A saddle sore in humans is a skin ailment on the buttocks due to, or exacerbated by, horse riding or cycling on a bicycle saddle. It often develops in three stages: skin abrasion, folliculitis (which looks like a small, reddish acne), and finally abscess.

Because it most commonly starts with skin abrasion, it is desirable to reduce the factors which lead to skin abrasion. Some of these factors include:

- Reducing the friction. In equestrian activities, friction is reduced with a proper riding position and using properly fitting clothing and equipment. In cycling, friction from bobbing or swinging motion while pedaling is reduced by setting the appropriate saddle height. Angle and fore/aft position can also play a role, and different cyclists have different needs and preferences in relation to this.

- Selecting an appropriate size and design of horse riding saddle or bicycle saddle.

- Wearing proper clothing. In bicycling, this includes cycling shorts, with chamois padding. For equestrian activity, long, closely fitted pants such as equestrian breeches or jodhpurs minimize chafing. For western riding, closely fitted jeans with no heavy inner seam, sometimes combined with chaps, are preferred. Padded cycling shorts worn under riding pants helps some equestrians, and extra padding, particularly sheepskin, on the seat of the saddle may help in more difficult situations such as long-distance endurance riding.

- Using petroleum jelly, chamois cream or lubricating gel to further reduce friction.

If left untreated over an extended period of time, saddle sores may need to be drained by a physician.

In animals such as horses and other working animals, saddle sores often form on either side of the withers, which is the area where the front of a saddle rests, and also in the girth area behind the animal's elbow, where they are known as a girth gall. Saddle sores can occur over the loin, and occasionally in other locations. These sores are usually caused by ill-fitting gear, dirty gear, lack of proper padding, or unbalanced loads. Reducing friction is also of great help in preventing equine saddle sores. Where there is swelling but not yet open sores, the incidence of sore backs may be reduced by loosening the girth, but not immediately removing the saddle after a long ride, thus allowing normal circulation to return slowly.

The symptoms can be mild or severe and may include:

- Not able to chew or swallow

- Sores on the inside of the cheeks or gums

- Fever

- General discomfort, uneasiness, or ill feeling

- Very sore mouth with no desire to eat

- Halitosis (bad breath)

Saddle nose is a condition associated with nasal trauma, congenital syphilis, relapsing polychondritis, granulomatosis with polyangiitis, cocaine abuse, and leprosy, among other conditions. The most common cause is nasal trauma. It is characterized by a loss of height of the nose, because of the collapse of the bridge. The depressed nasal dorsum may involve bony, cartilaginous or both bony and cartilaginous components of the nasal dorsum.

Gingivostomatitis symptoms in infants may wrongly be dismissed as teething. "Coincidentally, primary tooth eruption begins at about the time that infants are losing maternal antibody protection against the herpes virus. Also, reports on teething difficulties have recorded symptoms which are remarkably consistent with primary oral herpetic infection such as fever, irritability, sleeplessness, and difficulty with eating." "Younger infants with higher residual levels of antibodies would experience milder infections and these would be more likely to go unrecognized or be dismissed as teething difficulty."

Gingivostomatitis must also be differentiated from herpangina, another disease that also commonly causes ulcers in the oral cavity of children, but is caused by the Coxsackie A virus rather than a herpes virus. In herpangina, ulcers are usually isolated to the soft palate and anterior pillar of the mouth. In herpetic gingivostomatitis, lesions can be found in these locations, but they are almost always accompanied by ulcerations on the gums, lips, tongue or buccal mucosa and/or by hyperemia, hypertrophy or hemorrhage of the gums.

This most common form of impetigo, also called nonbullous impetigo, most often begins as a red sore near the nose or mouth which soon breaks, leaking pus or fluid, and forms a honey-colored scab, followed by a red mark which heals without leaving a scar. Sores are not painful, but they may be itchy. Lymph nodes in the affected area may be swollen, but fever is rare. Touching or scratching the sores may easily spread the infection to other parts of the body.

Skin ulcers with redness and scarring also may result from scratching or abrading the skin.

Herpes infections usually show no symptoms; when symptoms do appear they typically resolve within two weeks. The main symptom of oral infection is inflammation of the mucosa of the cheek and gums—known as acute herpetic gingivostomatitis—which occurs within 5–10 days of infection. Other symptoms may also develop, including headache, nausea, dizziness and painful ulcers—sometimes confused with canker sores—fever, and sore throat.

Primary HSV infection in adolescents frequently manifests as severe pharyngitis with lesions developing on the cheek and gums. Some individuals develop difficulty in swallowing (dysphagia) and swollen lymph nodes (lymphadenopathy). Primary HSV infections in adults often results in pharyngitis similar to that observed in glandular fever (infectious mononucleosis), but gingivostomatitis is less likely.

Recurrent oral infection is more common with HSV-1 infections than with HSV-2. Symptoms typically progress in a series of eight stages:

1. Latent (weeks to months incident-free): The remission period; After initial infection, the viruses move to sensory nerve ganglia (trigeminal ganglion), where they reside as lifelong, latent viruses. Asymptomatic shedding of contagious virus particles can occur during this stage.

2. Prodromal (day 0–1): Symptoms often precede a recurrence. Symptoms typically begin with tingling (itching) and reddening of the skin around the infected site. This stage can last from a few days to a few hours preceding the physical manifestation of an infection and is the best time to start treatment.

3. Inflammation (day 1): Virus begins reproducing and infecting cells at the end of the nerve. The healthy cells react to the invasion with swelling and redness displayed as symptoms of infection.

4. Pre-sore (day 2–3): This stage is defined by the appearance of tiny, hard, inflamed papules and vesicles that may itch and are painfully sensitive to touch. In time, these fluid-filled blisters form a cluster on the lip (labial) tissue, the area between the lip and skin (vermilion border), and can occur on the nose, chin, and cheeks.

5. Open lesion (day 4): This is the most painful and contagious of the stages. All the tiny vesicles break open and merge to create one big, open, weeping ulcer. Fluids are slowly discharged from blood vessels and inflamed tissue. This watery discharge is teeming with active viral particles and is highly contagious. Depending on the severity, one may develop a fever and swollen lymph glands under the jaw.

6. Crusting (day 5–8): A honey/golden crust starts to form from the syrupy exudate. This yellowish or brown crust or scab is not made of active virus but from blood serum containing useful proteins such as immunoglobulins. This appears as the healing process begins. The sore is still painful at this stage, but, more painful, however, is the constant cracking of the scab as one moves or stretches their lips, as in smiling or eating. Virus-filled fluid will still ooze out of the sore through any cracks.

7. Healing (day 9–14): New skin begins to form underneath the scab as the virus retreats into latency. A series of scabs will form over the sore (called Meier Complex), each one smaller than the last. During this phase irritation, itching, and some pain are common.

8. Post-scab (12–14 days): A reddish area may linger at the site of viral infection as the destroyed cells are regenerated. Virus shedding can still occur during this stage.

The recurrent infection is thus often called "herpes simplex labialis". Rare reinfections occur inside the mouth ("intraoral HSV stomatitis") affecting the gums, alveolar ridge, hard palate, and the back of the tongue, possibly accompanied by "herpes labialis".

A lesion caused by herpes simplex can occur in the corner of the mouth and be mistaken for angular cheilitis of another cause. Sometimes termed "angular herpes simplex". A cold sore at the corner of the mouth behaves similarly to elsewhere on the lips. Rather than utilizing antifungal creams, angular herpes simplex is treated in the same way as a cold sore, with topical antiviral drugs.

Bullous impetigo, mainly seen in children younger than 2 years, involves painless, fluid-filled blisters, mostly on the arms, legs, and trunk, surrounded by red and itchy (but not sore) skin. The blisters may be large or small. After they break, they form yellow scabs.

The term "labia" means "lip". Herpes labialis does not refer to the labia of the genitals, though the origin of the word is the same. When the viral infection affects both face and mouth, the broader term "orofacial herpes" is used, whereas the term "herpetic stomatitis" is used to specifically describe infection of the mouth; "stomatitis" is derived from the Greek word stoma that means "mouth".

The most obvious sign of thrush is usually the odor that occurs when picking out the feet. Additionally, the infected areas of the hoof will be black in color (even on a dark-horned hoof), and will easily break or crumble when scraped with a hoof pick. When picking the hooves around thrush areas, the differences between healthy and infected areas can be seen when white/gray tissue (healthy frog) is surrounding a dark, smelly (infected) area.

Most horses do not become lame if infected with thrush. However, if left untreated, the bacteria may migrate deeper into the sensitive parts of the hoof, which will result in lameness. Then, the horse may also react when its feet are picked out, and blood may be seen.

Thrush is a very common bacterial infection that occurs on the hoof of a horse, specifically in the region of the frog. The bacterium involved is" Fusobacterium necrophorum", and occurs naturally in the animal's environment — especially in wet, muddy, or unsanitary conditions, such as an unclean stall — and grows best with low oxygen. Horses with deep clefts, or narrow or contracted heels are more at risk of developing thrush.

Lameness is most commonly caused by pain, but may also be the result of neuromuscular disease or mechanical restriction. Lameness itself is a clinical sign, and not a diagnosis.

It can usually be corrected with augmentation rhinoplasty by filling the dorsum of nose with cartilage, bone or synthetic implant. If the depression is only cartilaginous, cartilage is taken from the nasal septum or auricle and laid in single or multiple layers. If deformity involves both cartilage and bone, cancellous bone from iliac crest is the best replacement. Autografts are preferred over allografts. Saddle deformity can also be corrected by synthetic implants of teflon or silicon, but they are likely to be extruded.

A nasal septal abscess is frequently a result of a secondary bacterial infection of a nasal septal hematoma. Individuals with this condition may also have fever, general malaise and nasal pain, including tenderness over the dorsum of the nose. A bilateral persistent nasal obstruction may also be present.

Polymelia (from Greek πολυ- = "many" plus μέλος (plural μέλεα) = "limb") also known as "hydra syndrome" is a birth defect involving limbs (a type of dysmelia), in which the affected individual has more than the usual number of limbs. In humans and most land-dwelling animals, this means having five or more limbs. The extra limb is most commonly shrunken and/or deformed.

Sometimes an embryo started as conjoined twins, but one twin degenerated completely except for one or more limbs, which end up attached to the other twin.

Sometimes small extra legs between the normal legs are caused by the body axis forking in the dipygus condition.

Nasal septal abscess is a condition of the nasal septum in which there is a collection of pus between the mucoperichondrium and septal cartilage.

Lameness is an abnormal gait or stance of an animal that is the result of dysfunction of the locomotor system. In the horse, it is most commonly caused by pain, but can be due to neurologic or mechanical dysfunction. Lameness is a common veterinary problem in racehorses, sport horses, and pleasure horses. It is one of the most costly health problems for the equine industry, both monetarily for the cost of diagnosis and treatment, and for the cost of time off resulting in loss-of-use.

CPL is a progressive disease, which begins below the fetlock and gradually moves up the leg. All legs are affected, the hindlimbs usually more seriously so. Initial signs include thickening, crusting and folding of the skin. These early signs may be hidden by the long hair (feather) on the horse's lower legs. Affected areas are itchy, causing the horse to stamp its feet and rub its legs, and painful, so that the horse may be reluctant to allow its legs to be touched. As CPL progresses, ulcers develop on the pasterns, and fibrosis leads to hardening of the skin and the development of nodules which may become baseball sized. Secondary infections with microbes or mites commonly cause complications. Infestations with the mange mite "Chorioptes equi" are very itchy, and lead to self-trauma and dermatitis.

The quality of the hoof is often poor; hooves are prone to cracks, splits and the development of thrush and abscesses; horses may develop laminitis. Chestnuts and ergots are often misshapen and irregular.

There are many oral and maxillofacial pathologies which are not fully understood.

- Burning mouth syndrome (BMS) is a disorder where there is a burning sensation in the mouth that has no identifiable medical or dental cause. The disorder can affect anyone but tends to occur most often in middle aged women. BMS has been hypothesized to be linked to a variety of factors such as the menopause, dry mouth (xerostomia) and allergies. BMS usually lasts for several years before disappearing for unknown reasons. Other features of this disorder include anxiety, depression and social isolation. There is no cure for this disorder and treatment includes use of hydrating agents, pain medications, vitamin supplements or the usage of antidepressants.

- Aphthous stomatitis is a condition where ulcers (canker sores) appear on the inside of the mouth, lips and on tongue. Most small canker sores disappear within 10–14 days. Canker sores are most common in young and middle aged individuals. Sometimes individuals with allergies are more prone to these sores. Besides an awkward sensation, these sores can also cause pain or tingling or a burning sensation. Unlike herpes sores, canker sores are always found inside the mouth and are usually less painful. Good oral hygiene does help but sometime one may have to use a topical corticosteroid.

- Migratory stomatitis is a condition that involves the tongue and other oral mucosa. The common migratory glossitis (geographic tongue) affects the anterior two thirds of the dorsal and lateral tongue mucosa of 1% to 2.5% of the population, with one report of up to 12.7% of the population. The tongue is often fissured, especially. in elderly individuals. In the American population, a lower prevalence was reported among Mexican Americans (compared with Caucasians and African Americans) and cigarette smokers. When other oral mucosa, beside the dorsal and lateral tongue, are involved, the term migratory stomatitis (or ectopic geographic tongue) is preferred. In this condition, lesions infrequently involve also the ventral tongue and buccal or labial mucosa. They are rarely reported on the soft palate and floor of the mouth.

Heel pain is very common in horses with navicular syndrome. Lameness may begin as mild and intermittent, and progress to severe. This may be due to strain and inflammation of the ligaments supporting the navicular bone, reduced blood flow and increased pressure within the hoof, damage to the navicular bursa or DDF tendon, or from cartilage erosion.

Affected horses display a "tiptoe" gait - trying to walk on the toes due to heel pain. They may stumble frequently. The lameness may switch from one leg to another, and may not be consistent. Lameness usually occurs in both front feet, although one foot may be more sore than the other.

Lameness is usually mild (1–2 on a scale of 5). It can be made worse when the horse is worked on a hard surface or on a circle.

After several months of pain, the feet may begin to change shape, especially the foot that has been experiencing the most pain, which tends to become more upright and narrow.

Navicular syndrome, often called navicular disease, is a syndrome of lameness problems in horses. It most commonly describes an inflammation or degeneration of the navicular bone and its surrounding tissues, usually on the front feet. It can lead to significant and even disabling lameness.

Nasal septal hematoma is a condition affecting the nasal septum. It can be associated with trauma.

Because the septal cartilage has no blood supply of its own and receives all of its nutrients and oxygen from the perichondrium, an untreated septal hematoma may lead to destruction of the septum. Immediate drainage is necessary. Failure to recognise septal hematomas, or treat in a timely fashion, can cause a saddle nose deformity.

Chronic progressive lymphedema (CPL) is a disease of some breeds of draft horse, whereby the lower legs becomes progressively more swollen. There is no cure; the aim of treatment is to manage the signs and slow progression of the disease. The cause of CPL is not known, although it is suspected that a genetic disorder of elastin metabolism prevents the lymphatic vessels from functioning properly, leading to edema of the lower limbs. CPL resembles the human disease elephantiasis verrucosa nostra.

Oral and maxillofacial pathology (also termed oral pathology, stomatognathic disease, dental disease, or mouth disease) refers to the diseases of the mouth ("oral cavity" or "stoma"), jaws ("maxillae" or "gnath") and related structures such as salivary glands, temporomandibular joints, facial muscles and perioral skin (the skin around the mouth). The mouth is an important organ with many different functions. It is also prone to a variety of medical and dental disorders.

The specialty oral and maxillofacial pathology is concerned with diagnosis and study of the causes and effects of diseases affecting the oral and maxillofacial region. It is sometimes considered to be a specialty of dentistry and pathology. Sometimes the term head and neck pathology is used instead, but this might imply that the pathologist deals with otorhinolaryngologic disorders (i.e. ear, nose and throat) in addition to maxillofacial disorders. In this role there is some overlap between the expertise of head and neck pathologists and that of endocrine pathologists.

Mud fever, also known as scratches or pastern dermatitis, is a group of diseases of horses causing irritation and dermatitis in the lower limbs of horses. Often caused by a mixture of bacteria, typically "Dermatophilus congolensis", and "Staphylococcus spp", mud fever can also be caused by fungal organisms (dermatophytes). Photosensitization, chorioptic mange mites, contact dermatitis and other conditions also contribute to some cases. This condition is also known as "dew poisoning," "grease heel," or "greasy heel".

Mud fever affects most horses and ponies during winter and early spring, resulting in painful sores and scabs, which in severe cases can make a horse lame. Mud fever most commonly affects the pastern and heel area but can also affect the upper leg, the belly, and in some cases the neck area (also known as Rain Scald). Non-pigmented skin tends to be more severely affected.

Saddle anesthesia is a loss of sensation (anesthesia) restricted to the area of the buttocks, perineum and inner surfaces of the thighs.

It is frequently associated with the spine-related injury cauda equina syndrome. It is also seen in conus medullaris, the difference is that it is symmetrical in conus medullaris and asymmetric in cauda equina.It may also occur as a temporary side-effect of a sacral extra-dural injection: