Donkeys vs Horses

Not all of our equine patients are horses and ponies. We look after donkeys and mules as well!

At first glance, donkeys may seem similar to horses, but they’re different species with unique needs. 

Donkeys are incredibly intelligent, cautious animals. They have different responses to stress and often get labelled as “stubborn,” but really, they’re just more thoughtful and less flighty than horses. Different approaches are needed to handle them successfully. 

Anatomically, there are lots of differences including hoof, mouth and body shape. They also metabolise feed differently and are prone to weight gain and laminitis. 

Vet care differs too—donkeys often hide signs of illness, so early signs can be subtle. They also respond differently to some medications.

Understanding these differences helps us provide better care for donkeys and mules. 

Infundibular Caries

Infundibular caries is a common dental issue in horses, affecting the infundibulum—the central, cup-like enamel structure in the upper cheek teeth. This area is naturally filled with cementum, but if it doesn’t form properly, food and bacteria can get trapped, leading to decay. Over time, this can cause painful infections, tooth fractures, or even sinus disease.

Regular dental exams help us catch these issues early and keep your horse’s mouth healthy and pain-free.

📞 If it’s been a while since their last check-up, get in touch today! Prevention starts with a closer look.

The Squamous Cell Carcinoma (SCC)

Last week we showed you the surgical resection of a growth on a penis. The reason for full resection was to achieve a diagnosis to ensure it was not a Squamous Cell Carcinoma. This week follows on from last weeks post, giving you more information on SCC disease.

SCC are frequently diagnosed in horses. They are the most common cancer of the eye. They are also the most common malignant skin tumour of horses: Malignant means they are rapidly changing and highly invasive. Over time they become high risk of spreading around the body. This is why we need to identify them and remove them ASAP.

What do they look like:

Solitary raised masses often with an irregular surface.

Most commonly affected areas:

Eye lids and third eyelid

Genitals- Penis or vulva

Face- lips and nose

Ears

Anal region

Horses most at risk:

Palamino, Grey and Coloured horses

Predisposing factors:

Sunlight exposure

Skin pigmentation

Smegma

Chronic skin irritation

Genetic predisposition is currently being investigated

Treatment:

There are a wide range of treatment options available depending on the location of the lesion. Surgical resection, cryotherapy and chemotherapy would be the most common.

Early treatment is key before local invasion occurs.

A new therapy is being investigated called Photodynamic Therapy: This is a medical treatment that combines light energy with photosensitising agent to target and destroy abnormal cells. And that team…. Is all I know about this treatment as it is new 😉

Prognosis:

Poor without early veterinary intervention

Willies need inspecting!

Penile growths are very common and when treated early are of low risk for future health concerns.

The first change that happens on a penis is usually small abrasions underneath the smegma (skin cells with oils). Checking the penis and removing all the smegma allows us to ensure no nasty lesions are developing.

Squamous Cell Carcinomas are tumours of the cells of the penis skin. They can be removed when they are small and solitary.

A great reason we sedate for our dentals is to provide a full penis WOF.

One of our patients this week had a growth that was very large (see photo).

I surgically removed this lesion under topical local anaesthetic and send it away to the laboratory.

Great news, this one was fully resected with good margins (no naughty cells were left behind) and it was only a large wart!!

Being proactive saves a lot of heart ache later on! Look after those willies!

Naso-Lacrimal Ducts

Tearing or Gunky Eyes…

Central Otago windy weather predisposes to blocked tear ducts.

The tear duct is the drainage portal from the eye to the nose. In many situations, but especially windy and dusty ones, the ducts can narrow or get fully blocked.

If your horse has tearing or gunky eyes, it is possible this duct could need flushing. The photo demonstrates how the tears drain into the nose (the green is a special dye used in eyes).

Get in touch if you have concerns about your horse.

Proud Cut

In 99.9% of cases, cutting a horse proud is near impossible.

When a client says my gelding was ‘cut proud’ what they mean is there was testicular tissue left in the horse when it was gelded.

My photo this week was simply to show you the anatomy of a castrated testicle within its sac, to help you understand how unlikely it is that a vet has made a mistake.

It is more likely that there is a different explanation such as only 1 testicle descended and only 1 testicle was castrated (Note: This is not a practice that I would recommend).

Testicle descent 101:

When a colt is young, the testicle migrates from the abdomen, through a hole in the abdominal wall, until it reaches the scrotal skin.

As it migrates, it gets enveloped in a fibrous sac call the ‘Tunic’. This tunic surrounds the testicle and the elements that allow sperm maturation before it enters the duct to the penis.

How I castrate my horses, is to cut through the skin, pop out this sac, and then use a special instrument called ‘Emasculators’ which clamp the cord and sac together above the testicle, before it is cut off.

Chorioptic Mange

Does your horse back up to objects and itch its legs?

Does your horse stomp their feet?

Your horse could be suffering from feather mites.

Feather mites are caused by a Chorioptic mite that likes to feed on skin debris from the legs of horses. They hide in the feathers and there are reports of them surviving for up to 70 days on or off the horse.

Mite size: 0.3mm

Mite life cycle: 3 weeks

Mite sprint speed: Very fast 😊

Where are they found?

Any horse can have feather mites, however the feathers on horses legs help to keep the mites warm through the winter months, hence feathered legs horses harbour the highest population of the mites.

Do not forget, the mites can also survive in the environment on objects such as fence posts, stables and bedding

Symptoms:

Itching is caused by crawling mites, however, not all horses respond as dramatically. Some horses can have mites without any symptoms.

Another very obvious symptom is dandruff like flakes at the skin surface and through the feathers: Mites feed on this scurf and it can be quite dramatic in chronic cases.

If a horse is very itchy, they can self mutilate and scabs and bleeding can be seen.

Treatment:

Treatment options are varied, but sadly none are licensed in NZ. Studies have been performed, so we have several good options including drugs which act systemically, and also drugs which are applied topically.

In addition there are topical products that can act alongside drugs to help in reducing re-infection.

Due to the life cycle of the mites, it is very important that treatments are repeated to ensure the mites from the hatched eggs are treated which can happen 7-10 days after initial treatment.

Do not forget the environment; treatment options are available for this also.

Will my normal wormer kill mites?

It has been shown that wormers, despite having the correct ingredient to kill the mites, do not reach a high enough concentration at the skin to be effective to reduce mite numbers to zero.

Helpful tips

1: Some horses are hypersensitive/allergic to the mites: This means even a very small number of them can cause severe itching/irritation.

2: Clipping away the feathers with not cure the issues; it can however make some topical treatments easier to apply and increase the kill rate during winter months.

3: In chronic cases of feather mites, thick crusts of skin flakes can form at the back of the knee; this is called Mallanders.

4: Given the ability of the mite to survive in the environment, re-infection poses a significant risk and full eradication is near impossible in many instances.

5: Non-clinical carriers are a likely source of re-infection.

Degloving Injuries

A degloving injury is one that involves the tearing away of a complete area of skin, with or without underlying soft tissue damage.

This week I wanted to share a case example with you: I think you will all agree, he is doing very very well! The photos are from day 0, and show his journey of 3 weeks.

This lovely boy was found in the morning after a sad and eventful evening: How did this happen…. Well who would know….

He had sustained a moderately severe degloving injury of the dorsal aspect of his LH canon bone.

The skin was torn away from the leg and was hanging down, very swollen, over the pastern region. There was some tearing of the extensor tendon, and marked contamination from the mud. In addition there was exposed bone which had been stripped from its protective cover called periosteum: This leaves the bone sensitive, and at risk of infection.

Treatment:

The area was cleaned, and a pressure bandage applied for a short period to the degloved skin when it was held back its normal position. The aim was to remove all the swelling in the skin tissue.

Next it was bandaged over a 24 hour period with a wet to dry bandage technique, to remove the last bits of dirt from the wound.

The following day, under general anaesthesia, the wound was stitched: I stitched this wound to give immediate protection to the bone and give the skin the best change to be viable, limiting the amount of second intention healing that needed to occur.

The horse was given pain relief and antibiotics, and was not lame.

Over the next 3 weeks, the stitched skin and bandage allowed a good environment for granulation tissue to form, and gave the skin the best opportunity to stay viable and knit back together.

The last picture shows you what we achieved in 3 weeks.

We wish this boy all the best for his recovery, and thank him for sharing his story.

Fibrosarcoma: aka the dreaded SARCOID

Sarcoids are a type of skin tumour.  We see them very commonly in Central Otago.

The areas most likely affected are the face and thin skinned areas; chest, groin, sheath.

Sarcoids can be locally aggressive and even if they look small on the surface, they can be widespread underneath: A bit like the tip of an iceburg.

There are 6 main presentations:

• Flat, scaley and hairless (Sparky)

• Round nodules (Luna)

• Wart like (Cabella)

• Granulation tissue like: Raised and ulcerated (Rachel McDougal)

• Mixed - two or more forms in one lesion. (cocoa)

• Very occasionally they can be deeply aggressive

Treatment options:

Treatment depends on the type and the location; each sarcoid needs a tailored treatment plan. It is important that this is understood.

The question of Marmite….does it work? In my experience I have healed 98% of my cases with a veterinary treatment plan. I have never used Marmite and have never been presented with a horse that has received marmite topically. I have seen no scientific reports of its efficacy.

What to do if you suspect one?

Do not put anything topical on a suspected sarcoid without advice from a vet. Get your diagnosis confirmed before starting treatment.

Why won't this Mud Fever go?

Have you been treating Mud Fever for months now and feel like it won’t go away? There is a possibility that the ‘Mud Fever’ you are treating is not Mud Fever at all and could be Vasculitis. 

What is the difference?

Mud fever (Dermatophilosis) is a bacterial or fungal infection of the skin. This infection often accumulates in areas of moisture and can commonly be seen around the lower limbs in periods of wet weather. Therefore we treat Mud Fever by keeping the areas clean and dry, and by using anti-bacterial/anti-fungal washes and topical creams. 

Vasculitis on the other hand is caused by an underlying immune-mediated condition whereby the immune system attacks the small blood vessels in the skin when the pink skin is exposed to sunlight causing large scabs on the skin. Although these two conditions may look similar, there are also clear differences. Treatment options are also very different for each condition: Mud Fever can be treated with antibacterial treatments and antibiotics whereas Vasculitis requires steroids. 

If you've been treating mud fever for months with little or no improvement, it is possible that vasculitis could be the underlying issue. Don’t hesitate to get in touch—we’re here to help.

A Bang to the Head

This lovely boy was purchased as an exciting new ride. Unfortunately, during the float ride home, he sustained an injury to the eye. The injury caused a rupture to the eyeball itself and can be seen around the edge of the eye near the junction of the brown colour (iris) and white colour (scleral-limbal border). When the eye ruptures in such a location, the brown iris is seen prolapsing through the hole. This luckily plugged the eyeball (globe) from losing too much internal fluid and therefore stopping the eye from becoming deflated.

A low-pressure eye (deflated eye) is at risk of retinal detachment and long-term blindness.

The client was able to treat the eye with pain relief and preventative antibiotics whilst the eye healed. However, the prolapsed iris was preventing the healing of the cornea.

So…. What was next…

Becci had to suture the eyeball closed.

With sedation and topical pain relief, the surgery was performed in our hospital crush. The prolapsed iris was trimmed, and special sutures were used in a tension relieving pattern to bring the edges of the cornea together.

An ocular treatment system was sutured into the eye to allow easy administration of antibiotics and anti-spasm drugs for the iris.

This horse is now 4 weeks post-surgery and the surgical site is free of infection and has fully healed. The sutures used will dissolve over the next 2-4 weeks.

Luckily due to the early detection by the owner, dedicated treatments by the owner, and a successful surgery, there are no long-term complications for this lovely horse.

Horse Side SAA Machine

A New addition to the Equipment Family..

A HORSE SIDE SAA MACHINE.

Our support to the local equine community shines through today as we can boast about another new vital piece of equipment, we have purchased to improve the ‘horse side’ quality of care we give. Read about it…

When a horse is off colour, has a swollen leg or unknown lump, often the big question is… ‘Is there infection’.

Our new machine gives us that answer in 10 minutes! We take the blood from the horse, prepare it in our horse side microlab, and then wait 10 minutes whilst our wonderful clients provide use with morning tea 😉

This is a very exciting tool which we have already utilized to make life saving decisions for horses.

Get in touch via Facebook Messenger if you want to know more.

Road Accidents

With the riding season in full swing, I wanted to let you all know about a piece of equipment I believe will improve horse safety when transporting them on the roads.

There is a piece of equipment called a ‘Trailer Aid’.

It assists with changing of horse float Tyres.

It allows you to change the horse float tyre without the need to take your horse off the float.

This will improve safety and confidence at the time of an incident, as many bystanders are not experienced in horse handling.

Maybe a present to ask Santa for?

Diastema - What is this?

It is the presence of a detectable ‘gap’ between the molars.

These can cause a lot of pain and discomfort for the horse.

More often than not, it is when this ‘gap’ is small, as food gets stuck, ferments, and causes gingival inflammation.

This inflammation causes pain and can progress to infection surrounding the ligaments of the teeth.

Diastemas often cannot be assessed fully and treated without the use of sedation.

Check out the photos of our new ‘Dental Packing Material’.

Following the use of our dental endoscope during routine dental assessments, we have found many of these painful gaps. So……..

We invested in this wonderful tool to hasten the recovery of your horses' mouths!

Importance of Radiographs

Radiography can be used for many different reasons:

• Fracture Assessment

• Assessment for dental health (resorptive lesions)

• Assessment for canine fractures

• Screening for cartilage lesions (OCD)

• Lamintis Assessment

• Podiatry and foot balance monitoring

• Radiographic guided medications

Any many more!

A Horses' Heart

Do you know, Horses have funny heart beats?

Horses commonly have rhythm disturbances in their hearts.

Compared to people, horses often function very well despite these abnormalities.

Horses have very large hearts with slow heart rate. This makes them more likely to form ‘Arrythmias’ or ‘Abnormal beats’.

A common and often normal rhythm disturbance: The heart skips a beat after every 3-4 pumps. This is heard with the stethoscope as a predictable moment of  ‘silence’. A great way to decide if this is normal or not is to trot up your horse. Increasing the heart rate abolishes this rhythm disturbance in a normal horse.

A second common finding which is abnormal: The heart no longer beats in a predictable way. This is caused by Atrial Fibrillation. The top half of the heart is the control centre to organise when the heart will beat. Because the horses heart is large and beats slowly, the main control centre for synchronising the contraction of the heart can lose this organised control. As a result, the heart doesn’t beat in an organised way, and for each heart beat, less blood is pumped around the body. This causes exercise intolerance, but at low level exercise, there would be no symptoms.

Next time we see your horse, ask to have a listen to the heart beating.

Its very slow, and very cool 😉

Pre-Spring Check List

Spring is around the corner, and we are all starting to bring our horses back into work.

DON’T MAKE A MISTAKE!

What do we need to check for?

Soft tissue injuries: Remember that muscular fitness is important. When bringing a horse back into work after winter turnout; warm up is vital to ensure a good blood supply to the muscles and prevent injury.

Saddle: Check the saddle fit as our horses have likely changed shape. We are surprised at how many horses have back soreness coming in this season. Horses have responded well to mesotherapy.

Seedy toe: Due to the wet conditions, many horses this year have developed seedy toe over the winter. If this is left untreated then abscessation is a high risk in the next few months.

Grass: The grass has started to grow and we have already seen some spasmodic colics. Start thinking about introducing Equishure to prevent that inflammation that happens with a sudden influx of highly digestible fibre arrives in the hind gut.

Shoes On or Off for the Winter?

Why do we shoe our sport horses?

Due to soft soles or to prevent over wearing of soles

To improve conformational abnormalities such as club feet, flat feet, soft tissue injuries

Improve traction for some disciplines

Rehabilitation/recovery from injury

What are the draw backs?

Cost

Excessive Nail holes-crumbly hoof walls

Loss of traction

Self-injury

Possible worsening of caudal hoof failure

Should I take them off for the Winter?

Yes if you have nice soil in your paddocks

Yes if you have a problem with caudal hoof failure

Yes if your horse isn’t being ridden

Yes if you have crumbly hoof walls

No if there is stoney soils and the horses soles are soft

No if there is stoney soils and the walls will chip

No if there would be detriment to the feet due to conformational abnormalities or injuries

Shoes on for Spring!

We are considering running a podiatry day at our facility in Spring this year.

This will help farriers set up your horses feet the best they can for the season.

There will be a special price for podiatry xrays

Pre-shoeing and post shoeing radiographs will be available.

Biscuits and coffee are a given 😉

Pentosan PolySulphate

Pentosan Poly Sulphate: Support those joints

Do you have a plan to keep your horses joints supple as they age? Have you noticed during the winter months that your horses is displaying signs of increased joint soreness?

Pentosan is our recommended first line joint health supplement to be used in all sport horses to help in the prevention of arthritis.

Why is pentosan the first pick as a starter for your joint health programme?

It is very affordable on a price per day basis, approx. $0.80 per day.

NOTE for comparison: Many non-scientifically proven oral products are $2 to $5 per day.

It is scientifically proven to reach therapeutic levels in the joint after intra-muscular injection.

It is shown to stimulation a healthier metabolism and reduce negative enzymes within the joint.

Once a joint is inflamed, we recommend the next step; a 3 way treatment approach.

With a combination of Pentosan (many trade names), 4 Cyte, and Arthramid, you are protecting the bone, cartilage and synovial lining of the joint, as each product works on a different aspect of the joint.

Please remember, do not wait until the start of the season to get a joint health assessment. Too many clients missed the start of last season due to subtle lameness conditions. Most pain associated with joints takes 2-4 weeks minimum to resolve.

Sputum

Yucky photo of the week!

SPUTUM: This is mucous made in the respiratory system.

This photo shows the sputum coughed up by a horse with a respiratory infection.

That VIRUS is circulating again!!

Many horses have only shown mild signs this season, however some horses have had prolonged disease; 2-4 weeks of nasal discharge and coughing.

How does the virus transfer:

Usually hands, nose contact, or feed and water buckets

How can we prevent severe disease:

We have veterinary products we can use to promote mucous movement!

Viral infections act on the mechanisms that affect mucous secretion hence the increased risk for bacterial invasion and secondary infection.

Veterinary medicines can help get that mucous moving which helps to prevent the need for antibiotics.

Antibiotics kill horses every day so we want to avoid them where possible.

Management changes that can help:

Soak hay

Graze grass where possible

No exercise during infection stage

Isolate your horse

If your horses has a snotty nose or is coughing for more than 5 days then please call us.