Optim Equine

06/10/2026

𝟔𝟎,𝟎𝟎𝟎 𝐯𝐬 𝟖𝟓𝟎.

Those are two numbers that tell us a surprising amount about how a horse’s diet can influence chewing behaviour.

A horse grazing at pasture can make around 𝟔𝟎,𝟎𝟎𝟎 𝐣𝐚𝐰 𝐬𝐰𝐞𝐞𝐩𝐬 𝐚 𝐝𝐚𝐲.

But the amount of chewing required to consume a particular feed can be dramatically different.

A 500 kg horse will take around 𝟒𝟎 𝐦𝐢𝐧𝐮𝐭𝐞𝐬 𝐚𝐧𝐝 𝟑,𝟒𝟎𝟎 𝐣𝐚𝐰 𝐬𝐰𝐞𝐞𝐩𝐬 𝐭𝐨 𝐜𝐨𝐧𝐬𝐮𝐦𝐞 𝟏 𝐤𝐠 𝐨𝐟 𝐡𝐚𝐲.

By comparison, 𝟏 𝐤𝐠 𝐨𝐟 𝐨𝐚𝐭𝐬 𝐭𝐚𝐤𝐞𝐬 𝐣𝐮𝐬𝐭 𝟏𝟎 𝐦𝐢𝐧𝐮𝐭𝐞𝐬 𝐚𝐧𝐝 𝐚𝐫𝐨𝐮𝐧𝐝 𝟖𝟓𝟎 𝐣𝐚𝐰 𝐬𝐰𝐞𝐞𝐩𝐬.

That’s a significant difference in chewing time and jaw activity.

We tend to think the role of chewing is simply to process feed. Yet it plays an important role in digestive health, including helping to protect the stomach lining against the development of gastric ulcers.

When horses are stabled, have limited access to forage, or a significant proportion of their diet comes from concentrates or processed feeds, their total daily chewing activity can be considerably reduced.

It’s one of those seemingly simple aspects of feeding that can have a much bigger impact on gut health than we might realise.

I’ve written more about the mechanisms behind this, and why chewing is so important for digestive and gut health in our horses, in the article below:

𝐓𝐡𝐞 𝐈𝐦𝐩𝐨𝐫𝐭𝐚𝐧𝐜𝐞 𝐨𝐟 𝐂𝐡𝐞𝐰𝐢𝐧𝐠
https://optimequine.com/the-importance-of-chewing

04/10/2026

𝙋𝙝𝙤𝙩𝙤𝙨𝙚𝙣𝙨𝙞𝙩𝙞𝙫𝙞𝙩𝙮 𝙞𝙣 𝙝𝙤𝙧𝙨𝙚𝙨…𝙇𝙪𝙘𝙚𝙧𝙣𝙚 (𝙖𝙡𝙛𝙖𝙡𝙛𝙖), 𝙘𝙡𝙤𝙫𝙚𝙧 𝙖𝙣𝙙 𝙤𝙩𝙝𝙚𝙧 𝙥𝙤𝙩𝙚𝙣𝙩𝙞𝙖𝙡 𝙘𝙤𝙣𝙩𝙧𝙞𝙗𝙪𝙩𝙤𝙧𝙨

Photosensitization (also known as photodermatitis) is light-induced inflammation of the skin (dermatitis) caused by a heightened sensitivity of the skin to sunlight.

This condition is non-contagious and often looks like sunburnt skin on our horses and ponies, and can often be difficult to diagnose or distinguish from sunburn.

It occurs in susceptible horses and ponies when phototoxic or photoactive substances accumulate in the skin and interact with sunlight. This can result in severe itchy, crusty and often painful dermatitis. It generally occurs in non-pigmented (i.e. white) skin and skin with little hair cover (such as the muzzle, eyelids, ears and coronary bands).

Equine photosensitivity may be caused by the ingestion of plant or fungal products, chlorophyll metabolites, or other chemicals. It can also occur in conjunction with the use of some medications.

Effects of ingestion of the offending substance may be cumulative and a horse may not develop signs of photodermatitis immediately.

Using lucerne/alfalfa or clover as an example, horses may not develop any clinical signs of photosensitisation until weeks after initially consuming the hay, chaff or pasture which is causing the reaction. We can be feeding our horses this feedstuff for quite some time without any issues, before seemingly all of a sudden, photodermatitis occurs.

This can be difficult and confusing, as we often expect clinical signs to appear immediately or very soon after consumption of the offending feed. This can lead to constantly changing our horse’s feed, in attempt to identify the culprit. As a result, this may significantly increase a horse’s risk of developing colic or laminitis.

Other recognised potential causes of photosensitisation include gluten sensitivity; reactions to drugs such as tetracycline antibiotics and phenothiazine tranquillisers; exposure to certain chemicals; and consumption of pastures rich in phosphorus fertilisers.

These are commonly overlooked, but from clinical experience, generally contribute to photosensitivity reactions more commonly than consumption of lucerne/alfalfa and clover alone, which are often thought to be culprits.

Photosensitisation may also occur as a result of impaired liver function in a horse (known as secondary photosensitivity/photosensitisation).

For these reasons, the effective prevention and treatment of photosensitisation should involve thorough analysis of diet, management, pasture, supplement and medication use in susceptible horses. In many cases, there may be more than one factor contributing to photosensitisation.

The complexity of the condition can also help to explain why simply applying topical creams or lotions and/or simply removing lucerne/alfalfa from the diet and/or adding a mycotoxin binder to our horse or pony’s feed often doesn’t provide a long-term or effective solution.

Removing certain feeds from a diet can also contribute to nutritional insufficiencies or deficiencies, which can sometimes further compound the problem.

For effective treatment and prevention of recurrence of photosensitivity, addressing the underlying cause(s) of the condition is paramount.

30/09/2026

𝗖𝗼𝗹𝗼𝘀𝘁𝗿𝘂𝗺 𝗾𝘂𝗮𝗹𝗶𝘁𝘆 𝗮𝗻𝗱 𝘁𝗶𝗺𝗶𝗻𝗴…𝘄𝗵𝘆 𝗱𝗼𝗲𝘀 𝗶𝘁 𝗺𝗮𝘁𝘁𝗲𝗿?

With foaling season now upon us in the Southern Hemisphere, it’s worth taking a moment to appreciate the importance of good quality colostrum.

Colostrum provides antibodies (immunoglobulins), which are concentrated in a mare’s milk during the 10-14 days prior to foaling. These immunoglobulins are essential in helping to provide immunity against common diseases in a foal’s first few weeks of life.

If a foal doesn’t receive or absorb adequate levels of colostrum within 16 hours of birth, it is predisposed to a higher risk of bacterial infection.

The capacity of the small intestine to absorb and transfer antibodies is greatest during the first 6-8 hours after birth. This is why the sooner a foal gets colostrum into it, the better.

𝐀 𝐟𝐨𝐚𝐥’𝐬 𝐚𝐛𝐢𝐥𝐢𝐭𝐲 𝐭𝐨 𝐚𝐛𝐬𝐨𝐫𝐛 𝐜𝐨𝐥𝐨𝐬𝐭𝐫𝐮𝐦 𝐝𝐞𝐜𝐥𝐢𝐧𝐞𝐬 𝐬𝐮𝐛𝐬𝐭𝐚𝐧𝐭𝐢𝐚𝐥𝐥𝐲 𝐚𝐟𝐭𝐞𝐫 𝟏𝟐 𝐡𝐨𝐮𝐫𝐬.

𝐖𝐢𝐭𝐡𝐢𝐧 𝟐𝟒 𝐡𝐨𝐮𝐫𝐬 𝐚𝐟𝐭𝐞𝐫 𝐛𝐢𝐫𝐭𝐡, 𝐭𝐡𝐞 𝐬𝐩𝐞𝐜𝐢𝐚𝐥𝐢𝐬𝐞𝐝 𝐢𝐧𝐭𝐞𝐬𝐭𝐢𝐧𝐚𝐥 𝐜𝐞𝐥𝐥𝐬 𝐰𝐡𝐢𝐜𝐡 𝐚𝐛𝐬𝐨𝐫𝐛 𝐜𝐨𝐥𝐨𝐬𝐭𝐫𝐮𝐦 𝐚𝐫𝐞 𝐫𝐞𝐩𝐥𝐚𝐜𝐞𝐝 𝐛𝐲 𝐜𝐞𝐥𝐥𝐬 𝐢𝐧𝐜𝐚𝐩𝐚𝐛𝐥𝐞 𝐨𝐟 𝐭𝐫𝐚𝐧𝐬𝐟𝐞𝐫𝐫𝐢𝐧𝐠 𝐚𝐧𝐭𝐢𝐛𝐨𝐝𝐢𝐞𝐬.

Colostrum contains three types of protein immunoglobulins:

*IgG- which helps to provide immunity against bacterial and infective diseases;

*IgM- for general immunity;

*IgA- which increases in milk after a mare has foaled. IgA is unique in that it is not absorbed into the body. It provides local gut protection against bacteria, viruses and other germs that can cause diarrhoea in a foal.

Colostrum also has a natural laxative effect- which helps stimulate a foal’s bowels to promote the passing of meconium (accumulated wastes).

22/09/2026

Tassie horse people- this event is for you! Join us for an evening where we discuss all things Equine Gastric Ulcer Syndrome, gut health and supplements…

Come along for an informative evening. Light refreshments available

https://www.facebook.com/share/19dDJZwbSQ/

18/09/2026

𝗗𝗼 𝘆𝗼𝘂 𝗳𝗲𝗲𝗱 𝘆𝗼𝘂𝗿 𝗵𝗼𝗿𝘀𝗲 𝗼𝗶𝗹?…

Oils are a highly debated topic in equine nutrition, and their use in horse feeds can divide people.

The type, quality and quantity of oil, along with the state of your horse’s gastrointestinal health and body condition, should all be considered before adding oil to your horse’s feed.

However, if you feed your horse oil of any kind, there is another important consideration that is often overlooked:

𝗛𝗼𝘄 𝗮𝗿𝗲 𝘆𝗼𝘂 𝘀𝘁𝗼𝗿𝗶𝗻𝗴 𝗶𝘁?

Oil exposed to heat, light and air can rapidly oxidise (become rancid). And importantly, this process can happen long before we can smell or taste that something is ‘off’.

𝙒𝙝𝙮 𝙙𝙤𝙚𝙨 𝙩𝙝𝙞𝙨 𝙢𝙖𝙩𝙩𝙚𝙧?

Rancid oil is not harmless.

As oil oxidises, it produces compounds that can contribute to oxidative stress and inflammatory processes in the body.

This is particularly important because many people feed oil with the intention of supporting their horse’s health and, in many cases, specifically to help reduce inflammation.

If that oil has been poorly stored and has oxidised, you may be inadvertently feeding something that works against the outcome you are trying to achieve, by potentially exacerbating inflammation.

So, if you feed oil, there are several simple things you can do to help preserve its quality:

𝐒𝐭𝐨𝐫𝐞 𝐢𝐭 𝐢𝐧 𝐚𝐧 𝐨𝐩𝐚𝐪𝐮𝐞, 𝐥𝐢𝐠𝐡𝐭-𝐩𝐫𝐨𝐨𝐟 𝐜𝐨𝐧𝐭𝐚𝐢𝐧𝐞𝐫. No clear bottles, particularly if the oil is exposed to light.

𝗔𝗹𝘄𝗮𝘆𝘀 𝗸𝗲𝗲𝗽 𝘁𝗵𝗲 𝗹𝗶𝗱 𝘄𝗲𝗹𝗹 𝘀𝗰𝗿𝗲𝘄𝗲𝗱 𝗼𝗻. Only take the lid off when pouring out oil for feed time.

𝗗𝗼𝗻’𝘁 𝗮𝗱𝗱 𝗼𝗶𝗹 𝘁𝗼 𝗵𝗼𝗿𝘀𝗲 𝗳𝗲𝗲𝗱𝘀 𝗮𝗵𝗲𝗮𝗱 𝗼𝗳 𝘁𝗶𝗺𝗲. Add it at the time of feeding.

𝗦𝘁𝗼𝗿𝗲 𝗼𝗶𝗹 𝗶𝗻 𝗮 𝗰𝗼𝗼𝗹, 𝗱𝗮𝗿𝗸 𝗽𝗹𝗮𝗰𝗲. Keep it out of direct sunlight and out of sheds or feed rooms that become hot.

𝗨𝘀𝗲 𝗶𝘁 𝗮𝘀 𝗾𝘂𝗶𝗰𝗸𝗹𝘆 𝗮𝘀 𝗽𝗼𝘀𝘀𝗶𝗯𝗹𝗲 𝗮𝗳𝘁𝗲𝗿 𝗼𝗽𝗲𝗻𝗶𝗻𝗴. Don’t use oil that has been sitting open for months!

It’s easy to overlook how we store oils, but if we are feeding them for their health benefits, we need to make sure we are looking after the oil properly too.

11/09/2026

𝗪𝗵𝗮𝘁 𝗵𝗮𝗽𝗽𝗲𝗻𝘀 𝗶𝗻 𝗮 𝗳𝗼𝗮𝗹’𝘀 𝗴𝘂𝘁 𝗱𝘂𝗿𝗶𝗻𝗴 𝘁𝗵𝗲 𝗳𝗶𝗿𝘀𝘁 𝗳𝗲𝘄 𝘄𝗲𝗲𝗸𝘀 𝗼𝗳 𝗹𝗶𝗳𝗲 𝗺𝗮𝘆 𝗺𝗮𝘁𝘁𝗲𝗿 𝗳𝗼𝗿 𝗺𝘂𝗰𝗵 𝗹𝗼𝗻𝗴𝗲𝗿 𝘁𝗵𝗮𝗻 𝘄𝗲 𝗼𝗻𝗰𝗲 𝘁𝗵𝗼𝘂𝗴𝗵𝘁...

The gut microbiota (the community of bacteria, fungi, viruses and other microorganisms living in the digestive tract) plays an important role in a foal’s development and health.

Increasingly, research is showing that what happens to this microbial community early in life may be associated with health and performance later on.

One factor that can significantly disrupt the developing gut microbiota is antibiotic use.

Antibiotics can be life-saving when they are genuinely needed, and responsible antibiotic use when treatment is indicated is incredibly important.

At the same time, antibiotics can alter the developing microbial community, and those changes persist beyond the initial treatment period.

Interestingly, research has found that foals given antibiotics during their first month of life had a higher risk of respiratory disease later in life. They also went on to have poorer athletic performance compared with foals that had not received antibiotics.

This highlights just how important the early-life period may be, and how much we still have to learn about the relationship between the gut microbiota, disease and athletic performance.

When antibiotic treatment is necessary, considering what happens to the gut afterwards is incredibly important.

Supporting the gut and helping to optimise digestive health following antibiotic treatment is an area I work closely with as an equine naturopath and clinical nutritionist. Every horse is different, so the approach needs to be individualised rather than simply reaching for a generic “gut supplement”.

The decisions we make for a foal in those first few months of life may have consequences that extend much further than we realise.

Sometimes, good horse care is about recognising when intervention is necessary, and then supporting the horse through the recovery that follows.

Have you considered gut health when managing a foal after antibiotic treatment?

04/09/2026

𝙒𝙝𝙮 𝙙𝙤 𝙛𝙤𝙖𝙡𝙨 𝙚𝙖𝙩 𝙢𝙖𝙣𝙪𝙧𝙚?

Eating manure (also known as coprophagy), is a common, yet transient phenomenon in foals.

Coprophagy is thought to potentially offer multiple health benefits in foals.

Foals will generally start consuming manure from about five days old. This habit may continue up until approximately three months of age, before gradually declining. By 19 weeks of age, the habit generally stops in most foals.

By consuming manure, foals are populating their digestive system with a variety of microbes: bacteria, protozoa, archea and fungi.

This habit is thought to be an important part of healthy gastrointestinal and immune system development: foals are born with a relatively ‘immature’ microbiome which is influenced by multiple factors in their early stages of life.

It is worth keeping in mind however, that if a foal is consuming manure from a horse with poor digestive health and/or a horse with a poor balance of microflora and/or a horse with a high parasite burden then this may potentially have adverse health effects in the foal.

Research suggests that a mare’s faeces may contain a pheromone known as deoxycholic acid.

This pheromone encourages the foal to consume the mare’s manure.

Deoxycholic acid is an important byproduct of intestinal bacteria which supports digestive system immunity (helping to protect against enteritis).

Interestingly, deoxycholic acid may also facilitate normal neurological development in foals through promoting myelination of nerves.

Good overall health really does start with a healthy gut!

30/08/2026

𝐅𝐎𝐀𝐋 𝐇𝐄𝐀𝐓 𝐒𝐂𝐎𝐔𝐑𝐒/𝐃𝐈𝐀𝐑𝐑𝐇𝐎𝐄𝐀

With foaling season now upon us in the Southern Hemisphere, it is worth revisiting the topic of ‘Foal Heat Scours/Diarrhoea’.

This is one of the most common types of diarrhoea to affect foals. Yet the name is a bit of a misnomer, and often leads to confusion as to the actual cause of this form of scours.

This yellowish, greenish, watery diarrhoea generally occurs in foals around 7-14 days of age, hence often coinciding when a mare comes into foaling heat.

We know however, that orphan foals and foals reared in isolation from mares commonly develop this characteristic type of scours: thereby indicating that mare hormonal fluctuations alone do not drive their development.

This type of diarrhoea is more accurately attributed to the changes occurring in the developing hindgut of the foal.

Foals of this age are starting to consume grass (having initially relied entirely on nursing milk from their dams).

The proper digestion of grass requires the actions of specific microbes in the hindgut. Foals aren’t born with these microbes- they are established upon exposure to feed and various environmental conditions.

Until the microbial population is well colonised in the hindgut and digestive enzyme secretion normalises in the foal, the fibre from grass remains largely undigested.

The result? Yellowish, greenish scours which often contain visible clumps of undigested grass.

Foal heat scours are generally nothing to be concerned about and are easily distinguished from infectious forms of diarrhoea (such as Rotavirus or Salmonella) which are systemic illnesses.

Foals experiencing foal heat diarrhoea do not have a fever, remain bright, alert, active and on suck.

There are other forms of non infectious diarrhoea in the foal which include lactose intolerance, overfeeding, ingestion of sand, administration of some antibiotics, and in some cases the use of NSAIDs (such as phenylbutazone ‘bute’ and flunixin).

26/08/2026

I’ll be back at The VET Expo in Sydney again this year, presenting on Day 2 — 10 September at 3:10pm.

I’ve presented at every Vet Expo since the event began, and this year I’ll be taking a deeper look at a subject that deserves closer consideration:

𝐑𝐞𝐯𝐢𝐬𝐢𝐭𝐢𝐧𝐠 𝐑𝐨𝐮𝐭𝐢𝐧𝐞 𝐏𝐫𝐞𝐬𝐜𝐫𝐢𝐛𝐢𝐧𝐠: 𝐔𝐧𝐢𝐧𝐭𝐞𝐧𝐝𝐞𝐝 𝐂𝐨𝐧𝐬𝐞𝐪𝐮𝐞𝐧𝐜𝐞𝐬 𝐨𝐟 𝐒𝐭𝐚𝐧𝐝𝐚𝐫𝐝 𝐄𝐪𝐮𝐢𝐧𝐞 𝐃𝐫𝐮𝐠 𝐏𝐫𝐨𝐭𝐨𝐜𝐨𝐥𝐬

Pharmaceutical therapies have an important place in veterinary medicine.

Corticosteroids, NSAIDs, gastric ulcer medications and antibiotics are all valuable tools, and in many situations they are absolutely necessary.

At the same time, even when these medications are used appropriately, they can have wider physiological effects that are important to consider.

In this session I’ll be looking at what can happen physiologically when these medications are used, particularly in relation to gastrointestinal function and the microbiome, nutrient absorption and metabolism, nutrient excretion, polypharmacy and drug interactions, and broader systemic effects.

I’ll also be discussing practical ways we can support the horse when pharmaceutical intervention is necessary, with the aim of minimising avoidable side effects and supporting physiological recovery.

This is a subject that sits at the intersection of veterinary medicine, nutrition and whole-horse health, and I’m looking forward to sharing some of the research, clinical considerations and practical strategies around it.

The Vet Expo | Sydney
📅 10 September
⏰ 3:10pm
🎤 50-minute extended session

If you’re attending, I’d love to see you there. It’s a conversation I hope will be useful to anyone involved in caring for horses.

21/08/2026

𝐖𝐡𝐞𝐧 𝐢𝐭 𝐜𝐨𝐦𝐞𝐬 𝐭𝐨 𝐝𝐞𝐯𝐞𝐥𝐨𝐩𝐦𝐞𝐧𝐭𝐚𝐥 𝐨𝐫𝐭𝐡𝐨𝐩𝐚𝐞𝐝𝐢𝐜 𝐝𝐢𝐬𝐞𝐚𝐬𝐞, 𝐰𝐡𝐚𝐭 𝐚𝐫𝐞 𝐰𝐞 𝐦𝐢𝐬𝐬𝐢𝐧𝐠?

There is a lot to consider when it comes to the healthy development of the young horse.

But finding clear, evidence-informed information that brings the different pieces together can be surprisingly difficult.

𝘿𝙚𝙫𝙚𝙡𝙤𝙥𝙢𝙚𝙣𝙩𝙖𝙡 𝙊𝙧𝙩𝙝𝙤𝙥𝙖𝙚𝙙𝙞𝙘 𝘿𝙞𝙨𝙚𝙖𝙨𝙚 brings those considerations together in one comprehensive resource, written for equine professionals and breeders, owners and others responsible for raising young horses.

It takes independent clinical perspectives, without promoting a particular feed, supplement or pharmaceutical product.

The aim is simple: to help make sense of a complex subject and support more informed decisions around the developing horse.

The guide is available to download at no cost.

𝐇𝐞𝐚𝐥𝐭𝐡𝐲 𝐨𝐫𝐭𝐡𝐨𝐩𝐚𝐞𝐝𝐢𝐜 𝐝𝐞𝐯𝐞𝐥𝐨𝐩𝐦𝐞𝐧𝐭 𝐬𝐡𝐨𝐮𝐥𝐝 𝐧𝐨𝐭 𝐛𝐞 𝐥𝐞𝐟𝐭 𝐭𝐨 𝐜𝐡𝐚𝐧𝐜𝐞.

Download your copy via the link in bio, or here:

https://optimequine.com/guides/