scott@vtx-cpd.com

Replying to Rosemary S. 01/11/2021 - 11:25

Hello.

Thank you for your brilliant question.

Bone marrow suppression, especially anaemia, is the most common clinical syndrome associated with FeLV infection, resulting from infection of both hematopoietic stem cells and bone marrow stromal cells. Most commonly anaemia will be non-regenerative. Progressive infection with active viral replication is usually required for bone marrow suppression. Regressive infection is only rarely associated with myelosuppression. Thus, in a FeLV antigen-negative cat with bone marrow suppression, testing bone marrow for FeLV by PCR is only sometimes helpful. The most common form of FeLV-induced anaemia is pure red cell aplasia, a severe nonregenerative anaemia with marked depletion and maturation arrest of erythroid precursors in the bone marrow (with the characteristic finding of a lack of reticulocytes but a high mean corpuscular volume [MCV]). Regenerative anaemia in FeLV-infected cats, indicated by increased reticulocytes and, in some cases, nucleated red blood cells (RBCs), is less common than nonregenerative anaemia and is often associated with coinfection with Mycoplasma haemofelis or other haemotropic Mycoplasma spp..

Some cats with immune-mediated haemolytic anaemia are progressively FeLV-infected, and in some, haemolysis precedes the emergence of myeloproliferative disease or lymphoma. This would be a specific reason to test in these cases.

Even if myeloproliferative disease was not to develop in these cases, the would be possible management benefits of knowing the FeLV/FIV status:

1. Progressively FeLV-infected cats should be kept indoors to avoid spread to other cats and exposure of the cat to other infectious agents carried by other animals.

2. “Routine vaccination programs” should be maintained in cats with progressive FeLV infection. They might not be able to mount an adequate immune response to vaccines and protection might not be comparable to that in a healthy cat. Therefore, testing for the immune response (e.g., antibody measurement after feline panleukopenia virus vaccine) and protecting against exposure should be considered.

Hope that helps a little.

Scott 🙂

• This reply was modified 3 years, 4 months ago by scott@vtx-cpd.com.

Replying to Rosemary S. 01/11/2021 - 11:30

Hey.

Really good question. I hope you are safe and well. The reasoning behind prophylactic use of omeprazole will be different between the Palladia and the NSAIDs. I presume the reasoning behind the use of omeprazole prophylactically with the Palladia will be to prevent gastrointestinal side effects. Although the NSAIDs will also cause gastrointestinal side effects, the mechanism of this is different with both drugs.

I must admit… I had to phone a friend with the actual answer to this question! I spoke to two oncology specialist colleagues, neither of them use omeprazole prophylactically with Palladia. If there is gastrointestinal upset with this drug, it is unlikely that the modification of gastric pH will help the situation. An antiemetic possibly, but often the drug has to be withdrawn.

Hope that helps a bit.

Scott 🙂

Replying to Becky Cooper 01/11/2021 - 15:17

Hello.

I hope you are well. It was indeed! We had to do a bit of editing… not sure everyone needed to hear my social catch up with Mairi at the beginning!

Will be uploaded in the next couple of days.

Hope you are enjoying the course.

Scott 🙂

Replying to Synnove S. 27/10/2021 - 08:23

Synnove.

Thank you so much for your question and your kind words.

Regarding bladder wall culture, this really has to be a tissue biopsy. Taking a roll prep from the bladder wall surface would probably still only represent what was going on in the bladder. The culture really has to be from the tissue to get an understanding of what is going on in the actual bladder wall. This can be done with surgical or cystoscopic biopsies.

The main issue with treating the inflammation and not infection is that there are many other factors at play regarding host immunity that will also be dealing with the infection. Whether bladder colonization causes clinical disease ultimately depends on bacterial gene expression. Bacteria contain genomic islands encoding fitness factors that promote commensalism and/or virulence factors and dictate the severity of the UTI.

The NSAIDs are just dealing with the inflammation. The hope would be that multiple other body factors will be dealing with the infection. There is no doubt that these situations when there are clinical signs, will require antibiotics.

I hope that helps.

Let me know if you have any other questions.

Scott 🙂

• This reply was modified 3 years, 4 months ago by scott@vtx-cpd.com.

Replying to elaine elder 12/10/2021 - 17:52

Hey Elaine!

They do indeed! Various studies have shown that α2-agonists reduce the perioperative levels of stress-related hormones and thus attenuate the stress response of surgery in dogs. Alpha2-agonists, typically xylazine, have been reported to induce an increase in serum glucose by suppressing insulin release, stimulating glucagon release, or both, in β and α cells of the pancreas, respectively. However, medetomidine given at doses of 10 and 20 μg/kg BW, IV, decreased insulin values significantly but was not found to alter plasma glucose concentrations in normal beagles. Differences in plasma glucose concentrations are likely associated with the greater specificity of medetomidine, compared with that of xylazine, at the α2-adrenoreceptors. The hyperglycemia associated with xylazine has been attributed to the actions at both the α2- and α1-adrenoreceptors.

The following study did demonstrate this effect in cats:

Effects of dexmedetomidine on glucose homeostasis in healthy cats

Abstract

Objectives
Alpha(α)2-agonist administration has been documented to increase blood glucose concentrations in many species. The aim of this study was to further describe the effect of dexmedetomidine on glucose and its regulatory hormones in healthy cats.

Methods
A randomized crossover study using eight healthy cats with a 14 day washout period was used to assess the effect of dexmedetomidine (10 μg/kg IV) and saline on glucose, cortisol, insulin, glucagon and non-esterified fatty acid (NEFA) concentrations at 0, 20, 60, 120 and 180 mins post-administration. Glucose:insulin ratios were calculated for each time point.

Results
Within the dexmedetomidine group, significant differences (P <0.05) were detected: increased median (range) blood glucose concentrations at 60 mins (11.55 mmol/l [5.9–16.6 mmol/l]) and 120 mins (12.0 mmol/l [6.1–13.8 mmol/l]) compared with baseline (6.05 mmol/l [4.8–13.3 mmol/l]); decreased glucagon concentrations at 120 mins (3.8 pmol/l [2.7–8.8 pmol/l]) and 180 mins (4.7 pmol/l [2.1–8.2 pmol/l]) compared with baseline (11.85 pmol/l [8.3–17.2 pmol/l]); decreased NEFA concentrations at 60 mins (0.281 mmol/l [0.041–1.357 mmol/l]) and 120 mins (0.415 mmol/l [0.035–1.356 mmol/l]) compared with baseline (0.937 mmol/l [0.677–1.482 mmol/l]); and significantly larger (P <0.05) glucose:insulin ratios at 60 mins compared with baseline. Insulin and cortisol concentrations were not significantly changed after dexmedetomidine administration.

Conclusions and relevance
Feline practitioners should be aware of the endocrine effects associated with the use of α2-agonists, particularly when interpreting blood glucose concentrations. The transient effects of dexmedetomidine on glucose homeostasis are unlikely to significantly affect clinical practice.

Hope that helps.

Scott 🙂

Replying to Rebecca C. 18/10/2021 - 19:16

Hello again.

Hope you are safe and well. I have popped some thoughts down regarding your other questions too:

The amount of blood vs. EDTA can definitely have am effect on the sample. What tubes do you use. It might be having a chat with the lab/manufacturer about the variability. Collection of a small blood volume with placement into a standard EDTA tube will cause shrinkage of red blood cells, because EDTA is hypertonic. This will cause a false decrease in the mean cell volume (MCV) and false increase in mean cell hemoglobin concentration (MCHC) of red blood cells. Crenation of red blood cells (echinocyte formation) will also be evident on the blood smear. This is a common artifact that we see in hematologic samples. Too much blood compared to EDTA will increase the risk of clot formation.

There is not an exact gauge guideline. Venipuncture should be minimally traumatic to minimize platelet activation and should be done using a minimum of a 23G needle, 21-22G is also fine for small animals. I would not go lower than 23G.

Regarding smears; any smears (blood or FNA) are best kept out the fridge once air dried. It is best to get them to the lab (as with everything) as soon as possible.

Hope that helps. Let me know if you have any questions.

Scott 🙂

Replying to Lesley M. 25/10/2021 - 19:46

Hey!

No pressure to speak. I am just conscious that I sometimes speak too muck and want to make sure people have time to ask questions too.

Hope you enjoyed the session.

Scott 🙂

Replying to Anisha A. 14/10/2021 - 15:21

Hello Anisha.

I hope you are safe and well.

I will make sure to ask Felipe this question tonight at the Q&A.

Hope you are enjoying the course.

Scott 🙂