People in Fort Collins, Colorado recently reported seeing what seem to be horned rabbits in recent weeks, resulting in these animals getting the nicknames “Frankenstein bunnies,” “zombie rabbits,” and “demon rabbits.”

Wild rabbits in Fort Collins, Colorado, have gained traction on social media as well as news outlets all over the world for their wart-like tumors that look like horn projections (Image courtesy of the American Veterinary Medical Association)

However, according to American Veterinary Medical Association (AVMA), these ‘demon rabbits’ actually have Shope papillomavirus (SPV), a well-known viral infection which was first described almost a century ago.

The virus is an endemic in cottontail rabbits and is transmitted primarily by fleas, mosquitoes, and ticks. It tends to appear in rabbits more often during warmer months when insect activity peaks.

SPV causes wart-like tumors that could keratinize into dark, hard, horn-like projections that grow on the rabbit’s head, ears, and eyelids, which can sometimes impair their vision or feeding. For most wild rabbits, their immune system resolves the infection and the growths regress eventually. This viral infection is rarely diagnosed in domestic rabbits, but it is serious when it is because the papillomas are more likely to become malignant. For domestic rabbits, if left untreated, it can progress to malignant cancer.

If a domestic rabbit is presenting with signs of SPV, veterinarians need to surgically or manually remove the nodules and send them to a pathologist for evaluation via histopathology. This will help the veterinary team determine the cause of the papillomas, whether they are benign or malignant, and if they have transformed to squamous cell carcinomas. These nodules occasionally go away on their own, but surgical removal is recommended because they can become malignant and can potentially metastasize to lymph nodes and lungs.

"Based mostly on experimental work, we know that malignant transformation happens in about 75% of infected domestic rabbits, compared to only around 5% of infected cottontails," Javier Asin Ros, DVM, PhD, DECVP, associate professor and diagnostic veterinary pathologist at the California Animal Health and Food Safety Laboratory at the University of California-Davis School of Veterinary Medicine, explained to the AVMA.

Although rare in domestic pets, veterinary professionals believe this is still something veterinarians should know its potential risks.

This recent wave of attention to SPV is due to residents in Fort Collins sharing photos and videos on social media of the rabbits with protrusions, gaining local, national, and international media attention within days of posting. The Colorado Parks and Wildlife confirmed the SPV diagnosis and emphasized that it poses a minimal risk to pets, humans, or other wildlife species. Veterinary professionals should recommend to pet owners to keep their rabbits away from cotton tails and to keep them up to date on their rabbit hemorrhagic disease vaccine.

Although unsettling to see these rabbits with SPV, veterinary professionals can see this story as a reminder of a long-known virus with occasional clinical significance, according to the AVMA.

"It can foster interest in this viral disease and perhaps encourage surveys in different states to see what wild rabbit species are affected and what factors influence malignant transformation," Ros said. "It’s also a good opportunity to remind people not to touch wild rabbits and to keep their pets protected," he concluded.

Nolen RS. Frankenstein rabbits? Veterinarians tell the real story. American Veterinary Medical Association. Published September 4, 2025. Accessed September 22, 2025. https://www.avma.org/news/frankenstein-rabbits-veterinarians-tell-real-story

PetMD Editorial. Shope Papilloma Virus in Rabbits: What It Is and How To Keep Your Bunny Safe. Petmd.com. Published October 2008. Accessed September 22, 2025. https://www.petmd.com/rabbit/conditions/viral/c_rb_shope_papilloma_virus

Articles

Wild rabbits in northern Colorado have been seen with horn-like lesions due to a viral infection. 

Are there Frankenstein rabbits in Colorado? 

Photos courtesy of UC Davis School of Veterinary Medicine

An avian patient gets prepared to be scanned in the small animal CT machine at the All Species Imaging Center in California. 

A new veterinary facility has opened at the University of California-Davis (UC Davis). The All Species Imaging Center is designed to be a central hub for advanced diagnostic imaging at the UC Davis William R. Pritchard Veterinary Medical Teaching Hospital (VMTH), according to the university.

The new center consists of 4 diagnostic imaging suites, 2 control rooms, a patient waiting room, a room used by radiologists for image interpretation, and staff office spaces. Each of the imaging suites have a unique purpose and house advanced technology as follows

Computed tomography (CT) for small animals

High field magnetic resonance imaging (MRI) for small and large animals

Positron emission tomography (PET) and CT for small and large animals

The large animal CT scanner is used with an equine patient.

The new MRI machine has replaced an older scanner that was used by the university for about 25 years. The CT scanner for small animals replaces a machine that was used by the VMTH for 15 years, according to the university.

"With these advanced scanners, we have been able to image areas of animals that we had never been able to scan before, such as the lumbar spine of horses and cows, the pelvis and stifles of horses, a full equine cervical spine, and the abdomen of a llama," Mathieu Spriet, DVM, MS, DACVR, DECVDI, DACVR-EDI, director of Imaging Services at the VMTH, said in a news release.

 "We believe this to be the best veterinary imaging facility on the West Coast and one of the top veterinary imaging facilities in the world."

The diagnostic imaging facility is also a home to the university’s advanced radiology training program. In this space, a dozen veterinary residents are trained by 8 board-certified radiologists.

The veterinary hospital at UC Davis is accredited by the American Animal Hospital Association. It is the main hospital in a university network that includes the UC Veterinary Medical Center in San Diego, and the UC Veterinary Medicine Teaching & Research Center in Tulare.

 The opening of the imaging center marks a milestone in the planned expansion of the veterinary medicine complex that will allow the university to eventually increase the student capacity from 600 to 800 individuals and help ease a veterinarian shortage in the region.

“We know that there are people every day that want to come for our care, and we can't fit them in,” Mark Stetter, DVM, DACZM, dean of the School of Veterinary Medicine, said in a 

 “The expansion allows us to train more students. It allows us to take care of more animals, and it allows us to do more of our groundbreaking research.”

Expansion of the veterinary medicine complex is expected to continue with multiple new facilities that will enable the university to provide care annually to approximately 20,000 more animals. Future structures planned as additions to the complex include a veterinary education pavilion, a primary care hospital, an equine hospital, a cancer center, a spay-neuter clinic, and a raptor center, according to the 

Warren R. UC Davis opens All Species Imaging Center. News release. University of California-Davis. September 17, 2025. Accessed September 19, 2025. 

https://www.vetmed.ucdavis.edu/news/uc-davis-opens-all-species-imaging-center

William R. Pritchard Veterinary Medical Teaching Hospital. UC Davis School of Veterinary Medicine. Accessed September 19, 2025. 

Denyer LA. UC Davis veterinary school undergoes major expansion, increasing capacity and addressing veterinary shortage. 

3. September 18, 2025. Accessed September 19, 2025. 

https://www.kcra.com/article/uc-davis-veterinary-school-major-expansion/67954651

The facility is used for all species and is part of a larger planned expansion for the university’s veterinary medicine complex.

UC Davis unveils a new diagnostic imaging center

ZyVet's Furosemide Tablets. (Image courtesy of ZyVet Animal Health)

ZyVet Animal Health has launched an FDA-approved generic form of furosemide tablets, used for managing congestive heart failure and chronic fluid retention in cats and dogs. The medication is the most commonly used veterinary diuretic for decreasing edema and pulmonary congestion caused by cardiac, renal, or systemic conditions.

In a news release announcing the drug’s launch, ZyVet said its formulation gives veterinarians a cost-effective option for long-term therapy “without compromising dosing flexibility or product availability.”

“We are happy to participate in the animal health segment and launch the first approved generic of Furosemide in the US,” Punit Patel, president and CEO of Zydus Americas, the parent company of ZyVet, said in a company news release.

 “Managing chronic conditions in pets is a long journey, and consistency in care makes all the difference. At ZyVet, we believe in ensuring that veterinarians and pet owners have reliable, affordable options they can count on, and this launch is another step toward making quality drugs accessible to all.”

According to ZyVet, the medication is available in more than one strength for patient-specific dosing.

Congestive heart failure occurs when the heart cannot pump blood effectively, leading to fluid buildup that may leak from blood vessels. In cats and dogs, left-sided heart failure can cause fluid pulmonary edema, while right-sided heart failure leads to pleural effusion or ascites.

Common signs of heart failure in felines are difficulty breathing; a large, round abdomen due to fluid buildup in the abdomen; exercise intolerance; lethargy; hiding; weight loss; and poor appetite. In felines, coughing is not a common symptom of the disease.

Arterial thromboembolism, the formation of blood clots that travel through the bloodstream, can occur in cats with advanced heart disease. These clots most often lodge where the aorta divides into the femoral arteries, which supply the hind limbs. This blockage, called a saddle thrombus, is very painful and can cause sudden loss of function in one or both back legs, leading to paralysis in the limbs and the limb feeling cold.

 Although less common, blood clots may also lodge in the front limbs, causing the same symptoms as a saddle thrombus but on the affected front limb.

Unlike in cats, the most common sign of congestive heart failure in dogs is a persistent cough alongside difficulty breathing. Coughing may occur when resting or sleeping. Excessive panting, getting tired more easily, loss of appetite, a swollen belly, and pale or bluish gums are also signs. Dogs will heart failure may also experience generalized weight loss and muscle wasting.

ZyVet launches affordable Furosemide tablets to support long-term heart care trusted diuretic for dogs and cats now available in a generic form. News release. ZyVet Animal Health. September 15, 2025.

Barnes C. Congestive heart failure in cats. VCA Animal Hospitals. Accessed September 19, 2025. https://vcahospitals.com/know-your-pet/congestive-heart-failure-in-cats

Congestive Heart Failure in Dogs. VCA Animal Hospitals. Accessed September 19, 2025. https://vcahospitals.com/know-your-pet/congestive-heart-failure-in-dogs

Generic furosemide is used to help manage heart failure.

Generic furosemide tablets for cats and dogs is launched

Happy Friday dvm360 readers! It is officially one week since we kicked off our Fetch Coastal event in its new location, National Harbor. Thank you to all our amazing faculty as well as our attendees and exhibitors for making our first Fetch National Harbor such a success. Now that we have officially wrapped up National Harbor, our final show, Fetch Long Beach is next! You can learn more about Fetch Long Beach, including wet labs, keynotes, and register 

Before checking out the conference page, here is what you can find from this week’s news coverage on dvm360.com:

 earlier this week that the state and federal officials confirmed that highly pathogenic avian influenza was detected in a dairy cattle herd in Nebraska, making this the first known case of bird flu in Nebraska.

In this Q&A with Zachary Wright, DVM, DACVIM (Oncology) from Fetch National Harbor, he 

 more about some of the latest cancer screen tests, plus what he hoped attendees would take away from his lecture during the conference.

 of The Blast Podcast presented by dvm360, sponsored by Blue Buffalo, our host Adam Christman, DVM, MBA, welcomed Alex Miller, VMD, MS, and Phil Richmond, DVM, CAPP, CPHSA, CCFP, talked about wellbeing in veterinary medicine, plus the Florida Veterinary Medical Association's Inspire program.

The American Veterinary Medical Foundation 

 the scholarship opportunities that are available to veterinary students, including ones for veterans, those with special interests within the industry, first generation students, and more.

A team of investigators in the United Kingdom 

 oronasal mucosal melanoma for the benefit of both canines and humans. The research was made possible through support from donations to the Humanimal Trust’s Cancer Discovery Fund.

Wrap up: First case of bird flu in dairy cattle confirmed by USDA, and other news 

Note that many of the upcoming industry events are being held in person or via a combination of live and virtual learning. Please visit individual event websites for details.

https://www.veterinarydentalforum.org/future-conferences

Association of Avian Veterinarians Annual Conference & Expo

American College of Veterinary Ophthalmologists

https://www.acvoconference.org/future-conferences

American College of Veterinary Surgeons Surgery Summit

American College of Veterinary Pathologists Annual Meeting

https://acvp.org/annual-meeting/annual-meeting/

https://registration.dvm360.com/fetch-long-beach-2025

American Association of Equine Practitioners Annual Convention

Upcoming industry events and association meetings are listed.

Veterinary conference calendar (September 2025)

ZyVet Animal Health announced earlier this week that its FDA-approved generic phenylpropanolamine hydrochloride tablets have been released after receiving its approval in June 2024. This product is the first time the agency has approved a generic form of the medication. The tablets are a treatment for managing urinary incontinence in canine patients due to urethral sphincter hypotonus.

According to the release, this condition is often seen in spayed females and aging dogs and can lead to accidents that could be embarrassing or frustrating to clients. The product, now available through ZyVet, will offer a relief solution for the pet while also supporting long-term client adherence.

“Urinary incontinence affects quality of life for both pets and their families. Our phenylpropanolamine hydrochloride tablets deliver both clinical reliability and affordability, enabling veterinarians to confidently treat more patients and maintain client [adherence],” Punit Patel, president and CEO of Zydus Americas, said.

"We’re proud to offer an option that removes cost as a barrier to compassionate care. With each launch, we reinforce that innovation doesn’t need to come with a premium price tag—and that every pet should have access to high-quality treatment options,” Patel continued.

The product is available in multiple strengths to support precise dosing, and it is designed considering the needs of clients and veterinary teams.

Canine incontinence affects 20% of all spayed female dogs and up to 30% of large breed dogs, but any dog can be affected by it.

's Fetch Nashville 2025 conference, Mark J. Acierno, DVM, MBA, DACVIM (SAIM), explained more on how veterinary teams can 

, including signs, causes, and the role patient history plays for incontinence.

Collecting a patient’s history is a crucial step for diagnosing incontinence in a canine patient. When talking to clients, include questions about timing, because a puppy dribbling constantly is a significantly different scenario than a middle-aged female dog who is spayed and wetting the bed at night.

 When and where can also be important questions to ask clients. Are they urinating on the bed or next to it? If it's happening in the middle of the night, what does that look like? By considering the timing of events surrounding the urination, it can help veterinary teams tell the difference between incontinence and other conditions.

Physical examination can also determine incontinence. Veterinary teams who are examining a patient who might have incontinence should obtain a detailed examination of the patient's genitalia. They should be on the lookout for anatomic abnormalities as well as wet or stained fur or scalding and dermatitis. During his lecture, Acierno also recommended that teams have the client prevent their dog from urinating prior to the appointment.

 The patient can then urinate during the appointment to allow the team to observe the pet and gain valuable information, such as whether the pet is straining normally and whether the patient postures correctly after urinating.

ZyVet launches first generic treatment for canine urinary incontinence. News release. ZyVet Animal Health. September 15, 2025. Accessed September 18, 2025.

Generic drug for urinary incontinence in dogs receives FDA approval. 

. June 11, 2024. Accessed September 18, 2025. https://www.dvm360.com/view/generic-drug-for-urinary-incontinence-in-dogs-receives-fda-approval

Weir M, Hunter T, Ward E. Urinary incontinence (urethral incontinence) in dogs. VCA Animal Hospitals. Accessed June 5, 2025. 

https://vcahospitals.com/know-your-pet/urethral-incontinence-in-dogs

Acierno MJ. How do we turn off this spigot? managing canine incontinence. Presented at: Fetch dvm360 Conference; May 30-31, 2025; Nashville, TN.

Bautista-Alejandre A. Diagnosing canine incontinence. 

. June 5, 2025. Accessed September 18, 2025. 

https://www.dvm360.com/view/diagnosing-canine-incontinence

The approved product is used for managing urinary incontinence in canine patients.