Blue-green algal poisoning

Also known as cyanobacteria


Potentially toxic cyanobacteria, or blue-green algae, may form dense blooms in fresh water bodies. This may be seen as a thick green coat or scum within the upper water layer and surface.  Blooms are mainly a problem in late summer and autumn.  They are associated with nutrient over-enrichment due to factors such as animals defecating and urinating in the water or fertiliser run-off.  Many blooms are not toxic, but all should be considered potentially so.  A range of cyanobacterial genera and species have been described including Microcystis aeruginosa and Anabaena circinalis.  Different cyanobacteria may produce hepatoxins and/or neurotoxins.

Affected animals may be found dead. Clinical signs due to neurotoxins may include: muscle tremor, staggering, salivation, hyperaesthesia, diarrhoea and recumbency. Clinical signs due to hepatotoxins may include: anorexia, dehydration, jaundice, hypersensitivity or stupor, photosensitivity and recumbency.

Diagnosis and tests available


Diagnosis is based on the visible presence of an algal bloom in animals’ drinking water confirmed by microscopic examination for blue green algae.

Test available


Sample(s) required

Days of the week test is conducted

Turnaround time1

Histopathology examination

Fixed tissue

Monday – Friday

Up to 5 days

Microscopic examination for blue-green algae

Water and scum



1 Turnaround times are provided as a guide only. For specific information about your submission please contact Customer Service.

Additional Information

Specimen requirements

Fixed tissue
  • Liver and kidney
  • Submit fixed in neutral buffered formalin at a 10:1 ratio of formalin:tissue
Water and scum
  • 100 ml
  • Submit chilled in a leak proof container

Further information

NSW DPI general information on blue-green algae.


Microscopic confirmation of the presence of cyanobacteria indicates the possibility of cyanobacterial poisoning, but does not confirm that the bloom is toxic.

Customer Service

Contact Customer Service for enquiries relating to testing and results, quotations and pricing, couriers, sample submission and invoicing.

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Phone1800 675 623

Operating Hours

8:30am-4:30pm Monday-Friday (excluding public holidays)

8:30am-12:00pm Saturday (for deliveries only)

Postal Address

Private Bag 4008, Narellan NSW 2567


For Animal export, Plant health or Veterinary quotations, please complete the online quotation request

For Edible oil & oilseed or Feed quality quotations and pricing enquiries, please contact DPI AgEnviro Labs at Wagga Wagga on (02) 6938 1957

For Plant nutrition, Soil health or Water quality quotations and pricing enquiries, please contact DPI AgEnviro Labs at Wollongbar on (02) 6626 1103

Submission Forms

Veterinary Specimen Advice Form

Please Note: These documents are not fully web accessible, please contact Customer Service ( for more information.

Courier services and specimen delivery

For NSW submissions, please contact the relevant Customer Service team for courier account details and to order consignment notes.

For submitters outside of NSW, Couriers can be contacted directly to make bookings and arrange collection of packages at the submitters own cost.

Commercial couriers may use either road or air transport and specimens should therefore be packed in accordance with International Air Transport Association (IATA) requirements. Most submission sent by veterinarians to the SVDL for testing are defined as “Biological Substance Category B” and must be packed according to the IATA packing instructions 650 (Biological Substance Category B). As requirements for transport can change, customers should consult with their transport agent to obtain current requirements.

Samples may also be hand delivered to the site during normal business hours (8.30am - 4.30pm).

Sample Type


Street Address

Animal (including aquatic animals)

NSW Animal and Plant Health Laboratories (APHL)

EMAI, Woodbridge Road, Menangle NSW 2568