Ewildagain.org

Aspiration in Juvenile Squirrels:
Etiologies, Treatments, Prevention
Shirley CaSey1 and MaCkenzie Goldthwait, dVM2 1wildaGain wildlife rehabilitation inC., eVerGreen, Colorado 2annie'S aniMal hoSpital, hiGhlandS ranCh, Colorado Abstract: Respiratory problems are, unfortunately, rather common in
What is Aspiration? juvenile squirrels in rehabilitation. Such problems often result from feeding practices, whether by a rescuer, volunteer or even rehabilitator. Aspiration refers to the process by which foreign Diagnostic methods as well as conventional, botanical, and homeopathic treatments are described. Practical and effective tips to prevent aspiration material, such as milk replacement formula, isotonic are included.
liquid, water, or small solid particles such as wood Key words: Squirrel aspiration, squirrel pneumonia, respiratory distress
dust, enter the respiratory system. in squirrels, treating aspiration, preventing aspiration, squirrel breathing The presence of foreign material in the lungs difficulty, squirrel feeding problems, rodent respiratory problems may cause inflammation and swelling. Additionally, some foreign material in the lungs, such as milk for- Respiratory problems are, unfortunately, rather com- mula, is a fertile medium for bacterial growth and mon in juvenile squirrels in rehabilitation. Members subsequent infection. Larger amounts of foreign of the public, veterinary clinic staff, and others often material in the lungs pose a greater risk of infection mistakenly conclude the rescued young squirrel is and also provide a growth medium for the bacteria. thirsty and hungry and attempt to feed it before con- In some cases, the volume of foreign material in tacting a rehabilitator. Although the motives are sin- the lungs is so large that the fluid actually prevents cere, the feeding technique often results in some of the animal from being able to inhale adequate air the liquid inadvertently entering the squirrel's respi- to breathe. Such severe cases are more accurately ratory system. The same thing may occur during feed- described as drowning, even though the respiratory ing by rehabilitators or their volunteers. Animals that condition was a result of improper feeding rather aspirate fluid into the lungs, such as water or milk than being submerged in water. replacement formula, may develop serious respiratory Juvenile squirrels that have fluid enter the air- conditions resulting in fatalities. This paper describes ways and nasal passages also are described as having aspiration, signs and symptoms, etiologies, methods aspirated. Fluid in the nasal passages may result in to prevent it, and several treatments, if needed. It inflammation or infections similar to that which also compares aspiration with several other respira- occurs in the lungs. If the squirrel had fluid come tory conditions in young squirrels. out of the nose during feeding, there is a fairly high probability that the feeding method caused fluid to enter the lungs, which is more serious. Shirley Casey, co–founder of WildAgain Wildlife Rehabilitation
A squirrel with other health problems, such as in Evergreen, CO, has been a licensed rehabilitator since 1986 dehydration, wounds, and abscesses, may be weaker and has rehabilitated 24 species of squirrels. Shirley is co–author of the "Squirrel Rehabilitation Handbook," which includes and more susceptible to quickly developing infections additional information on squirrel development and health. She from aspiration than would a healthy animal. An also publishes and presents around the country on a wide range animal whose health is already compromised may be of rehabilitation topics. using its resources to recover from other conditions Mackenzie Goldthwait, DVM graduated from Tufts University
and may have a slower or more difficult recovery School of Veterinary Medicine in 1989 with a special interest in wildlife medicine. She was the veterinarian at the Cape Wildlife from respiratory conditions.
Center in MA for 18 months. She is a veterinarian in Highlands Ranch, Colorado and works with wildlife, as well as providing training for rehabilitators and veterinary students on wildlife health. Dr. Goldthwait is a Master Birder and serves on the Board of Directors for the Audubon Society of Greater Denver.
Signs and Symptoms Because there are other reasons that a squirrel Some of the signs of aspiration are obvious. Others may not want to eat, the rehabilitator must consider are much more subtle, develop gradually, and are and evaluate those possibilities as well. For example, difficult to notice. Wild animals naturally attempt a squirrel that refuses formula may not yet be hungry to hide health problems so as not to appear vulner- for valid reasons, including the amount of formula able to predators, which makes it more difficult to it was fed earlier, feeding schedule, or increased con- detect a developing health problem. The more famil- sumption of solids. Other health conditions such as iar a rehabilitator is with what is normal, including stress, side effects of medications, or other conditions activity, respiration, sleep, appetite, and growth, the could reduce interest in food. Or the formula just better the chance of noticing the subtle initial clues. could be too hot and burning the squirrel's mouth. If The following describes physical signs of aspiration, other squirrels in the same environment, of the same both at the time of feeding and later, as well as some age, and on the same feeding schedule are hungry observational and circumstantial clues that might and eager to eat, the rehabilitator needs to closely suggest the animal aspirated during the feeding consider the reason for the specific animal's reluc- process, even though the actual aspiration may have tance to eat—which very well could be respiratory gone unnoticed when it occurred.
During Feeding. Among the first signs that the
Activity Level, Sleep, and Chill. Squirrels that
squirrel may be aspirating at the time of feeding are have aspirated tend to be less active than normal and obvious sneezing and liquid or bubbles of formula com- more lethargic. They may sleep more and be difficult ing from the nostrils. The squirrel may gag or choke, to arouse from sleep. They may chill much more eas- and back away from or fight the syringe, sometimes ily and quickly, and have difficulty maintaining nor- being mistaken as a ‘fussy eater.' The squirrel may have mal body temperature. A squirrel that feels cool due difficulty swallowing and/or regurgitate formula from to aspiration or another health issue, may raise the the mouth or through the nose. Regurgitation may fur to increase the insulating effect and warmth, and be a sign of having too much fluid to safely swallow. appear to have slightly ‘spikey' or ‘puffed' fur. The Regurgitation and vomiting are particularly difficult for squirrel may have a slight fever, with their external rodents due to the presence of a limiting ridge at the body temperature appearing warmer than that of the junction of the stomach and esophagus (Hillyer and cagemates or siblings. Since taking the temperature of Quesenberry 2004; Cunliffe–Beamer 1993). a juvenile squirrel can be difficult and even danger- The moment of aspiration should be apparent ous for the animal, it is not necessary. Depending on to the person feeding the young squirrel if obvious the level or intensity of these signs, the squirrel may sneezing or gagging suddenly occurs. However, there be in early or advanced stages of respiratory distress. are many cases where fluid enters the squirrel's trachea, Regardless, treatment likely will be needed to help or airway, without any obvious indication the liquid has moved down into the lungs. As a result, it is important for the rehabilitator to pay close attention during Respiration Level and Rate. Careful and skilled
feeding and watch for and recognize subsequent signs listening to a squirrel's respiration may reveal slight of respiratory problems. Respiratory conditions can sounds of respiratory difficulty, but other signs also deteriorate quickly and should not be taken lightly. provide key clues. Early stages may include a barely audible rhythmic ‘clicking' sound coming from the Reluctance to Eat. Signs of aspiration may appear
nose or chest, coinciding with inhaling and exhal- immediately, a few hours, a day, or several days later. ing. Normal respiration is relatively silent. Squirrels A squirrel that previously demonstrated a good with more severe and advanced cases of aspiration or appetite at regularly scheduled feedings may sud- pneumonia may have labored, shallow, and difficult denly refuse food or only swallow a couple of drops breathing, which may be audible to the caregiver, of formula instead of eating the expected amount. even without use of a stethoscope, or the caregiver This may be an indication the squirrel feels ill and/ might notice a mild vibration or rattle in the chest. or eating hinders respiration. Given the alternative The squirrel may breathe through an open mouth between eating and breathing, the squirrel instinc- rather than through the nose. The respiratory rate tively chooses to breathe. may be abnormally rapid or slow. They may be weak and even collapsed. Coughing is possible, but not common. These signs of severe respiratory distress Although it is possible for juvenile squirrels to aspi- indicate advanced disease that requires prompt and rate due to other reasons, such as being gavage– or targeted treatment to reduce further deterioration tube–fed, the most common cause of aspiration is and possibly death.
the process by which they are hand fed. This includes such considerations as feeding instruments, position Circumstantial Clues. In some cases, circum-
of the animal and feeding instrument, and the rate of stances may suggest a high probability that the flow with which the liquid is fed. squirrel has aspirated prior to being presented to the rehabilitator. The rescuer may mention having Volume Administered. Juvenile squirrels in the
read information online about feeding squirrels and wild only obtain a very small amount of milk in their offer to donate feeding implements and/or an open mouths at a time when suckling their mother that container of formula. These items are direct clues they swallow and repeat the process. as to the type of feeding instrument used as well as The mouths and throats of juvenile squirrels the type of liquid fed to the animal. Rehabilitators are quite small as is evidenced from examination of already collect information on the animals admitted multiple specimens. A neonate squirrel that weighs for rehabilitation, including rescuer's name and con- less than 20 g has an esophagus that is less than 0.06 tact data, source location of the animal, and reason in (0.15 cm) in diameter, approximately the diameter for rescue (fall, dog or cat attack, etc.). While collect- of the wire in a paperclip. A squirrel that weighs ing this information, it is useful to ask if the person between 50 and 100 g has an esophagus that may has given the animal any food, liquid, or medication. be 0.12 in (0.3 cm) in diameter, or the diameter of If the answer is yes, it is important to ask what, how a toothpick. A squirrel weighing between 100 and much, and type of feeding instrument. This can pro- 300 g has an esophagus that may be 0.15 to 0.33 in vide early information about the possibility of the (0.38–0.84 cm) in diameter, which approximates the animal having aspirated, such as if the person men- interior diameter of a 1–cc syringe. tions that the squirrel was "so excited and cute drink- People feeding young squirrels must always keep ing water from the eyedropper that he blew bubbles in mind that they have very tiny mouths and throats and must be diligent in efforts not to place too much Although some rescuers may admit to feed- liquid in the mouth at a time. Although some people ing the squirrel during this general data collection, may be experienced feeding young kittens and pup- others may be vague or deny it. However, evidence pies, as well as larger wild mammals, they may not of formula or other liquid matted on the fur on a appreciate the significantly smaller size of young squirrel's face or muzzle, or ‘plugs' of formula in the squirrels' mouths and throats. They can cause squir- nostrils are strong evidence the rescuer tried to feed rels to aspirate easily, especially if the squirrels are the animal. If there is any indication that the rescuer difficult to handle and unfamiliar with the feeding may have fed the squirrel, the rehabilitator needs to implement, such as squirrels that are recently admit- closely monitor it for signs of respiratory difficulty, as ted to rehabilitation. well as potential gastrointestinal disorders and other Many implements commonly used to feed liquid health problems.
to young squirrels express a larger volume of fluid Just as respiratory conditions can be present in than the animal may safely swallow. For example, a animals admitted from the public, a veterinary clinic, large syringe sold to administer medication to chil- or rescue organization, there also are instances when dren or even pets, expresses a volume acceptable for squirrels received from another rehabilitator may these animals with a larger mouth and throat capac- show early or later stages of respiratory difficulties. ity, but that far exceeds what a young squirrel may be This can be for several reasons, including inexperi- able to simultaneously take into its mouth and swal- ence or lack of training with feeding the species, low, while also breathing. inexperience with observing and addressing any of Some rehabilitators have used 6–cc, 12–cc, or the issues mentioned above, or even an overly large larger syringes to feed young squirrels because the caseload that may have prompted a more fast paced diameter of the syringe nozzles are the same as a 1–cc feeding practice and less monitoring of individual syringe and they believe it is possible to control the syringe plunger enough to limit the amount of fluid

Many rehabilitators find that a small syringe, such as a 1–cc or 3–cc, allows significantly more control over the amount and rate of fluid fed to the squirrel. However, even a 1–cc or 3–cc syringe can cause a young squirrel to aspirate if the plung-er moves farther and expels more fluid than the squirrel can comfortably take into its mouth, swal-low, and breathe. Also, if the squirrel is extremely small, such as less than 25 g, even a full drop of a formula from a 1–cc syringe, about 0.05 to 0.1 cc, may exceed the capacity of its mouth. Some rescuers have used eyedroppers and ear bulb syringes to feed squirrels. It is extremely difficult to control the amount of liquid expelled Figure 1. A very focused and skilled rehabilitator may be able from these devices. These implements as well expel a single drop of formula from different size syringes. as larger syringes easily can cause the animal to However, aggressive suckling or movement by the squirrel, or a distracted or less skilled caregiver easily may cause more than one aspirate, as the rate of flow is too large, fast, and drop to be expelled. Photo by Allan Casey. uncontrollable as to volume. Speed of Feeding. Most juvenile squirrels
have a healthy appetite and are eager to eat. The rehabilitator, who also may be very busy and eager to complete the task, may respond by feed-ing quickly. However, feeding liquid quickly may easily exceed the capacity of the young squirrel's mouth and throat. Feeding too rapidly can result in excess liquid coming out the nose or mouth, or aspiration. Like large feeding implements, rapid feeding is a common cause of aspiration in squirrels.
Feeding too quickly can result from a couple of primary factors. The rehabilitator may be rushed and inclined to provide too much vol-ume too quickly. Another factor is not providing adequate control of or ‘back–pressure' on the Figure 2. Comparison of the volume of formula expelled by a 0.25 plunger of the syringe. Young squirrels have a in (0.64 cm) movement of plunger in a 1–, 3–, 6–, and 12–cc strong sucking pressure needed to extract the syringe. The 0.25 in (0.64 cm) movement of plunger of a 12–cc milk from the mother's nipple, which excretes syringe results in 10 times the volume of the same 0.25 in move- ment of a 1–cc syringe. The larger volume of formula easily can milk at a very low rate. If the rehabilitator does cause a squirrel to aspirate—without rehabilitator even noticing. not exert adequate back–pressure on the syringe Photo by Allan Casey. plunger, an aggressively hungry squirrel can move a new or well–lubricated syringe plunger much going into the squirrel's mouth. It is indeed possible too quickly, resulting in an overload of formula into for a person with considerable control on a plunger the mouth, and airways or lungs.
of a larger syringe, such as a 6–cc syringe, to expel a single drop from the nozzle as shown in Figure 1. Length of Feeding Implement. The teats of
However, moving the syringe plunger a small dis- lactating female squirrels are 0.06 to 0.33 in (0.15– tance, such as a quarter of an inch (0.64 cm), results 0.085 cm) in length, depending on species. Smaller in a much larger amount being expressed from a 6–cc species, such as southern flying squirrels (Glaucomys syringe than the same quarter of an inch from a 1–cc volans), pine squirrels (Tamiasciurus hudsonicus), or syringe, as shown in Figure 2. many of the ground squirrels (Golden mantleus) have

Feeding Position.
Rehabilitator observations as well as video cameras of wild squir-rel mothers in nests reveal that the mothers generally recline on their sides or even more on their back when feeding their young. Neonate squirrels lean against the mother in a more upright or vertical position when they suck-le (Figure 4). Older and larger juvenile squirrels lie more on the stomach with the upper bod-ies and head angled toward the mother's teats. They use the front feet to hold, push, or ‘knead' the mother's mammary glands as Figure 3. Similarity of size and shape of nipples in wild lactating squirrels; species left to right are Abert's squirrel (Scurius aberti), golden–mantled ground squir- rel (Spermophilus lateralis), fox squirrel (Scurius niger). Photos by Shirley and Squirrels that are not held in Allan Casey. positions similar to the way they would suckle the mothers may be shorter and smaller teats than the larger tree squirrels uncomfortable and stressed and have difficulty swal- such as fox squirrels (Sciurus niger), eastern gray squir- lowing appropriately. Squirrels fed lying on the back rels (Scurius carolinensis), and Abert's squirrels (Sciurus may aspirate easily. If the squirrel's head is tipped too aberti). Figure 3 demonstrates the size and shape of far to the back, front, or side, the position may cause nipples of lactating squirrels in the wild.
difficulty swallowing. Squirrels that are not provided Many rehabilitators attach softer nipples to small with a secure surface under the body may be more plastic feeding syringes with the goal of making them stressed and squirm more during feeding, which can more comfortable or natural for the squirrel's mouth. result in them aspirating. While infant squirrels may Many of these nipples are longer than 0.5 in (1.27 be held in a more vertical position, older squirrels cm), thus exceed the length of the mother squirrel's with fur should not be held in the air or perched on teat. A nipple that is allowed too far in the back of a an unstable surface while feeding. Stressors and other young squirrel's mouth easily can result in ‘overflow' going down the trachea. Nipples that extend too far into the throat due to placement or the squirrel's enthusiastic suckling also may impede the swallowing response, again causing fluid to enter the trachea. Such aspiration may be unnoticed by the person feed-ing. Squirrels also can swallow or inhale the nipple itself causing an obstruction. Even if the rehabilitator tries to keep the nipple at the front of the squirrel's mouth, it can move farther back into the squirrel's mouth or throat because of the squirrel's suckling or because the rehabilitator is distracted and allows movement. Even without a supplemental nipple, some syringes have nozzles exceeding the 0.5 in length. Again, while the rehabilitator may try to keep the tip in the front of the squirrel's mouth, it is not unusual for a hungry squirrel to suck or pull the nozzle into Figure 4. Neonate fox squirrel (Scurius niger) suckling its the back of the mouth and aspirate.
mother. Photo by Sharon Baird. distractions that cause the squirrel to be agitated or possible a rehabilitator's attention may be distracted move also may result in gulping or inappropriate for a couple of seconds, such as hearing a phone ring, being asked a question, noticing a problem with The position of the rehabilitator during feed- another animal in rehabilitation, and so forth. In ing may affect the squirrel's position and ability to that momentary distraction, it is possible that the effectively swallow. For example, a rehabilitator that rehabilitator pushes the plunger too far and causes holds the syringe high may cause the squirrel to have the squirrel to take in too much formula, or they difficulty swallowing because the head is too high. forget to maintain adequate back–pressure on the Holding the syringe in an uncomfortable position syringe plunger. The same type of accident may hap- may reduce the rehabilitator's control on the syringe, pen if the rehabilitator is hurrying due to a hectic allowing the squirrel to suckle too much at a time schedule and heavy workload. Exhaustion due to and aspirate. A squirrel that is held too close to the workload, long hours, loss of sleep, and other stres- rehabilitator's body, especially the face, may try to sors can result in aspiration, as well as other prob- escape what they consider to be a predator, resulting lems, including overfeeding, missed medications, and in risky swallowing.
Animal Adjustment to Implement and
Cumulative Effects. Any one of the situations
Formula. Even with attempts by rehabilitators to
mentioned above can cause a squirrel to aspirate a lot create a comfortable and effective feeding implement, or a little. The aspiration may be more severe, faster, the instruments are different from the mother squir- and more difficult to correct if multiple factors are rel's teats. As a result, juvenile squirrels have to adjust combined. For example, a large volume of formula to the feeding implement, how liquid is disbursed, may be aspirated if the person is feeding with large and the density or viscosity of the liquid. The squirrel syringe with a long nipple that extends to the back of may exert the same type of forceful suckling that they the squirrel's throat. It could be worse if the syringe do with the mother, even though strong suckling is plunger stuck and then moved farther and faster, not needed as the rehabilitator releases liquid from resulting in a large gush of formula that entered the trachea and lungs. Additionally, newly admitted squirrels are accus- A relatively new rehabilitator or volunteer may be tomed to swallowing the thicker mother's milk. As feeding a fairly healthy 50 g orphaned squirrel that a result, the squirrel may get too much replacement is newly admitted with a large syringe. The juvenile formula too fast, swallow ‘wrong,' and aspirate some squirrel may aspirate simply because of unfamiliar- of the liquid. This is especially a concern for animals ity with the feeding method, different density of the that are new to rehabilitation being fed a rehydration liquid, or a syringe that is too large. Add a distrac- liquid, such as lactated Ringers solution or dilute tion, like spilling the jar containing the formula, and formula, both of which, by design, have more water a gush caused aspiration occurs. Then consider the content than full strength milk replacement formula.
same situation but with a dehydrated 100 g squirrel with a bruised chest, or a 20 g neonate. If the squir- Sticking Plunger. The seal on the plunger of
rel aspirated several times, it could cause the fluid to some syringes has a tendency to stick or move unpre- accumulate in the lungs, decrease respiratory capac- dictably after being used many times. This can cause ity, and provide a fertile medium for bacterial growth. the rehabilitator to use extra pressure to move the If the aspiration is not noticed immediately, such as plunger. The plunger then may move farther and by a rescuer, new rehabilitator, volunteer, or a very faster than expected, resulting in a gush or sudden tired and over–worked rehabilitator, the condition abundant flow of formula that may exceed the squir- rel's ability to swallow. This sudden rush of formula Any of these situations and others can cause can cause the squirrel to gag, choke, blow bubbles a young squirrel to aspirate. But if multiple things from the nose, or aspirate formula into the lungs. happen and/or are not noticed until the animal's condition has deteriorated, the animal is much more Distractions. Rehabilitators and volunteers have
difficult to treat and survival is less certain.
many responsibilities and activities. They are busy. As much as they try to focus on feeding carefully, it is Differential Diagnoses A bulb syringe marketed for use with infant children Aspiration itself is not a disease, but a physical might be helpful to gently remove fluid from the action. However, it can cause disease very easily and mouth and throat.
rapidly. Aspiration pneumonia is the most common Pneumonia may be the result of conditions other sequela (consequence). The signs to look for have than aspiration. For example, pneumonia may be been discussed above. All of the below conditions viral or bacterial from a penetrating chest wound, require veterinary consultation.
or a broken rib, or due to spread of infection from Aspiration pneumonia usually affects the cranial other parts of the body. ventral lung fields, the lower front area of the ani- Difficult respiration also may be due to chest mal's chest. Viral pneumonia, on the other hand, trauma, including hemorrhage or air in the pleural causes congestion and inflammation in all lung space (space in the chest outside the lungs), bruising fields. Spread of bacteria, from infected wounds or of the lungs, or fractured ribs. infections in other parts of the body, to the lungs Fractured sinuses or other head trauma can be through the blood (hematogenous) also causes con- a reason for nasal infection or discharge, instead of gestion and inflammation in all lung fields. aspirated fluid in the nasal cavities.
Careful auscultation (listening with a stetho- scope) can distinguish the types of pneumonia. Treatment Considerations Quiet breath sounds are audible in all fields of In order to understand treatment options for aspira- healthy lungs. Consolidation or congestion causes tion cases, it is important to understand the nature the absence of normal lung sounds. What often is of the condition and other influences. How severe heard is a smacking sound as the inflamed thickened was the aspiration? Amount aspirated? Is the fluid in alveolar membrane opens to admit air on inspira- the nasal passages or sinuses? Is it in the lungs? Both? tion (inhalation). If these sounds are heard under A tiny amount of formula in the nose of an older the front legs, aspiration pneumonia is likely present. juvenile squirrel might be sneezed out quickly and Patients with pneumonia very rarely have nasal dis- easily. Another option is to gently tip the squirrel forward and encourage the drop to come out. Some Upper respiratory infections also are possible rehabilitators have prompted squirrels to sneeze by sequelae of aspiration. The part of the upper respira- gently blowing toward the squirrel's nose. tory tract affected depends how far into the lungs the A tiny drop in the nose of an infant squirrel foreign substance was aspirated. If the fluid went up may be removed by placing an eyedropper or human the nose then rhinitis (inflammation of nasal pas- infant nasal aspirator over the nostril and gently sages) or sinusitis (inflammation of the sinuses) is evi- extracting the drop. Whereas a large gush of fluid dent. If fluid went into the trachea or bronchi then that went into the lungs is unlikely to be removed tracheitis (inflammation of the trachea) or bronchitis easily, and has to be absorbed by the body. A larger (inflammation of the bronchi) is evident. Very harsh, volume of liquid in the lungs would increase the raspy upper respiratory noises are audible when lis- amount of inflammation. tening to the lungs. Bloody or purulent (pus–filled) Also consider the squirrel's condition, overall nasal discharge is present through coughing, sneez- health, and symptoms. Is the animal showing sign ing, or both.
of respiratory distress? Did the aspiration just occur? Drowning, on the other hand, is very often Have several days passed? Is there a concern that the accompanied by copious amounts of nasal discharge squirrel is in serious condition? Is there a concern the same color as the substance that was aspirated, that the squirrel might have just aspirated and the severe dyspnea (difficulty breathing), cyanosis (blue rehabilitator wants to prevent infection from color to the mucous membranes), and complete absence of any lung sounds at all. Drowning is a medical emergency and requires the rehabilitator to remove as much fluid from the lungs as quickly and safely as possible. If the animal has a large amount of fluid in the lungs, consider turning the animal upside down, pressing gently on the chest, and allow-ing the fluid to flow out of the respiratory tract. Supportive Care.
ing from the intestinal tract). The limited antibiotic choice in rodents can make some infections difficult • Feed very carefully to avoid further aspiration.
to treat (Hillyer and Quesenberry 2004: Harkness • Provide supplemental heat for the compromised and Wagner 1989; Cunliffe–Beamer 1993).
Rehabilitators are encouraged to consult with • Reduce activity level. Place in a smaller cage their veterinarians prior to initiating treatment with either alone or with fewer cagemates so there is antibiotics. Antibiotics should be targeted to the less play and activity.
specific bacteria present. Without testing through • Provide extra hydration. Depending on the sever- an actual culture, history and symptoms are essential ity of the respiratory condition, administering to make an educated guess as to the type of bacteria isotonic fluids subcutaneously may be preferable involved. The correct dose and proper length of treat- to oral fluids.
ment are critical for success. Antibiotic treatment for • Ensure excellent nutrition.
confirmed pneumonia is considerably longer, pos- • Use a vaporizer or humidifier with warm or sibly over four weeks, than treatment for an upper room temperature water to make breathing easier respiratory infection. When using antibiotics, it is and more comfortable. This moisture also helps vital to administer a probiotic twice daily to reduce with hydration and allows easier expectoration of the risk of disruption of gut flora and development Expectorants generally are not well tolerated or useful in rodents. Some veterinarians have admin- • Squeeze the animal's chest. istered Lasix® (furosemide, Sanofi–Adventis US, • Shake the animal upside down to try to ‘shake Bridgewater, NJ) in severe cases of pneumonia to reduce the amount of fluid in the lungs. While oxy- • Apply salves with strong odors that are sold gen is very important in animals with severely com- for use with people, such as Vicks® VapoRub® promised lungs, oxygen chambers are not commonly (Proctor & Gamble, Cincinnati, OH), that could available at rehabilitation facilities. A squirrel that irritate the skin and nasal passages, as well as cannot breathe without supplemental oxygen is likely cause severe stress due to squirrels' highly sensi- to have a poor prognosis for recovery due to chronic tive sense of smell.
lung scarring.
• Attempt artificial respiration, which could push the fluid further into the lungs.
Botanical Medication. There are many plants
• Allow the animal to become dehydrated.
that have been used to treat respiratory problems • Stop feeding the animal. Rather, take care to feed for thousands of years. Some strengthen the overall very carefully and slowly using a 1–cc syringe immune system and the body's general ability to with a short nipple so the animal gets adequate recover from respiratory infection, such as echinacea. nutrition but does not aspirate again.
Some reduce respiratory inflammation; others are expectorants that help the body to get rid of mucous Conventional Medication. Antibiotics used
or excess fluid, such as by coughing or sneezing. in squirrels with confirmed pneumonia or upper These treatments may be highly effective.
respiratory infections include those with targeted Some veterinarians suggest starting with echi- effectiveness against bacteria present in the lungs and nacea to strengthen the immune response and for airways, such as enrofloxacin (Baytril®, Bayer Animal upper respiratory infections. On the basis of research Health, Montville, NJ) for Pasteurella and E. coli spp., with human patients and traditional preparations, penicillin for Staphylococcus and Streptococcus spp. the hydroethanolic liquid extracts may be preferred and chloramphenicol for a multitude of organisms. (Wynn 2007). Many herbalists prefer to give echina- However, penicillin related drugs such as amoxicil- cea three times a day and repeat at up to two to four lin and amoxicillin trihydrate/clavulanate potas- hours in acute stages. While echinacea is available in sium (Clavamox®, Pfizer animal Health, New York, both dried and liquid forms, the liquids are easier to NY) are not recommended for rodents, including administer to a squirrel. Other herbs may be added squirrels, because the drugs can cause a variety of to or used with the echinacea to address more symp- problems, such as hemorrhagic gastroenteritis (bleed- toms. Dosages of herbs vary depending on purity,

quality, and strength of the prod-uct, condition of the animal, size of animal, and more, The book Veterinary Herbal Medicine (Wynn 2007) lists dosages for a variety of herbs.
Other veterinarians may select Chinese herbal medicines. While some of these botanical medicines may be available over–the–counter without a prescription, consulta-tion with a veterinarian is impor-tant to ensure effective results and to prevent problems.
Homeopathic Medication.
Veterinarians using classical home-opathy recommend oral admin- Figure 5. Comparison of a modified squirrel nipple with a lactating female squirrel istration of a total of one or two teat shape and size. Photos by Allan Casey. doses of homeopathic Phosphorus 30c in the acute and early stages of respiratory dis- the barrel. While the individual O–ring syringes are tress due to aspiration (e.g., in the first 48 hours slightly more expensive than some others, ultimately of respiratory problems) (Casey and Black 2002; they are less expensive due to the ability of using Casey and Herman 2004). Later stages of respiratory them for so many feedings. distress due to aspiration may involve other homeo- The Monoject™ (Kendall Brands, Division of pathic remedies, such as one or two total doses of Covidien, Mansfield, MA) with Luer tip is another Sulphur 30c or Carbo vegetabilis 30c, according to option used by rehabilitators. The syringe nozzle homeopathic principles. The homeopathic remedies length and diameter are the same as the O–ring in 30c potencies that are mentioned above are avail- syringe and nipples fit the same. The Monoject™ able from homeopathic veterinarians, online sources, syringe is designed to have a needle attached to be or pharmacies.
used for injections, therefore only intended for a sin-gle use. While an individual syringe is less expensive Preventing Aspiration than the O–ring syringe, the black rubber seal on the Appropriate Feeding Implements. Small
plunger tends to stick after multiple uses and clean- syringes, 1–cc and 3–cc, can be used to effectively ings. The 3–cc Monoject™ syringes are available from and safely feed formula to suckling squirrels as they many veterinary supply distributors; 1–cc syringes are allow the rehabilitator to have good control over the not available from veterinary supply distributors, but flow of liquid. These syringes are easy to clean and are available from veterinary offices or pharmacies disinfect, accurately disperse amounts of formula cal- and may require a prescription for purchase.
culated for the size of the animal, and are easily avail- Use a 1–cc syringe when orally administering able for purchase and inexpensive.
water, lactated Ringer's solution, or similar fluids, or Many rehabilitators find the O–ring syringe with when feeding a newly admitted squirrel.
slip tip to be very effective. The nozzle length is about Do not use a bulb syringe or eyedropper for feed- 0.33 in long (0.84 cm) and the diameter is 0.03 ing because they are difficult to control and easily in (0.08 cm). Supplemental nipples fit well on the cause aspiration.
standard slip tip nozzle, while the O–ring oral slip tip (used for human dosing) is wider and too large Short Nipple. Placing a small plastic or silicone
for the mouth of younger and/or smaller squirrels. nipple (Mothering Kit silicone nipple, Classic The O–ring plunger slides easily in the barrel and Products®, Elwood, IN) on the tip of a syringe can the syringes can be washed, disinfected, and reused help control formula flow and effectively soften the thousands of times without the plunger sticking in feeding instrument that is placed into the young

The modified nipple is made from placing 0.5 in of the tip of the white silicone nipple on a 1–cc syringe (O–ring or Monoject™ with slip tip Luer nozzle). The silicon nipple tip is pushed through the opening in the base of the Zoologic® elongated nipple that has the tip removed (Figure 6). When an infant squirrel takes the nipple tip into its mouth, the base of the elongated nipple stops them from sucking the nipple in too far and risking aspira-tion. The squirrel can hold or pump the wider base easily. It is also easy to draw formula through the nipple into the syringe as well as to clean after feedings. For squirrels with fully erupted teeth (the eyes also are open), consider putting the syringe nozzle through the bulbous base of the nipple so the squirrel has a place to put its paws when feeding. For example, remove the narrow part of the Zoologic® elongated nipple and place the nozzle of the 3–cc syringe through that opening (Figure 6). Avoid using a soft nipple with squirrels with fully erupted teeth because they can bite off and swallow the nipple tip causing a gastric foreign body or inhale it causing a respiratory obstruction.
Feeding Position. As mentioned above, the feeding
position of unfurred infant squirrels is different from older squirrels that do have fur. Infant squirrels are wrapped in a small piece of soft cloth and held more vertically for feeding, similar to the position they use Figure 6. A modified feeding nipple using silicone nipple and base of Zoologic® Elongated Nipple with long tip removed and positioned on a 1–cc syringe (left and center). Syringe on right (3–cc) shows modi- fication and placement of the Zoologic® Elongated Nipple for an older squirrel. Photos by Allan Casey. squirrel's mouth. Use a soft nipple that is the approximate size and shape of the lactating squirrel's teat (Figure 6). The modified feeding nipple shown has Figure 7. A juvenile Abert's squirrel (Scurius aberti) held in a sternally been the most effective and most simi- recumbent position on towel and fed with syringe at 90º angle. Line A indi- lar to the mother squirrel and allows cates rehabilitator's fingers curled over syringe plunger to control amount of the young squirrel to grip or push the formula expressed. Left thumb and forefinger (B) form ‘U–shaped collar' base as it would the mother when suck- to maintain squirrel in position. Middle and ring fingers (C) curve under the body to stabilize position and reduce chance of escape. Photo by Allan

when suckling the mother. A juvenile squirrel with fur is fed more hori- zontally in a sternally recumbent position. Feed the squirrel on a stable surface, such as a countertop or a table with a rolled towel, or even a person's lap with a towel. Allow the squirrel to assume a natural, com- fortable, and secure position. The squirrel should be leaning forward on a stable surface, and angled slightly upward, similar to the position when suckling the mother. Some rehabilitators use a towel rolled into a shape like the mother squirrel's torso to be helpful support and give the squirrel a surface to ‘knead.' The syringe should be at approximately a 90º angle to the squirrel's Figure 8. Overhead view of rehabilitator's fingers in ‘U–shaped collar' to hold young pine squirrel's head steady dur- head, as shown in Figure 7.
ing feeding. Photo by Allan Casey. Hold the squirrel securely in that position with your fingers resting on the collarbone in a ‘U–shaped' collar shown in Figure 8. Do not place the fingers in front of the throat or mouth. Allow only the tip of the nipple or syringe nozzle into the squirrel's mouth, since that is the approximate length of the mother squir-rel's nipple. Preventing the squirrel from taking a syringe nozzle or nipple more than one–third inch into its mouth reduces risk of aspiration. Keep a finger on the syringe plunger stem (Figure 7) in order to maintain bet-ter control over the amount administered. This helps prevent a squirrel that is vigor- Figure 9. Angling a short syringe tip without nipple in fox squirrel's cheek to reduce excessive suckling pressure. Photo by Allan Casey. ously sucking from getting too much at a time. Avoid holding the syringe as if giving an injection since that does not allow as much plunger control. Directing the nozzle of the syringe slightly toward the squirrel's inner cheek is another way to reduce the amount of suction pressure, especially for older juvenile squirrels that tend to suckle quite vigorously (Figure 9). This would be like a person sucking on a straw directed into the inner cheek instead of the center of the tongue.
Feed Slowly. Feed slowly, a little at a
time. Allow the squirrel adequate time to take the formula into the mouth Figure 10. Fabric positioned over squirrel's head during feeding to reduce dis- and swallow before giving more. Do tractions; muzzle, mouth, and front feet must be visible to rehabilitator to feed not rush the feeding. Feed using a slow safely and effectively. Photo by Allan Casey. and intermittent ‘push–pause, push–pause' pattern When a rescuer calls about a young squirrel, when feeding with a syringe. The ‘push' provides a explain the importance of getting it to a rehabilitator. drop of liquid; the ‘pause' allows time to swallow and Also explain that as much as he or she may want to breathe. It is the difference between one person giv- feed it, a baby squirrel very easily can inhale the liq- ing another a sip of water, allowing time to swallow, uid and develop fatal pneumonia, even if the rescuer breathe, and then giving another sip, rather than has experience feeding pets.
steadily pouring water down the person's throat. Watch the squirrel's natural feeding rhythm and don't Have a Plan. Understand aspiration, causes, and
allow animals that try to rush the feeding to do so.
ways to prevent it, as described in this paper. Ensure The rate of the push–pause is much slower when that others, such as volunteers, helping to feed juve- feeding smaller and younger squirrels, those that are nile squirrels are trained and skilled in effective feed- new to rehabilitation and adjusting to the feeding ing methods and how to prevent problems. Be alert method, and with liquids that are thinner than full to signs of aspiration. If aspiration is suspected or strength formula.
there are strong signs that the animal is developing respiratory problems, monitor closely, consult with a Reduce Distractions. This means feeding the
veterinarian, and initiate treatment as needed.
squirrel in a quiet room that does not have many As always, a positive working relationship with other activities that could distract the caregiver or the a veterinarian is essential, and should be established squirrel. It means focusing on the feeding and not before a crisis occurs. using the time to catch up with phone calls, socialize with volunteers, or other activities.
Preventing Aspiration is Minimizing the activities and distractions helps Better Than Treating it! reduce the animal's stress and increases its ability to Aspiration that occurs during rehabilitation is a pre- focus on eating. In some cases, wrapping much of the ventable situation. Specialized syringes and nipples squirrel's body in a soft cloth, such as a knit tee shirt described above can make a difference, as well as fabric or small hand towel, can help reduce visibility using an appropriate feeding position, feeding slowly of distractions, give the squirrel a secure surface to with a push–pause pattern, reducing distractions, and grab, and also help reduce risk of an older juvenile ensuring those responsible understand and use effec- squirrel getting loose in the rehabilitation facility tive feeding practices.
(Figure 10).
Product Resource Training and Supervision. If a volunteer or new
O–ring feeding syringes and silicone nipple products rehabilitator is helping with feeding, training and are available from <www.Squirrelsandmore.com>.
demonstrations on general rehabilitation practices and feeding techniques are essential. Explain poten- tial problems, how to avoid them, and what to do Casey, S., and B. J. Black. 2002. Homeopathic First if they occur, such as aspiration and escapes in the Aid Tips for Wildlife. New York State Wildlife rehabilitation facility. Have the new person learn by Rehabilitation Council–Training Manual. feeding some ‘easy to feed juvenile squirrels' that are Available at: <http://www.ewildagain.org/ familiar with eating from the syringe while the reha- bilitator observes, coaches, and assists over multiple Casey, S., and J. Herman. 2004. Homeopathic feeding sessions. Considerations in Treating Acute Respiratory As skill increases, continue the person's training Conditions in Wildlife. Journal of the American with squirrels of different ages, sizes, and health con- Holistic Veterinary Medical Association. 23(3): ditions. Do not assume that a single feeding session or working with just one or two squirrels means the Cunliffe–Beamer, T. L. 1993. Applying Principles trainee has skills for all squirrels. Continue regular of Aseptic Surgery to Rodents. Animal Welfare monitoring and coaching to help ensure the person Information Center Newsletter. April–June, 4(2): provides quality care and to reduce the risk of prob- 3–6. Available at: <http://www.upstate.edu/dlar/ Harkness, J., and J. Wagner. 1989. The Biology and Moore, A., and S. Joosten (editors). 2002. NWRA Medicine of Rabbits and Rodents, 3rd edition. Lea Principles of Wildlife Rehabilitation: The Essential and Febiger: Philadelphia, PA.
Guide for Novice and Experienced Rehabilitators. Hillyer, E., and K. Quesenberry. 2004. Ferrets, Rabbits National Wildlife Rehabilitators Association: St. and Rodents: Clinical Medicine and Surgery. W. B. Saunders: Philadelphia, PA.
Phatak, S. R. 1993. Materia Medica of Homeopathic Wynn, S. and B. Fougere. 2007. Veterinary Herbal Medicine. B. Jain Publishers: Kishan Kunj, Delhi, Medicine. Mosby: St. Louis, MO.
Phatak, S. R. 2002. Materia Medica of Homoeopathic Additional Resources Medicines. B. Jain Publishers: New Delhi, India.
Aiello, S., and A. Mays. 1998. Merck Veterinary Schar, Douglas. 1999. Echinacea: The Plant that Boosts Manual, 8th edition. Merck and Company, Inc: Your Immune System. North Atlantic Books: Whitehouse Station, NJ. Berkley, CA.
Blackmer, R., A. Casey, and S. Casey. 1997. Beyond Schoen, Allen, and Susan Wynn. 1998. Conventional Allopathic Medicine: Options Complementary and Alternative Veterinary Medicine: Considered by Wildlife Rehabilitators. Journal of Principles and Practice. Mosby: St. Louis, MO.
Wildlife Rehabilitation. 20(4): 7–13. Schroyens, F. 2004. Synthesis: The Source Repertory. Blackmer, R., A. Casey, and S. Casey. 1998. Homeopathic Book Publishers: London, Exploring the Concept of the Minimum Dose: Wildlife Rehabilitators Consider Homeopathy. Vermeulen, F. 1997. Concordant Materia Medica. Journal of Wildlife Rehabilitation. 21(1): 14–21.
Emryss vy Publishers: Haarlem, Netherlands.
Casey, S. 2003. Modifying a Feeding Nipple. Wynn, S., and S. Marsden. 2003. Manual of Natural Available at: <http://www.ewildagain.org/pubs/ Veterinary Medicine: Science and Tradition. Mosby: Casey, S., and T. Bush. 2000. Homeopathic First Aid with a Sample of Wildlife Cases. Wildlife Copyright 2011 Shirley J. Casey and Mackenzie Rehabilitation. 18: 67–74.
Goldthwait. All rights reserved. Printed with permis- Casey, S., and A. Casey. 2003. Squirrel Rehabilitation sion of the authors. Handbook. WildAgain Wildlife Rehabilitation, Inc: Evergreen, CO. Available for purchase. Chapman, J., and G. Feldhamer. 1992. Wild Mammals of North America. Johns Hopkins University Press, Baltimore, MD.
Day, C. 1998. The Homoeopathic Treatment of Small Animals: Principles and Practice. C. W. Daniel Co. Ltd: Cambridge, England.
Facinelli, J., A. Casey, and S. Casey. 1997. Finding and Using Holistic Veterinary Services. Journal of Wildlife Rehabilitation. 20(4): 14–19. Gray, Bill. 2000. Homeopathy: Science or Myth. North Atlantic Books: Berkeley, CA.
Laber–Laird, K., M. Swindle, and P. Flecknell. 1996. Handbook of Rodent and Rabbit Medicine. Permagon: Tarrytown, NY.
Miller, E. (editor). 2000. Minimum Standards for Wildlife Rehabilitation, 3rd edition. National Wildlife Rehabilitators Association, St. Cloud, MN.

Source: http://www.ewildagain.org/pdf/AspirationinSquirrels.pdf