TUBERCULOSIS (Mycobacterium tuberculosis var. hominis, M.
tuberculosisvar. botis, M. tuberculosis var. avium)
This progressive disease of primates has been reported in macaques,
gibbons, orangutans, chimpanzees, squirrel monkeys, owl monkeys, and other
primates. It is marked by caseous lesions (tubercles) that may be found in
any organ of tissue. Atypical mycobacteria have been isolated from
The clinical signs are cough, chronic loss of body weight, dull hair coat,
diarrhea, dyspnea, depression, anorexia, and kyphosis.
Diagnosis can be confirmed by a positive tuberculin test, positive
thoractic radiographs, and cultures or stains of stomach mucus obtained by
gastric lavage, and fecal cultures. Newly acquired primates should be
tuberculin tested immediately and at 30 days, and annually thereafter. The
tuberculin test is administered intradermally by injecting 10,000 units of
mammalian tuberculin (0.05 to 0.1 ml) into the skin of the eyelid with a
12 mm, 2s to 28 gauge needle.
Individuals should be chemically restrained, allowing a complete physical
examination at the same time. Test readings should be made at 24, 48, and
72 hours. Erythema and edema of the injected eyelid show a positive
reaction to the test. Sputum cultures, gastric lavage, and fecal cultures
are recommended in diagnosing and monitoring tuberculosis in former
reactors that may be anergic.
Radiographic examination of the thorax will often confirm a diagnosis of
tuberculosis but should not be depended upon as the primary criterion,
since pulmonary involvement does not always occur in primates and the rate
of visceral tuberculosis is high.
Treatment of tuberculosis in nonhuman primates, especially those belonging
to private individuals, should be discouraged because of the public health
hazard. The veterinary clinician is also obligated to recommend that all
people exposed to the animal seek medical attention.
The recommended treatment for rare and endangered species and
exceptionally valuable experimental animals may be undertaken if the
owners and researchers are made fully aware of the public health hazard
and are prepared to adhere to strict quarantine procedures during the
extended treatment periods. The agent of choice is isoniazid administered
orally in a sweet carrier at a rate of 10 to 20 mg per kg per day for one
to two years. Some investigators feel that the animal may be maintained on
isoniazid for the remainder of its life. Viable mycobacteria normally
disappear from the sputum and feces of isoniazid-treated animals in three
to 18 weeks. Isoniazid is a potent inhibitor of vitamin B6; therefore, B6
should be supplemented to primates on chronic treatment.