- New clinical guidance: AAHA’s 2026 One Health guidelines address emerging parasitic threats affecting canine and feline patients.
- 21 parasites covered: The document provides guidance on 12 emerging parasites of greatest concern and identifies nine additional parasites of potential concern.
- Drug resistance: Antiparasitic resistance and responsible medication use are central themes.
- One Health approach: The recommendations consider animal health, human exposure risks and environmental factors affecting parasite transmission.
- Client communication: Veterinary teams are encouraged to discuss parasite prevention, zoonotic risks and barriers to antiparasitic medication use.
- Free access: The guidelines are available online through AAHA and in the Journal of the American Animal Hospital Association (JAAHA).
The American Animal Hospital Association (AAHA) has published its 2026 One Health Guidelines: Emerging Concerns in Canine and Feline Parasitology, providing veterinary professionals with updated recommendations for managing emerging parasitic infections and infestations in companion animals.
Released October 29, 2026, the guidelines address 12 emerging parasites considered of greatest concern in dogs and cats, along with nine additional parasites identified as potential concerns.
The resource provides practical recommendations for parasite recognition, diagnostic testing, treatment, prevention and communication with pet owners.
The guidelines also emphasize the importance of incorporating One Health principles into parasite management, recognizing the connections among animal health, human health and environmental conditions.
Four Factors Driving Emerging Parasitic Threats
AAHA identifies four primary factors contributing to the emergence or increasing importance of parasitic diseases in companion animals.
Antiparasitic use and resistance: Frequent exposure to antiparasitic medications and intensive treatment practices can increase selection pressure for resistant parasite populations.
Environmental and host changes: Changes in climate, land use and animal movement can alter parasite distribution, potentially expanding the geographic areas where certain infections occur.
Increased animal movement and interaction: Pet travel, relocation, disaster-related sheltering, daycare attendance and off-leash activities can create additional opportunities for parasite transmission, particularly when screening is limited.
Improved detection and awareness: Advances in diagnostic technology and surveillance can identify infections that previously went undetected or unrecognized.
AAHA defines emerging parasites broadly to include those increasing in prevalence or incidence, newly recognized in a population, appearing or reappearing in a geographic area, or developing resistance to existing treatments.
Antiparasitic Stewardship Becomes a Central Focus
The guidelines emphasize that parasite prevention and treatment should not rely on a single intervention or uniform approach for every patient.
Instead, veterinary teams are encouraged to use multimodal parasite control strategies that account for patient risk factors, diagnostic findings, environmental exposure and appropriate antiparasitic use.
Kathryn Duncan, DVM, PhD, DACVM (Parasitology), co-chair of the guidelines, emphasized the need for individualized parasite management and effective communication with clients.
According to Duncan, no single solution can address all parasite control needs, making a combination of preventive measures, diagnosis, treatment and client education essential.
The recommendations also introduce antiparasitic drug stewardship principles intended to help veterinary professionals make informed medication decisions while considering the potential development of resistance.
One Health Approach Addresses Zoonotic Disease Risks
A major component of the guidelines is the integration of One Health principles into routine veterinary parasite management.
Some parasitic infections affecting dogs and cats can also present risks to people, making client education and appropriate preventive measures important components of veterinary care.
The guidelines encourage veterinary professionals to consider zoonotic transmission when evaluating parasitic infections and discussing prevention strategies with pet owners.
They also address the importance of recognizing potentially reportable parasitic diseases and understanding when state or other appropriate animal or public health officials should be contacted.
This approach positions veterinary teams as contributors to both companion animal health and broader public health surveillance.
Client Communication and Treatment Barriers Addressed
AAHA also places significant emphasis on communication between veterinary teams and pet owners.
The guidelines recommend discussing disease risks, prevention options, medication use and potential barriers to treatment in a way that encourages informed decisions.
Jason Stull, VMD, MPVM, PhD, DACVPM, co-chair of the guidelines, highlighted the importance of addressing client concerns about antiparasitic medications.
Stull noted that conversations about treatment hesitancy and barriers to medication use are often underrepresented in clinical guidelines despite their importance in successful parasite prevention.
By encouraging open dialogue, the recommendations aim to help veterinary teams improve client understanding and adherence to parasite management plans.
Guidelines Support Diagnosis, Treatment and Reporting
The 2026 AAHA guidelines are intended to help veterinary professionals incorporate emerging parasite considerations into everyday clinical practice.
Recommended areas of focus include selecting appropriate diagnostic tests, recognizing infections or infestations that may represent emerging threats, identifying suitable treatment approaches and discussing preventive measures with clients.
The document also addresses when veterinarians should consider notifying animal health or public health authorities about reportable infections.
These recommendations are particularly relevant as changing environmental conditions, animal movement and parasite resistance create additional challenges for companion animal parasite control.
Guidelines Available Free to Veterinary Professionals
The 2026 AAHA One Health Guidelines: Emerging Concerns in Canine and Feline Parasitology are available at no cost through AAHA’s website and in the Journal of the American Animal Hospital Association.
Veterinary professionals can access the resource at AAHA’s 2026 One Health parasitology guidelines.
Development of the guidelines was supported by Boehringer Ingelheim, Antech Diagnostics, Merck Animal Health and Zoetis.
The new resource adds to AAHA’s clinical guidance portfolio, providing veterinary teams with a framework for addressing emerging parasitic threats while supporting responsible treatment practices and client education.
Information sourced from the American Animal Hospital Association’s October 29, 2026, press release.
