Coccidiosis

What is Coccidia?
Coccidiosis (infection with coccidia) is a disease of rabbits caused by a class of single-celled organism known as a protozoa. These are parasites of epithelial cells (relating to or denoting the thin tissue forming the outer layer of a body's surface and lining the alimentary canal and other hollow structures) invading the mucosa of the intestine, colon and epithelium of various tissues. There are around 14 species of intestinal coccidia associated with rabbits and one species of Hepatic coccidia. A single rabbit can have two or more species at one time.

How can your rabbit contract Coccidia?
Coccidiosis is a disease that can be contracted from the environment and usually is present in multi rabbit situations as well as in shelters/breeding establishments where stocking rates are high and rabbits are kept in communal runs. Oocytes (eggs) passed in faeces require 2 or more days to become infective and in damp conditions can often remain in the environment for long periods of time. Other rabbits are infected by eating contaminated fresh vegetation like grasses.

How is Coccidia diagnosed?
A faecal test looked at under the microscope by a vet can determine if the rabbit is shedding coccidia eggs in their faeces.

• How does Coccidia affect your rabbit?
  Hepatic (liver) coccidiosis is caused by Eimeria stiedai. Young rabbits can be very susceptible, especially if introduced into an area of high environmental contamination. Infection can result in biliary obstruction and an enlarged fibrotic liver. Clinically this can be seen as weight loss, listlessness, thirst, wasting of the back and hindquarters, with enlargement of the abdomen due to ascites (the accumulation of protein-containing - ascitic, fluid within the abdomen), jaundice and diarrhoea depending on severity of infection. On abdominal X-rays, the liver and liver and gall bladder appear enlarged.weight loss, ascites (the accumulation of protein-containing - ascitic, fluid within the abdomen), jaundice and diarrhoea depending on severity of infection. Infected young are often underweight and have a pot-bellied appearance.

• Intestinal coccidiosis can be caused by numerous species of Eimeria. The intestinal form of coccidiosis mainly affects youngsters from the age of 6 weeks to 5 months and is attributed to stress, noise, transport or immunosuppression. It is mainly observed in young newly weaned rabbits, but is also found in older rabbits.

Infection is seen in the ileum and jejunum and can be diagnosed on post mortem with intestinal mucosa scrapings. Symptoms are a rough coat, dullness, decreased appetite, dehydration, loss of weight, depression and sometimes (profuse) diarrhoea, 4 to 6 days post-infection. If the loss of weight reaches 20%, death follows within 24 hours. It is preceded by convulsion or paralysis. During necropsy, inflammation and oedema are found in the ileum and the jejunum portions of the intestine. It is sometimes accompanied by bleedings and mucosal ulcerations.

This form of coccidiosis runs either as a chronic course during several weeks, or it ends in death within 10 days, preceded by coma and sometimes diarrhoea. Secondary infection can lead to their presence in the nervous system. The disease is often accompanied by secondary bacterial infection, in particular by Escherichia coli.

How can I treat Coccidia?
Treatment is with an oral medication and the most applicable in a pet rabbit situation is generally Toltrazuril / Baycox Piglet liquid or Co-trimoxazole / Deprim, which is an antibiotic and is available via a prescription from your vet in a paediatric suspension.
A faecal sample is then retested at the end of the treatment to ensure the rabbit is no longer shedding the coccidia eggs.

How to prevent your rabbit getting Coccidiosis
Prevention of this disease relies on good hygiene and keeping the bedding dry, foods from uncontaminated bowls and hay/salad racks, rather than allowing the rabbit to feed off the hutch floor. If rabbits are allowed access to an outdoor run, moving the run around the garden reduces the number of oocysts they are exposed to. Ultraviolet light from the sun helps disinfect the ground and destroy the coccidian eggs. Overcrowding should be avoided.

Healthy rabbits can be asymptomatic "carriers" of the protozoa. The oocysts (eggs) - shed with the faeces, will contaminate the environment, food and water. Although the disease occurs essentially in intensively managed animals, especially younger ones, it appears also in well cared for rabbits.

Treatment of the environment is important (e.g. 10% ammonia). Water crocks and feed hoppers should be disinfected and remain free of rabbit faeces. When treating a carpet, vacuum first in order to further penetration of the anticoccidial product. During treatment of the environment, rabbits should be kept in another part of the home to avoid the danger of contact with the products and possible intoxication.

Sources:
COCCIDIA IN RABBITS - The Unusual Pet Vets

Further Reading
Protozoal enteritis: Coccidiosis - MediRabbit