesia of the scrotum and cord. sometimes lcal anaesthetic is also injected directly into the testes. The anaesthetised scrotal area is thoroughly prepared using a disinfectant solution an a long deep midline cranio caudal incision is made over each anaesthetised testis through ventral skin, subcutaneous scrotal tissues and then through the external tunic, thus allowing extrusion of the testes directly to the outside. sectioning the avascular caudal ligament will help exteriorise the testes. The spermatic cord is simultaneously transected and crushed using an emasculator which should be kept in place for 2-4 minutes. absorbable ligatures can be placed on the spermatic cord but the surgical site is not sterile.
What are the risks of open castration?
Increase risk of haemorrhage, eventration and infection are present.
Describe the closed castration technique.
Incision only through skin and subcutaneous tissue but not through external vaginal tunic must be performed if inguinal herniation is suspected. closed technique prevents post operative gut prolapse /herniiation. Transfixing ligatures very effective at achieving haemostasis and thus the other major post operative complication (haermorrage) rarely occurs with closed. Older animals have larger testicular vasculature so should be castrated using ligatures under GA. More thorough preparation of the surgical site is possible and post operative infections are also less common. Can be performed through a single or two separate scrotal incisors. having incised the skin and dartos care is taken not to incise the shiny white external tunic, which is dissected from the surrounding fascia along the spermatic cord. Transfixing ligatures are inserted into the cord which is then emasculated a further 2cm distal to the ligature.
Discuss the complications of castration
Usual to have blood dripping from the scrotal wound foor up to 30 mi but should be in countable drops rather than a steady drip stream or spurt - the latter may indicate testicular artery has not been properly crushed or ligated. Pack with sterile gauze and observe if this reduces haemorrhage. if it does - this may just indicate that connective tissue seepage or subcut vasculature bleeding was the cause of the haemorrhage. If not - this indicates continuing haemorrhage from the testicular artery. Crush artery with forceps, if still not stopped bleeding - must give GA and explore. MUST BE GIVEN TETANUS ANTIITOXIN IF NOT VACCINATED. Some degree of post operative woound infection is common. If severe, affected horses will be febrile, have a swollen scrotum and prepuce and be stiff in their hindquarters. scrotal woounds should be large enough to allw clots to drain out. Low grade strep zooepidemicus infections will drain and normally resolve within a week. Prophylatic antibiotics are given by some. less common infection that may occur is about a week later with strep zoooepidemicus - development of infected granulation tissue protruding from the wound. - Needs digitally or gentle curettage by irrigation and penicillin administered. infection of the spermatic cord is funiculitis and grossly infected cord may need to be resected. A more long term spermatic cord infection is termed scirrhous cord which can rarely occcur often due to a staphylococcus infection. this will present may months later as a very firm scrotal swelling with purulent draining tracts, sometimes temporarily appearing and disappearig, especially following antibiotic treatment. Horses will invariably develop post operational oedema of the scrotum, prepuce. Hand walking or slow riding exercise, two or three times a day will help reduce such swellings and stiffness. Especially in stalions and older hoses post operative NSAIDS are indicated. Evisceration is poossible after an open castration. Most frequently just the omentum. If evisceration occurs after you have left te premises the owners hsould e tolt to protect and elevate the gut in a clean sheet - one should then replace the prolapsed guts into scrotum and suture the scrotum. the horse should then immediately be referred to an appropriate referral centre.
How can cryptorchidism be diagnosed?
Ultrasnography of the inguinal anal can determine if a retained testis is in the canal or abdmen. surgery on a cryptorchid must be performed under GA r by standing lapaorscopy. If horses over 3yo a resting plasma oestrone sulphate assay may be performed, if younger horse <3yo two blood samples are required one prior to and one after HCJ injection. a significant rise in testosterone indicates the presence of a functional testes in the animal.
How is a patent urachus treated?
Injection of tincture of iodine into or cautery of the lumen of the urachus with silver nitrate can be used to treat cases that persist beyond a week. Ligation may lead to abscessation and should be aovoided. A persistent patent urachus may lead to omphalophlebitis, purulent umbilical discharge, Abscessation of the urachus and cystitis and should be investigated by ultrasound and treated surgically.
Which are the most common uroliths in the horse?
Calcium carbonate calculi - have a sharp spiculated surface. Can become very large >1kg and mechanically irritate the bladder.
What are the clinical signs of urolithiasis ?
Frequent urination, haematuria, tail swishing, colic and straining. Occasionally smaller calculi will exit the bladder and can fully obstruct the urethra. Rectal exam will confirm. Passage of endoscope or urinary catheter. Palpation of peis and ultrasound. Remove via midline laparotomy. Urethral calculi - administration of spasmolytics/analgesics.
Where do epidermoid cysts develop?
An epidermoid cyst can develop in the false nostril lining, resulting in facial swelling int he area of the naso maxillary notch. These do not cause nasal airflow obstruction. Treatment is cosmetic.
What is alar fold colapse?
Flesh alar fold attached between the ventral concha and false nostril and occasionally can collapse during fast work and cause airflow obstruction and noise. diagnosis can be confirmed by suturing the alar folds too the nostrils bilaterally and assess if this stops noise.
What is the most common cause of epistaxis int he horse?
Exercise induced pulmonary haemorrhage.
May also be due to haemorrhage from trauma, guttoral pouch mycosis or ethmoid haematoma.
What can cause traumatic epistaxis in the horse?
Intubation or endoscope - passed into middle meatus - turbinates or ethmoturbinates traumatised. Or from ventral meatus if a wide tube is used or inadequate lubriaction. May occur due to a tear of rectus capitis muscles. (trauma to the head region after a heavy fall)
Which neoplasias commonly occur in the equine nasal cavity? What are the clinical sigs?
adencarcniomas, osteogenic sarcomas. usually very malignant, older animals. Local inflammation and secondary infection occur. Chronic unilateral purulent nasal discharge, malodorous breath, secondary sinus empyema, unilateral submandibular lymph node enlargement, nasal airflow obstuction, facial swelling, halitosis.
What is the cause of mycotic rhinitis?
Aspergillus fumigatus or pseudallescheria boydii.
What are the clinical signs of nasal mycosis
Unilateral malodorous mucopurulent nasal discharge and unilateral lymphadenitis, occasionally epitaxis. Mouldy cheese like white yellow or black coloured plaques on the turbinates or ethmoturbinates on endoscopy.
What is the treatment of mycotic rhinitis?
remove any large fungal plaques prior to topical therapy with natamycin or enilconazole solutions. treatment is usually successful. Confirmation can be made ia nasal swabs with isolation of a heavy pure growth of potentially pathogenic fungus.
How can teeth infection cause a purulent nasal discharge?
Infection of the first 2-3 maxillary cheek teeth usually results in a swelling with a discharging sinus tract n the affected side of the face, rostro dorsal to the facial crest. A small percentage will hwoever, discharge medially into the nasal caviyt, leading t a unilateral purulent malodorous nasal discharge. endoscopy may reveal a purulent granuloma or pus in the rostro lateral aspect of the middle meatus.
What is a progressive ethmoid haematoma?
An ethmoid haematoma is a haemorrhagic polyp with the histological appearance of a haematoma. these lesions which usually occur in adult horses generally protrude rostrally into the nasal cavity frm the ethmoturbinates, less commonly they grow laterally or dorsally into the sinuses. they bleed in small amounts over very long periods. mucopurulent as well as hemorrhagic nasal discharge may occur. most common cause of chronic unilateral epistaxis in the horse.
What is the treatment of ethmoid haetomas?
Repeated transendoscopic intra lesional formalin injections - surgical excision is traumatic with a less favourable long term prognosis.
What are the different causes of sinusitis in the horse?
1 - primary infective sinusitis 2 - dental apical infection or oro fistula 3 maxillary sinus cyts 4 - sinus neoplasia 5 - mycotic sinusitis 6 - sinus trauma 7 - intra sinus PEH lesions
What are the clinical signs of sinusitis?
Unilateral purulent nasal discharge, unilateral submandibular lymph node enlargement, possibly unilateral facial swelling, nasal airflow obstruction or epiphora, endoscopy will show discharge emanating from the naso maxillary aperture. direct endoscopy of the paranasal sinuses is possible through a small external sinus opening made under Local anaesthesia usually into the frontal sinus.
What is primary sinusitis? how does this occur?
The sinuses have poor natural drainage - mucosal inflammation with URT infections and simultaneous increased mucus production and decililation of the sinus epithelial cells results in less effective drainage. if secondary bacteiral infection occurs > sinus empyema. This can occur transiently with URT infections or due to inspissation of pus it may become chronic.
What is the treatment for primary sinusitis?
antibiotics
sinus lavage via frontal sinus trephine
Indwelling tubing with lukewarm dilute iodine or saline for 5-6 days.
Transendoscopic or surgical removal under standing sedation.
How does dental sinusitis occur?
Caused by infection of the apices of the upper 8s and 11s that lie within the maxillary sinuses. A copious and malodorous nasal discharge is often present and halitosis if infection involves the crown. Lateroblique radiographs of most value. CT optimal diagnostic. Extraction indicated.
What are maxillary sinus cysts?
these mucoid filled cysts develop int he maxillary and occasionally i the frontal sinuses. they can occur in all age groups including foals, very marked facial swelling and epiphora is a feature. cofirm by radiography. homogenous rounded radiodense cysts sometimes visible. surgically remove.
What is pharyngeal lymphoid hyperplasia?
Multiple large lymphoid follicles in the naspharynx. very common in young horse. regresses with maturity. normal adult horses have small follicles. not a cause of poor performance. Enlarge with respiratory infection.
What is intermittent dorsal displacement of the soft palate?
The free margin of the soft palate should normally be positioned tightly underneath the base of the eipglottis. if the soft palate displaces dorsally to the epiglottis, this will cause airflow obstruction with the production of loud abnormal gurgling expiratory and inspiratory noises & PP.
How can intermittent DDSP be diagnosed?
Dynamic overground or high speed treadmill endoscopy. Displacing palate transiently during resting endoscopy is not a good indicator that DDSP occurs at exercise. some DDSP affected horses show ulceration of caudal border of soft palate.
What are the proposed aetiologies of intermittent dorsal displacement of the soft palate? What are the associated treatments?
Primary dysfunction of intrinsic palate muscles - thermal cautery of palatal tissue.
Dysfunction of thyro hyoid muscle - tie forward surgery
Excessive caudal retraction of the larynx - Myectomy of strap muscles, sternothyroid tenectomy at insertion in thyroid cartilage.
Associated with damage to pharyngeal branch of vagus nerve - rest, treat concurrent inflammation
Non specific sign of hypoxaemia or exhaustion towards the end of strenuous work - rest, improve fitness.
why may permanent ddsp occur?
very rare compared to intermittent. often secondary to other diseases e.g epiglottic entrapment or sub epiglottic cysts. Others are due to congenital or acquired neuromuscular dysfunction of the soft palate or epiglottic muscles. Affected horses make loud and continuous gurgling noises at rest or at low level of exercise and may be mildly dysphagic.
What is epiglottic entrapment?
the rostral free aspect of the epiglottis becomes trapped in a pouch of mucosa that develops from the mobile sub epiglottic mucosa. Entrapment may be permanent/intermittent/exercise induced. if permanent, entrapping membrane and possibly the epiglottic cartilage may be swollen and ulcerated. Permanent or intermittent SP often occurs secondary to epiglottic entrapment.
How is epiglottic entrapment diagnosed? What is the treatment?
Abnormal expiratory oiises occur as air fills the pouch during expiration. on endoscopy an entrapped epiglottis loses normal flat, serrated appearance and becomes rounded, thickened, reddened or ulcerated. The normally prominent blood vessels on the dorsal aspect are now not visible. Treat by sectioning the entrapping membrane per nasum or per os using a hooked bistoury, or transendoscopic laser.
What are subepiglottic cysts? what do these cause?
Rare congenital structures mainly seen in standardbreds. they can deviate epiglottis dorsally causing airflow obstruction and possibly dysphagia, depending on the degree of epiglottic distortion.
What is epiglottic retroflexion?
Occasionally an abnormally dorsally angled epiglottis may be observed in resting horses without the presence of a sub epiglottic cyst. rarely seen as a dynamic disorder during high speed treadmill endoscopy where epiglottis sucked back towards laryngeal lumen.
What is aryepiglottic fold displacement?
The mobile folds between the arytenoids and epiglottis will sometimes become displaced medially into the airway during fast work and cause turbulence and noise.
what is the aetiology of RLN?
Unilateral idiopathic degenerative neuropathy of the left recurrent laryngeal nerve which innervates the intrinsic laryngeal muscles. Loss of abductor dysfunction occurs first but causes no clinical signs, but adductor muscle dysfunction - cricoarytenoideus dorsalis causes an inability to fully open the larynx during exercise. Occasionally unilateral laryngeal paralysis is caused by guttoral pouch mycosis or damage to the recurent laryngeal nerves in the cervical area.
How can RLN be diagnosed?
history - the type of noise and its onset in relation to fast work. RLN may be progressive in some. affected horses make an abnormal INSPIRATORY noise at exercise plus possibly poor performance. Palpate the dorsal laryngeal area for evidence of laryngeal muscle atrophy. Endoscopy at rest including during nasal occlusion and after swallowing.e valuate for asymmetry and asynchrony. laryngeal function graded from 1 normal to 4 total hemiparesis. do not evaluate in a sedated horse. Listen to respiratory sounds during fast exercse. treadmill or overground endoscopy do not correlate. Ultrasonography of the ipsilateral cricoarytenoideus muscle can show characteristic changes.
What is the treatment for RLN?
Mild cases - perform a vocalcordectomy or ventriculectomy or ventriculocordectomy to prevent vocal fold obstruction at work surgically or using a transendoscopic laser.
Severe cases need a tieback - a prosthesis mimics action of CAD muscle to permanently abduct the left arytenoid. complications include loss of surgical abduction, coughing due to aspiration tracheitis due to lack of aduction during swallowing, post operative wound ifectios.
What are the causes of bilateral laryngeal paralysis?
Hepatic encephalopathy, organophosphate or lead poisoning, GA.
What is laryngeal dysplasia?
Rare congenital abnormality with variable abnormal missing cricopharyngeal, thyroid and cricoid cartilage unilaterally or bilterally.
What are the clinical signs of tracheal collapse?
Occurs in small pony breeds and donkeys. Caused by a cartilage deformity or degeneration of the dorsal trachealis ligament that may cause separation of the tracheal mucosa from dorsal ligament. affected ponies show stridor, dyspnoea, exercise intolerance or may be undiagnosed due to low workload. If the problem is cervical trachea this causes an inspiratory noise whilst intra thoracic obstructions cause expiratory obstruction.
Describe temporary tracheostomy placement?
Usually performed on the standing horse under local. the upper third of cervical trachea where most superficial. skin prep. Local anaesthetic infiltrated. elevate head. 15cm midline skin ad Subcut incision. Incise muscle. Separation of the muscle over 7-8cm length the reveals the trachea. Lower horses head to normal position. A transverse stab incision is made int the annular ligament and this will induce a loud inspiratory noise as air rushes into trachea. extend incision on both sides to create a large opening. insert tracheostomy tube.
What are sarcoids?
the most common neoplasm affecting the horse. they are benign but can be locally aggressive. they are fibroma type structures. the aetiology is unknown but BPV or similar viral cause suspected. some evidence that they can be spread by flies.
Where are sarcoids most common?
head groin prepuce axillae and neck. >80% of horses with sarcoids have more than 1 lesion.
Describe the 6 different types of sarcoids?
Occult - area of slightly thickened skin with a roughened surface, often hairless and very slow growing.
Verrucous warty sarcoid - dry horny and cauliflower like, hairless and can have either a broad base or a stalk.
Fibroblastic sarcoid - resembles proud flesh, can be firm and nodular in its surface and may be ulcerated.
Mixed - mix between any types.
Nodular - entirely under the skin, easily shelled out.
Malevolant sarcoids - Rare, most aggressive type - tumours spread extensively through the skin with cords of tumour tissue interspersed with nodules and ulcerating fibroblastic lesions.
What are the different treatment options available for sarcoids?
Many treatments available.not one is very effective.
1. do nothing - if not causing interference, or ulcerated.
2. surgery - up to 40% recurrence. better results (80%) if wide margins taken or used to debulk large lesions. Laser surgery also good as seals blood vessels and lymphatics as it cuts. ligation or elastration of stalks of pedunculated sarcoids sometimes effective.
3. Cryosurgery - effective for lesions with limited size and deth, may cause extensive damage to surrounding structures and scarring.
4. BCG injection - very succesfull for perocular sarcoids, poor rate elsewhere, 2-3 injections several weeks apart, unknown mechanism of action.
5. Radiation - best results but very expensive and restricted, difficult around eyes or joints.
6. topical cytotoxic therapy - AW-4LUDES = secret formula applied topically on several occasions. obtained on case by case basis fom leahurst. Causes skin necrosis and scarring.
7. Intralesional chemotherapy 0 cisplatin or 5 flouracil
8 combination therapy best results.
What are the treatments available for melanomas?
( may change from benign > malignant).
Leave alone- unless causing a problem
Excision - wide and check margins. may be curative for discrete dermal lesions or helpful for debulking large lesions.
Cryotherapy - may need to repeat, combine with debulking
Cimetidine - systemic oral treatment. TID for 3 months.
Chemotherapy - intralesional cisplatin on at least 2 occasions.
Describe what causes squamous cell carcinomas and where they normally occur
Uv radiation, chronic irritation, previous wound, smegma, penile SCC. usually around the head / eye r external genitalia (vulva , penis) particularly non pigmented sk. Lesions are productive (papillary appearance) or erosive (nodular plaques and ulceration. locally invasive, slow to metastasise. may travel to local lymph nodes then the lung.
What may cause delayed non healing chronic wounds?
Infection - bacteria prolong inflammatory phase of wound healing, may produce collagenases which decrease wound strength.
Excess movement - particularly over high motion joints in the limbs.
Large skin defects - may just require more time if epithelisatio is occuring.
Presence of foreign body/necrotic tissue - inadequately debrided wounds, bone fragment remaining or bony Sequestrum post injury.
Excessive granulation tissue - proud flesh. limbs > trunk wounds. horses > pnies. V difficult for epithelium to grow over it once protruding higher than wound edge.
Systemic disease of the patient - cachexia, cushings.
What can be done to treat a non healing wound?
Remove necrotic tissue, foreign bodies, give topical ad systemic antibiotics. Immobilise to stop excess movements in a robert jones bandage or bandage and cast. Skin graft possible if large skin defect. Bandage with moderate pressure for excessive granulation tissue - excision of excess tissue, cut back to just below the surrounding skin surface - note granulation tissue can bleed a lot. Topical steroids - CARE ON AN INFECTED WOUD. reduces granulation tissue but also slows epithelisation too so don’t use for too long. biological dressings e.g amnion, skin grafts can reduce granulation tissue production. Cauterising compounds - copper sulphate, silver nitrate salicylic acid DO NOT USE.
Describe the preparation for the recipient site of a skin graft
need a fresh or granulating wound
If granulating - debride granulation tissue which reduces bacterial contamination. do not consider graft if infection present. consider topical treatment of recipient site after initial debridement. streps and pseudomonas often a problem so consider silver sulfadiazine.
What is the standard protocol for examination of the lame horse?
- History - concurrent disease, what is the horse used for, vaccination, insurance, previous lameness, duration and severity of lameness, any trauma, when was horse last shod.
- Observe at rest- assess weight bearing, look for swellings, foot
- Observe while moving - at walk, at trot, on lunge on soft and hard ground, use hoof testers once lameness is confirmed, flexion tests
- Palpate and maipulate-
- Diagnostic nerve/joint blocks - anaesthesia of sensory nerves to localise region of pain.
- Diagnostic imaging - radiographs, ultrasound, nuclear scintigraphy, MRI, CT - after a region of interest has been identified.
How does a unilateral forelimb lameness preset?
It will trot with its head nodding DOWN when the SOUND limb lands, as it tries to shift the weight off the painful limb.
How will a horse with a unilateral hindlimb lameness present?
A horse with a unilateral hindlimb lameness wil show an increased excursion of the gluteal region on the lame side at the trot.
IF severe a hindlimb lameness will result in a head nod mimicking lameness of the ipsilateral forelimb.
Where does the palmar digital nerve block alleviate pain from?
Most f the sole.
usually do not lose dorsal coronary bad sensation.
If performed distally unlikely to alleviate pain from the proximal interphalageal joint but will do so if needle is inserted mid pastern.
What does abaxial sesamoid block numb?
All of the hoof capsule, proximal interphalangeal joint, palmar pastern region including sesamoidean ligaments, DDFT, SDFT, distal part of tendon sheath.
What factors can affect hoof growth and quality?
Hereditary
Diet - methioine, biotin etc increase hoof growth
Environment - wet horn weak, ammonia rots horn, formalin damages hoof wall horn
Farriery - lack of farriery may cause imbalance. nail placement affects function. imbalance predisposes to cracks.
Describe the ideal balance of the hoof?
Toe angle equals pastern angle, toe angel equals heel agle, heels the same length and height. equal distribution of weight.
What is nail bind?
The nail has penetrated the sensitive tissues of the foot at the time of shoeing.
What are the pros and cons of shoeing horses?
they protect the hoof wall against wear & tear and improve performance, and give additional support on slippery surfaces,
but they add weight, they restrict expansion of foot during loading an cause problems if done incorrectly.
What is navicular syndrome?
A clinical manifestation of different pathological processes in the navicular bone, flexor surface of NB, DIP joint, DDFT, navicular suspensory ligaments, impar ligament. Due to increased pressure between the DDFT and NB in a flat foot with along toe/low heel - leading to remodelling of the NB - sclerosis,thickening sc bone and inflamation of the NB. analogous to degenerative joint disease.
what are the clinical findings with navicular syndrome?
Insidious onset, frequent stumbles, reluctant to work on circle, may point one foot, shortened stride at the trot, often bilateral lameness which is accentuated on the hard circle, diagnostic analgesia: will improve to PDNB, DIP and NB block. Take Upright navicular (dorsoproximal palmarodistal) and skyline navicular views (palmaroproximal palmarodistal oblique).
What is the treatment for navicular syndrome?
Foot care - support the heel, relax the DDFt.
NSAIDS
vasodilators
Intra articular or intra bursal corticosteroids - contra indicated if DDFT lesion present.
Tiludronate - reduces osteoclast activity.
Surgery - desmotomy of suspensory lig, decompression of navicular medullary cavity, neurectomy - 74% sound at 1year.
What is a hoof abscess ad how is it diagnosed?
most common cause of lameess, typically acute lameness, typically increase of digital pulse, any insult to the sole ca create a ideal medium for bacterial growth. Chronic cases may preset with cellulitis and systemic infection. Increase of digital pulse, use hoof testers and warm poultice, radiographs - may see gas shadow, antibiotics and anti inflammatories can be contraindicated.
How can you treat a hoof abscess?
release infection & allow adequate drainage, deridement of necrotic tissue, poultice until the infection is controlled, warm bath with povidone and magnesium salt. Tetanus prophylaxis. Antibiotics and anti inflammatories can be contraindicated.
What is the cause of a corn?
Bruise of sole at specific location: medial angle much more common than latera. usually due to pressure from heel of shoe either shod too short, shoe left on too long, dorsopalmar foot imbalance. Excessive heel loading leads to bruises/subsolar abscess. Bandage or poultice/corrective trim - re shoe.
What further investigations should you do if there is a puncture wound of the sole presented to you?
Common emergncy. rule out sepsis of synovial structures. commonly result in Subsolar abscesses. use radiographs, synovoocentesis, navicular bursa contrast study, MRI. Subsolar abscess is localised usng hoof testers - pare tract to release pus.
What is seedy toe or white line disease?
White line is a weak region due to the soft horn. a combination f bacteria and fungi produce separation of the white line. this occasionally produces lameness. typically an incidental finding. white line becomes filled with poor quality infected tissue. often secondary to laminitis. advanced cases cause instability of pedal bone or infection of laminae.
What is a keratoma?
A benign, hyperplastic keratin mass which arises from the epidermal keratin producing cells and originates at any point in the hoof wall and sole. it is a space occupying tumour, often causes recurrent hoof abscesses. Causes a disruption in the hoof architecture and allows bacterial infection and recurrent abscess. May cause pressure necrosis and resorbtion of pedal bone margin leading to characteristic radiographic lucency.
What is thrush and how is it treated?
an infection of the frog caused by wet environment, by fusibacterium necrophorum. black sticky discharge & terrible smell present. can result in under run sole and limb oedema. contracted heels may predispose to the condition. Trim affected parts of the frog ad move to a dry environment. Give antiseptic foot baths (povidone iodine)
How can septic pedal osteitis occur?
Due too a penetrating injury to the sole involving P3 a chronic subsolar abscess, blunt trauma.
How can septic pedal osteitis be treated?
Surgical debridement standing or under GA. Curettage of infected pedal bone. packing the area with antibiotic impregnated swab. regional perfusion with antibiotics. systemic antibiotics and anti inflammatory.
What is canker?
chronic pododermatitis of the germinal layers. gram negative bacterial infection of the stratum germinatum of the frogs epidermis. causes hypertrophic dermatitis of the frog and the bulbs of the heels.
What is quittor?
collateral cartilage infection - as a result of a hoof wall crack puncture wound, chronic abscess, or heel laceratio. causes a severe degree of lameness until adequate drainage is established. Causes chronic sepsis with intermittent purulent discharge above the coronary band.
Which vital structures can be affected in a heel bulb laceration?
Important to rule out sepsis of the synovial structures - Assess DDFT, collateral cartilages, navicular bursa, impar ligamnet, DFTS.
What structures may be involved when the hoof capsule/croary band is involved?
Ungular cartilages
DIPJ/NB/DFTS
Describe your management of a soolar penetration and what structures may be involved?
Check depth and direction of penetration BEFOORe removing object provided there is no risk of object penetrating further - do dorsopalmar and lateromedial radiographs. Mark entry wound on sole. Possible structures involved include NB, DIPJ, DFTS, DDFT, P3, digital cushion. - Can do synoviocentesis, contrast arthrography, MRI.
How should you lavage a wound?
With sterile saline (0.9%) - optimal lavage. OR 1tbsp table salt + 600ml water, or 0.05% chlorhexidine or povidone iodine. always lavage with saline after using these. avoid scrub solutions. use pressure 10-15PSI - 30ml syringe with a 19g needle.
What are the requirements for primary closure of a wound?
perform promptly, minimise contamination, use tension relieving suture patterns/techniques, not if infected, drains if dead space. always try too perform primary closure of the eyelid/distal limb wounds.
Describe how to dress a wound and place a support bandage and which materials you should use and what the purpose of these is.
Aim to minimise oedema with firm even pressure, absorb exudate, maintain temperature and moisture, allow gaseous exchange, immobilise the woound, protect from further contamination and trauma.
1 - primary dressing - chooose non adherent dressings. Meloln for on exudative. Allevyn for exudative. calcium alginates for healing by 2nd intention. collagen dressings foor healing by 2nd intention. hydrgels for contaminated wounds, hydrocolloids, manuka honey, amnion.
2.- secondary layer - use cotton wool or gamgee, absorbs exuate, secures primary layer, supports and protects.
3- Tertiary layer - vetrap, secures provides support and pressure.
Which regions are prone to developing skin rubs due to limb bandages?
Accessory carpal, medial malleolus, flexor tendons, gastrocneumius tendon.
