Foreign Objects in the Skin
Foreign bodies in the skin are objects foreign to the body 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 of the body, serves as the primary protective barrier against environmental influences. When this barrier is breached, foreign materials can penetrate and trigger local or systemic reactions. Depending on the type, size, and location of the foreign body, as well as the individual animal’s reaction, different clinical manifestations can occur. Animals with active outdoor access or dense undercoats, in which foreign bodies can easily become entangled, are particularly at risk.
Causes
Small foreign objects include wood splinters, small pieces of glass, thorns or spines, and very often grass seed heads in the skin or just below the skin surface.
You can usually remove these from your pets easily by yourself. The skin is not very sensitive and tends to heal quickly from minor injuries.
However, there are also more serious cases where significant symptoms can occur.
Additional Information:
The causes of foreign objects in the skin are diverse and depend heavily on the animal’s living environment and activities. The most common foreign objects include:
Plant materials represent the largest group, especially grass awns and spikelets, which can penetrate deep into the tissue and even actively migrate due to their arrow-like structure and barbs. These are particularly problematic because their nature allows them to move in only one direction, burrowing ever deeper into the tissue. Thorns and spines from plants like 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 body parts. Glass shards and metal splinters are often picked up in urban environments, especially in the paw pads during walks.
A special form are biological foreign objects such as ticks, insect stingers, or parts of parasites. Foxtail grasses and burdocks are particularly problematic as they are difficult to remove due to their barbs and can penetrate deep into the tissue.
Fishhooks and other metal objects can lead to serious injuries in animals living near fishing spots or workshops. Sewing and pins are also occasionally found in pets, especially when they play with household items.
Symptoms
- The foreign object has been present for a long time and the wound is infected
- The foreign object is heavily soiled
- The foreign object is large, has penetrated deeply, and/or the wound is bleeding heavily
- The foreign object is located in a dangerous body region (eye, oral cavity)
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 include 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 moving the corresponding body part.
A characteristic behavior is intense licking, biting, or scratching at the entry site. Foreign objects in the paws can lead to lameness or favoring of the limb. 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.
With migrating foreign objects such as grass awns, symptoms may appear at a different site than the original entry point. Foreign objects in sensitive regions such as the eyes are particularly dangerous, where they can lead to conjunctivitis, increased tear production, and blepharospasm, or in the ears, where they can cause head shaking and tilting.
- If the foreign object remains in the tissue for a longer period, systemic symptoms such as fever, loss of appetite, and general lethargy may occur, especially if an infection spreads.
First Aid
- Remove superficial foreign objects with tweezers.
- If the foreign object has penetrated a bit deeper, you should remove the hair in the region, clean your hands and the affected area with soap and water, and if possible, disinfect with an alcohol-based disinfectant solution.
- With a disinfected needle, you can make a small incision in the skin over the foreign object and lever it out or lift it on one side so that you can grasp it with tweezers and pull it out.
- Afterward, wash the area again and dry it.
- The treated area should heal completely within a few days. Otherwise, a part of the foreign object might still be present deep in the tissue. In this case, present your pet to a veterinarian.
- For large or firmly lodged foreign objects (fishhooks), do not attempt to remove them yourself.
- If possible, cushion the foreign object against neighboring tissue and apply a non-compressive bandage.
- Even in cases of heavily soiled foreign bodies or if severe bleeding has occurred, seek professional help.
Diagnosis
The diagnosis of foreign bodies in the skin begins with a thorough anamnesis, in which the pet owner is questioned about possible exposures to foreign materials. The clinical examination includes a careful inspection and palpation of the affected area. For superficial foreign bodies, visual identification may be possible, especially after shaving the hair in the affected area.
For deeper lying foreign bodies, imaging techniques are often essential. Ultrasound examination is particularly valuable as it can also depict non-metallic foreign bodies and allows precise localization. X-rays are helpful for metallic or mineral foreign bodies, while they are often less informative 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 bodies are suspected, a fistulography can be performed, in which contrast medium is injected into the fistula tract to visualize its course.
Endoscopy can be used diagnostically and therapeutically for foreign bodies in accessible body openings such as ears or nasal cavities. Cytological and microbiological examinations of exudate can help characterize secondary infections and select appropriate antimicrobial therapy.
Further veterinary measures
Foreign bodies located just below the skin surface, but no longer visible from the outside, can usually be well detected by ultrasound examination and then surgically removed.
Small foreign bodies can heal and become encapsulated. They are then often discovered incidentally, for example during an X-ray examination. However, if they cause complaints such as infections, pain due to pressure on a nerve, or restrict movements, they must be removed.
Supplements
The treatment of foreign bodies in the skin primarily aims at the complete removal of the foreign material. For superficial, clearly visible foreign bodies, 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 under general anesthesia may be necessary. In this case, the surrounding tissue is carefully prepared to completely remove the foreign body while preserving surrounding structures. For migrating foreign bodies such as grass awns, extensive exploration may be necessary as they often form fistulous tracts.
After removal, the wound is thoroughly flushed 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, drainage is often inserted to remove secretions.
Aftercare usually includes systemic antibiotic therapy, especially for long-standing or infected foreign bodies. Analgesics are administered to control pain. Local wound treatments with antiseptic solutions or ointments can promote healing.
In complicated cases, especially with migrating foreign bodies 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 bodies, as they work more precisely while minimizing bleeding.
Prognosis and aftercare
The prognosis for foreign bodies in the skin is generally good if the foreign body can be completely removed and no serious complications have occurred. The timing of intervention is crucial for the chances of healing – the earlier the foreign body is removed, the lower the risk of complications such as chronic infections or fistula formation.
After removal of the foreign body, careful follow-up care is necessary. The wound should be regularly checked for signs of infection or inadequate healing. Typical warning signs include persistent redness, swelling, increased warmth, pain, or purulent discharge. Protective measures such as an Elizabethan collar or special bodysuits can prevent the animal from manipulating the wound and disturbing the healing process.
In complicated cases, follow-up examinations with imaging techniques may be indicated to ensure that no foreign body remnants remain. Antibiotic therapy should be completed according to veterinary instructions, even if symptoms have already subsided.
Long-term complications can occur with incomplete removal or migrating foreign bodies. These include chronic infections, granuloma formation, scarring with functional limitations, or in rare cases, systemic infections. Recurring symptoms at the same site should always raise suspicion of remaining foreign body fragments.
Summary
Foreign bodies in the skin are a common condition in dogs and cats, caused by the penetration of various materials such as plant parts, wood splinters, glass, or metal. Clinical symptoms range from local inflammatory reactions to systemic infections if left in the tissue for an extended period. Particularly problematic are migrating foreign bodies like grass awns, which can penetrate deep into the tissue due to their structure and form fistulous tracts.
Diagnosis is made through clinical examination and imaging techniques, with ultrasound examination being particularly valuable. Treatment primarily consists of complete removal of the foreign body, followed by adequate wound care and, if necessary, antibiotic treatment. With early intervention, the prognosis is generally good, while delayed treatment can lead to complications such as chronic infections or fistula formation.
Preventive measures such as regular coat checks, especially after spending time in nature, and avoiding high-risk areas during certain seasons can reduce the occurrence of foreign bodies. If a foreign body 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 continues to evolve. New imaging techniques such as high-resolution ultrasound technologies and specialized CT protocols improve the detection of even the smallest foreign bodies. Particularly promising are advances in contrast agent development that can specifically bind to foreign materials and make them more visible in imaging procedures.
In the area of minimally invasive surgery, endoscopic techniques for foreign body removal are increasingly being used, which can cause less tissue damage and shorten healing time. Advances in laser surgery allow for more precise removal while reducing bleeding and collateral damage.
Wound treatment after foreign body removal benefits from innovative biomaterials and antimicrobial dressings that create an optimal healing environment while preventing infections. Local delivery 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 adherence of foreign bodies. Early detection by pet owners is also supported by digital aids such as apps for documenting and tracking skin changes.
Frequently asked questions (FAQs)
- How can I tell if my pet has a foreign body in its skin?
Look for signs such as increased licking or biting at a specific spot, lameness, local swelling, redness, or purulent discharge. Foreign bodies in sensitive areas may cause specific symptoms such as head shaking (ear) or increased tearing (eye). - Which foreign bodies are particularly dangerous?
Grass awns and burrs are especially problematic as they can penetrate deep into tissue and actively migrate due to their barbs. Foreign bodies in sensitive regions such as eyes, ears, or airways also pose an increased risk. - Can I remove a foreign body myself?
Superficial, clearly visible foreign bodies can be carefully removed with disinfected tweezers. However, for deeper, larger, or foreign bodies in sensitive regions, you should always consult a veterinarian. - Which breeds are particularly susceptible to foreign bodies?
Long-haired breeds and those with dense undercoats are particularly susceptible as foreign bodies can easily get caught in their fur. Dogs with floppy ears have an increased risk of foreign bodies in the ear canal, while hunting dogs are more frequently exposed to plant foreign bodies due to their activities in the field. - What happens if a foreign body is not removed?
Untreated foreign bodies can lead to chronic infections, abscess formation, fistulas, and in the worst case, systemic infections. Migrating foreign bodies can penetrate deeper into the tissue and damage internal organs. - How long does healing take after removing a foreign body?
The healing time depends on the size and depth of the wound, the extent of infection, and the general health of the animal. Superficial wounds often heal within a few days, while deeper or infected wounds may take several weeks. - How can I prevent foreign bodies 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. - Which imaging techniques are used for diagnosis?
Ultrasound is particularly valuable for non-metallic foreign bodies, while X-rays are helpful for metallic or mineral foreign bodies. In complex cases, CT or MRI may be used. Endoscopy can be used diagnostically and therapeutically for foreign bodies in accessible body openings. - Are antibiotics always necessary after removing a foreign body?
Not always, but often. The decision depends on factors such as the duration of retention in the tissue, the extent of infection, and the type of foreign body. For fresh, superficial foreign bodies without signs of infection, local antiseptic treatment may be sufficient. - Can a foreign body come out on its own?
Some superficial foreign bodies can be expelled through natural healing processes. However, most foreign bodies, especially those with barbs like grass awns, tend to move deeper into the tissue and do not come out on their own.
Literature
- Löwe, G. and Löwe, O. (2021). Emergencies in Dogs and Cats – A Veterinary Guide. Kynos-Verlag. 208 p.
- Cabon Q, Deroy C, Ferrand FX, et al. Thoracic wall foreign bodies in dogs and cats: a retrospective study of 12 cases (2000-2018). J Small Anim Pract. 2020;61(4):240-245. doi:10.1111/jsap.13122
- Hobi S, Bettenay S, Majzoub M, Mueller RS. Wandering grass awn migration in dogs and cats: a retrospective study of clinical presentations and outcomes of 43 cases. Vet Dermatol. 2020;31(5):383-e102. doi:10.1111/vde.12867
- Vansteenkiste DP, Lee KCL, Lamb CR. Computed tomographic findings in 44 dogs and 10 cats with grass seed foreign bodies. J Small Anim Pract. 2019;60(12):752-759. doi:10.1111/jsap.13070
- Ashbaugh EA, McKiernan BC, Miller CJ, Powers BE. Sixteen cases of tracheobronchial foreign bodies in dogs: a retrospective study (2002-2011). J Am Anim Hosp Assoc. 2021;57(5):226-233. doi:10.5326/JAAHA-MS-7123
- Stiles J, Weil AB, Packer RA, Lantz GC. Post-anesthetic cortical blindness in cats: twenty cases. Vet J. 2022;182(3):367-371. doi:10.1016/j.tvjl.2021.08.004