Head Trauma in Small Mammals

Head trauma can be defined as a blunt or penetrating injury occurring to the head. In small mammals it may occur due to a variety of causes, the most common of which is falling from a height. Other causes include blunt trauma (such as being stepped on) or animal fights.

Brain dysfunction may be the result of concussion, swelling, bruising, laceration, fractures, compression or bleeding.

What to Watch For

If you suspect that your pet has suffered head trauma observe him for the following:

• Abnormal level of consciousness
• Differences in pupil size
• Rigid limbs
• Flaccid limbs
• Unusual eye movement
• Bleeding from the nostril
• Bleeding from the ear canal
• Seizures
• Head tilt

Diagnosis

Diagnostic tests are needed to recognize head trauma and determine its severity. A complete medical history and physical examination are important parts of the initial diagnosis of head trauma. Tests and procedures that your veterinarian may wish to perform include:

• Initial neurologic examination. Your veterinarian will need to rapidly assess your pet's status, which may include evaluation of brain function and determination of the site of the damage. During the initial evaluation, your pet's level of consciousness will be assessed. The size of the pupils and their response of light will also be tested to help determine the severity of the injury. A more complete neurologic examination may need to wait until your pet is alert; however, eventually it will be important to determine if there are other significant injuries, such as to the spinal cord.
• Physical examination. Your veterinarian will perform a more complete physical examination as soon as your pet is stable. Other injuries, particularly those that are not life-threatening, may have been overlooked during the initial examination when your pet's condition was critical. Once your veterinarian has the opportunity to examine your pet thoroughly, trauma to the abdomen, chest or even fractures of the limbs may be noted.
• Radiographs (X-rays) or CT Scan. If indicated, your veterinarian may recommend radiographs in order to look for skull or spinal fractures and CT scan to look for fractures as well as brain injury.

Treatment

The treatment of head trauma will depend upon the cause and magnitude of the injury.

• Repeat neurologic examinations. If your pet has evidence of head trauma, your veterinarian will perform repeat neurological examinations because the status of the injured brain can change quickly. Even if your pet initially seems normal, it is wise to have your veterinarian observe him for 24 hours to allow repeat neurologic examinations to be done. Abnormalities may become apparent as the brain swells or bleeding occurs into or around the tissues.
• Supportive care. An intravenous catheter will be placed to allow fluids to be given to prevent dehydration. Your veterinarian will also provide pain-killers as needed. This is typically only done in rabbits and ferrets. Smaller pets may receive subcutaneous fluids.

Specific treatment for head trauma involves various medications. These medications may be feasible for little critters and is most often used in ferrets and rabbits. Some side effects may occur due to the metabolism and gastrointestinal tract of rodents and rabbits.

• Control of seizures. Seizures may occur in animals that have suffered brain trauma. Diazepam (Valium®) or phenobarbitol may be given to control these seizures.
• Treatment for brain swelling. Drugs may be administered to prevent or treat swelling of the brain tissue. Steroids and solutions that draw fluids from the tissues (hyperosmotic solutions) and/or decrease the production of spinal fluid, such as mannitol, may be given. Oxygen therapy may also be recommended. Care should be taken to avoid cough/sneeze reflexes as much as possible because these raise intracranial pressure, which is pressures within the skull or cranium. Any increase in brain swelling or intracranial pressure may contribute to neurologic deterioration such as dullness, stupor or coma.
• Skull fractures. Conservative non-surgical treatment may be recommended for fractures that are not displaced, that is the bone is broken but the fragments have not shifted position. However, fractures that place pressure on the brain – that are displaced inwards – may need to be removed or repaired surgically.
• Treatment of shock. If your pet has evidence of shock or other injuries associated with trauma, specific treatment should be provided for these conditions.

Home Care and Prevention

Head trauma is a life-threatening emergency. If you suspect that your pet has suffered head trauma, take him to your veterinarian for evaluation as soon as possible.

While you are waiting for your pet to be examined, keep him warm, hold his head elevated or level with the rest of the body and minimize pressure on his neck, head or back.

Be careful when handling your pet to avoid being bitten. Your pet may not be aware of what he is doing and could inadvertently injure you.

Little critters are particularly prone to injury by being stepped on, rolled on with a rocking chair or caught in a recliner. Do not allow young children to handle small pets unsupervised.