These are adult Toxocara cati, large roundworms that are common in kittens and puppies. Clinical presentation is as in this cat, and worms can be seen in vomit or feces.
Affected animals may have mucoid diarrhea or—with early infection—coughing due to larval migration causing eosinophilic pneumonia.
Kittens are infected by eating embryonated infective eggs or—rarely—by transmammary transmission (vs. T. canis in dogs – transplacental and transmammary transmission is common).
Dx: Identify adult worms in vomit or feces or eggs in feces. Must distinguish the spherical, pitted-shelled eggs of T. canis and T. cati from the oval, smooth-shelled eggs of Toxascaris leonina.
Tx: Pyrantel (most widely used; considered safe during pregnancy), milbemycin, moxidectin, piperazine, emodepside, fenbendazole, or selamectin. Tx the queen in last week of pregnancy, then Tx nursing queen and kittens. Eggs are sticky, making it difficult to decontaminate the environment.
ZOONOTIC: humans can develop visceral larva migrans or ocular larva migrans.
Strongyloides stercoralis adults are only ~2 mm in length and almost transparent.
Trichuris vulpis (whipworms) are 45–75 mm long and slender with a thicker posterior (~1/3 the worm).
Ancylostoma tubaeforme (hookworms) are 12–15 mm long. Click here to see A. caninum (similar).
Spirocerca lupi are bright red and 40–70 mm long.
Images courtesy of Kalumet and Beentree.
