Symptoms and Treatment of Canine Infectious Tracheobronchitis

1 Canine Infectious Tracheobronchitis

Clinical symptoms of canine infectious tracheobronchitis

Affected dogs have a paroxysmal cough that worsens with exercise, excitement or weather changes. Touching the trachea triggers coughing. With much respiratory secretion, harsh alveolar sounds and dry/wet rales are heard. Mixed infection: depression, fever, poor appetite, purulent nasal discharge, persistent cough, and digestive upset with vomiting and diarrhea.

Differential diagnosis

(1) vs. canine parainfluenza virus infection

Both show fever, depression, reduced appetite, nasal discharge and cough.

Difference: parainfluenza starts with serous nasal discharge that thickens, improving in about a week; with mixed infection cough lasts weeks or is fatal. A few dogs show only hind-limb paralysis and hemorrhagic enteritis with swollen tonsils. Specific fluorescent antibody detects positive cells in tracheal/bronchial epithelium.

(2) vs. canine distemper

Both show fever, serous or purulent nasal discharge, cough, lethargy and reduced appetite.

Difference: distemper shows biphasic fever, conjunctivitis/keratitis, red sclera. Severe cases have purulent discharge and neurological signs (head tremor, spinal twisting, limb twitching). Scrapings stained show light-blue nuclei, rose cytoplasm, red inclusions.

(3) vs. canine heartworm disease

Both show cough worsening after exercise.

Difference: heartworm cases show strong heartbeat, liver pain on palpation, pleural effusion, generalized edema, anemia, jaundice; microfilariae seen in peripheral blood.

(4) vs. canine tuberculosis

Both show cough and reduced appetite.

Difference: tuberculosis cases are sleepy, progressively emaciated, with foul breath. Necropsy shows gray-yellow nodules in trachea and lymph nodes; fresh lesions have red halos, old ones calcified. Sputum smears show thin red-staining bacilli.

(5) vs. canine lobular pneumonia

Both show fever, cough, nasal discharge, reduced appetite and depression.

Difference: lobular pneumonia is not contagious, with rapid breathing. Chest percussion shows focal dullness over the cardiac lobes; auscultation reveals rales and crackles. No diarrhea.

(6) vs. canine bronchitis

Both occur in winter/spring, with fever, initial cough, nasal discharge; chest auscultation shows increased breath sounds and dry/wet rales.

Difference: bronchitis is not contagious, no vomiting/diarrhea, and Bordetella bronchiseptica cannot be isolated.

(7) vs. common cold in dogs

Both show fever, cough, nasal discharge, reduced appetite and depression.

Difference: cold is not contagious, usually triggered by sudden cold, bathing or air conditioning. Lung sounds usually unchanged, no severe cough.

Notes

Diagnosis is mainly based on the cough pattern, dry/wet rales on auscultation, no obvious percussion changes, and X-ray showing coarse bronchial shadows without focal lesions.

Prevention and treatment

(1) Prevention

1. Keep the environment clean; regularly disinfect cages and bowls.

2. Isolate affected dogs promptly.

3. Inactivated single or combined vaccines against Bordetella bronchiseptica, canine parainfluenza and canine adenovirus type II give up to 96% protection.

(2) Treatment

Treatment is antibacterial/anti-inflammatory and prevents secondary infection.

1. Ampicillin: 20-30 mg/kg orally 2-3 times daily; or 10-20 mg/kg SC/IM/IV 2-3 times daily.

2. Cefazolin sodium: 15-30 mg/kg IM or IV.

3. Clavamox (amoxicillin-clavulanate suspension): 0.1 mL/kg SC or IM.

4. Enrofloxacin injection: 1 mL/kg SC.

5. Interferon: 100,000-200,000 IU per dose, SC or IM.