Back to Basics
Rats often don’t exhibit sign of illness until they are well into a medical emergency. It is important to check your rat often for any medical abnormalities.
Any time that you handle your rat is an opportunity to check it for problems. Awareness of your rat’s physique and behavior will help you see any changes that indicate the need for a trip to the vet.
Health checks are easier if your rat is a willing subject. It is helpful to get your rat used to being checked and to being held on its back.
Emergency situations should be managed and the rat stabilized before proceeding with a total physical assessment. How you begin your assessment should be no different for rat than it would be for any victim of emergency. Treat the life threatening event first remembering to follow the ABC’s of emergency care by assessing their Airway, Breathing and Circulation.
For rats that are elderly, or debilitated the health check should begin with the areas or systems most affected, and the rat should be permitted short rest breaks during the health check in order to minimize any stress to the animal.
*A note for vets: because a rat may often be or become hypothermic when sick, injured,or debilitated, it is important to place a towel (or warmed towel) on a cold, metal exam table before placing the rat on the table.
Abnormal: chronic weight loss, rapid/acute weight loss, rapid/acute weight gain, gradual weight gain often indicates developing obesity.
Weight is an important factor, and weight loss can often be a first indicator of developing illness in the rat. It is also an important factor when determining the correct dosage to be used should your rat require any medication for illness.
Abnormal: hypothermia, hyperthermia.
Get to know what your rat’s normal temperature “feels” like so you can recognize when the rat is too cool to the touch or fevered.
Abnormal: Lethargy, agitation, restlessness, circling in relation to illness. The absence of movement of facial whiskers (vibrissae). Jerking/seizures, paresthesia, paralysis. Biting in an otherwise docile rat, abnormal permanent one-sided tilt to head.
Note: That cloudiness in the lens can be a common finding in older rats.
Abnormal: Red or yellow discoloration of sclerae, cloudiness, ulcerations, protrusion/swelling, enophthalmia (small recessed eye), microphthalmia (small eye), sunken eyelids.
Bulging eyes may be indicative of SDAV infection, tumors, or an abscess behind the eye.
Note: Porphyrin can be distinguished from blood as it will fluoresce when using a Wood’s lamp, and blood will not.
Abnormal: Discharge, odor, growths/protruding mass, crusting, or hardening of pinna (tips of ears). It is important to smell the ears when doing health checks as this can be one of the signs of ear infection. In addition ear infections can many times be accompanied by a head tilt.
Note: Swelling near base of ear may indicate a Zymbal’s gland involvement (e.g. tumor, abscess).
Abnormal: Misalignment, lost tooth, brittle pure white teeth, swelling, redness, pus, foul odor, persistent drooling/wetness around mouth, cyanosis or paleness of lips or gums.
Note: Incisors should be even, not too long, and not piercing the cheek or gum.
Oral infections can be aggressive and need early medical intervention to be resolved. Be sure rat is able to eat.
Abnormal: Porphyrin (rust-colored) staining that remains around the nose, or is excessive. Noisy nasal breathing (e.g. snuffling).
Abnormal: Edema/swelling near cheeks below ear may indicate infection (e.g., abscess) or tumor. Swelling of neck may be indicative of SDAV infection, or if more localized, tumor formation.
Normal breath sounds in the rat are relatively quiet. Rats are obligate nose breathers and breathing is done primarily through the nose until there is respiratory compromise. The normal respiratory rate is 71-146 depending on size of rat.
Abnormal: Wheezing, congestion, clicking noises (can also be present during sleeping). Labored breathing requiring the use of accessory (abdominal muscles) muscles to help assist breathing, retracting (a sucking in of the sides of the chest), gasping (open mouth breathing), sputum.
Head tucking and extending accompanied by drooling can indicate choking.
A rat with a respiratory infection often exhibits other signs that may include; discharge (e.g. porphyrin: rust-colored staining) from the eyes or nose, poor appetite, hunched posture, or puffed up fur (piloerection). The rat will need to be seen and treated by your veterinarian. Signs that appear to be respiratory related may also involve the heart.
Abnormal: slow heart beat, missed heart beats, rapid heart beat faster than normal rate.
Abnormal: Lumps, edema/swelling, enlargement of liver, spleen, kidneys, areas of sensitivity/pain, emaciation and or cachexia, loss of fat and or muscle mass, rashes, cuts, bite wounds, bruising.
Note: Detecting if lumps feel connected to the skin or are moveable under the skin, and whether painful versus non-painful, may be of help in determining whether the lump is a tumor, abscess or cyst.
Abnormal: Hard, bloated, distended, swollen, sunken.
Abnormal: Diarrhea, bleeding, rectal protrusion, lacking color, dry and flaking, unusually foul smelling.
Note: Constipation may be present in rats that are dehydrated.
Abnormal: Excessive urination may indicate diabetes, or glomerulonephrosis. Decreased urine, absence of urine, or dark concentrated urine may indicate dehydration, and or renal failure.
Bleeding may indicate infection or stones. Hunched posture chewing on feet is indicative of pain and seen in instances of bladder stones.
Examine your female rat’s vaginal opening for any discharge or blood. In a non-pregnant rat this could mean a problem such as: uterine infection (often mycoplasma), cysts, or tumor.
Abnormal: Bleeding, odor, thick white plugs, paraphimosis, priapism.
In males, particularly elderly males or those that have hindlimb issues, check the penis for discharge. (Occasionally you will need to inspect closer by very gently pushing back the sheath to make sure that there is no blockage, very gently cleansing if needed, and gently return sheath in place.
Note that anatomically the male rat has an open inguinal canals that permits the testicle(s) to migrate in and out of the abdomen.
Abnormal: Missing testicle(s) not associated with neutering, cryptorchidism (testicle does not descend into scrotum), masses, lumps, bites, wounds.
Abnormal: Inflammation, sores, bumps, paleness, cyanosis. Concentric constriction on tail can indicate ringtail.
Abnormal: Inflammation, raised red areas, open sores on bottom of feet (hind) can be indicative of bumblefoot, requiring treatment.
Note: Rats housed on smooth flooring may not effectively wear down the sharp points of their nails. Cautious clipping of the nail tips, avoiding the cuticle, may be needed.
Abnormal: Soiled, piloerection, hair loss unrelated to genetics, nits.
Abnormal: Scratches, scabs, cuts, wounds, bleeding, lumps, rashes.
Note: Watch your rat’s behavior to see if it is scratching excessively.
Check skin and fur for possible parasites. Fleas and lice are large enough to see. Mites are harder to see, but often you will see nits on the hair shaft or a characteristic scabbing around the rat’s shoulders and neck.
Note: Non-invasive tests for proprioception and mobility include “hopping” and “wheel-barrow” tests.
For “hopping” test, place rat on a firm surface. Place hand under the chest for support and raise up the front of the rat, and with the other hand lift up and hold one hind foot. The rat will normally hop to one side to maintain balance.
For “wheel-barrow” test, place rat on firm surface. Lift and gently hold up rat’s hind limbs and move gently forward like pushing a wheel-barrow. The rat will normally maintain balance and mobility by walking on its forepaws.
Abnormal: Watch for trembling, limping, tilting, circling, weakness in the limbs, stiffness or knuckling in the digits of forepaws or hindfeet. A rat exhibiting any of these signs as well as: “hunched up” posture or lethargy can indicate an ill or injured rat.
Using two fingers take a little fold of skin on the rats back and lift it up (similar to the appearance of tent). When you release your fingers the skin should return to its normal position. If the skin stays raised, even for a few seconds, your rat may be dehydrated.
Note: Rats that are moderate to seriously ill may tend not only to reduce their food intake but their fluid intake as well. Measurement of weight loss should be monitored along with the use of a pinch test.
Posted on July 19, 2010, 12:06,
Last updated on March 2, 2011, 20:39