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− | ==Description== | + | {{OpenPagesTop}} |
− | Dogs are rarely infected with [[:Category:Mycobacterium species|''Mycobacterium'' spp.], tuberculosis , M bovis , and occasionally M avium or M fortuitum which are the causative agents of tuberculosis [[Respiratory Bacterial Infections - Pathology#Tuberculosis|in cattle]], either from human or farm animal source
| + | ==Introduction== |
| + | [[:Category:Mycobacterium species|''Mycobacterium'' spp.]] have a '''wide host affinity''' and pathogenic potential. They are able to survive intracellularly and produce '''granulomatous inflammations'''. Mycobacterial infections can be divided into three forms: '''tuberculous, lepromatous and opportunistic'''. |
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− | ==Signalment==
| + | The '''tuberculous bacteria''', ''M. tuberculosis'' and ''M. bovis'' produce nodular granulomas in their hosts. |
− | Dogs of any age or breed in contact with tuberculosis infected people or cattle. | + | |
| + | The ''M. avium-intercellulare'' complex (MAC) includes many saprophytic organisms that are '''opportunistic''' and produce granulomas in their hosts. |
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| + | Dogs and cats are susceptible to ''M. tuberculosis'' and ''M. bovis'' but are more resistant to infections by MAC. There appears to be a higher degree of ''M. bovis'' infection in cats. |
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| + | The incidence of true tuberculosis has decreased and rarely affects dogs and cats, but cases are seen in parts of the world where there is a high degree of exposure and where the disease is endemic. |
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| + | Dogs and cats can become disseminators when the organism localises in the intestinal or respiratory tracts. |
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| + | The '''lepromatous organism''' includes ''[[Mycobacterium lepraemurium]]'' which causes Feline Leprosy and which occurs through bites or from contact with infected rats. |
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| + | See also the general page on [[Tuberculosis|tuberculosis]]. |
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| + | ==Clinical signs== |
| + | The predominant signs in small animals are '''respiratory and digestive''', but there can be some skin lesions. |
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| + | Infections are often '''asymptomatic and insidious'''. |
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| + | In '''dogs''', common signs include: fever, weight loss, anorexia and harsh non-productive coughing. |
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| + | '''Dogs and cats''' may develop hypersalivation, retching, dysphagia and tonsillar enlargement due to oropharyngeal lesions. |
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| + | '''Cats''' may have weight loss, anaemia, vomiting and diarrhoea. |
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| + | '''Cutaneous lesions''' may include single or multiple ulcers, abscesses, plaques and nodules, commonly on the head, neck and limbs. |
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| ==Diagnosis== | | ==Diagnosis== |
− | The intradermal tuberculin test can produce flase negative results in the dog. | + | Intradermal skin testing in dogs and cats is '''inconsistent and unreliable'''. |
− | ===Clinical signs===
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| + | '''Radiographs''' may show: nodular soft tissue opacities in the lungs, most commonly in the caudal lung lobes. |
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| + | The diagnosis is may by '''cytological and cultural examination''', and histopathology of biopsy material. |
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| + | On '''cytology''': organisms vary in number, but numerous organisms may be visible in the smear. With Wright's stain, the organisms are rod-shaped, refractile and non-staining. An '''acid-fast stain''' is needed to highlight the organism. |
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| + | '''Culture or PCR''' is then necessary to differentiate between mycobacterial species. |
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| + | The pathogen is slow-growing and requires special media and several weeks to establish visible colonies. |
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− | ===Pathology===
| + | '''Post-mortem examination''' will reveal: firm multifocal nodules, with necrotic centres in the caudal lung lobes, liver, kidney, pleura and peritoneum. The lesions are often exudative, discharging a yellow fluid into the thorax and abdomen. |
− | On post mortem examination firm multifocal nodules, with necrotic centres are found in the caudal lung lobes, liver, kidney, pleura and peritoneum. The lesions are often exudative, dicharging a yellow fluid into the thorax and abdomen.
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| ==Treatment== | | ==Treatment== |
− | Euthansia is advised due to the zootic potential of the disease.
| + | Dogs and cats with true tuberculosis infections can be a source of infection for humans with grave consequences for public health, and in most cases '''euthanasia''' is performed. |
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| + | Because infections with the MAC organisms are opportunistic, usually with an environmental source, '''treatment''' may be attempted. |
| + | '''Two or three antibacterials''' should be used intercurrently for '''6-9 months'''. Drugs such as rifampicin, clarithrocymic, clofazimine, doxycyline and enrofloxacin have been used. Treatment should be continued until all clinical signs of the disease have resolved. |
| + | The response is '''variable''' and treatment is usually more successful in cats. |
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| + | ==References== |
| + | Hoskins, J. (2001) '''Veterinary pediatrics''' ''Elsevier Health Sciences'' |
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| + | Muller, G. (2001) '''Small animal dermatology''' ''Elsevier Health Sciences'' |
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| + | Ettinger, S. (2001) '''Pocket companion to textbook of veterinary internal medicine''' ''Elsevier Health Sciences'' |
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| + | ==Links== |
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| + | <big>'''[[Tuberculosis|General page on Tuberculosis]] |
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| + | '''[[Mycobacterium bovis|Bovine Tuberculosis]] |
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| + | '''[[Mycobacterium avium|Avian Tuberculosis]]</big> |
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| + | {{Learning |
| + | |literature search = [http://www.cabdirect.org/search.html?q=%28title%3A%28mycobacterium+%29+OR+title%3A%28tuberculosis%29%29+AND+od%3A%28dogs%29 Canine Tuberculosis publications] |
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| + | {{review}} |
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| + | {{OpenPages}} |
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| + | [[Category:To Do - Helen]] |
| + | [[Category:To Do - Review]] |
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− | [[Category:Dog]][[Category:To_Do_- lizzyk]] | + | [[Category:Respiratory Diseases - Dog]] |
| + | [[Category:Expert_Review]] |
| [[Category:Respiratory_Bacterial_Infections]] | | [[Category:Respiratory_Bacterial_Infections]] |