scott@vtx-cpd.com

Great question.

I have made some comments under your text below. I did not want to miss anything!

A 13yo MN PWD presented for multiple diarrhoea episodes (5 within the same day) and lethargy. He is on long term meloxicam for management of OA. No other historical abnormalities noted. The diarrhoea contained. No melena or haematochezia and were judged to be a normal colour. His vet opted to run full CBC and Biochemistry. Clinical examination all wnl apart from pale pink mms.

So, I wonder whether there could be a degree of GI bleeding. The absence of melena does not rule out GI bleeding. In humans, it has been experimentally determined that at least 50 to 100 mL of blood must be ingested before melenic (is that a word?!) stool is appreciated. Normally with chronic GI bleeding the anaemia would ne microcytic and hypochromic. I would definitely consider a faecal occult blood in this patient.

We know the severity of the anaemia will influence the degree of response we get from the bone marrow. His anaemia is mild and so his response would also be mild. However 2 weeks down the line and he is still mildly anaemic (would expect an adequate response in 3-5d), he has never had a reticulocytosis.

I think that what you were seeing on the blood smear was quite appropriate for the degree of anaemia. You are right, the anaemia is mild. The 3-5 day mark is more relevant for haemolysis/bleeding. In the context of this case the anaemia is more likely to be due to chronic inflammatory disease. This could be the OA or even something diagnosed. Inflammatory cytokines suppress erythropoiesis, erythropoietin release, and response to erythropoietin, and sequester iron via hepcidin. This cytokine release will be ongoing and will be the reason you are not seeing the anaemia ‘bounce back’.

The question is in older dogs would we expect a reduction in an ability to respond to anaemia or do we investigate this dog further, for a cause? likely as a mild, non-regenerative anaemia?

This is a great question. This definitely a thing in people:

https://pubmed.ncbi.nlm.nih.gov/31230730/?from_term=anemia+response+with+ageing&from_pos=3

I cant find any evidence to say that this is something we worry about in dogs and cats. As with many things, our patients probably don’t live long enough to have some of the issues ageing people do. I would not worry about an anaemia of this degree if the dog is well. I would be looking for a focus of chronic inflammation if I was to investigate and would consider bone marrow biopsy if looking non-regenerative.

Hope that helps.

Scott 🙂

Hello again.

My general recommendations would be:

1. An isotonic, oligomeric, fat-restricted liquid diet can be fed initially, with a gradual transition first to a polymeric liquid diet and then to an easily assimilated, fat- and fiber-restricted diet. I have recently been discussing with Hills their new microbiome diet. I wonder if this might be a good option here?

2. Malabsorption of fat- and water-soluble vitamins and minerals also can occur, and dietary or parenteral supplementation could be required. Parenteral cobalamin supplementation is essential if the ileum has been resected. I would consider Cobalaplex (Protexin). I think this is a good option as there is a probiotic as well as folate too.

3. Proton pump inhibitors can be used in the postoperative period to counteract possible hypergastrinemia.

4. Antimicrobial agents can be necessary if the ileocecocolic junction has been resected or if secondary SIBO is suspected. If metronidazole has not been helpful I would consider tylosin at 10mg/kg TID. This comes in powder form and has to be made up in gelatin capsules (which is obviously a massive pain). The alternative is to get the re-formulated tablets from Summit Medical.

5. If the response to diet and antibiotics is poor, antisecretory agents (loperamide, diphenoxylate, or octreotide) could be required. Bile salt binding resin (e.g., cholestyramine) might help reduce colonic secretion caused by bile salts malabsorbed after ileal resection; ursodeoxycholic acid has been shown to enhance intestinal adaptation in a feline surgical model.

Hope that helps.

Scott 🙂

Hello.

So sorry for delay! Can I ask a couple of further questions?

1. Any improvement with consistency with the addition of metronidazole?
2. Would you mind sharing the details of the histopathology?
3. How much intestine in total do you think you removed?

Scott x

Hey.

I think it is almost impossible that it could be the Cobalaplex (which I think it is a good idea by the way!).

Could it be a build up effect of using the Aktivait? Problem with that theory would be that you would have to take him off it too see. It could also be doing him a lot of good and we would not want to risk making him worse in other ways.

I suppose it could also just be an ageing change in itself?

Scott x

You are right. It is definitely a thing and quite well recognised now.

Let me know how the treatment goes.

I found another useful review:

https://pubmed.ncbi.nlm.nih.gov/22720812/?from_term=feline+cognative+dysfunction&from_pos=1&from_exact_term=feline+cognitive+dysfunction

Scott 🙂

Amazing answer Simon. Could not have said it better myself!

Let me know if you have any other questions.

Scott 🙂

So… based on the clinical presentation my neurology specialist pal made the following comment:

“Although cerebellum is compatible with some of the current clinical signs, the fact that he also was unresponsive and no proprioception may indicate that the brainstem is also affected. Either way, I agree with you that intracranial seems the most likely. As you said, ischaemic encephalopathy and neoplasia sound like the most likely differential diagnosis… There may be a potato arising/compressing the caudal fossa (brainstem +/- cerebellum)”.

I will follow up at the clinic and see if I can get more information about the actual case outcome.

Hope that helps.

Scott x