Whirling Disease (Myxobolus cerebralis) in Fish

 

By Carl Strohmeyer-PAMR 35+ years experience

Whirling Disease (Myxobolus cerebralis) in Fish, primarily SA Cichlids

Whirling disease is a disease of freshwater fish caused by the myxozoan parasite Myxobolus cerebralis. This infection/infestation is most commonly found in the wild found in the salmonid family of fish.

What is noteworthy mostly for prevention is that the parasite has two hosts — the fish itself and a freshwater oligochaete worm, popularly known as the Tubifex tubifex. This is a major reason these worms should not be fed, but unfortunately are a common source of cheap protein for many fish farms, especially those selling to discounters.

There are two spore stages for Myxobolus cerebralis, one released from the fish and infective for worms, the other released from worms and infective for fish. Generally, the earlier the fish is first exposed and the higher the parasite exposure dose, the greater is the severity of the disease.
Water temperature also has an influence on all stages of the parasite life cycle since it slows its cycle over 70°F (21°C), as spores are released from the worm host when the temperature is between 10°C and 15° C.
However once infected, and while a higher temperature will check the spread, it will not significantly help for an infected fish based on my experience.

"Whirling Disease" gets its name from the radical tail-chasing swimming behavior of heavily and often fatally infected fish.
Clinical signs result from the presence of the parasite spores in the cartilage, causing inflammatory changes and pressure on spinal nerves. However, fish may become infected with the parasite and never show clinical signs; resulting in a difficult positive diagnosis of infection in these fish.



Reference: Disease Strategy Manual - Whirling disease

---

---

SIGNS OF INFECTION/DIAGNOSIS

Please note that symptoms do not always appear and even then these symptoms do not confirm a diagnosis of Myxobolus cerebralis, only microscopic slides can confirm.

• Infected Fish will "whirl" forward in an awkward, corkscrew-like pattern instead of swimming normally. This behavior change generally takes about 35 to 80 days after initial infection.
  So if you have had your fish for 6 months in an aquarium kept at 80°F (27°C), most likely your fish does NOT have Whirling Disease


• It is much more common for new fish to be infected with Myxobolus cerebralis, especially that come from discounters selling fish from fish farms utilizing ponds or using Tubliflex worms as a cheap source of protein.
  It is also noteworthy that this is more commonly a disease of cooler water fish based on the life cycle, HOWEVER, I have had several confirmed cased of Whirling Disease in Cichlids in particular.


• Fish infected with worms also infected with Myxobolus cerebralis may have lower body mass and may be discolored in the area near the tail

This video below shows a trout with advanced "Whirling Disease", also displaying darkening of the tail that sometimes occurs in advanced stages.


YouTube; Whirling Disease


TREATMENT

• Prevention is the #1 treatment; KNOW YOUR FISH SOURCE or your Retailers fish source!
  Retailers selling fish distributed by Aquatropic is a good starting point.
  Reference: Aquatropic


• Nitrofurazone (Furan 2) combined with AAP ParaGuard for in tank treatment.
  Methylene Blue, sodium chloride, along with Quick Cure or ParaGuard in a Fish Bath
  And Metronidizole & praziquantel as part of a fish food soak.
  
  Further Fish Bath Information:
  Fish Baths, Dips, Swabs
  
  Further Fish Food Medications Soak Information
  Aquarium Medications; Food Delivery of Medications
  
  Recommended Product Sources that support this FREE Information and the Aquarium/Pond Keeping Hobby:
  *AAP Metronidizole
  *AAP ParaGuard
  *AAP Quick Cure
  *AAP Nitrofurazone/Furan 2
  *AAP PraziPro (Praziquantel)
  *AAP General Cure (source of BOTH Praziquantel/Metronidizole)


• Unfortunately the now defunct fish pharmaceuticals company; "Aquatronics", had an excellent product specifically for "Whirling Disease" that was very effective from my experience, especially for Discus and other Cichlids. The above remedy closely mirrors this previous Aquatronics product.

References:

*Ichthyophonus in Fish
A similar disease in both symptoms and the fact both are more common in cooler waters or carried from cooler waters.

*Wikipedia; Myxobolus cerebralis


Other Recommended Reference & Product Sites


Freshwater Aquarium Care; Basics to Advanced

Premium UVC Replacement Lamps
For TRUE Premium, Hot Cathode, Low Pressure UVC Germicidal Bulbs, not the low output bulbs/lamps commonly sold at Amazon & eBay



Premium USDA Aquarium Safe Silicones




*Columnaris & Fungus Infections in Fish

*How Aquarium Medications Work; Part 1


SunSun HBL Power "Hang On Back" (HOB) Aquarium Filter
211 Gallons Per Hour Flow Rate (800 LPH)
For Aquariums up to 40-45 Gallons





The best in Quartz, Under gravel, and Titanium Submersible Heaters:



Aquarium Heaters








AquaRay Ultra Premium Aquarium LED Lights
Highest in PUR, The ONLY LED with an IP67 rating or higher for water proofing along with a full 5 year warranty to back them up! Why purchase brands without this rating such as the Finnex, Current, or Fluval only to be essentially placing an electronic light emitting device over your humid aquarium with little or no guarantee? In the long term, you WILL PAY MORE!