Insect bite hypersensitivity

Insect bite hypersensitivity

Tuesdays with Tony

Ah, Florida. We have a lot of fun stuff here… beautiful beaches and great places to ride your horse. You know what we also have in plenty? Bugs. Yep, I’m sure you have noticed the bugs. Between the heat, the humidity, and the bugs, Florida in summer can be kinda hard on your cat. I mean horse. Hard on your horse.

As the Springhill cat, I like to spend time laying on the bench outside the clinic, but when I’m ready to take a break from Florida summer I just stare at the clinic door until my minions let me in. Unfortunately, it’s not as easy for your horse to escape the flies and gnats that are part of our summers. Have you noticed that some horses have a much harder time of it than others? They itch themselves like crazy, they scratch their mane and tail out, their ears are rubbed raw, and they just look miserable.

So why does one horse look awful while the rest of the herd is doing fine? Because that poor itchy horse is allergic to the bites of insects, specifically their saliva, making him hypersensitive to its effects. Insect bite hypersensitivity (also called seasonal pruritic dermatitis) causes intense itchiness, hair loss, and abrasive skin damage. It’s usually caused by gnats, flies, or mosquitoes, though any biting insect can be the culprit. The most common locations you’ll see skin lesions are the ears, the face, the bottom of the belly, and the tail head, though badly affected horses can have bumps and hair loss all over their body.

To get your itchy horse some relief, my docs recommend a combination of strategies.

Decrease your Horse’s Exposure to Insects

Keep his environment as clean and free of manure as you can. Removing manure and standing water will help to decrease fly populations. A feed-through fly inhibitor can also reduce the number of flies breeding on your property, though it is really only effective if every horse on the property is on it. These products are often easily available at your local feed store.

You may need to stable your horse to avoid the times when gnats are most active – that’s at dawn and dusk. Box fans in the stall are useful because gnats aren’t very good fliers and will avoid a strong air current. Fly sheets and fly masks (the kind with ears) can help. You can apply fly spray, but it doesn’t usually last long and is rarely effective by itself.

Omega-3 Fatty Acid Supplements

These healthy oils help to decrease inflammation in the skin and promote a healthy hair coat. They can be very beneficial for horses with insect hypersensitivity and other types of allergies. Ground flax seed is a good source of Omega 3s, such as Triple Crown Naturals Golden Ground Flax.

Bathing and Topical Products

Bathe your horse at least once a week during insect season. Colloidal oatmeal or hydrocortisone shampoos can reduce the itch and soothe the irritated skin. My docs really like the Equishield products – they make a great shampoo called IR, for itch relief. In between baths, cool water rinses can reduce the sweat, irritants, and allergens on his skin.

Equishield IBH salve works great for those focal areas where your horse needs extra help – like his ears and face. It helps to soothe the itch as well as repel the bugs. For larger body areas, or places with thick hair like the mane and tail head, the IBH spray works best. These products are an important part of our summer arsenal, and we’ve got a good supply here at the Clinic if you need some.


The allergy can be so bad that some horses need to be placed on a steroid during the insect season to break the itch cycle. Steroids are effective, easy to administer, and relatively inexpensive, but they have to be used with caution. The goal of the bathing, supplements, and insect control I just described is to reduce the need for steroids as much as possible. But when a horse really needs them, these medications can really help that poor horse get some relief. Antihistamine medications may be used as well, but alone they’re often not effective.

Springhill Equine Veterinary Clinic

Most horses with insect bite allergy can be managed with a combination of these lifestyle and medication strategies. So if your horse is itchy, bumpy, crusty, or looks like a moth-eaten sweater during our lovely Florida summers, give my docs a call!

Until next week,

~ Tony

P.S. There’s a new video out on my YouTube Channel, make sure you go check it out!

Tuesdays with Tony is the official blog of Tony the Clinic Cat at Springhill Equine Veterinary Clinic in Newberry, Florida. If you liked this blog, please subscribe below, and share it with your friends on social media! For more information, please call us at (352) 472-1620, visit our website at, or follow us on Facebook!

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More Adventures of the Horse Doctor's Husband
The Ears Have It

The Ears Have It

Tuesdays with Tony

The Ears Have It 


First things first: please don’t forget that my biggest Meet Tony Event of the year- Open House- is coming up in just a few short weeks! Mark your calendars for Springhill Equine’s 12th Annual Open House on Saturday, September 29th from 10 am – 2 pm. This year you will visit booths themed after favorite movies, enjoy delicious BBQ, and explore what our local vendors have to offer, while getting entered to win a free Wellness Package for one of your horses! I’ll plan on seeing you all there.

Do you ever feel like your week has a theme? For example, you and two of your friends all get a flat tire, or you see a snake in your backyard then the next day you see one on your way in to work, or you hit 2 squirrels with your car within the span of a few days? Well, this week’s theme was definitely ears. We have seen itchy ears, swollen ears, abscessed ears, allergic ears, hyper-sensitive ears, and even an ear with a tick in it! So, I quizzed the docs on the common ear problems horses get, and how to recognize and treat them. Do you know what to do if your horse’s ears are driving him nuts?


My horse won’t let me touch his ear

So first, a few questions. Does your horse normally let you touch his ear? Because most horses generally don’t love it. Is it just one ear, or both ears? Both ears make it more likely to be an itchy, allergic, hypersensitivity condition. One ear makes us think of trauma such as a laceration or bruise, or perhaps a tick inside the ear. Side note: the docs tell me that in vet school they teach you that ear ticks are a super-common thing that you will encounter all the time…but in real life they are extremely rare. However, if your horse develops a sudden extreme hypersensitivity in one ear with no other symptoms, an ear tick is definitely on the rule-out list.

If your horse’s ears are irritated in any way, you’re probably darn right that he won’t let you touch them…they hurt! Spoiler alert: it’s going to require a good amount of sedation, a step stool, and a fancy light called an otoscope to get a good look in there. Read as: Call your vet.


But doc, this just happened today!

Far and away the most common ear problem our docs encounter is chronic, thickened, irritated ears secondary to a gnat allergy called “Culicoides hypersensitivity.” Often the vet doesn’t get called until the horse itches his ear so badly that he cuts it on something, and the owner finally takes note when blood and/or pus are streaming out of the ear. Without fail, they claim this “just happened” and the ears were normal a few days ago. While the wound may be new, the underlying condition that led the horse to be so uncomfortable that he self-traumatized his ear has taken months, or even years, to develop.

Springhill Equine Veterinary ClinicCulicoides (kyōō′lĭ-koi′dēz′) is a species of gnat very common here in Florida. Many horses are actually allergic to the saliva of this gnat, so every bite by one of these annoying little devils sends the poor horse into an itching frenzy. The early signs of this gnat allergy include frequent scratching and hair loss in the ears, mane, base of tail, and chest. Over time the skin in these places will become thickened, there will be multiple open bite wounds, the hair will be completely gone, and the horse will constantly be scratching on anything and everything he can find. Horses with chronic Culicoides hypersensitivity will often develop a “cauliflower ear” appearance over a period of years. Once this happens, the ears will never return to their original shape.

What can I do for my horse’s poor ears?

It is best and most successful when owners treat horses with gnat allergies early and often. Look closely at your horse’s ears. Is the hair thinning inside and around the edge of the ear? Are there tiny bug bites inside? Do you see any scabs or blood? Is the skin normal, or is it becoming thickened?

At this early stage, you should be able to get the problem under control with just some topical medication and fly gear. We always recommend a fly mask with ears for these horses; fly sheets, neck pieces, leg covers, etc. can be added at your discretion. The topical medication that works best for this condition is Equishield IBH (that stands for Insect Bite Hypersensitivity). It comes as a salve or a spray, depending on your preference. We find that the IBH salve works great for ears, but the IBH spray is awesome when you need to treat a larger area.

itchy horses Springhill EquineOnce the ear has gotten to a point where there is a secondary laceration, abscess, or hematoma, it can be difficult to treat. While we always try conservative options first, these horses sometimes have to undergo surgery under general anesthesia to drain the ear, followed by weeks with the ear taped down against the horse’s head to allow for continued drainage. No fun.

If you have tried the fly protection and IBH products, but your horse is STILL uncontrollably scratching, talk to our docs about a systemic treatment such as an antihistamine to break the chronic itch cycle. There is even a new drug on the market called Apoquel that has been used to treat itchy dogs, but is now finally getting some attention for use in horses. While the medication is pricey for a 1000 lb animal, we have seen promising results with it so far!

As a cat who suffers from itchy skin, let me tell you that constantly feeling itchy is no fun. If (God forbid) I lived outside swarmed by the very creatures that made me so itchy, I would be miserable! So thank you in advance for not ignoring your itchy horses.

Fondly yours,


P.S. Want more itchy horse info? Check out Dr. Lacher’s podcast on itchy horses. It’s the latest episode of Straight from the Horse Doctor’s Mouth. You can listen right from our website, or subscribe wherever you get your podcasts! What’s a podcast, you ask? It’s just like a radio talk show, except you can listen to it on your phone or your computer whenever you want to. Try it out, and see what the thousands of other subscribers have already figured out 😉

P.P.S. If you haven’t subscribed to this blog yet, make sure you scroll down to the purple box and sign up. Don’t rely on Facebook to deliver my weekly wisdoms to you, they’re very unreliable!

Tuesdays with Tony is the official blog of Tony the Clinic Cat at Springhill Equine Veterinary Clinic in Newberry, Florida. If you liked this blog, please subscribe below, and share it with your friends on social media! For more information, please call us at (352) 472-1620, visit our website at, or follow us on Facebook!

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