dogs and cats 13 Flashcards

Question

Treatment trail antibiotics for a well but vomiting cat which use, when respond and what if don't

Answer 1

§ Amoxicillin 20 mg/kg bid for up to 6 weeks § Metronidazole 10mg/kg bid for maximum 3 weeks § Again should respond within 1-2 weeks and after 3-4 week course may only need dietary management § IF STILL NO RESPONSE TO DIET - need to 'support' the cat and happy with diagnosis move onto BELOW

Answer 2

§ Nutrition, micronutrient and fluids § Cobalamin □ Supplementation improves clinical signs in cats with GI disease □ This is regardless which diagnosis and treatments □ Options ® Treat and measure response or ® Treat empirically (250ug injection once weekly for 4-6 weeks)

Answer 3

1. Ultrasound ○ May be normal or show loss of layering with IBD, small cell lymphoma ○ May show masses, lymphadenopathy, focal intestinal thickening or effusion and can get samples 2. Endoscopy ○ Limitation access to biopsy - good quality biopsy takes experience and training ○ Gastric good ○ Overlap with IBD in intestine ○ Tricky to get ILEUM -> access from the colon 3. Exploratory laparotomy § Increased morbidity § Increase yield § Can assess disease outside of intestine § Can biopsy ileum easily

Answer 4

1) prednisolone 2) other corticoteroids - not as effective - dexamethasone, budesonide 3) other immunosuppressives - chlorambucil 4) other therapies - not properly evaluted - mega-3 fatty acids, probiotics - don't use

Answer 5

○ Start to taper every 3-4 weeks until reach minimum effective dose ○ Continue diet and continue antibiotics for first 2 weeks of prednisolone ○ Side effects § PU/PD and alopecia (minimal) § Development of diabetes is a risk

Answer 6

- not as effective as above ○ Dexamethasone § Only if cannot give oral medication and not eating well enough to place in food § 1/6th to 1/8th the oral pred dosage q 36-48 § Profound immune suppression ○ Budesonide § Not evaluated in cats

Answer 7

``` ○ Only if histologic diagnosis 1. Chlorambucil § Current choice as add on § Generally well tolerated 2. Ciclosporin § Be careful with latent toxoplasmosis § Not evaluated in feline IBD ```

Answer 8

not properly evaluated 1) Omega-3 fatty acids § May interfere with palatability of diets, and cause diarrhoea 2) Probiotics - waste - DON'T USE § Lack of translational benefits in people § Well tolerated in cats § Recent abstracts suggests not effective in feline IBD

Answer 9

- This is a 'good' tumour - Response to therapy 75-90% - Majority of cats alive and in remission at 2 years ○ Median remission 897 days

Answer 10

- Still support (cobalamin) - Still antibiotics and diet - Initial therapy ○ Prednisolone 3mg/kg once daily, reducing to 1-2mg/kg once daily when have clinical remission ○ Chlorambucil 2mg q 48 hours, 15mg/m^2 q 24 x 4 q 3 weeks, 20mg/m^2 q 2 weeks same as IBD

Answer 11

- DIFFERENTIATE VIA -> Immunohistochemistry and PAR sample | - Important due to prognosis -> IBD better prognosis than small cell lymphoma

Answer 12

Cholangiohepatitis/cholecystitis - most common ○ Antibiotics ○ Vitamin K if severe

Answer 13

- Complete remission in 50-75% - Overal median remission 4-8 months, overall MST 6-8 months - Have longer survival if initial good response - Often unwell, so need nutritional support - Recent study shows bacteraemia in cats with LC lymphoma

Answer 14

``` Treatment basics - Cobalamin - Antibiotics - Nutritional support Treatment options - Palliative prednisolone - Palliative surgery - Multi-agent chemotherapy - Radiation therapy ```

Answer 15

1) Common disturbances: ○ Dehydration ○ Electrolyte imbalances: § Hypochloraemia, Hyponatraemi, Hypokalaemia ○ Acid-base disturbances: 2) Treatment/correction of these pre-op problems important to: ○ Optimise outcomes ○ Prevent complications 3) Fasting for elective procedures can minimise risk of spillage but decreases gastric fluid pH 4) If gastro-oesophageal reflux anticipated –consider H2 antagonist or proton pump inhibitor ○ Rapid induction and airway control if vomiting reflux likely (prevent aspiration)

Answer 16

- Cardia - terminal part of oesophagus, gastro-oesophageal sphincter - Fundus - can be affected during GDV - Body - largest part - Pyloric Antrum - funnelling down into smaller cylinder -> WHERE DO GASTROPEXY Pylorus - outflow of stomach, muscular sphincter into proximal duodenum

Answer 17

1. Hepatic branch 2. Splenic artery 3. Celiac artery 4. Cranial mesenteric artery - supplies all intestines 5. Renal artery 6. Testicular/ovarian 7. Caudal mesenteric - colon

Answer 18

DRAINIAGE -> all to the portal vein -> liver -> recirculation of bile salts - Important with porto-systemic shunts -> portal vein and caudal vena abnormal communication -> bile salts and other facts bypass liver -> hepatic encephalopathy

Answer 19

- Gentle tissue handling - Accurate apposition of tissue layers - Preservation of vascular supply - Accurate haemostasis - Prevention of contamination - Recognition and appropriate treatment of contamination

Answer 20

- Adequate visualisation of the entire abdomen is important: - Ventral midline coeliotomy: ○ Xiphoid to pubis ○ Balfour Abdominal Retractors - self-retaining -> hold abdominal wall apart ○ Laparotomy Sponges ○ Suction - poole suction tip -> prevent contamination of GI content - Examine the ENTIRE gastro-intestinal tract: ○ Systematic -> cranial left first ○ Visual & Tactile –pulses, peristalsis, colour - Don’t miss the second lesion

Answer 21

§ Agents present in tissues at time of incision (30 mins) § Selected for efficacy vs expected organisms § 1st generation Cephalosporins OK for gastric and small intestinal procedures § 2nd generation for colonic procedures (also mixed infections generally) § Not continued > 24 hrs post-operatively unless break in asepsis

Answer 22

§ Stomach 102/ gram - FIRST GENERATION § Small Intestine 104 / gram - FIRST GENERATION § Large Intestine 1010 / gram –also ^ No’s Anaerobes - SECOND GENERATION

Answer 23

○ Clean contaminated -> contaminated - DUE TO BREAK IN ASEPSIS § Without appropriate treatment -> peritonitis, death -> broad-spectrum antibiotics - Techniques to reduce gross contamination / spillage: a. Orogastric intubation -> help with feeding after surgery - PLACE PRE SURGERY b. Isolation –moistened laparotomy sponges c. Stay sutures –large full thickness bites d. Suction

Answer 24

1. Prophylactic antibiotic therapy becomes therapeutic antibiotic therapy 2. Therapeutic therapy initiated with empirically selected agents based on expected organisms BUT MODIFIED based on microbial CULTURE & SENSITIVITY from sample taken AFTER LAVAGE 3. Debridement of gross materials/contaminants 4. Lavage 200-300ml/kg (Seim1995) ○ Reduction in bacterial load ○ Removal of adjuvant materials ○ Removal of inflammatory mediators

Answer 25

- Perform routinely prior to abdominal closure if hollow viscus entered - Change gloves prior to lavage - Use separate instruments to close post-lavage - Lavage fluids 37-39 degrees C: ○ Cooler fluid exacerbate hypothermia ○ Warmer fluids result in vasodilation →hypotension and increases adhesions ○ isotonic - All natural fluid and irrigation fluid is removed following lavage: ○ Residual fluid reduces immune clearance of debris and micro-organisms and is an adjuvant for peritonitis ○ Poole Suction tip

Answer 26

``` - Indications: ○ Removal of Gastric Foreign bodies ○ Removal of neoplastic lesions ○ Removal of severe focal mucosal erosive lesions ○ Removal of necrotic stomach wall (GDV can occur) ○ Obtain Biopsy samples - Ventral Stomach Wall: ○ Relatively avascular area ○ Long axis vs short axis ○ Position influenced by indication ```

Answer 27

- Synthetic monofilament absorbable materials are preferred: - swayed on ○ Reduced tissue trauma from tissue drag ○ Reduced wicking - Taper point needle–smaller holes vs cutting - 2-layer simple continuous appositional closure: ○ Mucosa/Submucosa - higher collagen content -> appositional simple continuous or interrupted ○ Serosa/muscularis

Answer 28

``` - Indications: ○ Gastrotomyclosure (rare) ○ Gastrectomy(reduces spillage) ○ Anastamosis - Deploy 2 or more rows of titanium staples: ○ Rows of staples may be of same or different sizes ○ +/-integrated knife for tissue division - Advantages: ○ Rapid ○ Consistent spacing and closure - Types 1. Linear Staplers 2. circular staplers ```

Answer 29

- Want to get them eating as soon as possible - Gastro-intestinal motility can be reduced by: ○ Handling ○ Desiccation ○ Incision –Disturbs myoelectricalconduction from pacemaker ○ Opioids AVOID ○ Pain ○ Recumbency/lack or early ambulation ○ Lack of enteral nutrition - Poor motility results in: ○ Pain ○ Anorexia ○ Vomiting ○ Gastric distension

Answer 30

1. Analgesia 2. IVFT to: ○ Replace ongoing loss ○ Supply Maintenance ○ Maintain perfusion 3. Prokinetic Therapy: ○ Cisapride, Ranitidine, Metoclopramide, Erythromycin 4. Enteral (into staomch) or parenteral (into bloodstream (bypass stomach)) nutrition

Answer 31

○ Patients without adequate nutrition for 3 or more days ○ Evidence of more than 10% weight loss ○ Inadequate mm mass ○ Serum albumin < 2.5 g/dLin cats / <2.1 g/dLin dogs

Answer 32

opening of the small intestines - Indications: - determined via clinical signs, history, imaging ○ Foreign body removal ○ Access to the major duodenal papilla for common bile duct cannulation ○ Tissue biopsy - Technique 1. Isolation of affected segment: § Moistened laparotomy sponges § Milk chyme away from incision § Assistant finger clamps or Doyen intestinal forceps 2. Anti-mesenteric incision through UNAFFECTED intestinal wall 3. Suction to remove luminal fluid

Answer 33

- Closure ○ Single layer appositional (simple continuous, simple interrupted, staples) -> start above the incision site ○ Submucosa provides suture holding strength ○ Everted mucosa may be trimmed if required ○ Sutures must engage submucosa–full thickness passage easiest. ○ 3mm bites –Full thickness -3mm apart ○ 3/0 for larger dog, 4/0 for cat or smaller dog - Omentalisation: ○ Perform routinely ○ Vascular supply, seals leaks

Answer 34

- Full thickness samples for histopathology: ○ (if endoscopic bxfails or location unsuitable) ○ Multiple sites (Gastric, duodenum, jejunum, LN) ○ Colon generally not sampled routinely due to increased risk of more significant complications - Techniques: ○ Suture Lift Wedge ○ Dermal punch biopsy - full thickness of the wall - Not benign procedure –12% incidence of peritonitis and death (Shales 2005) ○ Attention to technique important

Answer 35

``` intestinal resection and anastomosis - Indications: ○ Severely damaged intestine ○ Damage to segmental vascular supply ○ Intestinal neoplasia ○ Segmental incarceration/strangulation ```

Answer 36

1. Isolate segment and identify good mesenteric vessels 2. Milk chyme from site 3. Doyen intestinal forceps 4. Ligate vasculature 5. Excise tissue –ensure sufficient tissue extends from Doyen forceps to increase ease of closure 6. closure - Suture onto mesenteric side, knot OUTSIDE OF LUMEN, second suture on antimesenteric side (simple interrupted)

Answer 37

1) end to end - most common 2) side to side - functional end to end 3) mucosal eversion

Answer 38

□ Most commonly performed technique □ Appositional patterns recommended: ® Inverting patterns narrow lumen ® Everting patterns increase adhesions ® Apposition -> Primary healing & rapid bridging of the mucosal defect ® Single layer appositional closure: ◊ Simple continuous –separate each side i.e.180 degrees then180 degrees -> avoids purse-string effect ◊ Simple interrupted } Correct tension produces apposition without crushing tissues.

Answer 39

□ GIA staplers x2 or 1 □ Antimesenteric border -> puts row of staples down combining the two ends, cut in the middle of the 2 suture rows to create an opening between the two side, then staple up the top off and cut (creating pants)

Answer 40

§ Vary spacing of sutures - mild sparsity only § Transect smaller segment a an angle (sort side is anti-mesenteric to preserve blood supply) § Spatulation of smaller segments -> linear incision along antimesenteric border to increase lumen diameter

Answer 41

stitch intestines together - Indications: ○ Prevention of recurrence of intussusception (Oakes 1994) ○ Performed over small intestine from jejunum to ileum: § Recurrence at site distant from original site § Avoid kinking and sharp bends § Sutures must penetrate submucosa - Controversial ○ Rate of complications > rate of recurrence (Applewhite2001) ○ High experimental morbidity in cats (Nash 1998)

Answer 42

1) gastro-oesophageal reflux 2) septic peritonitis 3) adhesions 4) short bowel syndrome 5) ileus

Answer 43

○ May be silent ○ Reported in 57% of orthopaedic cases (Wilson 2006) ○ Likely higher in GIT surgical cases -manipulation ○ Results in oesophagitis and if severe potentially stricture ○ Shorter periods of fasting may increase gastric fluid pH

Answer 44

○ When occurring in the post-operative setting –most commonly assoc with enterotomyor anastamotic dehiscence ○ 7-16% incidence (Hosgood1988, Allen 1992, Ralphs 2003) ○ 12% incidence after full thickness biopsy (Shales 2005) ○ Risk Greatest in debridement phase 3-5 days post-op § Risk Factors: □ Pre-operative peritonitis □ Presence of a Foreign body □ Hypoalbuminaemia □ Delayed enteral Feeding

Answer 45

``` ○ Less common in dogs/cats than in humans and horses due to active fibrinolysis ○ Contributing factors: § Ischaemi- Haemorrhage § Foreign Bodies § Infection ○ May result in obstruction ```

Answer 46

○ Malabsorption from lack functional length of small intestine: § Reduced surface area § Gastric and intestinal hyper-secretion § Bacterial Overgrowth § Decreased transit time ○ Risk if > 50% length resected ○ Proximal resection better tolerated vs distal ○ Results in persistent diarrhoea, steatorrhea, weight loss, electrolyte disturbances

Answer 47

○ Appropriate treatment and time -> adaptation: § Increase in villus length and crypt depth (over 3 mths) § Fluid and electrolyte therapy § Early enteral nutrition: □ Fibre is a key component: ® Stimulates adaptation, modulates motility, ^ water absorption, Binds bile salts -> reduces secretory diarrhoea □ Glutamine –preferred energy source for enterocytes § If unsuccessful –loperamide/ antimicrobials ○ Prognosis –variable (length resection, presence ICV)

Answer 48

``` ○ Common after GIT surgery -> Careful handling ○ High sympathetic tone ○ Clinical Signs: § Pain, Vomiting, Regurgitation, Abdominal Distention (NB similar to peritonitis) ○ Treatment/prevention 1. Correct underlying causes: □ Sepsis □ Electrolyte disturbance □ Uraemia □ Pain 2. Prokinetics □ Metoclopramide, Ranitidine, Cisapride 3. Early Enteral Nutrition ```

Answer 49

1) peritoneal defecnce mechanisms compromised 2) intense inflammation reaction 3) pro-inflammatory mediations -> PG's -> increase vascular permeability 4) third space of fluid, albumin, clotting factors 5) protein loss -> coagulopathy 6) systemic inflammation and microthrombi - SIRS 7) fluid loss and vasodilation -> decrease CO 8) reduced perfusion - anaerobic metabolism 9) acidosis secondary 10) catecholamine and cortisol response -> increase O2 demand 11) poor perfusion, disruption mucosal barriers -> bacterial translocation 12) endothelial damage and circulatory stasis promoter hypercoagulable state

Answer 50

○ Poor perfusion of organs ○ Poor renal perfusion inhibits renal buffering mechanisms ○ Reflex rigidity inhibits ventilation

Answer 51

○ Gastric mucin –anti-complement effect ○ Bile salts –lower surface tension and lyse RBC’s releasing Hb ○ Haemoglobin –Hb interferes with phagocytic cell chemotaxis and phagocytosis and provided Fe for bacterial metabolism ○ Barium

Answer 52

○ Primary Peritonitis: § Peritonitis without identified cause § FIP, monobacterial infections (Culp 2009) ○ Secondary: § Most common –leakage of intraluminal content from GIT or urogenital tracts. § Polymicrobial § Mortality rates up to 85% (Ralphs 2003) ○ Aseptic/Sterile Peritonitis: § Inflammation without infection (pancreatitis, desiccation, surgical biomaterials, gossypiboma (retained surgical sponge), Chemical –urine and non-septic bile)

Answer 53

a. Identify and correct cause b. Reduction bacterial load c. Removal of gross contaminants and inflammatory mediators d. Prevention of recurrence e. Provide route for enteral nutrition

Answer 54

- GIT perforation/leakage most common cause (47-63%) - Previous abdominal surgery is a significant cause of Septic peritonitis (46% cases had surgery in 2 weeks prior to presentation) - Risk factors for peritonitis after surgery: ○ Pre-operative Peritonitis ○ Hypoalbuminaemia ○ Intestinal FB - Leakage rates from full thickness biopsy 12% ○ Increase total bacterial load and percentage of anaerobes aborad

Answer 55

1) necrosis from GDV 2) penetrating FB 3) trauma 4) ulceration with perfusion - NAIDS 5) feeding tube leakage 6) pancreatitic abscess 7) pyometra

Answer 56

1) midline laparotomy 2) debridement - removal of source 3) lavage 4) omentalisation 5) serosal patching 6) closure and drainge 7) post operative support

Answer 57

○ Xiphoid to pubis | ○ Full and systematic examination of the peritoneal cavity (see previous lecture on laparotomy)

Answer 58

2. Debridement - remove the source ○ Removal / repair of source: (examples) § Cholecystectomy § GIT Resection and anastomosis § Liver lobectomy § Ovariohysterectomy (Pyometra) ○ Suture biomaterials with prolonged absorption profile 3. Lavage ○ Reduction in bacterial load, removal of adjuvant materials and inflammatory mediators ○ 200-300ml/kg ○ Addition of AB or antiseptics has no reported benefit and may result in chemical peritonitis ○ Intraperitoneal iodine induces toxicity and chemical peritonitis in dogs

Answer 59

○ Described for prostatic abscesses, pancreatic cyst and pseudocysts ○ Successfully used for plugging 20mm duodenal defects § Healing complete at 8 weeks ○ Omental wrapping: § Seal small leaks § Provide drainage & immunocompetent cells § Vascular supply and angiogenenic potential § Wrapping to prevent omentalisation resulted in leakage and septic peritonitis (McLaughlin 1973)

Answer 60

○ Peritonitis associated with increased risk of dehiscence (Crowe 1984) ○ Proteolytic activity results in collagen degradation ○ Serosal patching recommended for anastomoses and areas of hollow viscusorgans with potential for leakage (Crowe 1984): § Placement of serosa of healthy small intestine loops over focal regions of hollow viscous organs suspected of being unhealthy ○ Reduced mortality in a canine experimental model

Answer 61

1) primary closure without drainage 2) primary closure with drainage 3) open peritoneal drainage 4) VAC laparostomy

Answer 62

® Primary problem identified and addressed ® Bacterial load reduced and residual contamination minimal ® Mortality rate 46% ® ICU care and plasma not available –preclude open abdominal drainage

Answer 63

``` Jackson-Pratt drains most common - negative pressure resulting in fluid flow from abdomen □ Potential problems: ® Nosocomial infection ® Occlusion of drains with omentum ® Ineffective drainage □ Benefits include: ® Reduced risk evisceration ® Reduced risk nosocomial infection ® No need for second sxprocedure to close abdomen –but cannot inspect viscera ```

Answer 64

□ Benefits reported: ® Improved removal of bacteria, foreign material and inflammatory mediators ® Improved O2 tension –reduces anaerobe survival ® Affords early planned, serial re-exploration □ Technique a) Cranial 1/3-2/3 of the linea alba left partially open with a loose simple continuous monofilament suture pattern (1-6 cm gap) b) Falciform ligament excision c) Tack omentum to areas of leakage to prevent occlusion of opening d) Sterile technique for bandage changes –in surgical suite under GA –allows serial re-inspection e) Bandages weighed to assess fluid loss□ Mean open drainage duration 4 days in retrospective clinical studies (Greenfield 1987, Woolfson1986)

Answer 65

□ Criteria for closure unclear but recommendations: (Woolfson1986) ® Improvement in colour and clarity of drainage fluid ® Reduction in volume drainage fluid ® Absence bacteria on cytology ® Repeat culture at closure –40% patients had different MC&S results (Greenfield 1987) and positive results increased mortality (Woolfson1986) □ Nosocomial infection recognised complication □ Superiority of open drainage not established in any trials in clinical reports in either humans or animals → Not done very commonly

Answer 66

``` ® Visceral protective layer (?) ® Open cell foam ® Suction catheter ® Circumferential Occlusive film seal ® Continuous Negpressure -75-125mmHg via Suction unit ® Changed q 48 hrs □ Time to closure: 2 days □ Reduced morbidity & Mortality in Humans vs Open Drainage - CHOOSE THIS OVER OPEN DRAINAGE ```

Answer 67

a. Analgesia b. Enteral nutrition –maintain protein, glutamine maintains enterocyte health c. Maintenance fluid, electrolyte, acid-base balance § Protein energy imbalance major contributor to mortality (Tennant 1993) d. Feeding tube placement as proximal as possible to maximise physiology unless a contraindication for proximal GIT use exists ○ Jejunostomy has the highest rate complications 17-42% (Orton 1986)

Answer 68

- Mortality rates remain high 20-70% (Hosgood1988) 85% Ralphs - Published survival rates: ○ Open drainage 52-80% ○ Primary closure 54% ○ Closed suction drainage 70% ○ Vacuum 50%

Answer 69

Fasting leads to: - Intestinal mucosal atrophy - Increased enterocyte apoptosis - Change in mucin composition - Decreased glutamine and arginine transport Role of nutrition - Prognosis is poorer if negative nitrogen balance ENTERAL NUTRITION is best for intestinal mucosal health - Decrease cytokine production - Increase mucosal blood supply and stimulate local growth factors

Answer 70

1. Partial parenteral nutrition - only supplies part of nutrition and energy - not common 2. Total parenteral nutrition 3. Assisted enteral nutrition - most common

Answer 71

- Requires central venous catheter ○ Strict asepsis required - longer length of time - gloves, aseptic technique needed - Gradual introduction to full RER ○ At least 40 mEq/L potassium to prevent refeeding syndrome - Also amino acids (not taurine), dextrose and lipids ○ Not calcium or fat soluble vitamins ○ Lipid reduced if high serum triglycerides ○ Protein content reduced if hepatic/renal disease

Answer 72

- Mechanical - Phlebitis - Thrombosis - Septic - Metabolic - Gut atrophy - most common

Answer 73

- BEST ONE TO USE ○ Reduction inflammatory markers ○ Reduction intestinal permeability ○ Improved survival ○ Improved morbidity What about post intestinal surgery? Balancing act - Concern about healing intestinal incision -Best way for intestine to heal is to be healthy - Best way for intestine to be healthy is to be fed

Answer 74

Principles - Ensure all other treatments adequate ○ Fluid/electrolyte ○ Analgesia ○ Anti-emetic - Ensure no coagulopathy - Assess anaesthetic risk How long for? ○ Short-term if end-end anastomosis or post GDV (max 24 hours) ○ Short-term fine (< 48 hours) in mild-moderate cases pancreatitis ○ Majority of mild-moderate cases will resolve - If able to eat, and wants to eat then feed a low-fat food - Don’t stop feeding if one break-through vomit - Avoid food aversion in hospital by force feeding

Answer 75

1) NO - nasooesophageal tube - needs to be long enough to sit in distal 1/3 oesophagus - Oxygen catheters or soft infant feeding tubes - very small so small amount of food - Will need to feed Ensure or equivalent in Aust/NZ supplemented with whey protein after first 24-48 hours 2 )Oesophagostomy tubes - My technique of choice with ≥ 3 days no food including pre-hospital) - Technically easy to place - Allows for thicker liquid and blended foods - Well tolerated - Can commence feeding immediately - Requires general anaesthesia for placement - PLACE IN DURING SURGERY - Can lead to SEVERE gastric reflux if placed into the stomach ○ Don’t feed when animal recumbent and feed slowly

Answer 76

- 12-14 F cats - 16-18 F larger dogs Management - Clean and change bandage daily for 3 days then q 2-3 days - Can use as soon as awake - Check position before feeding and flush before and after feeding - Can remove easily -> just remove sutures and remove