05/10/2026
Meet Rosie – my canary in the coal mine! 🐥🌱
Apparently Rosie decided my recent Spring is Springing post needed a real-life case study.
After recent rain on the Central Coast – nothing like the rainfall being seen in parts of Victoria, but enough to get the pasture growing, followed by warm, sunny spring weather, Rosie’s manure became noticeably softer. By the afternoon it was very soft and had developed a distinctly sour, acidic smell.
But her manure wasn’t the first thing that told me something wasn’t right.
When we headed out for a ride that morning, she was unsettled. Initially, it wasn’t particularly obvious what was wrong and she was still willing to continue.
On the way back, however, she became increasingly quiet and reluctant to go forward. When I applied my leg, she turned towards me and put her ears back.
That was enough.
I got off and walked her back to the float 🚶♀️🐎
Once there, even her hindleg posture had changed. This wasn’t Rosie being “naughty” or deciding she didn’t want to work. She was uncomfortable – and she was communicating it.
🧩 Putting the pieces together – the recent weather, rapidly changing spring pasture, unusually soft and acidic-smelling manure, behavioural changes and apparent abdominal discomfort – my suspicion was pasture-associated hindgut disturbance, potentially involving a drop in hindgut pH.
Rapidly growing pasture can change considerably after rain followed by warm, sunny conditions. Changes in both the amount and composition of fermentable carbohydrate reaching the hindgut can alter microbial fermentation, increase production of organic acids and potentially reduce hindgut pH.
The result can be changes in manure consistency and odour - and, importantly, changes in how the horse actually feels.
Rosie’s manure was particularly significant because this is very unusual for her. I know what her stress-related manure looks like when she travels or gets unsettled and this was different.
I have a pH meter and would have loved to have measured one of those very fresh, very smelly samples at the time but I didn't have it with me and once we got home she stopped producing them! 😂
Faecal pH does not directly tell us the pH inside the caecum or colon, so it cannot diagnose “hindgut acidosis”. However, repeated measurements in the same horse, alongside diet, manure consistency and clinical observations, can still be useful. I’ll now establish a normal faecal pH baseline for Rosie so I have something to compare with if this ever happens again.
Rosie has always been particularly sensitive to changes in her diet and pasture, which is why I call her my "canary in the coal mine". She tends to tell me very quickly when something isn’t agreeing with her.
And this time, she did.
By the following morning, after I had closed off the kikuyu-dominant back paddock while continuing her normal hay and chaff, she was already looking far more comfortable. Her manure had improved, her abdominal sensitivity had settled, and the classic Rosie face had disappeared.
That doesn’t prove exactly what was happening inside her gut, but the timing was certainly interesting.
And it was a very good reminder:
Listen when your horse’s behaviour changes.🧡
Reluctance to go forward, ears back when the leg is applied, irritability or simply seeming “not quite right” can be communication - not disobedience.
Spring pasture changes can show up as more than weight gain and “fresh” behaviour.
Sometimes your horse tells you through their manure.
Sometimes they tell you under saddle.
And sometimes, like Rosie, they make absolutely sure you get the message. 🌱👿
