Paul’s Story: When One Alpaca’s Neurologic Signs Led Us to Horner’s Syndrome

“I am not a vetrinarian, when presented with any medical issue with alpaca's seek medical experts in vetrinary care. Our goal is to educate, share Paul’s story, and help owners have better conversations with their veterinarians — not to prescribe treatment. Decisions must be made with a licensed veterinarian who can evaluate the individual alpaca, its weight, condition, symptoms, medical history, and legal medication-use requirements”

This story is not meant to diagnose another alpaca. It is not meant to replace a veterinarian. It is being shared so alpaca owners can learn what to watch for, what to document, what questions to ask, and why clear communication with a veterinarian matters so much.

Alpacas are not cattle. They are not sheep. They are not goats. They are camelids, and many owners quickly learn that finding veterinary care with deep camelid experience can be difficult. In some areas, there are no emergency large-animal veterinarians nearby. In other places, the nearest university hospital may be hours away. Even when help is available, many veterinarians are trained more heavily in traditional ruminants, while alpacas are sometimes treated through the closest available comparison.

That is one of the reasons I wanted to share Paul’s story.

Paul is a six-year-old male alpaca. One early morning, about a week ago, I noticed that something was clearly wrong. He was walking poorly on his right side. His head was tilted to the right. The right side of his face was drooping. His right ear was drooping. His mouth and jaw did not look normal. Everything abnormal seemed to be happening on the right side.

My mind immediately went to PEM, also known as polioencephalomalacia. PEM is a serious neurologic disease seen in ruminants and camelids, and it has historically been associated with thiamine problems, though high sulfur intake and other causes may also be involved. Camelids are listed among the species affected by PEM.

But Paul was not acting like an animal who had completely given up. He was strong. He was alert. He was still very interested in the girls. His biggest deficits were one-sided: right-sided walking problems, right head tilt, right facial droop, right ear droop, drooling, and later, right eye changes.

That one-sided pattern made the case feel more complicated.

The cranial nerve piece

When an alpaca has drooping on one side of the face, an ear that will not move, drooling, a weak-looking lip or jaw, a head tilt, or abnormal eye responses, it raises concern for the nerves of the head and face. These are called cranial nerves.

In Paul’s case, several cranial nerves or related nerve pathways became important to think about.

Cranial nerve VII, the facial nerve, helps control facial movement. It affects the eyelids, ears, lips, nostrils, and facial expression. A problem with this nerve can cause a drooping ear, drooping lip, poor blinking, drooling, and food or water falling from the mouth. Merck Veterinary Manual describes facial nerve problems as affecting the eyelids, ears, lips, and nostrils, and notes that affected animals may drool or drop food and fluid from the mouth.

Cranial nerve VIII, the vestibulocochlear nerve, is connected with hearing and balance. A head tilt can point toward the vestibular system, which may involve the inner ear, the brainstem, or related nerve pathways. Middle and inner ear disease can cause signs such as head tilt, facial nerve palsy, Horner’s syndrome, dry eye, pain, hearing changes, and vestibular problems.

Cranial nerve II and cranial nerve III, the optic and oculomotor nerves, come into the discussion when vision, pupil response, and eye reflexes seem abnormal. A slow eye response does not automatically mean blindness. It may involve the eye itself, the optic pathway, the facial nerve’s role in blinking, or other neurologic pathways.

Cranial nerve V, the trigeminal nerve, can matter when jaw tone, chewing, and facial sensation seem abnormal.

The important lesson is that signs like Paul’s do not point to only one simple answer. They can involve the eye, the ear, the facial nerve, the vestibular system, trauma, infection, inflammation, or a deeper neurologic issue.

The first plan: thinking about PEM

Because Paul had sudden neurologic signs, PEM was high on the concern list. When PEM is suspected, veterinarians commonly think about injectable thiamine, also called vitamin B1, as a key emergency treatment. Veterinary references describe parenteral thiamine, meaning thiamine given by injection, as the primary treatment for PEM, and early treatment is important.

Common veterinarian-directed PEM treatment may include injectable thiamine, supportive care, a quiet and safe environment, protection from injury, hydration and nutrition support, and temperature regulation. In more severe cases, veterinarians may also consider medication for brain swelling or seizures. Those decisions belong with a veterinarian because drug choice, dose, route, withdrawal considerations, and safety risks vary by animal and situation.

In Paul’s case, I moved him into our indoor health pen where we could better regulate his temperature, footing, safety, and environment. Then I called my veterinarian. We reviewed the symptoms and discussed my plan of care.

At that point, we were both leaning toward PEM as one possible explanation. We also decided that a course of oxytetracycline would be started under veterinary direction for three doses, followed by reevaluation.

That part of the story is important. We were not treating “Horner’s syndrome” with oxytetracycline. We were working through a real-time medical situation with a veterinarian, where PEM was one concern and infection or other underlying causes still had to stay on the list.

Over the next couple of days, I started to see small improvements. Paul’s walking became normal again. Some of the drooping of his lip seemed a little less. The drooling stopped.

But his right ear still was not moving. His vision seemed to be there, but the reflex response seemed slow. Then his right eye started tearing a lot.

When we looked closer, we saw cloudiness in the eye. That became a new concern. If an alpaca has facial nerve dysfunction and cannot blink or protect the eye normally, the eye can become irritated, dry, injured, or ulcerated. Facial nerve problems can reduce eyelid movement and put the cornea at risk.

Under veterinary direction, we started treating the eye with an antibiotic ointment three to four times per day.

Again, the medication lesson matters. The antibiotic eye ointment was not treating PEM. It was not treating Horner’s syndrome directly. It was being used because Paul’s eye had become a specific concern, likely related to poor eye protection, tearing, cloudiness, or possible corneal injury.

For about two days, things seemed stable.

Then a new problem appeared.

Paul developed swelling on his right flank. It looked almost like a water bag under the skin, and it was painful to touch. Once again, I called my veterinarian and reviewed everything: the neurologic signs, the medications, the eye, the swelling, and Paul’s overall condition.

He still had no fever. He was urinating well. He was passing his magic beans. He was eating, alert, and still acting like Paul in many ways.

At that point, trauma became a stronger possibility.

That made sense. When the girls start having babies, the boys know. The noses go up, the hormones rise, and the fighting can start. It is very possible that a traumatic event happened that we did not witness.

Then the drooping in Paul’s jaw seemed to go backward a bit. The swelling on the right side of his abdomen seemed to be stabilizing. Everything else was about the same.

During one of our conversations, my veterinarian mentioned Horner’s syndrome.

At first, I did not fully connect the dots. In fairness, when you are worried about an animal you love, you do not always put two and two together right away.

Later, while researching in my camelid medicine and surgery book and reviewing veterinary references, I realized that Horner’s syndrome was not simply “an eye problem.” It is a neurologic sign caused by disruption of the sympathetic nerve pathway to the eye and nearby facial structures. Classic Horner’s syndrome signs include a drooping upper eyelid, a small pupil, a sunken-looking eye, elevation of the third eyelid, and narrowing of the eye opening. Merck Veterinary Manual shows a llama with classic Horner’s syndrome signs, which is helpful as a camelid visual reference.

But Paul’s case was more complicated than classic Horner’s syndrome alone.

Paul had right-sided facial droop. Right ear droop. Drooling. Head tilt. Slow eye response. Eye tearing and cloudiness. Later, right-sided flank swelling.

Those signs made us think more broadly: facial nerve involvement, vestibular involvement, eye protection problems, possible ear involvement, possible trauma, possible infection, possible swelling or abscess, and possibly Horner’s syndrome as one part of a bigger picture.

That is why Horner’s syndrome should be understood as a sign, not always the final diagnosis.

Teaching note: PEM treatment vs. Horner’s syndrome treatment

This is one of the biggest lessons from Paul’s case.

PEM and Horner’s syndrome are treated differently.

PEM is often approached as a neurologic emergency where injectable thiamine is commonly central to veterinarian-directed treatment. Horner’s syndrome is different. There is no single medication that treats Horner’s syndrome itself. Horner’s syndrome means the nerve pathway to the eye and face has been disrupted somewhere, so the real question becomes: why?

Is there trauma?
Is there ear disease?
Is there facial nerve injury?
Is there eye damage from poor blinking?
Is there infection?
Is there an abscess?
Is there swelling?
Is there a mass?
Is there a deeper neurologic problem?

That is why treatment may shift as the case changes.

In Paul’s case, oxytetracycline was part of the veterinarian-directed early course while PEM and other possible causes were being considered. Antibiotic eye ointment was added when the eye became a concern. Later, as trauma, swelling, infection, or another underlying process became more concerning, Paul was changed to penicillin, one dose per day for many days, under veterinary direction.

Penicillin is not a Horner’s syndrome medication. Oxytetracycline is not a Horner’s syndrome medication. Antibiotic eye ointment is not a PEM medication.

These medications were part of Paul’s individual veterinarian-directed course as his signs changed.

That distinction is important because owners should not copy Paul’s treatment plan for another alpaca. Another alpaca with similar signs may need a very different plan.

The plain-language medication contrast

Middle and inner ear disease are especially important to keep in mind because they can cause several signs that overlap with Paul’s case. Veterinary references list Horner’s syndrome, dry eye, facial nerve palsy, head and neck pain, decreased hearing, head tilt, abnormal eye movements, and vestibular signs among possible findings with middle or inner ear disease.

Why Paul’s story matters

Paul’s story is not being shared because I have all the answers. It is being shared because alpaca owners often find themselves trying to make sense of complicated symptoms with limited access to camelid-specific veterinary care.

When something like this happens, time matters. Observation matters. Documentation matters. Communication with the veterinarian matters.

If an alpaca has one-sided facial drooping, ear drooping, a head tilt, drooling, poor blinking, a tearing eye, a cloudy eye, a small pupil, a sunken-looking eye, poor coordination, or unexplained swelling, those signs should not be ignored.

Owners should document:

• Which side is affected.
• Whether the ear, eyelid, lip, nostril, jaw, or eye looks abnormal.
• Whether the alpaca can blink normally.
• Whether there is tearing, cloudiness, discharge, or squinting.
• Whether there is head tilt, circling, stumbling, or poor balance.
• Whether appetite, urination, manure, temperature, and attitude are normal.
• Whether there may have been trauma, fighting, breeding behavior, halter injury, injections, surgery, or recent handling.
• What medications were given, when they were given, and what changed afterward.

The more clearly an owner can describe the signs, the better the veterinarian can help sort through possibilities such as PEM, trauma, ear disease, facial nerve injury, eye injury, infection, abscess, swelling, or Horner’s syndrome.

Today, Paul is still fighting. He is strong. He is alert. He is still Paul. His walking improved. The drooling stopped. The eye is being treated. The flank swelling is being watched. His medication plan has changed as the case has changed, and he is now receiving penicillin under veterinary direction.

God willing, we will see him improve.

Right now, it feels like a Hail Mary. But sometimes with alpacas, especially when the signs are unusual and veterinary access is limited, the best thing we can do is keep learning, keep documenting, keep communicating with the vet, and keep fighting for the animal in front of us.

If Paul’s story helps even one alpaca owner recognize that a drooping ear, facial droop, head tilt, tearing eye, cloudy eye, or one-sided neurologic change is not something to ignore, then sharing it is worth it.

The goal is not to replace veterinarians.

The goal is to bring alpaca medical issues to the table so owners and veterinarians can have better conversations, ask better questions, save time, and hopefully save lives.