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How to Tell if Your Marmoset Monkey Is Sick

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Marmosets, small South American monkeys also referred to as New World monkeys, are susceptible to the same diseases as humans. Similar to raising a small child, adolescent marmosets should be vaccinated for measles and tetanus, and sick individuals should avoid all contact with monkeys. Before adopting a marmoset into your family, check with your local authorities to ensure they're legal to possess in your area.

Wasting Away

Marmoset monkeys are susceptible to wasting syndrome, a bodily invasion of the pancreatic worm Trichospirura leptostoma, which is transmitted through the household cockroach. For this reason, household sanitation is extremely important and cockroaches should never be fed to marmoset monkeys as a protein food source. Infection causes the marmoset's pancreas to malfunction, leading to malnutrition, diarrhea and dehydration. The most common symptoms of infection include chronic diarrhea, weight loss, hair loss at the base of the tail and paralysis of the hind legs.

The Kiss of Death

The herpes simplex virus 1, which causes cold sores in humans, is easily transmitted and extremely dangerous to marmoset monkeys. More than 80 percent of humans are carriers of the virus, even though they may never exhibit any symptoms. The dormant herpes simplex virus resides in the trigeminal nerve, one of the many facial nerves. When dormant, this virus can shed from carrier humans through the saliva, particularly if the person is stressed or ill. Marmosets contract herpes simplex 1 through contact with saliva. As a precautionary measure, never allow your marmoset to kiss anyone, including you, on the mouth, never feed them from your mouth or allow them to have an object that has been in contact with your mouth, and avoid all contact with your marmoset if you are ill or have fever blisters. Symptoms of the herpes infection in marmosets include a decrease in appetite, lethargy, diarrhea and a high fever. As it worsens you may see red or swollen lips, blisters or lesions on the tongue, gums or in the mouth, a droopy face and inability to blink and seizures.

Lymphocytic Choriomenangitis

This mouthful of a disease, also known as LCMV, has occurred in captive marmosets both in private homes and in zoos. The primary carrier for the lymphocytic choriomeningitis virus is the common house mouse, although mice can transfer the disease to rats, hamsters, gerbils and guinea pigs. Captive marmosets are at higher risk due to increased chance of exposure to urine, feces, saliva or bedding materials of house mice. Zoo outbreaks have been the result of feeding infected mouse pups to marmosets. Once infected, symptoms include shortness of breath, loss of appetite, extreme lethargy and jaundice -- the yellowing of skin and eyes.

Early Warning Signs

Marmosets can succumb quickly to a variety of diseases. Knowing your monkey's normal behaviors will help you quickly determine if he has fallen ill. A marmoset's tail, while not prehensile, is expressive. A sick monkey's tail will be limp and lifeless, and can be the first visual cue something is amiss. When you first bring your marmoset home, or while he is well, take his temperature daily for a week and record each reading. If you suspect your monkey has fallen ill, take his temperature and compare it with your baseline readings. Any increase of more than a couple of degrees, combined with any unusual behaviors, should be immediately referred to your exotic animal veterinarian. Diarrhea is the most common marmoset illness, caused by parasites, bacterial infections or changes in the diet, and should be treated immediately.