Clinical Case

Question 1

Polo

• 13 yrs
• MN
• DSH
• Only cat in the house and has lived with the current owners since he was a kitten

General history

• Indoor and outdoor cat
• Fed a standard mix of wet and dry supermarket brand cat food
• He has been indoors more over last few weeks
• Owners describe him as ‘more clingy’ – he likes to be with them when they are sitting down in the evenings instead of being out and about
• His appetite has been variable, and they think he has lost some weight
• He has been passing softer light coloured stools in the last 3-4 weeks – this change seemed to occur gradually but may have been noticed more because he has been using his litter tray more than normal
• He came into the vets 3 weeks ago – he was given a 10d course of metronidazole and his owners were advised to feed a commercial low fat, bland, high protein (chicken) tinned food only. He ate that reasonably well but there has been no change in his stools and his appetite still comes and goes.

Physical Examination

• Bright and alert when he emerges from the cat basket
• BCS 3/9 and poorly muscled
• He weighs 240g less than at his last appointment
• No thyroid mass is evident in the cervical region despite prolonged palpation
• Rectal temperature 38.4oC
• Heart rate and pulse rate 180, no murmur heard on auscultation
• Mucous membranes are pink with CRT <2 seconds
• Thoracic auscultation is normal and respiratory rate is 24 breaths/min
• Abdominal palpation reveals a doughy feel to the SI and a mobile mid-abdominal tubular mass which elicits some discomfort on palpation
• The kidneys feel normal
• No other abnormalities are evident
• Mass wasn’t palpated on previous visit to the vets

What are your differentials?

Answer 1

• Foreign body
• Alimentary lymphoma
• Triaditis
• IBD – would explain the changes in stool, weight loss and lack of response to metronidazole but it doesn’t explain the abdominal mass
• Biliary tract disease (because of the lighter coloured stool)
• Small intestinal disease
• Intestinal torsion – not common in cats and not a likely cause of an abdominal mass
• Pancreatitis – could explain some of the problems but doesn’t fit with the abdominal mass
  
  • Sometimes chronic pancreatitis in a cat can cause a mass lesion but in this case the mass is too mobile for that to be the case (pancreatic masses are normally more fixed in place)
• Other neoplasia e.g. leiomyoma/leiomyosarcoma (much less common), MCT or adenocarcinoma
• Haemangiosarcomas are very rare
• FIP – always on list for any unwell cat and can cause intestinal mass in ileo-caecal-colic region; can also cause lymph node masses
• Intussusception (can be chronic or acute)
  
  • 2ry to an intestinal mass – esp given Polo’s age
  • Associated with intestinal FB
  • Associated with parasitic, protozoal, bacterial or viral enteritis
  • Idiopathic?
• Enlarged lymph nodes (neoplasia, granuloma)

Question 2

Physical Examination

• Bright and alert when he emerges from the cat basket
• BCS 3/9 and poorly muscled
• He weighs 240g less than at his last appointment
• No thyroid mass is evident in the cervical region despite prolonged palpation
• Rectal temperature 38.4oC
• Heart rate and pulse rate 180, no murmur heard on auscultation
• Mucous membranes are pink with CRT <2 seconds
• Thoracic auscultation is normal and respiratory rate is 24 breaths/min
• Abdominal palpation reveals a doughy feel to the SI and a mobile mid-abdominal tubular mass which elicits some discomfort on palpation
• The kidneys feel normal
• No other abnormalities are evident
• Mass wasn’t palpated on previous visit to the vets

Why was this mass not reported at the last appointment?

Answer 2

• Weight loss could have made it easier to palpate now than it was before
• The mass could have got bigger à tumours generally grow
• It might be that whatever has caused the intussusception has been a chronic problem but the intussusception itself is an acute presentation

Question 3

Physical Examination

• Bright and alert when he emerges from the cat basket
• BCS 3/9 and poorly muscled
• He weighs 240g less than at his last appointment
• No thyroid mass is evident in the cervical region despite prolonged palpation
• Rectal temperature 38.4oC
• Heart rate and pulse rate 180, no murmur heard on auscultation
• Mucous membranes are pink with CRT <2 seconds
• Thoracic auscultation is normal and respiratory rate is 24 breaths/min
• Abdominal palpation reveals a doughy feel to the SI and a mobile mid-abdominal tubular mass which elicits some discomfort on palpation
• The kidneys feel normal
• No other abnormalities are evident
• Mass wasn’t palpated on previous visit to the vets

Should we consider euthanasia?

Answer 3

• It should always be an option – we have no idea about the family’s circumstances e.g. finances

Question 4

General history

• Indoor and outdoor cat
• Fed a standard mix of wet and dry supermarket brand cat food
• He has been indoors more over last few weeks
• Owners describe him as ‘more clingy’ – he likes to be with them when they are sitting down in the evenings instead of being out and about
• His appetite has been variable, and they think he has lost some weight
• He has been passing softer light coloured stools in the last 3-4 weeks – this change seemed to occur gradually but may have been noticed more because he has been using his litter tray more than normal
• He came into the vets 3 weeks ago – he was given a 10d course of metronidazole and his owners were advised to feed a commercial low fat, bland, high protein (chicken) tinned food only. He ate that reasonably well but there has been no change in his stools and his appetite still comes and goes.

Physical Examination

• Bright and alert when he emerges from the cat basket
• BCS 3/9 and poorly muscled
• He weighs 240g less than at his last appointment
• No thyroid mass is evident in the cervical region despite prolonged palpation
• Rectal temperature 38.4oC
• Heart rate and pulse rate 180, no murmur heard on auscultation
• Mucous membranes are pink with CRT <2 seconds
• Thoracic auscultation is normal and respiratory rate is 24 breaths/min
• Abdominal palpation reveals a doughy feel to the SI and a mobile mid-abdominal tubular mass which elicits some discomfort on palpation
• The kidneys feel normal
• No other abnormalities are evident
• Mass wasn’t palpated on previous visit to the vets

What is your plan for him?

Answer 4

• If we have any concern that we didn’t do enough of a thorough clinical exam e.g. the lymph nodes then definitely go back and re-check and maybe biopsy any enlarged LNs
  
  • Cats are less likely to have enlarged peripheral LNs even with lymphoma
• Biochem & haematology – check liver parameters etc. in case he has other concurrent disease going on (based on his age)
  
  • Haematology to check white blood cells i.e. if he has lymphoma he might have strangely shaped WBCs
  • Septic peritonitis associated with the mass could cause significant increase in WBCs
  • Any evidence of anaemia of inflammatory disease?
• Ultrasound (ideally conscious) – will move things forward more than haem and biochem
  
  • Will give us a lot of information quite quickly
• Radiography of chest and abdomen – thoracic in particular is excellent to look for metastatic disease (saves the cat going through anything more invasive if we do find mets)
  
  • Right and less lateral (or lateral and DV)
• Urinalysis – check glucose levels to rule out diabetes and check USG
  
  • Urine is better for checking glucose because checking blood could just represent stress hyperglycaemia
• Total T4
  
  • We couldn’t feel a thyroid mass and isn’t particularly tachycardic or desperately hungry so hyperT4 is probably not high on our list, but we might want to check for completeness
• Check kidney function
• Trypsin-like immunoreactivity
• Cobalamin and folate
• Unfortunately, FIP is very difficult to diagnose therefore also difficult to rule out – on the initial haem and biochem there might be markers e.g. high globulin, low albumin, mild lymphocytosis/lymphopaenia, or he might be slightly jaundiced/high bilirubin
  
  • The best way of diagnosing FIP would be finding the virus in macrophages à would require a tissue sample or a sample of abdominal fluid

Question 5

Thoughts on these bloods?

Answer 5

• Nothing particularly worrying with RBCs or WBCs
• Low lymphocytes – more likely to be a response to vague inflammational stress
• Occasional reactive lymphocytes seen on blood smear
• Low TP
• Low albumin – marginal mild hypoalbuminaemia (could have been losing a bit of protein in diarrhoea or that he’s got a little bit of an inflammatory response going on since albumin is an acute phase protein)
  
  • Not suggestive of protein-losing enteropathy because in that case both albumin and globulins are low
  • Not severe enough to be causing ascites
• Normal globulin (might be proportionally high which could be why the TP is low)
• High urea
• Normal creatinine
• High ALT (mild elevation) – more specific indicator of liver inflammation and hepatocellular damage
  
  • AST is similar to alanine transaminase (ALT) in that both enzymes are associated with liver parenchymal cells. The difference is that ALT is found predominantly in the liver, with clinically negligible quantities found in the kidneys, heart, and skeletal muscle, while AST is found in the liver, heart (cardiac muscle), skeletal muscle, kidneys, brain, and red blood cells.
  • As a result, ALT is a more specific indicator of liver inflammation than AST, as AST may be elevated also in diseases affecting other organs, such as myocardial infarction, acute pancreatitis, acute haemolytic anaemia, severe burns, acute renal disease, musculoskeletal diseases, and trauma.
  • In terms of whether he has a primary or secondary hepatopathy, it’s more likely this is a reaction due to whatever is coming up the hepatic portal vein from his gut (the mass lesion)
• Low cobalamin (normal folate) à decreased serum folate can be due to jejunal abnormalities leading to malabsorption of folate
  
  • Increased folate can be consistent with bacterial overgrowth/dysbiosis; EPI; high intake/supplementation
  • Increased cobalamin can be due to high intake, supplementation or immunoproliferative disease
  • Decreased folate could be due to proximal SI damage, low diet intake or drugs
  • Decreased cobalamin could be due to distal SI damage, bacterial overgrowth/dysbiosis, EPI, hereditary malabsorption or low diet intake
• High monocytes
• USG 1.038 (normal) – he’s concentrating his urine very well
• Normal dipstick – not diabetic
• Low normal potassium – if we’re going to have him on fluids and if he’s not going to eat for a while we may need to supplement potassium (otherwise it will just keep going down)
• Normal glucose considering he’s a cat in a stressful situation

Question 6

How would you perform an ultrasound and what would this tell us about an abdomen?

Answer 6

• How would you perform ultrasound?
  
  • Starve patient if you have time
  • Systematic approach
  • A full scan? – cats especially
  • Sedate if necessary
• What can it tell us?
  
  • Single or multiple organs involved
  • GI tract:
    
    • Wall thickness
    • Dilated with fluid?
    • Layers:
      
      • Normal?
      • Is there a prominent muscularis layer? How would you biopsy if it is?
      • Is the mucosal layer patchy?
      • Are the layers lost?
    • Motility
  • Any fluid we can sample?

Question 7

On ultrasound we can see prominent mucosal layer around some of the gut and clear evidence of an intussusception

What are the options for Polo? include drugs e.g. GA

Answer 7

• Stabilisation
  
  • Get Polo onto fluids – be mindful of the low protein and the potassium level
• GA protocol
  
  • Pre-med – think about what ASA grade Polo fits into
  • Induction with Propofol
  • GA using Iso or Sevo
• Surgery
  
  • We need to do an exploratory laparotomy to investigate the abdomen – we could have the intussusception due to a particularly nasty tumour or something and if that’s the case we need to find that
  • We need to make the owner aware that we are not 100% sure what we will find on the exploratory laparotomy because if it turns out during surgery that euthanasia is the best option for the cat at least the owners have been warned
  • Ex lap procedure:
    
    • Midline incision
    • When it comes to exploratory surgery we have to consider contamination – it could be that there is already a peritonitis and necrosis of the intestines
    • May require extra drapes and swabs – use bigger sized swabs due to the mess created by an ex lap procedure (bigger ones are less likely to get lost in the abdomen) and always make sure to count them in and out
  • In an intussusception the intestines can become necrotic very quickly
  • Doyen clamps are atraumatic and help to prevent contamination of the abdomen
    
    • We need to empty the portion of intestine before we start making our incisions (by milking the material through)
    • We may have faecal material and/or gas in the intestines, so we can put a needle in before we make our incision to release any gas/fluid in a controlled manner
• Post-op care
  
  • Immediate
  • Short-term
  • Discharge

Question 8

Polo Histopathology

• The mass lesion in the intussusception was a benign intestinal polyp
• Histopathology on biopsies taken from a number of sites in the intussusception and from the margins of the resected tissue showed epitheliotropic (small cell) lymphoma
• The lymph node biopsy showed lymphoid hyperplasia only with no evidence of neoplasia

How could we treat?

Answer 8

• Treatment similar to IBD therapy
• Combination chemotherapy
  
  • Oral prednisolone (alternate day)
  • Oral chlorambucil (every 2 weeks)
• Cobalamin supplementation – B12 supplementation is crucial when it is as low as it was on Polo’s blood test
  
  • Without cobalamin supplementation Polo would probably have continued to deteriorate
• Monitoring – make sure weight is increasing and also making sure he is a happy cat/has a good quality of life

Question 9

What factors affecting SI wound healing?

Endogenous (6)

Exogenous (5)

Answer 9

• Endogenous factors
  
  • Nutritional compromise – may need to consider using a feeding tube
  • Hypoalbuminaemia? – probably won’t have major effect on wound healing
  • Anaemia (severity, volume)
  • Leucopenia
  • Peritonitis – he’s got a bit of fluid in abdomen but probably modified transudate due to intussusception rather than septic peritonitis
  • Age?
• Exogenous factors
  
  • Corticosteroids
  • NSAIDs – he’s a GI case and we’re not sure what we’re going to find in surgery
  • Chemotherapy
  • Radiotherapy – unlikely to be necessary with a GI tumour
  • Surgical technique

Question 10

Discuss the use of antibiotics in an exploratory laporotomy

Answer 10

• Indications
  
  • Contaminated or dirty surgery
  • Obstruction, ileus
  • Bacterial translocation (can occur due to handling of the necrotic gut)
• Choice of drug
  
  • Cephalosporin 1^st/2^nd/3^rd gen
    
    • Cefuroxime 20mg/kg IV
  • There aren’t actually many antibiotics around that we can use IV in small animals
• Route of drug
  
  • IV 30 min < surgery
• Duration of therapy
  
  • Contaminated: 24h
  • Dirty: therapeutic – 5d?