What are HABs and how are they dangerous to pets?

A harmful algal bloom (HAB) occurs when cyanobacteria begin to grow quickly in a water body, creating colorful scum or “blooms”. Some algal blooms are not dangerous, but HABs release dangerous toxins into the water. These toxins can pose a threat both to animals and their

owners. Since pet owners often allow their animals to drink from and swim in these water bodies, pets have an increased risk of cyanotoxin exposure.

How do pets get exposed to HABs?

Symptoms depend on the type of toxin and exposure route: dermal, ingestion or inhalation. Pet exposure to cyanotoxins typically occurs after swimming or drinking from contaminated water. Other exposures occur when animals lick their fur after swimming or by eating the surface scum on the beach. The severity of the illness depends on the amount of water and algal cells ingested, the animal’s body size, the amount of food in the animal’s stomach, and the sensitivity of the species and individual animal.

What can I do to reduce risk of HAB-related illness in my pet?

  • Use BeachGuard to track HAB advisories in Ohio – Click Here
  • Keep people, pets and livestock out of water with blooms.
  • If your pets do enter the water, be sure to rinse them off with clean, fresh, HAB-free water so they do not lick algae off their fur or skin where toxins may be present.
  • Do not let your pet eat algae off the beach as toxins may be present.
  • Do not water lawns or gardens with water from HAB-impacted lakes or ponds.
  • Follow posted water body closures announced by state agencies or local public health authorities.

What are the symptoms of HAB-related illnesses?

  • Depression
  • Incoordination or weakness
  • Loss of appetite
  • Excessive drooling
  • Muscle twitching
  • Seizure
  • Respiratory failure
  • Vomiting & diarrhea
  • Abdominal tenderness
  • Jaundice
  • Dark urine
  • Rashes
  • Allergic reactions
  • Hives

What should I do if my pet is ill from a HAB exposure?

If your pet is ill and you suspect HAB exposure, seek immediate veterinary attention. Once your pet has been cared for, contact your local health district to report the illness using the “HAB Animal Illness Report Form” using the web address provided below.


Contact Us

Report animal illness to your local health district and the Ohio Department of Health.
Find your LHD using the web tool: www.odh.ohio.gov/GetMvLHD
Report a HAB-related illness using the form: www.odh.ohio.gov/HABAnimalForm

Ohio Department of Health, Bureau of Environmental Health and Radiation Protection
246 N High St, Columbus, Ohio 43215
Phone: (614) 644-1390 Email: BEH@odh.ohio.gov