Here we report the case of a diagnostic and treatment challenge in a four-month old dog from England, presented with one-month history of unproductive cough. Antigen blood test for
- Baermann technique
- morphologic identification
- molecular identification
Nematodes parasitising the respiratory tract of mammals, commonly referred as lungworms, are increasingly reported in Europe as a cause of infection in animals and humans (Traversa
Canine crenosomosis is typically characterised by bronchitis with a dry, unproductive cough that can be elicited by tracheal palpation, with occasional gagging (Cobb & Fisher, 1992). High parasite burdens may induce mucoid or mucopurulent discharge from the airways along with a chronic and productive cough, which could detrimentally affect dogs’ quality of life (Conboy, 2009). In most cases, mild to moderate bronchial patterns with a diffuse interstitial component (more evident at the diaphragmatic lobes) is observed on radiographs (Unterer
A four-month old, entire female, wirehaired Dachshund was referred to The Wylie Veterinary Centre, Upminster, Essex UK, in November 2015 with a one-month history of unproductive coughing, refractory to non-steroidal anti-inflammatory drugs (NSAIDs) and several broad spectrum antibiotic therapies (including cefovecin, metronidazole, amoxicillin and clavulanic acid). The patient lived with another dog in a semi-rural area in Essex (UK). In mid-October, she was core vaccinated against canine distemper, hepatitis, parvovirus, parainfluenza and leptospirosis and treated with a topical parasiticide containing 10 % imidacloprid + 2.5 % moxidectin.
After a physical examination, blood was collected from the jugular vein for a complete blood count (CBC), serum chemistry profile and an antigen blood test specific for the detection of
In order to assess the lungs, heart and chest wall, the dog was premedicated with acepromazine and butorphanol, and general anaesthesia was induced with propofol and maintained with isoflurane after tracheal intubation. Lateral and dorso-ventral radiographic projections of the thorax were taken at full inspiration. A flexible bronchoscopy was performed, as well as, a bronchoalveolar lavage (BAL) with 15 mL of warm sterile saline instilled and aspirated five seconds later. The BAL was stored in sterile tubes for cytological evaluation.
A qualitative floatation analysis with a sucrose solution, a sedimentation test and a Baermann technique were performed with fresh faecal samples collected through an enema. Larvae were stored in 70 % ethanol and sent to the Parasitology Unit at the Faculty of Veterinary Medicine, ULisboa (Portugal) and to the Department of Veterinary Medicine, University of Bari (Italy) for morphological and molecular parasitological identification. In order to perform molecular characterization, larvae were isolated from the suspension using a 10 μl micropipette and stored in phosphate buffer saline (PBS) solution. Genomic DNA was extracted using a commercial kit (DNeasy Blood & Tissue Kit, Qiagen, GmbH, Hilden, Germany), in accordance with the manufacturer’s instructions, and partial mitochondrial 12S rRNA (~330 bp) and nuclear 18S rRNA (~1700 bp) genes were amplified as previously described (Latrofa
On physical examination the dog was bright, alert and responsive with a body condition score of 3/9. Her inspiratory effort was increased and an unproductive cough with terminal retch was noticed during the consultation, although there was no response on tracheal pinch. On thoracic auscultation, normal respiratory sounds were slightly exaggerated over the entire lung field, although there were no adventitious lung sounds. Her heart sounds were normal with synchronous femoral pulses. Her rectal temperature was within normal limits and no enlarged lymph nodes were noticeable. CBC revealed eosinophilia, with no other abnormalities and serum chemistry was unremarkable. The antigen blood test specific for the detection of
Lateral and dorso-ventral radiographic projections of the thorax were taken at full inspiration, revealing a normal cardiac silhouette, enhancement and thickening of the bronchial walls spreading into the periphery of the lung fields, and a diffuse increase in pulmonary opacity throughout the lungs (Fig. 1). Flexible bronchoscopy was performed and visualization of the trachea and bronchioles revealed a moderate quantity of mucous and absence of foreign bodies, nodules or masses. After inspection of all primary and secondary bronchioles, a bronchoalveolar lavage (BAL) was performed. During the instillation, a single motile white worm was observed on the mucus of the bronchial wall and cytological evaluation of the BAL showed the presence of a non-septic exudate with marked eosinophilic infiltration.
After the visualization of the nematode in the respiratory tract, an enema was performed to collect fresh faecal samples. Qualitative floatation analysis and sedimentation test were negative. The sediment collected from the Baermann apparatus revealed the presence of several motile larvae under light microscopy. A quantitative Baermann was performed, revealing 6066 larvae per gram of faeces (LPG). Several filiform C-shaped larvae were visualized, 260 – 290 μm long and 12 – 14 μm wide, consistent with
The patient was treated with a second administration of 10 % imidacloprid + 2.5 % moxidectin spot-on. However, at a re-examination 13 days after the spot-on application, L1 of
Here we report a case of natural infection by
Further studies are needed to investigate long term effects and potential complications when other concomitant infections are present. Clinicians should be mindful that
Successful treatments in naturally infected dogs have been reported with the use of febantel, fenbendazole, ivermectin, milbemycin oxime (Bihr & Conboy, 1999) and moxidectin (Colella
Baermann tests should be performed more routinely to perceive the real prevalence of this lungworm and to understand if it is a rare parasite or just rarely diagnosed. Besides, practitioners should include crenosomosis in the differential diagnosis of respiratory diseases in dogs, particularly in areas where foxes are present, and should foster targeted preventive therapy against this lungworm infection.