20. Protozoan diseases of the GIT- aetiology, symptoms, diagnostics, differential diagnostics, therapy and prevention

What is coccidiosis and what birds does it commonly infect?

Coccidiosis is a protozoan disease of the GIT that commonly infects poultry and many other birds.

What is the family of the protozoa that causes coccidiosis?

Eimeriidae

Are coccidia species-specific?

Yes, coccidia are species-specific.

Give some examples of Eimeria species that infect chickens.

E. acervulina, E. necatrix, E. maxima, E. brunetti, E. tenella

How are birds infected with coccidiosis?

Birds are infected with coccidiosis by the fecal-oral route (ingestion of contaminated feed, water, litter, and soil).

How do coccidia damage the intestines?

Coccidia damage the intestines by destroying epithelial cells and traumatizing the intestinal mucosa and submucosa.

What factors influence the severity of intestinal damage in coccidiosis?

The severity of intestinal damage is directly proportional to the number of sporulated oocysts ingested and the species of coccidia involved.

What are the clinical signs of coccidiosis?

Clinical signs of coccidiosis can range from decreased growth rate to severe diarrhea and high mortality.

How can E. tenella be identified based on clinical signs?

E. tenella infects only the ceca and can be recognized by bloody droppings.

How is coccidiosis diagnosed?

Coccidiosis can be diagnosed based on clinical signs, necropsy, and fecal smears/floats.

How is coccidiosis treated?

Coccidiosis is treated with anticoccidial drugs, such as sulphonamides.

How can coccidiosis be prevented?

Coccidiosis can be prevented by using ionophores in feed, toltrazuril, and commercial coccidiosis vaccines.

List some diseases that can be confused with coccidiosis.

Necrotic enteritis, ulcerative enteritis, salmonellosis, ascariasis, capillariasis, hemorrhagic disease, leucosis, blackhead, bluecomb, and hemorrhagic enteritis in turkeys.

What is the causative agent of histomoniasis?

Histomonas meleagridis

What birds are affected by histomoniasis?

Histomoniasis can affect a wide range of birds, including turkeys, chickens, peafowl, grouse, quail, and ducks.

How are birds infected with histomoniasis?

Birds can be infected with histomoniasis through ingestion of embryonated eggs of the nematode Heterakis gallinarum (indirect transmission) or by ingesting fresh feces (direct transmission).

How does Histomonas meleagridis cause lesions in the ceca and liver?

Histomonas penetrates the cecal wall and multiplies extracellularly, causing lesions in the mucosa. After entering the liver through the portal system, it creates necrotic foci that increase in size as the parasite multiplies.

What are the clinical signs of histomoniasis?

Clinical signs of histomoniasis include listlessness, reduced appetite, drooping wings, unkempt feathers, yellow droppings, and cyanotic head (blackhead).

What are the post-mortem lesions of histomoniasis?

Post-mortem lesions of histomoniasis include typhlitis (cecal inflammation), characteristic hepatic lesions (irregular, round necrotic foci in the liver), and possible peritonitis if the cecal wall perforates.

How is histomoniasis diagnosed?

Histomoniasis can be diagnosed based on clinical signs, microscopic examination of smears from the ceca and liver lesions, and post-mortem examination.

Is there a treatment for histomoniasis in food animals?

There is no approved treatment for histomoniasis in food animals.

How can histomoniasis be prevented?

Histomoniasis prevention includes the use of flubendazole to kill Heterakis and nitarsone for prophylaxis.

What are some diseases that can be confused with histomoniasis?

Salmonellosis, coccidiosis, aspergillosis, and trichomoniasis.

What is the causative agent of trichomoniasis?

Trichomonas gallinae (protozoan parasite)

How are birds infected with trichomoniasis?

Trichomoniasis is spread through contaminated water.

What are the clinical signs of trichomoniasis?

Trichomoniasis is characterized by typical lesions called "yellow buttons" at the beak cavity, infraorbital sinuses, pharynx, esophagus, and glandular stomach. Birds may also exhibit watery ocular discharge, blindness, anorexia, dysphagia, weight loss, dyspnea.

How is trichomoniasis diagnosed?

Diagnosis of trichomoniasis involves microscopic examination of wet or stained smears from crop swabs or, in post-mortem examination, smears from the boundary layer between normal and affected tissue. Culture techniques can also be used.

How can trichomoniasis be treated?

Trichomoniasis can be treated with medications like metronidazole, carnidazole, or ronidazole.

How can trichomoniasis be prevented?

Preventive measures for trichomoniasis include good sanitation, preventing bird-to-bird contact, quarantining new birds, maintaining clean drinking water, avoiding overcrowding, and implementing good biosecurity measures.

What diseases can be confused with trichomoniasis?

Trichomoniasis can be confused with candidiasis, Newcastle disease, infectious coryza, and avian influenza.

What is the causative agent of hexamitiasis

Spironucleus meleagridis (nematode)

What is hexamitiasis characterised by?

foamy/watery diarrhoea (catarrhal enteritis)

What is the treatment for hexamitiasis?

food animals: none

non-food animals: metronidazole

What causes cryptosporidiosis in poultry?

C. baileyi, C. meleagridis

What is the typical clinical sign for cryptosporidiosis in poultry?

water diarrhoea