New combination Lyme/leptospirosis vaccine approved

Veterinary teams face obstacles of many types when recommending vaccines for their patients. Many of these are related to their clients’ feelings and beliefs around vaccination, concerns about cost, and in some cases a lack of understanding of the risks posed by infectious diseases to their pets.  

The manufacturers of one new vaccine hope to alleviate some of these concerns with a low-volume combination vaccine option.  

On June 15, 2026, Elanco announced the USDA approval of TruCan™ Ultra Lyme-L4, the first 1/2 mL combination leptospirosis/Lyme vaccine for dogs.  

Jill Pattee, DVM, Medical Strategy Lead for Infectious Diseases at Elanco, sees TruCan™ Ultra Lyme-L4 as an option for practices “who utilize a three-year schedule for distemper-adenovirus-parvovirus vaccination and are looking to provide annual Lyme disease and leptospirosis protection to dogs with one injection.”  

Pattee pointed out that this combination vaccine negates the need for a second injection in pets needing both leptospirosis and Lyme vaccination. “This may help pet owners say ‘yes’ to vaccine protection from Lyme disease,” she added.  

 Leptospirosis: a core vaccine  

In 2023, the American College of Veterinary Internal Medicine (ACVIM) published an updated consensus statement on leptospirosis in dogs. In this consensus statement, the authors highlighted the risk that leptospirosis poses to all dogs, while also emphasizing the safety of modern leptospirosis vaccines. Given these factors, the ACVIM recommends leptospirosis vaccination for all dogs over 12 weeks of age, regardless of lifestyle or geographic reaction. In 2024, the AAHA Canine Vaccination Guidelines were updated to include leptospirosis as a core canine vaccine. 

George Moore, DVM, PhD, Professor Emeritus of Epidemiology at Purdue University College of Veterinary Medicine, said this change was warranted because “leptospirosis is recognized as the most widespread zoonosis in the world due to the large number and variety of reservoir animal hosts.” Additionally, Moore stated, “treatment of infection can be costly and unsuccessful, yet 4-serovar leptospirosis vaccines for dogs in the US are very effective in preventing infection.” 

This change in leptospirosis vaccination guidelines represented a significant change in veterinary medicine. In a study examining the vaccination status of pets in early 2020, only 63.4% of dogs with current core vaccinations had received a leptospirosis vaccine in the preceding 14 months.  

Lyme disease: vaccinate at-risk dogs 

While leptospirosis is now regarded as a core vaccine, Lyme vaccination is recommended for at-risk dogs. However, as the range of ticks increases in many areas, the number of dogs at risk of Lyme disease is increasing.  

“Transmission of Lyme disease, and other tick-borne diseases, is best prevented by prevention of tick feeding,” stated Moore. However, tick prevention compliance can vary and gaps in preventive efficacy may occur. Moore added, “Lyme vaccination should therefore be considered in high-risk areas when there are indications of failing to control tick attachment and feeding on the pet.” 

While the previously mentioned study found that 63.4% of dogs current on core vaccinations were also current on leptospirosis vaccination, that number was even lower for Lyme disease. In 11 states identified by the Centers for Disease Control as having a high risk of Lyme disease, only 47.9% of dogs current on core vaccines were also current on Lyme vaccine. This suggests vaccination gaps among at-risk dogs.  

Vaccine hesitancy in pet owners  

Vaccine hesitancy has increased dramatically in human medicine since the start of the COVID-19 pandemic. Unfortunately, this vaccine hesitancy also appears to be spilling over to pets; a 2023 study found that 52% of dog owners exhibited some degree of canine vaccine hesitancy.  

While numerous strategies have been discussed to overcome vaccine hesitancy, client education plays a key role.  “I believe clients are trusting of their veterinarians,” stated Moore. “Veterinarians can build on existing trust by reinforcing or educating on current disease threats to pets in their geographic areas, the high costs of inpatient treatment compared to costs of vaccination(s), and the current safety of small animal vaccines.” Effective education can help clients make informed decisions, encouraging them to comply with their veterinarian’s vaccine recommendations.  

 The value of combination vaccines 

Combination vaccines may also play a role in overcoming vaccine hesitancy. While veterinary studies are limited, studies of human pediatric patients published in 2007, 2009, and 2017 all found that combination vaccines were associated with increased vaccine compliance.  

Combination vaccines also support the Fear Free movement in veterinary medicine. When a pet is due for multiple vaccines within a single visit, combination vaccines decrease the number of potentially uncomfortable injections that must be administered.   

Finally, combination vaccines can simplify vaccination schedules. Most core canine vaccinations are given every three years. However, leptospirosis, Lyme, and Bordetella vaccination must be given annually when recommended. “Protection can be maintained and compliance may be enhanced,” stated Moore, “by using multivalent vaccines when available.” 

Further reading: 

Vaccine hesitancy and the importance of client communication 

AAHA guidelines designate Leptospirosis vaccine as core 

Leptospirosis in rats: A One Health study 

From the Guidelines: Summer travel vaccinations for dogs 

Pet parasite risks are evolving. Is your practice prepared? 

Photo credit: StockSeller_ukr/iStock via Getty Images 

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