“Not So CUTE-rebra “

(Cuterebra)

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Thumper is a 1 year old male Netherland Dwarf rabbit that presented to the Route 516 Animal Hospital for a lump on his neck. His owner was concerned that he had been bitten by an insect or tick. Upon examination, Thumper was a healthy bunny. The lump was located on the dorsal, middle area of his neck. His skin was red, thickened, and hard to the touch. The raised lump had a very symmetrical hole located centrally with a small amount of fluid visible. After seeing this lump we diagnosed Thumper with Cuterebra.

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Cuterebrae are large bot flies which 3 larval stages that commonly infect rabbits, rodent, and even outdoor cats. The life span of the adult is short and focused solely on reproduction. The larvae hatch under the rabbit’s skin in a fatty layer called the subcutis. They tend to pupate in the axillary (armpit), inguinal (groin), and cervical (neck) areas which results in a 1-3 cm swelling that encapsulates the larvae. The hole seen at the center of the swelling is the breathing hole. Cuterebra larvae can cause different levels of pathology. Some rabbits are unaffected while others can become weak, dehydrated, lame, and go into shock. Some larvae will migrate through the nose, eyes, sinuses, ear canals, and brain which can be fatal.

Treatment involves surgically removing the offending larvae through the breathing pore. This must be performed with care because crushing the maggot can release a toxin that results in anaphylaxis. After this, the dead tissue should be cut away and the patient placed on antibiotics and pain meds. Cuterebrid infection is prevented by keeping pets indoors and with fly control.

 

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The larva in Thumper’s neck was removed without incident and he recovered nicely. However, it took his owner longer to recover from the shock of seeing a live squirmy maggot peeping out of a breathing hole in her beloved bunny’s neck. If your cat, rabbit, or pet rodent has a lump on its body, especially if there is a hole in the middle, take him or her to your veterinarian.