Health officials in the US are sharing that medetomidine and vatinoxan hydrochlorides injection (Zenalpha), a medication approved for dogs for sedation and analgesia, and can be used under extralabel drug use regulations for cats, pocket-pets, exotics, zoo, and wildlife species for restraint and sedation, has emerged as a dangerous adulterant in the illegal drug supply. Medetomidine, which received approval from the FDA in March 2022, is now often being mixed with other illicit drugs such as heroin and fentanyl.

Illicit medetomidine was first identified in Maryland in 2022 and has now spread to California, Colorado, Illinois, Missouri, and Pennsylvania, with overdose clusters present in Chicago, Illinois; Philadelphia, Pennsylvania; and Pittsburgh, Pennsylvania in early 2025. Medetomidine, which is a racemic mixture of dexmedetomidine and levomedetomidine, is not a controlled substance and was not approved for use in humans. Despite this, dexmedetomidine enantiomer is considered the pharmacologically active component that is responsible for the sedative and analgesic effects of the drug. Dexmedetomidine, which has separate approvals from the FDA for use in animals and humans, is often used for sedation in humans in the intensive care unit (ICU). 

From May 11-17, 2024, Chicago reported 181 suspected opioid overdoses in 3 hospitals, with 12 of them confirmed illicit medetomidine-involved cases. Most patients exhibited slow heart rate, altered mental state, and a poor response to naloxone.

Philadelphia reported 165 people hospitalized with a previously unseen withdrawal syndrome that is now linked to illicit medetomidine between September 2024 and January 2025. Of the patients who were hospitalized, most required an ICU visit, and almost a quarter of them were intubated. For these patients, traditional treatments for opioid withdrawal failed, and dexmedetomidine was an effective way to control the patients' symptoms due to the drug’s similar pharmacological properties to medetomidine.

In Pittsburgh, almost 24 patients were evaluated between October 2024 and March 2025, with 10 confirmed to have illicit medetomidine exposure. Most of the patients "deteriorated rapidly" before arriving at the hospital with symptoms including extreme autonomic hyperactivity, including agitation, hypertension, and tachycardia.

 Of those 10 patients, 9 required ICU admission, and all responded to dexmedetomidine when other medications did not work.

“This cluster of confirmed medetomidine-involved overdoses is the largest yet reported, and the landscape of adulterants in the illegal drug supply is ever-changing and expanding. The recent addition of xylazine has led to a concerning trend in deaths potentially resulting from adulteration in the fentanyl supply, and the emergence of medetomidine further complicates the opioid overdose crisis,” the CDC’s 

stated. “Clinicians and persons who use illegal drugs should be aware that medetomidine can be present in the drug supply. Although medetomidine effects cannot be reversed with naloxone, if a person might be overdosing, the use of naloxone or any other opioid overdose reversal medication is recommended. In addition, connecting persons at risk for overdose to evidence-based treatment, services, and support can save lives.”

Health officials finding different illicit veterinary sedative in US drug supply. News release. American Veterinary Medical Association. June 23, 2025. Accessed July 1, 2025. 

https://www.avma.org/news/health-officials-finding-different-illicit-veterinary-sedative-us-drug-supply

Nham A, Le JN, Thomas SA, et al. Overdoses involving medetomidine mixed with opioids — Chicago, Illinois, May 2024. 

. 2025;74(15):258-265. doi:10.15585/mmwr.mm7415a1

Huo S, London K, Murphy L, et al. Notes from the field: suspected medetomidine withdrawal syndrome among fentanyl-exposed patients — Philadelphia, Pennsylvania, September 2024-January 2025. 

. 2025;74(15):266-268. doi:10.15585/mmwr.mm7415a2

Ostrowski SJ, Tamama K, Trautman WJ, Stratton DL, Lynch MJ. Notes from the field: severe medetomidine withdrawal syndrome in patients using illegally manufactured opioids — Pittsburgh, Pennsylvania, October 2024-March 2025. 

. 2025;74(15):269-271. doi:10.15585/mmwr.mm7415a3

Articles

Health officials are finding medetomidine is now emerging as a dangerous adulterant in the illegal drug supply and is often mixed with other illicit drugs.

Illicit veterinary sedative found in US drug supply 

Sucralfate Tablets USP 1 gram are being voluntarily recalled by Nostrum Laboratories (Nostrum Labs), according to the FDA. The move comes after Nostrum Labs filed for Chapter 11 bankruptcy in September 2024, shutting down all operations and laying off all operational staff in its United States facilities. Due to this shutdown, the company no longer has an active Quality department that can oversee product safety and compliance for Sucralfate Tablets USP 1 gram.

In veterinary medicine, sulfacrate is used off-label for treating ulcers and erosions in the mouth, esophagus, stomach, and small intestine of dogs, cats, ferrets, reptiles, birds, and horses. The short-acting drug helps ulcers heal by creating a coating over them that protects them from stomach acids. The most common adverse effect associated with sulfacrate use is constipation. Vomiting has also been reported, particularly in cats.

The Nostrum Labs recall only applies to all Sucralfate Tablets USP lots within their expiration date that were manufactured by Nostrum Labs after June 2023. The product was distributed to wholesalers, retailers, manufacturers, medical facilities, and repackagers. No other products by Nostrum Labs are affected by the recall.

According to a company announcement, Nostrum Labs cannot guarantee that its sucralfate tablets will continue to meet all of the product’s intended specifications for the rest of its shelf life. As a result, the use of any leftover product or distribution of it should stop immediately.

“The discontinuation of Nostrum Labs’ quality program means that the Company is unable to assure that this product meets the identity, strength, quality, and purity characteristics that it is purported or represented to possess,” Nostrum Labs wrote in the announcement.

 “While specific risks to patients from use of an adulterated product cannot always be identified or assessed, it is also not possible to rule out patient risks resulting from the use of such a product.”

According to the company, there have been no reports of adverse events to date related to the recall. Nostrum Labs is informing via email and US mail all parties who may have received the product from them, including distributors and anyone the company shipped the tablets to directly. In addition, they are asking these parties to immediately notify their subsidiaries, individual receiving sites or warehouses, customers, retailers, and consumers.

“All lots of this product should be destroyed,” Nostrum Labs stated in its announcement.

The company is not accepting any returns of the recalled tablets. Clients with questions about the recall can contact the company at recallcoordinator@nostrumlabsrecall.com. Veterinarians and other healthcare providers should be notified if patients taking the medication have experienced any issues that may be related to the drug.

Any adverse effects or quality problems related to the use of the recalled tablets can be reported to FDA’s MedWatch Adverse Event Reporting program through mail, fax, or online (www.fda.gov/medwatch/report.htm).

Individuals who prefer to report by mail or fax can download the necessary form at www.fda.gov/MedWatch/getforms.htm or request one by calling 1-800-332-1088. Once completed, the form can be mailed to the pre-addressed location or faxed to 1-800-FDA-0178.

Nostrum Laboratories, Inc. issues voluntary nationwide recall of Sucralfate Tablets USP 1 Gram within expiry. US Food and Drug Administration. July 11, 2025. Accessed July 23, 2025. https://www.fda.gov/safety/recalls-market-withdrawals-safety-alerts/nostrum-laboratories-inc-issues-voluntary-nationwide-recall-sucralfate-tablets-usp-1-gram-within#recall-announcement

Gollakner R. Sucralfate. VCA Animal Hospitals. Accessed July 23, 2025. https://vcahospitals.com/know-your-pet/sucralfate

Nostrum Laboratories cannot guarantee the safety of Sucralfate Tablets USP 1 gram manufactured after June 2023.

Off-label ulcer treatment is voluntarily recalled

In this video interview with dvm360, Jeba Jesudoss Chelladurai, BVSc, MS, PhD, DACVM (Parasitology; Immunology), shares what could happen if anthelmintic resistance continues to spread and unchecked in companion animals 

dvm360 interview with Jeba Jesudoss Chelladurai, BVSc, MS, PhD, DACVM (Parasitology; Immunology)

During this interview with dvm360 at the 2025 American Veterinary Medical Association Convention in Washington, DC, Jeba Jesudoss Chelladurai, BVSc, MS, PhD, DACVM (Parasitology; Immunology)

emphasized that the continued spread of resistance could severely limit treatment options for veterinary patients, causing suffering for both animals and their owners. Throughout the interview, she shared that this resistance can have an impact on One Health because hookworms can cause skin infections in humans. 

Below is a transcript of the interview, edited lightly for clarity 

Jeba Jesudoss Chelladurai, BVSc, MS, PhD, DACVM (Parasitology; Immunology):

My name is Jeba Jesudoss Chelladurai. I'm a veterinarian by training. I am a specialist in veterinary parasitology and board certified in veterinary parasitology and Immunology. I'm an assistant professor at Auburn University College of Veterinary Medicine.

Yeah, so if resistance continues to spread even further, we will lose our ability to treat our patients, and so then our patients will suffer, and so will the owners. And then, with things like hookworms. It becomes a one health issue, mainly because hookworms can cause human infections, especially in the skin. It causes a condition called cutaneous Laurel migrants. And so we, if we do not have these antiometrics work overtime, we will see more human cases, just more distress all around so.

Videos

How serious of a threat is resistance to clients and patients?

Potential consequences of anthelmintic resistance 

“How long does [a] tick have to feed to transmit an infection?” Susan E. Little, DVM, PhD, DACVM, Krull-Ewing Professor of Parasitology at the Center for Veterinary Health Sciences at Oklahoma State University in Stillwater, posed to her audience during a lecture at the 2025 American Veterinary Medical Association (AVMA) Convention in Washington, DC, this July.

“The true answer is: It depends,” Little answered.

The answer to how long a tick must feed to transmit a pathogen depends on several factors. These factors may include tick species, pathogen type, tick life stage, environmental conditions such as temperature and humidity, and the type of host.

As Little would go on to explain, no studies have investigated the minimum time it takes for North American ticks to transmit pathogens to dogs. To date, the available data are extrapolated from studies on mice, guinea pigs, and dogs in other parts of the world.

Moreover, many of these studies have been conducted using immature ticks, or nymphs, instead of adult ticks.

“Larvae feed in about 3 to 5 days...nymphs feed in about 5 to 7 days...adults feed for 7 to 14 days or longer, so their physiology is different. How quickly they get into that rapid feeding process that will lead to transmission varies for the different stages,” Little said.

Species that may primarily infect dogs during their adult stage, such as 

 can also influence the timing and efficiency of pathogen transmission.

When it comes to environmental factors, Little noted that most tick species in North America live in wildlife and nature and consequently spill over into dogs and people. The brown dog tick, however, is unique for living in homes and kennels, primarily infesting dogs.

Another factor that may contribute to differences in the transmission of pathogens is how the tick finds a host, according to Little. “We often think of ticks as passively questing. They crawl up vegetation, wave that first pair of legs, wait for something to walk by and brush against the vegetation, and then [the] tick transfers over to the hair, coat, or the clothing of the host, right?” Little said. Although this is true for ticks in

genera, Little explained, it is not the case for brown dog ticks and ticks in the 

 are drawn to the pheromones and carbon dioxide the hosts give off, their shadow, and movement. Similarly, brown dog ticks pick up on environmental cues that signal a dog is nearby and run after these canines.

Some species, like the American dog tick and 

 (deer tick), can move approximately 12 to 18 inches toward a host through static electricity. “Ticks have a static charge on them, so even if you don't brush the vegetation, even if you're very careful to stay in the center of the trail, the tick will still move across a little air space there to get to the host. They're not flying, but they're being drawn by that static charge,” Little said.

Once the tick reaches the host, it will move toward its preferred feeding site. According to Little, in dogs, most 

 usually attach themselves along the back of a dorsal surface, and 

“This matters because when you're examining a dog for ticks, we can't just look in the ears and down the back and be done,” Little said, explaining that lone star ticks can bury themselves in inguinal or axillary areas. She noted that the brown dog tick is notorious for hiding between a dog’s toes.

Once attached, ticks secrete saliva containing vasodilators, platelet inhibitors, anesthetics, and anti-inflammatory compounds that not only help the tick feed but also modify the host's immune response, making it more susceptible to pathogen transmission.

“One of the [other] issues for understanding how quickly the pathogen is transmitted is what we consider transmission, right?” Little said.

She explained that the definition of transmission can vary depending on polymerase chain reaction positivity, antibody seroconversion, and development of clinical disease.

 species, transmission speed has generally been found to be faster, with some studies showing it can be as early as 4 to 12 hours, as the pathogens are already in the tick’s salivary glands.

 Clinical symptoms, however, may take longer to show up.

 species take longer to transmit disease, with studies showing transmission time being generally between 24 and 48 hours or more.

 spirochetes are found in the tick’s midgut and need to move to the salivary glands and change their outer surface protein expression to be able to infect the host.

 is also long, with these pathogens being transmitted approximately after 48 to 72 hours or more due to a delay in the formation of infective stages.

Little S. Perfect timing: protecting dogs from tick-borne infections. Presented at: American Veterinary Medical Association Convention; July 18-22, 2025; Washington, DC.

From saliva to hunting strategies, ticks use a range of tactics that affect how quickly they can spread disease.

What affects the transmission of tick-borne pathogens?

The FDA has approved the first generic form of methimazole tablets for treating hyperthyroidism in cats. According to the FDA, the product—Methimazole Coated Tablets, developed by Felix Pharmaceuticals—received full FDA evaluation to ensure the tablets are the bioequivalent to the brand-name product Felimazole Coated Tablets by Dechra, which received FDA approval in May 2009 following a review of the product’s safety, effectiveness, and adequacy of the manufacturing process.

Methimazole Coated Tablets come in 2.5 mg and 5 mg doses and are orally administered. The medication is dosed at 2.5 mg to start. Any adjustments to the dose should be made in 2.5 mg increments. The maximum daily dose should not exceed 20 mg, divided into doses of no more than 10 mg for each single administration.

Only a licensed veterinarian can prescribe Methimazole Coated Tablets. “[P]rofessional veterinary expertise is needed to diagnose hyperthyroidism in cats and to determine whether Methimazole Coated Tablets are an appropriate treatment,” the FDA wrote in a news release.

“Continued veterinary monitoring is also needed to ensure that the dose continues to be appropriate to control the cat’s hyperthyroidism, as this disease can progress over time.”

After administering Methimazole Coated Tablets, veterinarians should wash their hands with soap and water to prevent exposure to the drug.

The FDA approval of Methimazole Coated Tablets follows an earlier approval of generic methimazole in a liquid oral solution for the treatment of hyperthyroidism in cats (Felanorm; Norbrook Laboratories), which was cleared by the FDA 

. Both Felanorm and Felimazole contain the same active ingredient.

Felanorm comes in 30 mL or 100 mL bottles with 1 mL and 5 mL dosing syringes and should also be administered in 2.5 mg increments every 12 hours.

 Like Methimazole Coated Tablets, the maximum total dosage of Felanorm is 20 mg per day divided, not to exceed 10 mg as a single administration.

A prevalent disease in cats, hyperthyroidism mainly affects cats who are middle-aged and older.

 Common clinical signs of hyperthyroidism include weight loss, increased appetite, polydipsia, and polyuria. Other signs include vomiting; diarrhea; hyperactivity; and an unkempt, matted, or greasy coat.

Diagnosis consists of a physical examination, which includes palpating the patient’s neck area to feel for an enlarged thyroid gland. Heart rate and blood pressure can also be taken. If thyroid disease is suspected, a blood chemistry panel should be ordered, as well as an analysis of thyroid hormone levels.

According to Cornell University, although the majority of feline patients with hyperthyroidism have elevated levels of the thyroid hormone T4 in their bloodstream, a small percentage of affected cats have T4 levels within the normal range.

 If hyperthyroidism is suspected but T4 levels are within the normal range, additional tests should be considered.

Treatment options include medication, radioactive iodine therapy, surgery, and dietary therapy. Overall patient health status, owner compliance with medicating the patient, and financial circumstances will influence the chosen treatment approach.

FDA approves first generic Methimazole Coated Tablets for treating hyperthyroidism in cats. News release. US Food and Drug Administration. July 22, 2025. Accessed July 22, 2025. https://www.fda.gov/animal-veterinary/cvm-updates/fda-approves-first-generic-methimazole-coated-tablets-treating-hyperthyroidism-cats?utm_medium=email&utm_source=govdelivery

Freedom of Information Summary: ANADA 200-814. FDA. June 27, 2025. Accessed July 22, 2025. https://animaldrugsatfda.fda.gov/adafda/app/search/public/document/downloadFoi/17172

Coppock K. Generic treatment receives FDA approval for cats with hyperthyroidism. 

. July 9, 2025. Accessed July 22, 2025. https://www.dvm360.com/view/generic-treatment-receives-fda-approval-for-cats-with-hyperthyroidism

Hyperthyroidism in cats. Cornell Feline Health Center. Accessed July 22, 2025. https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information/feline-health-topics/hyperthyroidism-cats#:~:text=Suggested%20Articles,and%20increased%20thirst%20and%20urination.

This latest approval builds on an earlier liquid formulation of generic methimazole for feline hyperthyroidism, which received FDA clearance earlier this month

FDA approves first generic methimazole tablet for feline hyperthyroidism

With today’s digital era facilitating the spread of misinformation, it is important for veterinary professionals to rely on evidence-based treatments. In a lecture at the 2025 American Veterinary Medical Association Convention in Washington, DC, Andrew Simpson, DVM, MS, DACVD, specialist at VCA Animal Hospitals, addressed a range of fads circulating in veterinary dermatology, one of which is the use of coconut oil for managing canine atopic dermatitis,

 a trend that has persisted for at least a decade.

“I feel like out of all [the topics we will cover,] this may have been the first one to arrive on the scene years ago where everybody was putting coconut oil, either adding it to the food or slathering it on their beloved furry pets,” said Simpson.

In human medicine, coconut oil has been shown to offer benefits for treating xerosis (ie., dry skin) and atopic dermatitis.

 However, in veterinary medicine, there is limited literature on the benefits of coconut oil, whether used topically or orally.

“What we're truly missing... [is] there [are] really no known placebo, controlled, randomized, double-blinded studies out there evaluating the clinical efficacy...or even potential adverse events of these [supplements],” noted Simpson.

test assessing potential toxicity or oxidative stress from canine epidermal keratinocytes (the primary cell types in the epidermis) exposure to organic virgin coconut oil found that the coconut oil “induced an increased disruption of plasma membrane integrity,” compared to the control group.

“So, [the study’s results] did raise concern for the toxicity potential at the level of these building blocks, or keratinocytes within the skin, although there [were] no indications of oxidative stress measured by nitride production,” said Simpson of the study, which was conducted at the University of Florida.

studies have shown potential antimicrobial benefits from using coconut oil, Simpson explained, but there are no studies that assess the clinical response in dogs naturally affected by bacterial or yeast infections.

Moreover, studies have found that omega-6 fatty acids can help reduce clinical signs of atopic dermatitis in dogs in addition to “influencing” superficial skin lipids and improving coat quality. However, coconut oil has very small quantities of this omega-6 fatty acids, rendering it a poor choice for managing skin conditions or improving coat health.

During his lecture, Simpson reminded attendees that although the use of supplements like coconut oil may circulate social media, veterinary professionals must remain cautious and look for scientific backing.

“Probably 50% of my clients are coming in having heard something online, or it showed up in a reel, or... on TikTok or on other social media platforms,” said Simpson. “And... I wonder how much the general practitioners are also hearing, ‘Well, what about this supplement?’ or ‘What about this test?’ or ‘I found this online,’ or ‘I was in this Facebook group and everyone kept mentioning this particular product or diagnostic, and what are your thoughts on it?’

“But we have to step back and say, ‘Well, where's the science behind it? Where's the evidence behind it?’,” he stressed.

Simpson A. Debunking derm fads. Presented at: American Veterinary Medical Association Convention; Washington, DC; July 18-22, 2025.

Nadora D, Burney W, Chaudhuri RK, et al.
Prospective, randomized, double-blind, vehicle-controlled study of topical coconut and sunflower seed oil-derived isosorbide. 

Boyd M, Morris JM, Santoro D. Plasma membrane integrity and oxidative stress index outcomes of canine progenitor epidermal keratinocytes (CPEKs) exposed to virgin coconut oil (VCO). 

 2019;30(6):553-e166. doi:10.1111/vde.12808

One study showed potential toxicity from coconut oil exposure, according to a session at the 2025 AVMA Convention.