Dog Esophageal Spirocercosis: Symptoms and Treatment

1 Dog Esophageal Spirocercosis: Symptoms and Treatment

Parasite traits and life cycle

Spirocerca lupi is light blood-red, coiled in a spiral. Males 30–40 mm with 4–5 pairs of small caudal papillae; females 54–80 mm, blunt tail, 1 pair of papillae, vulva at the rear of the esophagus. Eggs are long-oval, (30–37)×(11–15) µm, thick-shelled, with one curved embryo.

Eggs pass in feces, are eaten by dung beetles (intermediate host); the embryo hatches, molts, and becomes infective in the beetle’s trachea as a cyst. The beetle is eaten by amphibians, reptiles, birds (incl. chickens), or small mammals; the larval cyst survives in their gut lining and stays infective. A dog infected by eating the beetle or those animals has larvae burrow into the stomach or gut wall, migrate via blood to the aorta and esophagus, and mature in nodules there.

Clinical signs and pathology

Mild infections show no signs; only when the esophageal lesion becomes a granuloma pressing the esophagus does dysphagia, vomiting, drooling, and cough appear, lowering appetite. If bacteria infect a nodule, fever rises; some dogs die suddenly from aortic nodule rupture.

Differential diagnosis

1. Esophageal spirocercosis vs. glossitis

Both show drooling and abnormal swallowing.

Difference: glossitis shows red-swollen tongue mucosa, sometimes ulcers.

2. vs. esophagitis

Both show drooling, cough, dysphagia.

Difference: esophagitis shows distress with reflux of mucus and blood.

3. vs. esophageal obstruction

Both show drooling, vomiting.

Difference: obstruction has gagging without output, vomiting right after eating/drinking, and a palpable blockage.

4. vs. vomiting from chicken/fish bones

Both show vomiting with blood.

Difference: bone vomiting has no eggs; it stops once the bone is expelled or passes.

Note

In the esophagus: mild blockage, severe drooling and weight loss; in the stomach wall: eggs in vomit and stool; in the artery wall: sudden death from rupture. X-ray shows a tumor shadow in the upper third of the esophagus; barium shows dilation before the tumor, with periosteal proliferation in limbs. Eggs are heavy, so examine feces by sedimentation or saturated sodium nitrate flotation.

Prevention and treatment

1. Prevention

a. Safely dispose of sick dogs’ feces.

b. Kill the intermediate and vector hosts.

c. Avoid raw intermediate/vector animals.

2. Treatment

a. Albendazole, 50 mg/kg body weight, single oral dose.

b. Hexachloroparaxylene, 100–200 mg/kg, daily oral for one week.

c. Diethylcarbamazine citrate, 10 mg/kg, single oral dose.