# Miniature/Toy Poodle Bloodwork: High MCV & MCH and Poodle Macrocytosis



## curlflooffan (Mar 27, 2020)

I have no experience or knowledge about this but maybe you want to have a call or an email with your vet? or if you are still unsatisfied ask for a second opnion. There might be some other reasons why she/he felt that those high values were not a cause for concern. I have had several experiences with doctors for myself where I have had a symptom that I thought was a cause for concern but then it turns out that without accompanying symtpoms or other nuance it was just fine. 

For example a few years ago I had an insect bite that became inflamed and this little red line started to form from it up my arm. If you google red line going up arm you get sepsis warnings. So I freaked and went to the doctor but the doctor immediately saw that this was just a weird allergic response and not an infenction. I have also had times when I thought something was not a big deal but it turns out it was a little. This is even though I consider myself to be very well informed, I used to work alongside nurses in the care sector and I currently work in health policy.


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## Raindrops (Mar 24, 2019)

curlflooffan said:


> I have no experience or knowledge about this but maybe you want to have a call or an email with your vet? or if you are still unsatisfied ask for a second opnion. There might be some other reasons why she/he felt that those high values were not a cause for concern. I have had several experiences with doctors for myself where I have had a symptom that I thought was a cause for concern but then it turns out that without accompanying symtpoms or other nuance it was just fine.
> 
> For example a few years ago I had an insect bite that became inflamed and this little red line started to form from it up my arm. If you google red line going up arm you get sepsis warnings. So I freaked and went to the doctor but the doctor immediately saw that this was just a weird allergic response and not an infenction. I have also had times when I thought something was not a big deal but it turns out it was a little. This is even though I consider myself to be very well informed, I used to work alongside nurses in the care sector and I currently work in health policy.


I will, but I wanted to see if others in the breed have experience with it first so that I can go into the conversation with more knowledge about my concerns. I have doubts that vets are highly experienced with breed specific issues, and this seems to be something particular to miniature and toy poodles.


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## DogtorDoctor (Mar 20, 2020)

I have no personal experience with poodle macrocytosis, but I have some general hematology knowledge that I hope will be helpful for you before you have a chance to talk further with your vet! And one hour after starting this comment, I found myself on Google Scholar and, well, now this is longer than I meant for it to be. Sorry! 😅

TL;DR: poodle macrocytosis has not been found to cause clinical disease. 

Firstly, you are 100% correct that MCH is expected to increase with MCV! There are certain instances where it doesn't, but those are generally due to some sort of interference (which hopefully would've been seen as other changes in Misha's bloodwork results). Depending on how far down the rabbit hole you want to research, this is a great website. I've linked to the section about MCH, but the explanation about MCV is linked on the sidebar to the left if you're interested. This is geared towards veterinary professionals, so I will warn that it is rather dense. 

There's also a small paragraph discussing inherited red blood cell defects on a different page that reads, "Congenital dyserythropoietic anemia (CDA) has been attributed to defects in nuclear maturation or division in human patients. [It] is likely the cause of macrocytosis in miniature and toy Poodles, although the dogs are *not anemic* (Canfield and Watson 1989). CDA results in macrocytosis, with marked erythroid dysplasia in the bone marrow." Additionally, the 1989 article found a poodle with bone marrow dyscrasia to have normal to high levels of B12.

There isn't too much to talk about in terms of new research (a total of ~3 papers in the last 20 years), but I found one 2018 article ("_Persistent reticulocytosis in a case of poodle macrocytosis_") that had this to say: "Poodle macrocytosis has been described by several authors (Schalm, Canfield) and is considered to be a hereditary condition that affects both sexes, is asymptomatic, and nonprogressive." I believe the only true way to definitively diagnose this would be by sampling Misha's bone marrow, which I would be personally against doing in an otherwise healthy dog, but hopefully this will help put your mind at ease until you can talk with your vet!

Some questions I would have for you vet would be: 1) Is there a possibility of artifact (due to lipemia, sample handling, their machine, etc.), and 2) Was a blood smear performed (to confirm macrocytosis and rule-out other hematologic abnormalities)? 

Sorry again for how long this is, but I hope that you find some of it useful!


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## Raindrops (Mar 24, 2019)

DogtorDoctor said:


> I have no personal experience with poodle macrocytosis, but I have some general hematology knowledge that I hope will be helpful for you before you have a chance to talk further with your vet! And one hour after starting this comment, I found myself on Google Scholar and, well, now this is longer than I meant for it to be. Sorry! 😅
> 
> TL;DR: poodle macrocytosis has not been found to cause clinical disease.
> 
> ...


Thank you so much! This is very helpful. I really appreciate your expertise. I am a biologist so I am fairly good with research but I do feel some limitations when it comes to medical things, so it is wonderful to hear from somebody more knowledgeable. I'll check out the linked website. Glad that the MCH is linked and isn't indicative of an additional issue. I was also surprised at the lack of papers. Everywhere just mentions it is a breed issue and cites two other papers, so there's not much to go on. I'll attach a copy of the bloodwork so you can see, but it is indicated that there is no significant interference from lipemia. It says there was a blood smear reviewed by the technologist, though no notes other than that.

So glad the hereditary condition is known to be asymptomatic. I felt it would be good to document on here so that other poodle people can see if they experience the same issue.

Another note about the attached results... the BUN is very high but I know that's expected since he ate soon before the blood draw and has a lower Creatinine. The globulin's a bit perplexing to me but I'll see what vet thinks.


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## Liz (Oct 2, 2010)

Raw fed dogs tend to have high hematocrit values, which can elevate MCV. The relationship with MCH is escaping me at the moment and I can't google as I'm on a zoom call....


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## Raindrops (Mar 24, 2019)

Liz said:


> Raw fed dogs tend to have high hematocrit values, which can elevate MCV. The relationship with MCH is escaping me at the moment and I can't google as I'm on a zoom call....


Thanks for the insight! He does have a high hematocrit though it's within the normal range so that could be contributing to the high MCV. I hadn't heard anything specifically about MCV and raw, but it would make sense if that's also elevated. His MCV is so high that it kind of threw me off.


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## Liz (Oct 2, 2010)

MCV and MCH are calculations based on the other indicia and should be used along with the other numbers to determine if there's a problem. In other words, one or two numbers don't tell the whole story; you have to read the full panel. It's a bit like trying to figure out what image a jigsaw puzzle makes by looking at one or two pieces: you can't.

MCV is calculated from hematocrit and RBC; MCH from hemoglobin and RBC. And reference ranges are determined by kibble fed dogs, so the values differ because of hydration and protein quality.

Sounds like your vet is on top of it. It's always a bit scary when you see a number outside the reference range, but in this case the culprit is probably a high quality raw diet fed to a completely healthy and highly photogenic dog.


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## Raindrops (Mar 24, 2019)

Liz said:


> MCV and MCH are calculations based on the other indicia and should be used along with the other numbers to determine if there's a problem. In other words, one or two numbers don't tell the whole story; you have to read the full panel. It's a bit like trying to figure out what image a jigsaw puzzle makes by looking at one or two pieces: you can't.
> 
> MCV is calculated from hematocrit and RBC; MCH from hemoglobin and RBC. And reference ranges are determined by kibble fed dogs, so the values differ because of hydration and protein quality.
> 
> Sounds like your vet is on top of it. It's always a bit scary when you see a number outside the reference range, but in this case the culprit is probably a high quality raw diet fed to a completely healthy and highly photogenic dog.


Thanks! That makes sense then. So it may or may not be the breed issue causing it. Possibly both I guess.

He is very photogenic so that has to be a contributing factor


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## DogtorDoctor (Mar 20, 2020)

Raindrops said:


> I was also surprised at the lack of papers. Everywhere just mentions it is a breed issue and cites two other papers, so there's not much to go on.


Yeah, it can be fairly frustrating for some of the less common conditions, especially if there isn't a detrimental effect on affected animals. As funding is rather limited, most research is towards either things that are widespread or things that are deadly/life-altering. I do find it interesting that we aren't taught about breed-related macrocytosis, since we cover macrothrombocytopenia in CKCS quite extensively. I was actually very happy to have the chance to look into it!



Raindrops said:


> I'll attach a copy of the bloodwork so you can see, but it is indicated that there is no significant interference from lipemia. It says there was a blood smear reviewed by the technologist, though no notes other than that.
> 
> Another note about the attached results... the BUN is very high but I know that's expected since he ate soon before the blood draw and has a lower Creatinine. The globulin's a bit perplexing to me but I'll see what vet thinks.


I was able to see that the technologist referred to the blood smear as "WNL," which stands for "within normal limits." That means that s/he did not see any obvious abnormalities (normally including hemoparasites and changes to red and white blood cell indices). There is a quantified acceptable size for red blood cells, so theoretically the tech would be able to tell if there was a majority of cells that were "too large" or had irregular pallor to them.

Liz brought up some great points that I was unaware of! I'm not used to reading raw-fed bloodwork, but it makes total sense that there are values that are different from those of kibble-fed dogs. There is a frustrating lack of information out there about expected and normal changes in raw fed animals, so this is great education for me, haha. If you are ever concerned about Misha's kidneys in the future, there is a more sensitive renal test called SDMA (I believe only available through IDEXX) that is less likely to be affected by diet. Hopefully you don't need to worry about that for a very long time, if ever!

Increased globulins are a rather nonspecific finding and can be elevated with inflammatory processes or just simple dehydration. Since your vet has the whole picture, definitely bring it up with them, but I agree with Liz that it sounds like Misha is healthy (and adorable).


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## PeggyTheParti (Sep 5, 2019)

Um, I might need you all to weigh in on _my_ bloodwork!! Wow! What a fantastic thread. 

Glad to hear our beloved Misha's in good health, Raindrops.


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## Liz (Oct 2, 2010)

If you find any good studies @DogtorDoctor please share them. I'm googling right now, and all that's coming up for me is the same Hemopet study showing elevated BUN, creatinine, and hematocrit in raw fed dogs.


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## Raindrops (Mar 24, 2019)

Liz said:


> If you find any good studies @DogtorDoctor please share them. I'm googling right now, and all that's coming up for me is the same Hemopet study showing elevated BUN, creatinine, and hematocrit in raw fed dogs.


Yeah, I had read about this though his creatinine was low which was a bit unexpected. It is hard since raw diets can be quite different from each other so I don't know if the blood results are comparable. I would like to do bloodwork yearly for him along with titer tests, so it will be interesting to see how things change.


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## Liz (Oct 2, 2010)

@Raindrops There used to be a good forum to discuss feeding raw. I think it was called DogFoodForum. But there was a schism and one of the mods left to form PreyModelRaw, which never really took off. If you search the archives on DFF, you might find good info about bloodwork. Of course, it's all anecdotal and every prey model raw diet is different, but it's all we have until someone publishes research into noncommercial foods.


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## DogtorDoctor (Mar 20, 2020)

I was able to find two articles that aren't horrible, @Liz. Unfortunately, it looks like more research just isn't out there yet. I still have university access to articles, so I'm hoping that you are able to use the links to see the full articles if you want to read the rest of them.

Article 1 was published in JAVMA in 2013. There is a single paragraph discussing chemistry and CBC abnormalities, which I have quoted for your convenience.
"Even in otherwise healthy dogs and cats eating raw meat-based diets (RMBDs), serum biochemical values may deviate from laboratory reference ranges. Serum albumin and cholesterol concentrations were higher than the reference ranges in cats fed an RMBD, compared with concentrations for those fed dry extruded diets. In a study in dogs, those eating an RMBD had significantly higher concentrations of BUN and serum creatinine and a higher Hct, compared with results for control dogs that were assumed to be eating commercial dry extruded diets or moist pet food diets."
The study to which they refer is by Wynn SG, Bartges JW, Dodd WJ, and I was unfortunately unable to find it anywhere.
I could not find who funded this study, nor any disclosed conflicts of interest. The authors are boarded nutritionists and internists from various veterinary schools in the United States and one in Scotland.

Article 2 was published in the Journal of Animal Science in 2018 and is a bit more interesting. This one was much more in-depth about biochemical changes due to diet. The results of serum metabolite differences can be found in this table. Let me know if the link doesn't work for you and I can screenshot it.
The only comment made in the discussion that I felt was relevant to our main question was as follows: "Most metabolites remained within reference ranges throughout the study. The serum triglyceride results were curious, however. Interestingly, the dogs fed the kibble diet had much higher serum triglyceride concentrations than the dogs fed the raw and mildly cooked diets despite containing a much lower fat content." The concluding paragraph stated: "In conclusion, all diets tested in this study were well tolerated and dogs remained healthy throughout the study. The mildly cooked and raw diets were highly palatable and maintained fecal quality and serum chemistry measures. Compared to the extruded diet, these diets had greater nutrient digestibility, resulted in reduced blood triglyceride concentrations, and shifted fecal microbiota populations and metabolite concentrations."
The study was funded by Freshpet and the authors didn't list credentials, although it was presented at the American Academy of Veterinary Nutrition Clinical Nutrition and Research Symposia.


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## Liz (Oct 2, 2010)

The Wynn et al. study is likely the Hemopet study (Dodds = Jean Dodds). The Freshpet study is helpful. Nice to see that conclusion supported.


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## DogtorDoctor (Mar 20, 2020)

Yep, I thought so too! Hopefully there will be more funding as the raw industry grows. Although, from this study, it looks like any changes should be very minor, which is great!


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## Raindrops (Mar 24, 2019)

Yes, I wish there were more legitimate studies out there. I know the BUN of wild wolves also averages quite high so it is sensible for that stat to be higher. Thank you guys so much for the discussion. It has been so helpful.


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