Intestinal Coccidiosis in Rabbits
Coccidiosis is a common, widespread problem in rabbits. It is an important economic and complicating disease. Coccidia may act as a copathogen in other infections. As with the other causes of enteritis [ infection of the intestines] , changes in management practices such as feeding can predispose to infection and disease.
Clinical disease occurs most frequently in weanlings. The stage that causes the most damage is the sexual stage that results in extensive destruction of enterocytes and other cells within the lamina propria.Signs predominate in young rabbits and may include anorexia, debilitation, and pendulous abdomen with hepatomegaly noted on abdominal palpation. Mortality is low except in young rabbits.
Signs predominate in young rabbits and may include anorexia, debilitation, and pendulous abdomen with hepatomegaly noted on abdominal palpation. Mortality is low except in young rabbits.
Coccidial oocysts from a domestic rabbit. Higher magnification.
An antemortem diagnosis can be made by examination of feces by direct smear, flotation or concentration/flotation methods. It can be difficult to identify E. steidae oocysts in fecal specimens since they may not be readily shed in the bile. On necropsy, the recognition of the flat liver lesions and identification of oocysts in the bile provide diagnostic information. The histological appearance of liver with identification of intraepithelial coccidial organisms will allow diagnosis from tissue biopsies.
Colibacillosis, Tyzzers disease, clostridiosis, viral enteridities and mucoid enteropathy.
Gross lesions: The cecum and colon contain dark green to brown, watery, foul smelling material. The mucosa is congested and edematous.
Histo: Location of the lesions is dependent on the species involved. Destruction of enterocytes, villous atrophy, marked heterophilic infiltration and presence of gametocytes and oocytes.
Pathology: An enlarged liver with multifocal, flat, yellow-white lesions containing yellow exudate and occasionally a distended gallbladder that contains bile may be seen at necropsy (A.). The pathognomonic microscopic lesion is marked periportal fibrosis surrounding enlarged bile ducts lined with hyperplastic bile duct epithelium that harbors inflammatory cell infiltrates, and E. stiedae macrogametes, microgametocytes and oocysts.
Diagnosis: Fecal flotation or mucosal scrapings with microscopic examination for oocysts. Bacterial culture should also be performed, as there are often coinfections.
- Abdominal distention
- Bloody stools, feces, hematochezia
- Congestion oral mucous membranes, erythema, redness oral mucosa
- Dark color stools, feces
- Dryness oral mucosa
- Increased borborygmi, gut sounds
- Melena or occult blood in feces, stools
- Palpable dilated bowel internal paplation
- Parasites passed per rectum, in stools, feces
- Unusual or foul odor, stools, feces
- Lack of growth or weight gain, retarded, stunted growth
- Polydipsia, excessive fluid consumption, excessive thirst
- Sudden death, found dead
- Swelling mass anus rectum
- Underweight, poor condition, thin, emaciated, unthriftiness, ill thrift
- Weight loss
- Dullness, depression, lethargy, depressed, lethargic, listless
- Colic, abdominal pain
- Pain on external abdominal pressure
- Pain, tail, anus, perineum
- Cold skin, cool ears, extremities
- Dryness of skin or hair
- Matted or dirty hair
- Moist skin, hair or feathers
- Rough hair coat, dull, standing on end
Good sanitation is very important as coccidiosis is spread by feces, treatment includes oral sulfa drugs (sulfa quinoxaline most common, Sulfa methazine, sulfa pyradiazine).
- Good sanitation and husbandry are essential. Usually two or more days
at room temperature are required for the oocysts to sporulate to the
infective stage. Thus regular cleaning should reduce the possibility of
exposure to large numbers of the sporulated forms.
- Hot water and detergent or 10% ammonia solution, are examples of
cleaning solutions that will kill oocysts.
- Separation of sucklings from the dam at an early age has been
recommended as a means to reduce exposure to coccidia.
- Anticoccidials Previously, sulfaquinoxaline (0.05% in the drinking water or 0.03% in the feed) was commonly used. Robenidine hydrochloride is now widely used as an anticoccidial by feed manufacturers (50 mg/kg of feed). However, resistant strains of Eimeria have been identified (Peeters, 1987). It should not be fed to does during pregnancy or lactation, since it does have adverse effects on reproductive functions.
Treatment: Drugs approved as coccidiostats for rabbits used for meat in US include sulfamerazine (0.02% in water), sulfaquinoxaline (0.05% in water or 0.03% in feed), sulfamethoxine (75 mg/kg BW in feed), and lasalocid (68-113 gms per ton of feed). Hepatic coccidia are difficult to eliminate with anticoccidial therapy, and lasalocid has been the most successful of the listed drugs in treating hepatic coccidiosis.
Control: Rabbits should be housed on wire-meshed floors. Bottoms of cages are to be brushed daily to remove adherent feces, and cleaned and disinfected regularly (1% chlorox). Weanlings should be raised separate from adults. Feeding fresh greens or hay will prevent use of forage that may be contaminated with droppings from wild rabbits.