Foreign objects in the skin

Author: Dr. med. vet. Gisa Löwe | Last modified: 17.02.2026
Content
Download/Print
Content
Download/Print

This might also interest you:

Foreign bodies in dogs and cats

 

Foreign object in the skin
A foreign object in the skin is a penetrated object such as a wood splinter, thorn or awn in the subcutaneous tissue. It causes local pain, swelling, redness and often abscess formation. Awns in particular can migrate and trigger deep infections.

Foreign objects in the skin are foreign objects that penetrate the skin barrier and remain in the tissue. In dogs and cats, this is a common problem that can occur in varying degrees of severity. The skin, as the largest organ in the body, serves as the primary protective barrier against environmental influences. If this barrier is broken, foreign materials can penetrate and trigger local or systemic reactions. Depending on the type, size and location of the foreign object and the individual reaction of the animal, different clinical manifestations can occur. Animals with active exercise in nature or with a dense undercoat in which foreign objects can easily get caught are particularly at risk.

Causes

Small foreign objects include wood splinters, small pieces of glass, thorns or stingers, and very often seed heads of grasses in the skin or just below the skin surface.
You can usually remove these yourself from your animals. The skin is not that sensitive and tends to heal quickly with minor injuries.
However, there are also more serious cases in which clear symptoms can occur.

Additions:

The causes of foreign objects in the skin are varied and depend heavily on the animal’s living environment and activities. The most common foreign objects include:

Plant materials are the largest group, especially grass awns and barbs, which can penetrate deep into the tissue due to their arrow-shaped structure and barbs and can even actively migrate. These are particularly problematic because their nature means that they can only migrate in one direction and can burrow deeper and deeper into the tissue. Thorns and stingers from plants such as roses, blackberries or cacti can also penetrate deeply and break off.

Wood splinters often occur when chewing on sticks or playing with wooden objects and can become lodged in the gums, paws or other parts of the body. Glass shards and metal splinters are often picked up in urban environments, especially in the paw pads during walks.

A special form is biological foreign objects such as ticks, insect stingers or parts of parasites. Foxtail grasses and burrs are particularly problematic because their barbs make them difficult to remove and can penetrate deep into the tissue.

Fishhooks and other metal objects can lead to serious injuries in animals that live near fishing spots or workshops. Sewing and pins are also occasionally found in pets, especially if they play with household objects.

Symptoms

Foreign objects in the skin of dogs and cats

Typical Symptoms:

  • Swelling, pain, licking/chewing/gnawing, lameness
  • Punctiform entry point (e.g. awn/thorn)
  • Redness, warmth, possibly serous secretion

Alarm signs:

  • Rapidly increasing swelling/pain, purulent discharge
  • Fever, apathy, clear lameness
  • Foreign body near eye/joint/chest or deep puncture wound

Escalation/course:

  • 24–72 h: Abscess formation typical, especially with awns
  • Migrating awns → changing swelling, fistulous tracts over days–weeks
  • Increasing pain despite immobilization → deeper involvement

 

The symptoms of foreign objects in the skin vary depending on the location, type of foreign object and duration of stay in the tissue. Typical signs are local inflammatory reactions with redness, swelling and increased warmth in the affected area. Many animals show clear pain behavior when touching the affected area or when moving the corresponding part of the body.

A characteristic behavior is intense licking, biting or scratching at the entry point. Lameness or protective posture / guarding posture can occur with foreign objects in the paws. Fistulous tracts with purulent secretion often develop if the foreign object remains in the tissue for a long time. These fistulous tracts can recur even if the infection appears to have healed.

In the case of migrating foreign objects such as awns (e.g. seed heads of wild oats), the symptoms can occur at a different location than the original entry point. Foreign objects in sensitive regions such as the eyes, where they can lead to conjunctivitis, increased tear flow and blepharospasm, or in the ears, where they can cause head shaking and torticollis, are particularly dangerous.

If it remains in the tissue for a longer period of time, systemic symptoms such as fever, loss of appetite and general fatigue can occur, especially if an infection spreads. A particular danger and additional problems can arise if the foreign object:

  • has been lying there for a long time and the wound is infected,
  • is heavily soiled,
  • is large and has penetrated deeply,
  • a blood vessel has been injured and the wound is bleeding heavily,
  • is located in a dangerous region of the body (eye, oral cavity).

Special considerations for cats

Bite and scratch injuries with embedded hair or dirt are not uncommon in cats. Bite injuries are often found around the head, neck, flanks, and base of the tail. A cat’s skin “closes” small Wounds quickly, but fluid and pus can collect underneath. This very often leads to Abscesses.

First Aid

  1. Pull out superficial foreign objects with tweezers.
  2. If the foreign object has penetrated a little deeper, you should remove the hair in the region, clean your hands and the affected region with soap and water and, if possible, also disinfect with an alcoholic disinfectant solution.
  3. Using a similarly disinfected needle, you can scratch the skin over the foreign object and lever the foreign object out or lift it on one side so that you can grasp it with tweezers and pull it out.
  4. Then wash the area again and dry it.
  5. The treated area should heal completely within a few days. Otherwise, part of the foreign object could still be present in the depth. Then introduce your animal to a veterinarian.
  6. For large or stuck foreign objects (fishhooks), do not try to remove them yourself.
  7. If necessary, pad the foreign object against the neighboring tissue and apply a non-compressive bandage.
  8. Also seek professional help for very dirty foreign objects or if there has been severe bleeding.

When should you see a vet sooner?

Urgency from Green to → Yellow if pus, severe swelling, lameness, fever, or foreign object deep/near eye/chest/abdomen.

Diagnosis

The diagnosis of foreign objects in the skin begins with a thorough medical history, in which the pet owner is asked about possible exposures to foreign materials. The clinical examination includes a careful inspection and palpation of the affected area. Visual identification may be possible for superficial foreign objects, especially after shearing the hair in the affected area.

Imaging techniques are often essential for deeper foreign objects. Ultrasound is particularly valuable because it can also display non-metallic foreign objects and enables precise localization. X-rays are helpful for metallic or mineral foreign objects, while they are often less meaningful for organic materials such as wood or plant material.

In more complex cases, computed tomography (CT) or magnetic resonance imaging (MRI) can be used to determine the exact location and extent. If migrating foreign objects are suspected, fistulography can be performed, in which contrast medium is injected into the fistulous tract to display its course.

Endoscopy can be used diagnostically and therapeutically for foreign objects in accessible body openings such as ears or nasal cavities. Cytological and microbiological examinations of exudate can help to characterize secondary infections and select the appropriate antimicrobial therapy.

Further veterinary measures

Foreign objects lying close to the skin surface but no longer visible from the outside can usually be easily detected by an ultrasound examination and then surgically removed.
Small foreign objects can heal and become encapsulated. They are then discovered later rather by chance, for example during an X-ray examination. However, if they cause discomfort such as infections, pain due to pressure on a nerve or restrict movement, they must be removed.

Supplements

The therapy of foreign objects in the skin is primarily aimed at the complete removal of the foreign material. In the case of superficial, clearly visible foreign objects, this can often be done on an outpatient basis under local anesthesia. The affected area is first thoroughly cleaned and disinfected to minimize the risk of infection.

For deeper or larger foreign bodies, surgical intervention may be required under general anesthesia. The surrounding tissue is carefully prepared to completely remove the foreign body while protecting surrounding structures. For migrating foreign bodies like awns, extensive exploration may be necessary, as these often form fistulous tracts.

After removal, the wound is thoroughly rinsed with sterile saline solution or antiseptic solutions to remove contaminants and bacteria. Depending on the size and location of the wound, primary wound closure or open wound treatment may be indicated. In infected wounds, a drainage is often inserted to drain secretions.

The aftercare usually includes systemic antibiotics, especially for long-standing or infected foreign objects. Analgesics are administered to control pain. Local wound treatments with antiseptic solutions or ointments can promote healing.

In complicated cases, especially with migrating foreign objects that could not be completely removed, repeated interventions may be necessary. Modern treatment methods such as laser surgery can offer advantages for certain types of foreign objects, as they work more precisely and minimize bleeding at the same time.

Prognosis and aftercare

The prognosis for foreign objects in the skin is generally good if the foreign object can be completely removed and no serious complications have occurred. The timing of the intervention is crucial for the chances of healing – the earlier the foreign object is removed, the lower the risk of complications such as chronic infections or fistula formation.

Careful aftercare is necessary after the foreign object has been removed. The wound should be checked regularly for signs of infection or inadequate healing. Typical warning signs are persistent redness, swelling, increased warmth, tenderness or purulent secretion. A lick guard such as a neck collar or special bodysuits can prevent the animal from manipulating the wound and disrupting the healing process.

In complicated cases, follow-up examinations with imaging techniques may be indicated to ensure that no foreign object residues remain. Antibiotic therapy should be carried out completely according to veterinary instructions, even if the symptoms have already subsided.

Long-term complications can occur with incomplete removal or with migrating foreign objects. These include chronic infections, granuloma formation, scar tissue formation with functional limitations or, in rare cases, systemic infections. Remaining foreign object residues should always be considered in the case of recurring symptoms in the same area.

Summary

Foreign objects in the skin are a common disease in dogs and cats caused by the penetration of various materials such as plant parts, wood splinters, glass or metal. The clinical symptoms range from local inflammatory reactions to systemic infections if they remain in the tissue for a longer period of time. Migrating foreign objects such as grass awns are particularly problematic because their structure allows them to penetrate deep into the tissue and form fistulous tracts.

The diagnosis is made by clinical examination and imaging techniques, with ultrasound examination in particular providing valuable services. The therapy consists primarily of the complete removal of the foreign object, followed by adequate wound care and, if necessary, antibiotic treatment. With early intervention, the prognosis is usually good, while delayed treatment can lead to complications such as chronic infections or fistula formation.

Preventive measures such as regular coat checks, especially after stays in nature, and avoiding risk areas during certain seasons can reduce the occurrence of foreign objects. If a foreign object is suspected, veterinary help should be sought promptly to avoid complications.

Outlook on current research

Research in the field of foreign body diagnostics and therapy is constantly evolving. New imaging techniques such as high-resolution ultrasound and specialized CT protocols improve the detection of even the smallest foreign bodies. Particularly promising are advances in contrast agent development, which specifically bind to foreign materials and make them more visible in imaging procedures.

In the field of minimally invasive surgery, endoscopic techniques are increasingly being used for foreign body removal, which cause less tissue damage and can shorten healing time. Advances in laser surgery enable more precise removal while reducing bleeding and collateral damage.

Wound treatment after foreign body removal benefits from innovative biomaterials and antimicrobial dressings, which create an optimal healing environment and can prevent infection at the same time. Local release systems for antibiotics and anti-inflammatory substances enable targeted therapy with minimal systemic side effects.

A growing area of research is the development of prevention strategies, including special protective clothing for dogs in high-risk environments and impregnating agents for the coat that can reduce the adhesion of foreign bodies. Early detection by pet owners is also supported by digital tools such as apps for documenting and tracking skin changes.

Frequently asked questions (FAQs)

  1. How can I tell if my pet has a foreign object in its skin?
    Look for signs such as increased licking or biting at a specific area, lameness, local swelling, redness, or purulent discharge. Specific symptoms such as head shaking (ear) or increased tear flow (eye) can occur with foreign objects in sensitive areas.
  2. Which foreign objects are particularly dangerous?
    Grass awns and barbs are particularly problematic because their barbs allow them to penetrate deep into the tissue and actively migrate. Foreign objects in sensitive regions such as the eyes, ears or airways also pose an increased risk.
  3. Can I remove a foreign object myself?
    Superficial, clearly visible foreign objects can be carefully removed with disinfected tweezers. However, you should always consult a veterinarian for deeper, larger foreign objects or those located in sensitive areas.
  4. Which breeds are particularly susceptible to foreign objects?
    Long-haired breeds and those with a dense undercoat are particularly susceptible, as foreign objects can easily get caught in the coat. Dogs with floppy ears have an increased risk of foreign objects in the ear canal, while hunting dogs are more frequently exposed to plant foreign objects due to their activities in the field.
  5. What happens if a foreign body is not removed?
    Untreated foreign objects can lead to chronic infections, abscess formation, fistulous tracts and, in the worst case, systemic infections. Migrating foreign objects can penetrate deeper into the tissue and damage internal organs.
  6. How long does healing take after removing a foreign object?
    The healing time depends on the size and depth of the wound, the extent of the infection and the general health of the animal. Superficial wounds often heal within a few days, while deeper or infected wounds can take several weeks.
  7. How can I prevent foreign objects in the skin?
    Regular coat checks after walks, especially in areas with tall grass or grain fields, can help. Avoid areas with known risks such as broken glass or thorny bushes. For dogs with long fur, regular grooming, especially between the toes and around the ears, can reduce the risk.
  8. Which imaging techniques are used for diagnosis?
    Ultrasound is particularly valuable for non-metallic foreign objects, while X-rays are helpful for metallic or mineral foreign objects. In complex cases, computed tomography (CT) or MRI can be used. Endoscopy can be used diagnostically and therapeutically for foreign objects in accessible body openings.
  9. Are antibiotics always necessary after removing a foreign object?
    Not always, but often. The decision depends on factors such as the duration of stay in the tissue, the extent of the infection and the type of foreign object. Local antiseptic treatment may be sufficient for fresh, superficial foreign objects without signs of infection.
  10. Can a foreign object come out on its own?
    Some superficial foreign objects can be expelled through natural healing processes. However, most foreign objects, especially those with barbs such as grass awns, are more likely to move deeper into the tissue and do not come out on their own.

Literature

  • Ashbaugh, E. A., McKiernan, B. C., Miller, C. J., & Powers, B. E. (2021). Sixteen cases of tracheobronchial foreign bodies in dogs: A retrospective study (2002–2011). Journal of the American Animal Hospital Association, 57(5), 226–233. https://doi.org/10.5326/JAAHA-MS-7123
  • Cabon, Q., Deroy, C., Ferrand, F. X., Beguin, J., Cachon, T., Fau, D., & Viguier, E. (2020). Thoracic wall foreign bodies in dogs and cats: A retrospective study of 12 cases (2000–2018). Journal of Small Animal Practice, 61(4), 240–245. https://doi.org/10.1111/jsap.13122
  • Hobi, S., Bettenay, S., Majzoub, M., & Mueller, R. S. (2020). Wandering grass awn migration in dogs and cats: A retrospective study of clinical presentations and outcomes of 43 cases. Veterinary Dermatology, 31(5), 383–e102. https://doi.org/10.1111/vde.12867
  • Löwe, G., & Löwe, O. (2021). Notfälle bei Hund und Katze – Ein tierärztlicher Ratgeber (208 S.). Kynos-Verlag.
  • Stiles, J., Weil, A. B., Packer, R. A., & Lantz, G. C. (2022). Post-anesthetic cortical blindness in cats: Twenty cases. Veterinary Journal, 182(3), 367–371. https://doi.org/10.1016/j.tvjl.2021.08.004
  • Vansteenkiste, D. P., Lee, K. C. L., & Lamb, C. R. (2019). Computed tomographic findings in 44 dogs and 10 cats with grass seed foreign bodies. Journal of Small Animal Practice, 60(12), 752–759. https://doi.org/10.1111/jsap.13070