For veterinary professionals
October 21, 2026
A lung mass on a rabbit radiograph or necropsy table raises an immediate question: infection, or cancer? In older intact does, that question has a familiar answer more often than many of us expect. A 2026 retrospective necropsy study from Subash and colleagues is a useful reminder to look at the uterus before we assume a primary lung tumor.
Subash et al. reviewed 608 rabbit necropsies performed between May 2019 and December 2025. Twelve rabbits had pulmonary masses. Most were older than three years, and 10 of the 12 were female.
Half of the masses were non-neoplastic: abscesses, granulomatous inflammation, or bronchopneumonia. The other half were neoplastic. That puts neoplastic lung-mass prevalence at 0.98% (6/608) in this necropsy population. Of those six neoplastic cases, five were metastatic uterine adenocarcinoma. Only one was a primary lung tumor.
The abstract does not state whether these were pet or farmed rabbits, so the absolute prevalence may not match a companion-animal caseload. The pattern still matters for clinical practice.
The strength is sample size: 608 necropsies give a clearer sense of how often we actually see pulmonary masses, and how often neoplasia is metastatic from the uterus rather than primary. The split between neoplastic and non-neoplastic disease is clinically useful.
Limitations are real. This is a necropsy series, so it overrepresents animals that died or were euthanized with significant disease. The abstract does not separate pet from production rabbits, and we do not get imaging correlation, clinical signs, or survival data from this summary. A single primary lung tumor among six neoplastic cases is too few to characterize primary pulmonary neoplasia in rabbits.
When I see a pulmonary mass or nodule in an older intact doe, I treat uterine adenocarcinoma metastasis as the leading neoplastic differential until histopathology says otherwise. I still keep abscess and granulomatous disease on the list, because half of the masses in this series were non-neoplastic.
Before elective OHE in a senior intact doe, I discuss thoracic radiographs or CT when available, especially if there are any respiratory signs, weight loss, or reduced activity. If we find lung disease, I am honest about staging uncertainty until we have tissue. If we proceed to surgery, the uterus and any accessible lesions go for histopathology.
For colleagues managing similar cases, the practical sequence is: reproductive history, thoracic imaging, plan surgery or medical management based on the whole picture, and never skip histopathology on excised tissue.
Subash A, Dhanush Krishna B, Naidile KR, et al. Pathology of pulmonary masses in rabbits: a retrospective study of 608 rabbit necropsy cases. J Vet Anim Sci. 2026;57(3):408-413. doi:10.51966/jvas.2026.57.3.408-413
If you have a rabbit with a lung mass, questions about imaging before OHE, or histopathology interpretation for uterine adenocarcinoma, I'm glad to help. I see referrals and colleague consults at Priest Lake Veterinary Hospital, (615) 361-4646. See the referral information for veterinarians.
This content is for educational purposes for veterinary professionals. It doesn't establish a VCPR or replace clinical judgment for an individual patient. Drug use and doses should be checked against current references and adjusted for each case.