Older Horse Mystery Weight Loss and Mental Confusion

[StormyDay]

Sorry for the novel.
TLDR: 22YO OTTB with spooky behavior change and weight loss, no liver/kidney/protein issues, eating a LOT of food.

I took on a 22 YO OTTB last spring. He was a bit underweight but not terrible. Mostly just not a ton of top line. He had to have some teeth pulled and basically has no upper front teeth. Over the summer he just hung out; plan was for him to gain weight over the summer and then I’d put him into work sometime in the winter so that he could go get leased out in the spring. He’s a really good guy, has all the buttons, and would love a kid to pack around over poles and cross rails.
He gained weight well, but slowly as one would expect with an older OTTB, over the summer and early fall on 4 pounds TC Senior Gold (plus a 1/2 pound ration balancer since it wasn’t quite enough for the minerals) and grass. As winter set in (mid November) I started feeding free choice 2nd cut hay and upped his grain to 6 pounds. At the beginning of December I noticed he was dropping a bit of weight, so I added two more pounds of TC Senior Gold, plus a cup and a half of oil. I also kept him in for 24 hours with the hay he gets outside to make sure he was eating ok. He ate about 25 pounds in that amount of time. (And I wouldn’t be surprised if he actually eats more when out with his buddies; he was a bit concerned about being inside for that time). Total estimated calorie consumption per day is 38,000.
Right after Christmas I pulled his blankets off after our cold spell and went ‘woah. What the heck?’ He looked like he had lost 50 pounds in a week.

Well, then on Sunday night he acted strange. Like he couldn’t figure out where the gate was to go to his stall. He was whinnying for his grain but couldn’t seem to find the door. I thought it was weird but didn’t think much of it. Then the next day he was afraid of his feed bucket and me.

Had the vet out, and she agreed this was very weird. He is getting more than enough calories. All of the other ancient ones are looking very nice on this hay, and clearly he was eating it no problem. His behavior had also changed considerably; very twitchy, scared of everything. This was the horse who didn’t spook at anything and was so, so chill. Teeth are still missing but no worse. No issues with any of the neuro exam. However, he has a grade 3/5 heart arrhythmia which is new since he was vaccinated in October.

The results for his liver, kidney, and protein levels came back normal. We are testing for EPM but the results won’t come back until next week. He has no incoordination, ataxia, isn’t lame, stiffness, etc. None of the symptoms I’ve seen with it. Cushings comes to mind, but doesn’t explain the behavior change and besides being skinny he has no other symptoms of that either.

Hes UTD on vaccines, was dewormed twice this fall, no previous known injuries or issues.

Thoughts? Maybe I’m just on edge but I’m dreading this ends with me digging a very large hole. I’ve lost one cat in the past three months and another is currently on her last days. I can’t take 2023 and it’s only 4 days in!

[Amy3996]

Did your vet assess his vision? That comes to mind with spookiness and disorientation. Possibly test for Lyme?

I may be in the minority here, but 8lbs of feed for a 22yo doesn’t sound that outlandish. Could you give him a lunch and bump those calories up even more? Early 20s isn’t out of the realm of possibility for reduced digestive efficiency.

[SummerRose]

Is malabsorption syndrome a possibility? If the horse is not absorbing the nutrients from his food, that can cause deficiencies that may lead to behavioral changes and dementia. If it hasn’t been ruled out, I think it’s something that would be worth discussing with your vet.

Unfortunately, this is what ultimately led to the loss of my elderly mare. She was eating well but dropping weight rapidly. She did not have any issues with dementia but even eating well, she was losing weight fast. Hopefully this isn’t your horse’s issue but it’s something to consider.

[StormyDay]

@Amy3996

Did your vet assess his vision? That comes to mind with spookiness and disorientation. Possibly test for Lyme?

I may be in the minority here, but 8lbs of feed for a 22yo doesn’t sound that outlandish. Could you give him a lunch and bump those calories up even more? Early 20s isn’t out of the realm of possibility for reduced digestive efficiency.

Yes vision was checked, no issues that could be seen there.
I wish I could, but he won’t eat more. I actually tried to go up to 10 lbs (4 morning 6 night) and he would just leave about half the morning grain.

[StormyDay]

@SummerRose

Is malabsorption syndrome a possibility? If the horse is not absorbing the nutrients from his food, that can cause deficiencies that may lead to behavioral changes and dementia. If it hasn’t been ruled out, I think it’s something that would be worth discussing with your vet.

Unfortunately, this is what ultimately led to the loss of my elderly mare. She was eating well but dropping weight rapidly. She did not have any issues with dementia but even eating well, she was losing weight fast. Hopefully this isn’t your horse’s issue but it’s something to consider.

I’m not very familiar with it, and I can’t seem to find a lot of info online. Do you know if there’s other common symptoms?

[SummerRose]

Here are some articles that discuss malabsorption syndrome:

eve-8-6-mair.pdf

If the disease
process is limited to the small intestine, then weight loss may
be the only clinical sign, and it becomes important to rule out
other causes of weight loss. Although malabsorption
syndromes affect the digestion and absorption of
carbohydrates, protein and fat, diagnostic tests in the horse
usually concentrate on dysfunction of carbohydrate
digestion/absorption. Determination of inadequate fat
absorption is of limited importance in the horse, although
malabsorption of fat soluble vitamins may result in clinical
conditions, such as dermatitis, neurological diseases, and
retinal dysfunction. Increased protein loss from the intestine
(protein-losing enteropathy) is more commonly associated
with large intestinal disease due to the larger surface area of
the equine large intestine. However, concurrent small
intestinal malabsorption and significant protein-losing
enteropathy are likely to cause severe and rapid weight loss.
Apart from weight loss, other clinical signs seen in horses with
infiltrative intestinal diseases include colic, lethargy, dermatitis,
diarrhoea and dependent oedema

https://beva.onlinelibrary.wiley.com/doi/abs/10.1111/j.2042-3292.2006.tb00466.x

Malassimilation Syndromes in Large Animals - Digestive System - Merck...

Intestinal Disorders Other than Colic in Horses - Horse Owners - Merck...

Signs of malabsorption and maldigestion vary, depending on the underlying disease condition. Insufficient energy, weight loss, and possibly low blood protein concentrations are characteristics of these syndromes. Longterm weight loss, muscle wasting, or a reduced growth rate are common. Excessive eating may be seen, because the nutrients that are taken in do not effectively stimulate the brain areas that normally indicate fullness. More commonly with small-intestinal malabsorption, loss of appetite is present. Diarrhea may occur; however, small-intestinal disease may be extensive before diarrhea develops because the large intestine can compensate and absorb the increased fluid. In adult horses, diarrhea usually indicates large-intestinal disease.

Abnormal pain may result from bowel inflammation, abscesses, adhesions, or partial obstruction. Abnormal fluid buildup under the skin (edema) or in the abdomen (ascites) and weakness may develop later in the disease, especially if protein loss is present. Skin and eye abnormalities, arthritis, and liver or kidney disease may indicate immune system reactions, particularly with inflammatory bowel disease. Skin abnormalities seen with malabsorption-related skin disease include a thin hair coat, patchy hair loss, and areas of scaling and crusting that are often symmetrical.

Small-intestinal malabsorption cannot be determined by physical examination or by routine laboratory data.

investigating-equine-weight-loss-suspected-gastrointestinal-disease.pdf

I’m hoping that your horse’s weight loss turns out to be caused by something easily identifiable and treatable. I’ve been lucky enough to have some great horses live to ripe old ages but keeping the oldsters healthy and happy can be a challenge. Worth it, IMO, but definitely bittersweet sometimes.

[punchy]

My former Cushings pony had dementia. Might be worth testing for it, although it does seem odd that your horse wouldn’t have the seemingly usual ‘cushings coat.’ Speaking of, if he’s blanketed, maybe that problem isn’t as easy to see? Can you feel an undercoat that feels dense and healthy?

I also seem to recall my vet telling me that the season change was instrumental in onset/acceleration, but it was all a long time ago and I could be wrong about that.

[NancyM]

I acquired an older mare years ago now, and was pretty sure that dimentia or senility did become a problem. We put her down. Have known lots of older horses over the years, have never seen another case like this one old mare… So it’s not a common thing.

[carman_liz]

I had a gelding that started acting weird. Freaking out with me next to him like I always was while he ate or grooming him, running thru my tape gate and broke a ton of fence posts one evening. He was getting vision issues but his issues were more dementia type things. Kicked out randomly, would spook over nothing. He kept weight though. That started in the fall, I let him go in late spring when he always had the ‘I’m tired mom’ look that let me know it was time before the insanely hot summer temps started.

What about a cancer bloodwork type test? Any swelling thru the chest or any other areas? I hate to have to ask that, but weight loss out of the blue when he is eating everything you give him and always has hay in front of him sounds ominous. I am so sorry you are going thru this, I hope a vet can get you answers and he starts gaining weight back soon for you

[carman_liz]

Back to add a silly question…I know ottbs are hard keepers sometimes and we just had that insane cold snap…but, when was the last time a fecal was pulled? If he is eating everything in sight and worms in his intestines are eating it then he will mever gain the weight back.

A good dose of whatever appropriate wormer based on a fecal might be an easy peasy solution that was missed but easily fixed?

[2tempe]

When you mentioned heart arrhythmia - is it a murmur or is it A-fib?
I had an older TB gelding who was diagnosed with both at about 17. No symptoms, they were found during an ordinary evaluation. I was told to watch for lethargy, exercise intolerance, weight loss.

He was fine for quite a long time and remained in light work until about 24. There came a time where he was “not there” mentally - different than yours, but staring into space, ignoring his people, and he was dropping weight while eating plenty. Then one day he had ventral edema; vet said heart sounded like a “sneaker in the dryer”. We put him down several days later.
Only a non-vet opinion here, but there may be a connection between the heart issue and other issues.
Do yo have easy access to a clinic where he could get heart ultrasound, EKG etc? OR can your vet do the heart ultrasound at his barn? It may help you get some answers.

[StormyDay]

@punchy

My former Cushings pony had dementia. Might be worth testing for it, although it does seem odd that your horse wouldn’t have the seemingly usual ‘cushings coat.’ Speaking of, if he’s blanketed, maybe that problem isn’t as easy to see? Can you feel an undercoat that feels dense and healthy?

I also seem to recall my vet telling me that the season change was instrumental in onset/acceleration, but it was all a long time ago and I could be wrong about that.

His coat seems totally normal. He’s actually been without a blanket for 4 days now because it’s randomly 65 degrees here, and still no signs of anything different than usual

[StormyDay]

@carman_liz

I had a gelding that started acting weird. Freaking out with me next to him like I always was while he ate or grooming him, running thru my tape gate and broke a ton of fence posts one evening. He was getting vision issues but his issues were more dementia type things. Kicked out randomly, would spook over nothing. He kept weight though. That started in the fall, I let him go in late spring when he always had the ‘I’m tired mom’ look that let me know it was time before the insanely hot summer temps started.

What about a cancer bloodwork type test? Any swelling thru the chest or any other areas? I hate to have to ask that, but weight loss out of the blue when he is eating everything you give him and always has hay in front of him sounds ominous. I am so sorry you are going thru this, I hope a vet can get you answers and he starts gaining weight back soon for you

I’ll ask about the cancer bloodwork if EPM comes back negative. The vet pulled extra in case we had to run more tests. No swelling. Other than being underweight he looks completely healthy.

[StormyDay]

@carman_liz

Back to add a silly question…I know ottbs are hard keepers sometimes and we just had that insane cold snap…but, when was the last time a fecal was pulled? If he is eating everything in sight and worms in his intestines are eating it then he will mever gain the weight back.

A good dose of whatever appropriate wormer based on a fecal might be an easy peasy solution that was missed but easily fixed?

I have not had a fecal pulled. I certainly can add it to the list of things to check. I dewormed him with two different kinds of dewormer this fall; ivermectin when the flies died, and pyrantel pamoate in early December.

[carman_liz]

Don’t quote me, but I think…only super ammie minded think…that quest plus is the only thing that kills strongylyes. Without a fecal you won’t know if he has those and that could be very easy to treat. The quest plus has Moxidectin that other wormers do not.

Since its introduction as an equine dewormer in the U.S. in 1997, moxidectin has been represented as having 2 major advantages over ivermectin equine dewormers: Longer fecal egg suppression (84 days vs. 56 days) and Effectiveness against encysted small strongyles (cyathostomes) .

Either that or it could be the heart thing. A person on here, mentioned sweeping the blood out of the jugular and watching to see if it backfills because thats a big heart problem symptom. Here is the screenshot of her advice that I saved to show my vet when I had my rescue mare for a short 1.5 months. We had to put her down because she was not gaining weight no matter what we gave her. She also had other issues, and had swelling in her chest between her legs, essentially if you were to feel for a sweaty chest between the legs then go about 6 inches up. It looked like a chickens 2 breasts and I could feel the ‘cutlets’. We did the sweep test, backfilled immediately, and she just was going downhill. I chose to give her one really good day before a really bad day happened. Sorry for the yellowstone youtube thumbnail in the screenshot…I was multitasking haha.

[StormyDay]

@2tempe

When you mentioned heart arrhythmia - is it a murmur or is it A-fib?
I had an older TB gelding who was diagnosed with both at about 17. No symptoms, they were found during an ordinary evaluation. I was told to watch for lethargy, exercise intolerance, weight loss.

He was fine for quite a long time and remained in light work until about 24. There came a time where he was “not there” mentally - different than yours, but staring into space, ignoring his people, and he was dropping weight while eating plenty. Then one day he had ventral edema; vet said heart sounded like a “sneaker in the dryer”. We put him down several days later.
Only a non-vet opinion here, but there may be a connection between the heart issue and other issues.
Do yo have easy access to a clinic where he could get heart ultrasound, EKG etc? OR can your vet do the heart ultrasound at his barn? It may help you get some answers.

I don’t know; she just said it was a 3/5 arrhythmia. But I’m thinking maybe I misremembered and it was a murmur.
I know that heart issues can definitely cause weight loss… I’m just not sure if the issue is secondary to the weight loss or is causing it.
I’m near a clinic, but realistically, I’d PTS before I start diving down the rabbit hole. There’s really nothing they can do if it is a heart issue, so if we rule out treatable causes….

[JB]

@StormyDay

His coat seems totally normal.

A lot of people think the stereotypical PPID coat is needed to think PPID, but that’s one of the more advanced symptoms in most cases. I would absolutely get him tested for PPID and Lyme disease. Like this week if at all possible.

@carman_liz

but I think…only super ammie minded think…that quest plus is the only thing that kills strongyles.

Ivermectin and moxidectin both kill adult strongyles

If you’re thinking about encysted strongyles, then while resistance has limited this to a large degree, there are still places where a Power Pack (5 days of double dosed fenbendazole) is effective

[carman_liz]

That is probably what I was thinking of. Like I said, my super ammie thought process which was my version of a disclaimer about it. I just thought run a fecal in case it is a super basic hey he needs to be wormed issue. Always appreciate your nutritional and medical knowledge thank you!! (Not being snarky, totally honest in my respect for you!)

[StormyDay]

@Amberley

A simple and cheap thing you could do is put him on Red Cell. I’ve seen some miraculous improvements in the older guys on that. If he’s low on B12 it would explain his behavior.

K, I ordered it. I’ve never actually seen a horse low in B12 but I guess anything is possible!

[StormyDay]

@JB

@StormyDay

His coat seems totally normal.

A lot of people think the stereotypical PPID coat is needed to think PPID, but that’s one of the more advanced symptoms in most cases. I would absolutely get him tested for PPID and Lyme disease. Like this week if at all possible.

@carman_liz

but I think…only super ammie minded think…that quest plus is the only thing that kills strongyles.

Ivermectin and moxidectin both kill adult strongyles

If you’re thinking about encysted strongyles, then while resistance has limited this to a large degree, there are still places where a Power Pack (5 days of double dosed fenbendazole) is effective

We pulled extra blood to run for PPID if everything else was negative; I’ll ask about Lyme too.