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Today's Veterinary Practice May/June 2014 68 | ParasiTe ProTocols tvpjournal.com Diagnosis. Infection with C vulpis is con- firmed by identi- f ying character- istic larvae with a conical head and conical, taper- ing tail (Figure 3) in the feces, or finding the worms in the bronchi at necropsy. Treatment (Table 2). Successful treatments described in the literature include fenbendazole, iver- mectin, and febantel. More recently, excellent results have been obtained using: • Milbemycin oxime at 0.5 mg/kg PO single dose • Topical application of 10% moxidectin, single dose. 8,9 Prevention. Routine use of monthly parasite control products containing milbemycin oxime or moxidectin are expected to prevent establishment of future infec- tions. Eucoleus aerophilus Distribution. Infection with E aerophilus is seen wher- ever dogs and cats are found, although foxes are consid- ered an important reservoir host. 10 Life Cycle. Eggs are shed in the sputum or feces, and em- bryonate in 30 to 50 days. Larvae are released when eggs or earthworm paratenic hosts are ingested and migrate by the bloodstream to the lungs. The larvae then pene- trate the alveoli and migrate up the air passages as they develop. They reach maturity in the epithelium of the bronchioles, bronchi, and trachea, threading their thin bodies through the epithelial surface. 1 Clinical Signs. Most infections with E aerophilus are clinically inapparent. If large numbers of nematodes are present, dogs may develop tracheitis, bronchitis and, sometimes, pneumonia, 11 which can cause: • Anorexia • Cough • Debilitation • Dyspnea • Nasal discharge. Diagnosis. The eggs passed in sputum or feces are char- acteristic, with polar plugs that are slightly askew of the central axis (Figure 4) and a granular shell. The eggs in the feces of dogs must be differentiated from those of Trichuris vulpis (larger), Eucoleus boehmi (contain a par- tially developed embryo when passed), and Pearsonema plica (present in feces contaminated with urine). 1 Treatment (Table 2) & Prevention. Extended courses of ivermectin or fenbendazole have been reportedly suc- cessful at eliminating infection, but anecdotal evidence suggests that routine preventives may not be protective against this nematode. develop in pulmonary capillaries. Larvae that hatch from the eggs move into an airspace; then are coughed up, swal- lowed, and passed in the feces. Snails and slugs feeding on the feces ingest the larvae and perpetuate the life cycle. 3 Clinical Signs. Infection with A vasorum produces dis- ease similar to that caused by D immitis: chronic cough, dyspnea, exercise intolerance, and anorexia. • Gagging and weight loss are the most common clinical signs reported. • Pulmonary hemorrhage can occur as larvae migrate into airspaces. • Granulomas develop in response to eggs and larvae, and pulmonary fibrosis occurs. • Pulmonary vascular lesions include thromboarteritis and intimal proliferation; pulmonary hypertension can lead to congestive right heart failure. 4 Diagnosis. Larvae can be de- tected in feces using the Baermann technique or fecal flotation, and are identified by the char- acteristic kink at the tip of the tail (Figure 2). Radiographic changes as- sociated with A vasorum in- fection include: • Diffuse peribronchial, inter- stitial, and alveolar densities • Enlargement of the right heart and pulmonary artery. Treatment (Table 2, page 70). Infections have been treat- ed with several different types of anthelmintics: • Albendazole or fenbendazole • Ivermectin • Levamisole • Moxidectin. Severe dyspnea and ascites may be seen after treatment; bronchodilators, expectorants, and diuretics may be re- quired to manage these post-treatment reactions. Prevention. Routine administration of topical moxidectin has been shown to protect dogs from infection with this parasite. 5 Dogs can also be protected by minimizing op- portunities to consume snails, slugs, and frogs. Crenosoma vulpis Distribution. This lungworm of foxes and other wild cani- dae is most common in the northeastern U.S. and the east- ern part of Canada. 6 Life Cycle. Dogs become infected when, like foxes, they ingest the snail or slug intermediate host. The nematodes migrate to the lungs and develop into adults, moving from the smaller bronchioles to the larger bronchi as they ma- ture. Clinical Signs. Infections may be asymptomatic or can induce bronchitis and bronchiolitis, resulting in chronic cough. 7 Figure 2. Posterior end of tail of first-stage Angiostrongylus vasorum larva in feces, demonstrating the tail kink just posterior to the tip. Figure 3. Posterior end of tail of first-stage Crenosoma vulpis larva in feces, demonstrating the conical, tapering tail. TVP_2014-0506_CAPC-CanineHelmiths_Part2.indd 68 5/24/2014 8:21:37 PM