RABBIT PARASITIC DISEASESDr. Heba M. Salem

Lecturer of Poultry Diseases

Faculty of Veterinary Medicine

Cairo University

EAR MANGE or CANKER ( التصمغ او األذن جرب )

FUR MITE INFESTATIONS or BODY MANGE (التأسد)

FLEAS, LICE and TICKS

Myiasis and Rabbit bot

ECTOPARASITES

EAR MANGE OR CANKER

• Psoroptes cuniculi (non-burrowing mites), the common ear mite of rabbits, causes ear mange

or canker.

• This condition is probably the second most common parasitic disease in commercial

rabbitaries after coccidiosis.

• The mite is readily transmitted by direct and indirect contact.

• The complete life cycle of the mite takes less than 3 weeks, and a severely infested ear can

contain as many as 10,000 mites.

EAR MANGE OR CANKER

Clinical signs

• The mites live in the ear canal and cause damage to the skin lining this area.

• Forming a brown exudates, waxy material soon covers the inner ear.

• This dark encrustation consists of cellular debris, keratin, dried blood, and mites in varying stages of development. In severe cases, the entire inner surface of the external ear may be involved.

• Infested rabbits scratch at and shake their head and ears. They lose weight, fail to produce, and suffer secondary infections, which may damage the inner ear, reach the CNS, and result in torticollis.

• The brown crumbly exudate should never be removed in a conscious rabbit, because this is very painful.

• The crusts will slowly slough off as the mites die and the tissue underneath heals.

• The incidence is much lower when rabbits are housed in wire cages instead of solid cages.

FUR MITE INFESTATIONS OR BODY MANGE

• Fur mites: Cheyletiella parasitovorax and Listrophus gibbus are two common mites inhabiting the skin of rabbits.

• Rabbits are infested with Sarcoptes scabei (burrowing mites)

• In healthy, well-fed rabbits these mites seldom cause a problem and rarely are noticed.

FUR MITE INFESTATIONS OR BODY MANGE

Clinical signs:

• If a rabbit becomes sick or is underfed, alopecia, sores, or scabs may develop in the neck or dorsal trunk areas. Intense itching may occur, which causes constant scratching with the hind legs and the consequent loss of hair and injury to the skin.

• Disease affects legs, face and may extend to all body parts

• The disease is characterized by the appearance white husks in the nose and mouth area and then the front legs and then followed by hair loss , rabbits become off food and lost their weight, and may be followed by mortality in the absence of treatment.

• These mites burrow into the skin and lay eggs. The rabbits are extremely pruritic, and the parasites are difficult to eliminate on domestic rabbits.

• The condition is extremely contagious and can be transmitted to people especially on the arms (zoonotic).

FUR MITE INFESTATIONS OR BODY MANGE

• Diagnosis of fur mites is best accomplished by scraping the skin of the affected area with a scalpel blade dipped in mineral oil till oozing of blood.

• Treatment

1. Local treatment

• 1 part iodoform, 10 parts ether (to dissolve the iodoform), and 25 parts mineral oil.

• Lindane (benzene-hexachloride) is also effective when used as a 0.25- percent suspension in oil.

• Mineral oil by itself may be used.

• Hydrogen peroxide H2O2

• Sulfer ointment

2. Systemic treatment

• Rabbits should be treated systemically with any of the miticides approved for use in dogs and cats.

• A variety of injectable ivermectin treatment regimens effective against both fur and ear mites have been reported, with the dosage of ivermectin0.2 ml S/C, two or three treatments 10–21 days apart. For 2-3 successive doses.

• Mites may also be treated with selamectin (Revolution) (20 mg topically every 7 days has been effective).

FUR MITE INFESTATIONS OR BODY MANGE

Parasite control in surrounding environment

• Disinfection of cages and batteries is a must (burning) or Weekly dusting of animals and bedding with permethrin and deltamethrin powder can control mites.

Prevention:

• Periodical microscopic examination

• Quarantine for a few days and checked for disease in newly introduced rabbits

• Hygienic measures should be applied by regular cleaning and disinfection

• Monthly injection of ivermectin (in non-pregnant dams)

FLEAS, LICE AND TICKS

• Rabbits are not commonly infested with fleas and lice, but the rabbit flea and lice have been reported on wild rabbits.

• Fleas of the Ctenocephalides felis, C canis, and Pulex irritans species can affect rabbits and many other animals.

• The rabbit tick, Haemaphysalis leporispalustris, is a common parasite of wild rabbits, but rarely is found on domestic rabbits because their housing is not compatible with the life cycle of the tick; however, this tick is one of the reservoirs of tularemia, a serious human disease.

• Take care to ensure that wild rabbits are not allowed access to areas in which domestic rabbits are being raised.Flea collars are also not recommended to be used in rabbits.

• It is important to also treat every cat and dog in the house, because the original host is not usually the rabbit.

CUTEREBRID FLIES (MYIASIS AND RABBIT BOT)

• Larvae of Cuterebra flies are common subcutaneous parasites of wild rabbits but infrequent

parasites of domestic rabbits. Rabbits are infected when the files deposits eggs on the fur.

Grub worms hatch from these eggs and burrow into the skin to form warbles. The larvae grow

under the skin and may get as long as three-quarters of an inch. When full-grown, the grubs

leave the skin, drop to the ground, and develop into adult flies.

• Control by deltamethrin or ivermectin

Myiasis and Rabbit bot

ENDOPARASITES

COCCDIOSIS

ENCEPHALITOZOONOSIS

TOXOPLASMOSIS

LARVAL WORM INFECTION

ROUNDWORMS

PINWORMS

COCCIDIOSIS

• Coccidiosis is the most prevalent parasitic disease of domestic rabbits.

• The problem less likely to occur in caged rabbits, mainly seen in intensively managed farms in deep litter system.

• Wire bottom floors greatly reduce the hazard presented by solid floors or slots. Feeders should be designed so that fecal contamination is held to a minimum. An automatic water system is recommended.

• Eimeria spp. are species specific, tissue specific and immune specific.

• In commercially reared broiler rabbits coccidiosis occurs in subclinical form leading to growth retardation and altered feed conversions.

COCCIDIOSIS

• Young rabbits (1-3 months) have a low immunity to coccidiosis and thus are more susceptible to the disease.

• Oocysts passed out in the feces require moisture, oxygen and warmth to sporulate and become infective. So, dry wire floors and automatic water systems hinder sporulation of parasite.

• Transmission of both the hepatic and intestinal forms is by ingestion of the sporulated oocysts, usually in contaminated feed or water.

• Not all species of coccidia are equally harmful, and rabbits tolerate moderate numbers.

• Severity of disease depends on the type of Eimeria and number of oocysts ingested.

COCCIDIOSIS

• There are two anatomic forms: hepaticcoccidiosis, caused by Eimeria stiedae

• Intestinal coccidiosis, caused by E. magna, E.irresidua, E. media, E. perforans, E.flavescens, E. intestinalis, or other Eimeria spp.

• The most dangerous of the intestinal formsare E. magna and E. irresidua.

• E. irresidua evokes the most severe tissuedamage.

Life cycle

COCCIDIOSIS

Intestinal Coccidiosis

• This form of coccidiosis can occur in rabbits receiving the best of care, as well as in rabbits raised under

unsanitary conditions. Typically, infections are mild, and often no clinical signs are seen. In early

infections, there are few lesions; later, the intestine may be thickened and pale. Good sanitation

programs that can eliminate hepatic coccidiosis do not seem to eliminate intestinal coccidiosis.

• Intestinal coccidiosis is generally diagnosed by fecal flotation and microscopic identification of the

oocysts (species).

COCCIDIOSIS

Symptoms:

• Rough coat, dullness, decreased appetite, dehydration and weight loss.

• Diarrhoea or scouring, sometimes bloody faecal material with matted dirty fur around the anus. In the early stages the rabbit may show signs of ill thrift. Rabbits appear lethargic, go off their feed, scour, become dehydrated and can die within 48 hours if left untreated.

• Rabbits may also develop intussusception, a blockage of the intestine caused by a telescoping of the bowel on itself. When weight loss is greater than 20%, convulsions or paralysis is seen, followed by death within 24 hours.

• The majority of deaths are a result of dehydration and secondary bacterial infections.

Post mortem

• On post mortem variable degrees of enteritis.

COCCIDIOSIS

Hepatic Coccidiosis

• Hepatic coccidiosis is most often subclinical, but growing rabbits may not make normal gains. Infrequently, death may follow a short course. Infections lasting more than 16 days can be recognized by the white, circular nodules on the liver.

• Clinical Symptoms Diarrhea (may be blood-tinged), Weight loss, Jaundice, Rough coat, Lethargy

• At necropsy, small, yellowish white nodules are found throughout the hepatic parenchyma. In the early stages, they may be sharply demarcated, whereas in the later stages they coalesce. The early lesions have a milky content. Older lesions may have a more cheese-like consistency.

• Microscopically. The nodules are composed of hypertrophied bile ducts or gallbladder.

COCCIDIOSIS

Diagnosis

• Diagnosis of this form of coccidiosis is based on the gross and microscopic lesions, along with demonstration of the oocysts in the gall bladder.

• An impression smear of a lesion in the liver examined under light microscopy often reveals oocysts.

• The oocysts may also be demonstrated by fecal flotation.

Treatment

• Sulfaquinoxaline, amprolium, salinomycin, diclazuril, toltrazuril.

• Treatment is best administered for a minimum of 5 days and repeated after 5 days.

• Rabbits treated successfully are immune to subsequent infections.

• Treatment will not be successful unless a sanitation program is instituted simultaneously.

COCCIDIOSIS

Prevention

# Sanitation and husbandry are the most important aspects.

1. Faecal material should be removed daily.

2. Overcrowding causes unnecessary stress and difficulty in maintaining hygiene in the rabbitry.

3. Avoid mixing litters at weaning

4. Wean youngsters as late as possible.

5. Anticoccidial medicated feed to weaned and non-lactating/pregnant does to prevent the development of coccidiosis.

6. Wire cage bottoms should be brushed daily with a wire brush to help break the life cycle of the protozoa.

7. Routine cleaning two or three times a week will decrease coccidial loads and is recommended for rabbitries experiencing coccidiosisproblems

8. Feeder and waterer should be disinfected regularly and remain free of rabbit feces.

9. Ammonia (10%) solution is lethal to oocysts and is the best choice to disinfect cages or equipment exposed to fecal material.

10.Elimination of fecal-oral transmission of infective oocysts is achieved by preventing feed hoppers and water crocks from becoming contaminated with feces.

ENCEPHALITOZOONOSIS

• Encephalizotoonosis is a very common chronic infection in domestic rabbits.

• This parasite is widely distributed amongst different mammalian species (dogs, cats, pigs, cows, horses and exotic carnivores). The disease of possible zoonotic risks.

• E. cuniculi is a protozoal parasite belonging to the phylum microspora, genus microsporidia, spore-forming obligate intracellular parasites.

• The spore is the infective form of the parasite, resistant to environmental changes and able to survive up to four weeks (month) at 22°c in dry conditions

• The spores are shed into the urine of infected rabbits and infection usually occurs via ingestion of urine contaminated food and water.

• Tracheal and transplacental routes of infection have also been reported as possible, but appear much less frequent.

ENCEPHALITOZOONOSIS

Target organs are primarily

1. The central nervous system

2. The kidneys

3. The eyes

4. The liver and heart may also be involved.

• In these organs the parasite’s damage can cause chronic inflammation and granulomas.

Factors are involved in the development of overt clinical disease:

1. the immune status of the rabbit

2. The route of infection and the strain of parasite involved.

• Carriers and asymptomatic infections are extremely common, during its life, for any reason, the infected rabbit becomes immunosuppressed the disease appeared.

ENCEPHALITOZOONOSIS

Clinical signs

A. Neurological signs are (head tilt, ataxia, circling, rolling, nystagmus are frequent findings, paresis or paralysis of one or both hind legs, seizures, behavioural changes)

• The degree of torticollis is considered an important prognostic factor in rabbits showing clinical signs.

Differential diagnosis:

• Pasteurella multocida, toxoplasma gondii, listeriosis ,viral infections (such as herpes simplex 1), degenerative disease and neoplasia have also been reported.

ENCEPHALITOZOONOSIS

B. Rabbits suffering from chronic renal failure

often present with nonspecific clinical signs

such as lethargy, weight loss, reduced

appetite leading to anorexia. polyuria,

polydipsia and urinary incontinence may or

may not be present and urine scalding of

the perineal skin is also commonly seen.

ENCEPHALITOZOONOSIS

C. Ocular lesions such as cataracts, hypopyon, phacoclastic uveitis, rupture of iris or even

blindness. these lesions are reported to be typically unilateral with occasional bilateral

• Younger rabbits are more susceptible for ocular form

ENCEPHALITOZOONOSIS

Diagnosis

• Histopathology

• Elisa

• Polymerase chain reaction (PCR)

Treatment

• Fenbendazole is, at present, the drug of choice as it has been shown to be effective in reducing clinical signs in an already established infection and to prevent it in exposed animals.

• Broad spectrum antibiotics can be prescribed when necessary to reduce the risk of secondary infections (after antibiotic sensitivity).

• Fluid therapy

• Renal wash

• Vit A, vit B complex

• Environmental disinfection.

TOXOPLASMOSIS

• Ingestion of infected cat faeces

• Sudden anorexia, pyrexia and death, possibly CNS signs

• The rabbit is not the final host; therefore it is not infectious to other rabbits. No cysts are found in rabbit faeces.

• Can infect humans eating undercooked rabbit meat

LARVAL WORM INFECTION

• Although adult tapeworm infections are rare in domestic rabbits, the discovery of larval

tapeworm cysts on the serosal peritoneum is common.

• Rabbits are intermediate hosts for two species of canine tapeworm, Taenia serialis and Taenia

pisiformis.

LARVAL WORM INFECTIONA. TAENIA PISIFORMIS

• The tapeworm Taenia pisiformis is a common parasite of carnivores like dogs, foxes, and sometimes of cats.

• The intermediate stageis characterized by the presence of bladder like structure in the abdominal/peritoneal cavity and liver. This intermediate larval stage is called Cysticercuspisiformis.

• The parasitic larvae use the hepatic portal vein to invade the liver of rabbits. The migration phase of the larva is usually accompanied by focal granulomatous hepatitis-like symptoms, a severe infestation can cause chronic extreme weakness or sudden death.

• Aberrant migration is possible. Some of these cysts have been found in the peritoneal fluids or in the lungs of a rabbit, filling almost all the cavity of the lung and causing respiratory distress. Brain cysticercosis leads to seizures, increased intracranial pressure, and altered mental status. On X-ray, there are signs of hydrocephalus, aseptic meningitis and/or calcified cysts.

LARVAL WORM INFECTIONB. MULTICEPS SERIALIS (TAENIA SERIALIS)

• In rabbits, cysts of Multiceps serialis are essentially found in the subcutaneous tissuesand muscle mass.

• The cysts are elongated and the larva can easily be seen.

• Differential diagnosis: Hematoma, tumor

ROUNDWORMS

• Rarely found in commercial rabbitaries.

• Obeliscoides, the stomach worm, is a very slender, reddish worm about one-half inch long. It made ulcération of the stomach wall.

• Trichostrongylus is about the same size but is found in the small intestine. It cause enteritis.

• Signs of infection depend on the degree of the infestation. Light infestations produce little effect; heavy infestation may cause diarrhea and emaciation.

Treatment:-

• Piperazine citrates or fenbendazole.

PINWORMS

• Passalurus ambiguus, the rabbit pinworm, usually is not clinically significant and rarely to be found.

Treatment:-

• Piperazine citrates or fenbendazole.