Periodic eye inflammation has been known for over 2000 years and is the most common eye disease in horses. It describes a recurring inflammation of the middle layer of the eye (uvea) in horses. In veterinary medicine, the term "equine recurrent uveitis" (ERU) is now used. The disease occurs repeatedly, initially at longer intervals and later at shorter intervals, and can lead to significant visual impairment. Since the affected horses often went blind from this disease and it was suspected that it was related to the phases of the moon, it was also commonly referred to as moon blindness.
The symptoms vary greatly depending on the severity of the inflammation and are therefore often overlooked in the early stages. As the disease progresses, the symptoms increase and owners notice a squinting eye or increased tearing. Since it is not always easy for animal owners to distinguish between relatively harmless conjunctivitis and more severe internal eye inflammation (which is often accompanied by reddening of the conjunctiva), a veterinarian should always be consulted immediately if this is suspected.
Depending on their exact location, the inflammatory processes occurring inside the eye cause varying degrees of pain, which is not always equally severe in every horse. ERU is characterized by its recurrent nature, which distinguishes it from other eye infections with similar symptoms. Typical symptoms of ERU include increased tearing, severe sensitivity to light, swelling and warmth of the eyelids, severe eyelid spasms, constricted pupils and, in some cases, damage to the cornea. As the disease progresses, apathy and fever may occur.
In order to make an accurate diagnosis, the animal's medical history is extremely important for the veterinarian. This is the only way to distinguish between simple and recurrent eye inflammation. In addition to a general examination, the veterinarian will perform a special eye examination using an ophthalmoscope to get a closer look at the inside of the eye and the back of the eye. In most cases, the diagnosis can be made based on the clear clinical symptoms. However, reliable detection of leptospira antibodies can only be achieved by removing fluid from the front chamber of the eye under short anesthesia. A blood test is recommended in all cases to obtain information about the horse's general health and any signs of inflammation.
The uvea of the horse's eye is unfortunately very susceptible to inflammation. For this reason, various general illnesses such as strangles or other respiratory diseases can lead to eye inflammation. Despite intensive research, however, not all factors involved in the development of ERU are yet known. According to the latest findings, the following factors are possible triggers:
While leptospires in particular were long considered the primary trigger of ERU, it is now believed that the bacteria primarily break through the barrier between the blood and the eye (the so-called "blood-eye barrier"), leading to autoimmune processes in the inner eye. The periodic nature of the inflammation is caused by inflammatory products remaining in the eye, which trigger a repeated inflammatory response upon renewed contact with the antigen.
The inflammatory process can cause adhesions to form between the iris and the lens, which, together with inflammatory products that deposit on the back of the lens, can lead to lens opacity. The inflammation also causes opacities in the vitreous body with membrane-like deposits, which further restrict vision. A discolored iris and fibrin deposits in the anterior chamber of the eye can still be detected by the veterinarian even after the acute phase. Inflammation can recur as early as 4 to 8 weeks after the first episode has subsided. The intervals between individual episodes are similar at first, but can become significantly shorter as the disease progresses. The inflammation can cause damage to the cornea, lens, and vitreous body, increased or decreased intraocular pressure, and adhesions between the iris and the lens. If repeated untreated episodes of inflammation cause the retina to detach from the back of the eye, this usually leads to irreversible blindness in the horse.
In the acute stage of the disease, conservative, local treatment of the affected eye is carried out. Depending on the degree of inflammation and the symptoms, pain-relieving and anti-inflammatory eye ointments or drops are used. Pupil-dilating medications are only useful if there is also severe pupil constriction. If these preparations are used, the affected eye must not be exposed to strong sunlight in the following days, as the medication prevents normal pupil reaction in the first few days. A dark box or an appropriate eye mask provides protection and prevents the retina from being damaged by excessive light. Discuss with your veterinarian which eye ointments or drops are appropriate in individual cases and whether general painkillers or anti-inflammatory drugs also need to be administered.
However, the disease cannot usually be controlled with medication alone. To prevent progressive damage to the eye and new flare-ups of inflammation, vitreous surgery is an option. Vitrectomy refers to the removal of the vitreous body, including all inflammatory products and bacteria, and its subsequent replacement with a substitute fluid. This surgical technique is recommended almost exclusively for leptospira-related inflammation. The operation is performed under general anesthesia and is only carried out by a few specialized veterinarians. If there is no damage to the lens or retina, the chances of success are very good, as vision is also improved by removing the cloudy vitreous body contents. Nevertheless, every operation and every anaesthetic always involves risks. Your veterinarian will therefore discuss with you the extent to which surgery is advisable for your horse.
If vitreous surgery is not recommended by the veterinarian due to advanced damage to the eye, it is possible to suppress further inflammation in the long term by implanting a chemotherapeutic agent.
The earlier treatment is started and the less damage there is to the eyes, the better the chances of completely preserving the eye's vision. With the help of vitrectomy, many horses affected by ERU can now be protected from further progression of the disease.if the inflammation has already caused irreparable damage to the lens or retina, the prognosis is very poor and blindness is to be expected.
Due to the complex causes of ERU, comprehensive prevention is virtually impossible. However, good housing conditions, high-quality feed and bedding, and hygienic drinking troughs are important factors in keeping horses' eyes healthy. As mice are considered to be carriers of leptospira, adequate pest control in the stable is also important.
It is also advisable to have regular preventive examinations carried out by a veterinarian on each individual horse in order to detect any changes or diseases at an early stage.
In centuries past, looking into a horse's mouth played an important role, albeit primarily to determine the animal's age. Today, the focus is more on dental care and dental disease in horses. Dental hygiene is a very important aspect of keeping horses healthy. Regular veterinary checks of the mouth and teeth should be carried out at least once a year. The annual check-up and routine dental treatment can be carried out by any equine practice. In the event of specific dental problems or complications, it is advisable to consult a practice that specializes in equine dentistry. Typical dental problems in horses include tartar and the formation of hooks and edges on the molars due to uneven wear. These issues can be quickly resolved during routine treatment, preventing further damage. But how can we, as horse owners, tell if our horse has dental problems?
Hoof cancer is a chronic disease of the hoof corium. Unlike hoof abscesses, hoof cancer does not cause individual cells to die, but rather leads to uninhibited growth of individual parts of the hoof corium, accompanied by a foul-smelling discharge and a lack of keratinization of this tissue. The term "hoof cancer" was coined due to the appearance of this excessively grown, cauliflower-like tissue, although it is not a form of cancer.
Borna disease, also known as contagious encephalomyelitis or head disease of ungulates, is a rare viral disease of the nervous system that mainly affects horses and sheep. However, other animals and humans are also susceptible to the Borna virus. The disease was first described in 1813, when a whole group of cavalry horses fell ill in the town of Borna.
What is a fun night of dancing for many people is unfortunately a sensitive issue for a lot of dog owners: New Year's Eve fireworks frighten our noise-sensitive four-legged friends and can lead to major problems.
Uveitis is an inflammation of the uvea, the middle layer of the eye. It can be divided into anterior and posterior inflammation and manifests itself through a narrow pupil and reddened conjunctiva.
Due to its appearance, the neck lump is also known as a talpa, which means mole tumor. It describes all inflammatory enlargements of the soft tissues in the neck area of the horse. The majority of cases are due to inflammation of the bursa located under the neck band.
It happens in the paddock or even in the stall: your horse injures itself and may be bleeding. What should you do? Is it just a small scratch, a bump, or even a huge, gaping wound? Do I need to call the vet, or can I treat it myself, and if so, how? How can I minimize the risk of injury in the future? Kicks, bites, falls, or foreign objects can cause cuts, puncture wounds, abrasions, bruises, contusions, or burns in horses, which may require veterinary treatment depending on their severity. The severity of an injury always depends on its location and the involvement of surrounding structures, such as muscles, tendons, or joints. As with humans, a distinction is made between covered and open injuries in horses. In covered injuries, the horse's skin is undamaged, which is why this type of injury is not always easy to detect. For example, a kick may have caused a bruise that we as owners may only notice when grooming or when the horse is lame. Damage to the skin is referred to as an open injury or wound. This results in bleeding of varying severity, but even here, smaller wounds can be overlooked due to the coat.
Ear infections in dogs are one of the most common reasons for visits to the veterinarian. However, the condition is often detected too late and not treated consistently. The anatomical structure of the ear canal in dogs and its length make it prone to inflammation. Due to various factors, some dog breeds are even more susceptible to inflammation in the ear area. Outer ear infections, also known as otitis externa, are the most common type. Middle and inner ear infections are less common. However, if not detected early, these can develop into chronic conditions that require intensive treatment.
Skin fungus, also known as dermatomycosis, is one of the most common infectious skin diseases in cats. It resembles many other skin diseases in appearance and is therefore not always easy to diagnose. Many types of fungus are also transmissible to humans, meaning that it is a zoonosis.
Is your dog moving more stiffly, reluctant to go down stairs or jump into the car? Is he limping or does he have a swollen joint? Around 20% of all dogs develop joint diseases such as arthritis and osteoarthritis during their lifetime. But what is the difference between them?
If your horse is rubbing itself more than usual, you should take a closer look, as itching can be a key symptom of many skin diseases or allergies in horses. However, some metabolic disorders can also cause itching in horses. This condition is very stressful for your animal and should therefore be examined and treated by a veterinarian as soon as possible.
It is a dramatic sight for us as owners when our own horse suddenly cannot bend its hind leg and can barely walk. In many cases, the kneecap dislocation resolves itself and the horse runs normally again. If the dislocation does not resolve, a veterinarian must remedy the situation by skillfully manipulating the horse and leading it backwards or sideways so that it can walk normally again. A brief digression into the anatomy of the knee joint provides a simple explanation for this phenomenon.
