Horse scratching and shedding: Finding what to feed an itchy horse can be daunting, as the feed itself can be a trigger for itchy skin and so much more. For PSSM horses it can be even worse. There are a lot of pitfalls that normal horses can avoid that will send a PSSM horse crashing. One of those pitfalls is shedding season. Jax has been doing amazing since last August, so when he started having a couple little issues last month I was a bit surprised.
I’ve read anecdotally that other PSSM horses have issues during shedding season, but never really understood the reason. It’s around the same time that grass can start growing if it’s unusually warm, and I always attributed our spring issues to that – even though Jax does great on pasture, and doesn’t seem overly sugar sensitive.
As I kept researching (a daily part of my life now!) I found that hyperkalemia, or high blood potassium symptoms, seem to be a huge part of what goes wrong every year, so that led me to the belief that high potassium levels in spring grass growth could be what triggers these spring issues.
PSSM Horse Scratching and Shedding: Shedding Stresses Liver and Kidneys?
This theory is still highly plausible, but I’ve recently come across another theory: shedding season is especially hard on the kidneys and liver, and even healthy horses can improve during this season with liver and kidney support. Many believe that shedding is a general stressor for horses, but what happens if a particular horse already has one or two stressed organs – say, the kidneys and liver? Will the extra stress show up there first?
Now, why would a PSSM horse have a more drastic reaction to something like this? The quick answer is that PSSM is hard on the kidneys (and liver). First let’s look at Negative Nitrogen Balance (NNB) – when too little protein is consumed for the horse’s needs, the body begins to catabolize the muscles in favor of supporting the organs.
PSSM1 horses aren’t as susceptible to this as PSSM2 horses (it’s one of the major symptoms for PSSM2 horses, and Jax has fallen prey to it several times in the past). When a horse ties up or goes into NNB, the muscles break down and the damaged cells are excreted through the kidneys – this is VERY hard on the kidneys, and many PSSM horses lose their battle due to kidney failure.
When the kidneys are stressed or aren’t functioning properly, they won’t excrete potassium or chloride properly… see where this is headed? If the potassium and chloride levels increase too much it can tip them into an electrolyte imbalance, and high potassium affects calcium levels (drops it, sometimes to dangerous levels). Salt is the universal helper for lowering potassium, but what if chloride isn’t being removed properly due to kidney stress?
What to feed an itchy horse: As an interesting aside, my horse doesn’t handle salt supplementation. I give him salt licks in the field and that’s it – feeding it in his hard feed is just asking for an itchy horse (that will eventually spiral into other symptoms)!
PSSM Horse Scratching and Shedding: Seasonal “High Potassium” Symptoms
In early 2019, Jax started having his typical high potassium symptoms:
- Herd bound and aggression
- attacked his field mate and drew blood, almost running him through a fence – happened twice
- Spookiness and mild behavioral changes
- Spooking includes panicked staring into space and bolting on occasion
- Won’t stand still, constantly anxious
- Horse scratching and itching – rubbing mane out
- Trembling neck and chest muscles
- Bounding pulse in neck
- Prone to choke, possibly due to bronchospasms and larangospasms
- Head shaking and flicking
I raised his salt and magnesium in an effort to balance potassium, believing that calcium is high enough in the diet to not warrant supplementation – it was his worst year yet for symptoms. There were signs that it was affecting his heart, and he was head shaking to the point it was very obvious (he’d had minor signs that could be explained by other things before, this was the first time I was left without a doubt – he’s a head shaker in the wrong circumstances).
This past year (Feb. 2020) I started seeing the signs again, and I began raising salt and mag – again things got much worse, so I removed them completely… And he got better! Not without symptoms, but definitely improved!
PSSM Horse Scratching and Shedding: Seasonal Changes Call for Seasonal Management Practices
What to feed an itchy horse: Renew Gold is moderate potassium, and is the only feed Jax handles well [Update Feb. 2023 – he no longer handles any bagged feed or forage pellets/cubes]. I ended up taking him off all hard feeds for a couple days to lower potassium levels and again saw improvement, but he needs his fat (for P1) and protein (for P2) so I had to find a way to get him back on his feed [Update Feb. 2023 – he no longer needs higher amounts of fat and protein! See Jax’s current diet].
What to feed an itchy horse: I looked more into HYPP (Hyperkalemic Periodic Paralysis) diets and learned that calcium and oats are huge for managing these horses, and decided to try them on Jax. I slowly built up to 24g of added calcium and 1/3 cup of oats along with .4 lb of Renew Gold added back to the diet (down from the 1 lb he normally gets) – this became his carrier for the rest of his supplements to be added back into the diet, but I left additional magnesium and salt out of the diet for a few more days. [Update Feb. 2023 – calcium carbonate had side effects, but chelated calcium has been doing wonderful things for Jax for the past 2 years!]
Oats were used because they’re high in sugar (also an electrolyte!) – sugar causes an insulin spike which pulls potassium back into the cells, but it also pulls sugar into the muscles which isn’t what you want for a P1; but sometimes you have to pick the lesser evil, at least for a time. All of the symptoms disappeared, and he never progressed to head shaking. Keep in mind that I feed only a handful of oats at a time.
What to feed an itchy horse: we’re not out of the woods yet as we have about 2-3 more months in our usual yearly cycle, but so far he’s doing amazing! I left him on a handful oats for about 3-4 weeks, but did take him off recently as he’s not been in high amounts of work. He’s now handling up to .6 lb of Renew Gold, 24g of calcium, and no oats, and he’s on a total of 8g of mag and 2 tbsp of iodized salt with no issues. I may add oats back as we raise work levels if needed. [Update Feb. 2023 – adding back magnesium and salt didn’t last long, as troubles quickly started back up!]
What to feed an itchy horse: The last couple of years have lead me to the conclusion that one diet doesn’t fit all seasons for my horse… [Update Feb. 2023 – this is still true, but the only change I make now is a slight raise in chelated calcium in the more stressful months.]
PSSM Horse Scratching and Shedding: Signs the Kidneys are Having Troubles
That covers the potassium issue for now, but the underlying cause of kidney stress is just revealing itself. A few days ago I took Jax for a hand walk; right before that I could see Jax-hairs floating in the wind he’s shedding so bad right now! For the first time in months, he stopped to urinate while working, and he had a really hard time urinating and there was some blood at the end of the stream.
Usually when he pees “blood” (it’s actually broken muscle cells) he’s also highly symptomatic and losing muscle (clear signs of NNB) – this time he’s moving beautifully and holding muscle well – leading me to the conclusion that this is not his usual PSSM symptoms but is strictly a kidney issue.
If you’ve looked into symptoms of kidney stress and toxicity (see symptoms for electrolyte imbalance and kidney stress in PSSM horses), you’ll see a lot of similarities with PSSM, making it very difficult to tease out specific symptoms. I’ve been a huge proponent of herbs, and give Jax herbs specific for kidney support quite often, which I think is one of the reasons he’s been doing so well!
What to feed an itchy horse: I put him back on our regular kidney herbs and he hasn’t shown anymore signs of kidney discomfort, however, I’m getting ready to try Silver Lining Herbs’ Kidney mix for a more comprehensive detox (have it ordered, just waiting for it to get here!). I’ll update this page with my findings, but so far I’m seeing reviews that it helps with lumbar pain, muscle loss, and many other issues that typically crop up with Jax during this season – so I’m mildly optimistic that we’ll see even more improvement than we did last year!
[Update February 2021: I still had to use some of my herbs with the Silver Lining Herbs mix. While their mix is great for general kidney health, my horse seems to need antibiotic-type kidney herbs on top, making me think he’s prone to infections and UTIs.]
PSSM Horse Scratching and Shedding: Far-Reaching Consequences
Itchy horses and scratching are just the beginning – one of the worst issues related to high potassium is that there are some subtle links to low grade laminitis. Jax goes through LGL every June – about 1-2 months after the potassium symptoms begin to subside, and just after he stops shedding (it takes him months to lose his very thick winter coat – does taking longer increase shedding stress?).
These laminitis episodes happen every year since I got him 9 years ago. Every. Year. I’m looking forward to seeing what happens this year after taking a far more proactive approach to shedding and electrolytes! If I’m right, then this may be the last link in getting him managed almost perfect – fingers crossed! [Update Feb. 2023 – Jax hasn’t had a laminitic episode since getting his electrolytes balanced with added calcium, with chelated calcium being the only form that doesn’t have side effects.]
What To Feed An Itchy Horse?
Horse itching skin and scratching: to see Jax’s current feed management, see my PSSM Feed Regime post! Cliff notes: I couldn’t balance potassium with salt like others on the forums seem to have luck with. But, fixing the calcium levels seems to be doing the trick! See notes on trialing chelated calcium for Jax here.