Exotics: Rabbits Infectious Diseases

Question 1

What kind of virus causes myxomatosis?

Answer 1

Leporipoxvirus
Introduced into Europe in 1952

Question 2

How does myxomatosis spread between rabbits?

Answer 2

• Direct contact
• Inhalation
• Biting arthropods (fleas, mosquitoes, cheyletiella mites)

Question 3

What does clinical disease depends on?
What are the clinical signs?

Answer 3

Clinical disease
* Viral strain
* Season (vectors life cycle)
* Environmental temperature (cold)
* Age (maternal ABs 4-5 weeks)
* Immune function
* Vaccination status

Clinical signs
* Eyelid thickening and purulent eye discharge
* Nodules on ears, lips, nares, eyelids, external genitalia
* Occasional pneumonic signs
* Infertility
* Death by starvation

Question 4

What is shope fibroma?

Answer 4

Different leporipoxvirus
Naturally infects american rabbit species
Induced self-limiting fibromas/fibromatosis
Cross-immunity against myxomatosis

Question 5

What is the treatment for myxomatosis?
How is it prevented?

Answer 5

Trreatment- euthanasia
Prevention:
Vaccination- from 5 weeks
External parasite control
Avoid contact with wild rabbits

Question 6

1. What type of virus causes viral haemorrhagic disease?
2. How is it transmitted?
3. How does it cause disease/death?

Answer 6

1. Calcivirus
2. Urine, faeces, aerosols, biting insects
3. Liver- initial replication inside hepatocytes
   Necrotising hepatitis- DIC and acute liver failure
   DIC causes fibrinous thrombi (lungs, heart, kidneys) leading to haemorrhage and organ failure

Question 7

What are the clinical signs?
How is it diagnosed?

Answer 7

Clinical signs
* Sudden death
* Fever
* Increased RR
* Collapse, hypotension
* Neurological signs
* Haemorrhages
* In rabbits > 4 weeks
* Younger rabbits resistant to infection

Diagnosis
* Clinical signs
* Gross path: severe necrotising hepatitis, enlarged spleen, haemorrhages
* Histology
* PCR

Question 8

What is the treatment and prevention for rabbits against viral haemorrhagic disease?

Answer 8

Treatment- Euthanasia
Young rabbits under 4 weeks can survive infection

Prevention:
Vaccination against VHD-1 and 2
From 5 weeks of age
Yearly boosters

Question 9

What are the 3 conditions papillomatosis can refer to?

Answer 9

• Shope papillomavirus- can cause SCC-like neoplasia in domestic rabbits
• Oral papillomavirus- benign wart-like growths in the oral mucosa, self-limiting
• Ano-rectal papillomatosis- not viral induced. Cauliflower masses that bleed easily

Question 10

1. What causes the disease ‘snuffles’
2. What causes pathogenicity

Answer 10

1. Pasturella multocida
2. Several strains
   * primary inimmunosupressed,
   * secondary in abscesses
   * Can avoid phagocytosis, complement and other defences
   * Endotoxin production
   * Adhesion and filaments help infect hosts cells

Question 11

What can cause an outbreak of pasturellosis?

Answer 11

• Subclinical URT infection
• Transmitted within a group- direct contact, aerosols
• Stress immunosuppresion- overcrowding, pregnancy/lactation, poor husbandry, nutritional deficiencies
• Ccauses clinical signs- spreads to other tissues- resp tract, tympanic bullae

Question 12

What are the clinical signs of pasturellosis in rabbits?

Answer 12

1. Rhinitis ‘snuffles’
2. Pneumonia
3. Genital infections
4. Wounds and abscesses
5. Dacryocystitis
6. Otitis media/interna

Question 13

How is pasturellosis in rabbits diagnosed?

Answer 13

Challening
Culture and sensitivity- deep nasal swab performed under sedation/GA
Serology- doesn’t indicate an active infection
PCR

Question 14

How can pasturellosis be managed?

Answer 14

• Reduce stress and overcrowding
• Improve husbandry
• Increase ventilation
• Avoid temperature fluctuations
• Isolate symptomatic rabbits
• Antibiotics based on C&S + supportive + treat specific problems

Question 15

1. What causes ‘rabbit syphillis’?
2. How is it transmited?
3. How does it present?
4. What is required for a definitive diagnosis?
5. What are DDXs?
6. How is it treated?

Answer 15

1. Treponema paraluiscuniculi
2. Sexual transmission, vertical transmission
3. Nodes, crusty lesions that can ulcerate- vulva/prepuce, lips and nostils
4. Histo and silver stains
5. Myxomatosis, ano-rectal papillomatosis
6. Penicillin SC at weekly intervals

Question 16

Rabbits

1. What possible agensts are involved in bacterial enteritis?
2. What can be other causes of diarrhoea?

Answer 16

1. Several possible agents- tyzzer’s disease, clostridial entorotoxaemia, salmonella, E. coli, Campylobacter
2. Other causes: Coccidiosis, Diet changes, Dysbiosis

Question 17

1. What age of rabbits are mostly affected by Tyzzer’s disease?
2. What are the main pathological findings?
3. What is it often secondary to and how is it diagnosed?

Answer 17

1. Mostly young 6-12 weeks
2. Acute phase: diarrhoea, sudden death
   Chronic: intestinal fibrosis/stenosis, liver necrosis
3. Secondary to stress- Serology?, PCR?

Question 18

1. What toxins do clostridial enterotoxaemia produce?
2. What are the main causes?

Answer 18

1. Iota toxin
2. Diets rich in starch- caecum overload
   Stress
   Antibiotics- specially if administered PO (B-lactams, clindamycin, streptomycin, erythromycin)

Question 19

1. What is the approach to a rabbit with diarrhoea?
2. What should be taken for the minimum patient database?

Answer 19

Diarrhoea
1. Fluid therapy- SC or IV depending on severity
2. Diet managment- high fiber, low sugar/starch
3. Antibiotics- fluoroquinoles, metronidazole
4. Other medication: analgesics, cholestryamine, maropitant

Minimum patient database:
* Weight
* Dehydration %
* Temperature
* Gut sounds
* Blood glucose
* Routine faecal testing

Question 20

Rabbits

1. What are the two presentations of coccidiosis?
2. What are the clinical signs of each?
3. What are the risk factors?

Answer 20

1. Intestinal coccidiosis (13 different sp), Hepatic coccidiosis (E. stiedae)
2. Intestinal coccidiosis- Diarrhoea and weight loss
   Hepatic- Diarrhoea, weight loss, heptomegaly and jaundice, higher mortality
3. Groups, Age

Question 21

How is coccidiosis in rabbits treated?
What can also be considered?

Answer 21

Treatment:
* TMP and Sulfas
* Toltrazuril
Consider:
* Supportive care
* Diet managment
* Reduce stress/improve husbandry

Intestinal- rabbits become immune
Hepatic- chronic/permanent changes

Question 22

What internal parasites can more uncommonly infect rabbits?

Answer 22

Oxyurids- passalurus ambiguus
* Commensal
* Can cause problems in young rabbits
* Can be controlled with any wormer

Tapeworms- rabbits are intermediate hosts
* Cysticercus pisiformis- peritoneal cavity, liver
* Coenurus serialis- SC tissues
* Echinococcus granulosus

Question 23

What external parasites can infect rabbits?

Answer 23

• Fleas- cat and dogs more common
• Lice- haemodipsus ventricosus occasionally
• Mites-
  Ear mites- psoroptes cuniculis
  Skin mites- Cheyletiella parasitovorax
  Fur mites- Leporacarus gibbus

Question 24

1. How are external parasites in rabbits diagnosed?
2. What are mites secondary to?
3. How are they treated?

Answer 24

1. Identical to Small (skin scrapes, skin strips)
2. Inability to groom- dental disease, arthritis, spinal disease. Immunosupression
3. Imidaclopride, selamectin, moxidectin
   Do not use Fipronil in rabbits

Question 25

1. What flies cause fly strike 2. What are the commonly affected areas in rabbits? 3. What are the risk factors?

Answer 25

1. Maggots of Lucilia sp and Calliphora sp 2. Tale base and perineum 3. Outdoor, higher temperatures, soiled skin, overweight, difficulty grooming, uneaten caecotrophs

Question 26

How is flystrike managed in rabbits?

Answer 26

Euthanasia in severe cases Remove maggots: * Sedation * Clip and manually remove * Ivermectin SC * Bathe in dilute iodine solution * Dry affected areas with blow dryer Analgesia- Meloxicam ± buprenorphine Supportive care: fluids, gut motility stimulants, ABs if secondary infection

Question 27

How can flystrike be prevented in rabbits?

Answer 27

Cyromazine- licensed Inspect rabbits twice daily during risk season Clip any mats Provide good husbandry, hygiene and diet Regular health checks- early detection of risk factors

Question 28

1. What causes encephalitozoonosis in rabbits? 2. When do clinical signs develop? 3. How is it transmitted?

Answer 28

1. Encepalitozoon cuniculi- microsporidia 2. Intracellular obligate parasite- clinical signs develop when infected cells rupture with spored 3. Inhalation/ingestion of spored shed mostly in urine, vertical

Question 29

1. What clinical signs can present with encephalitozoonosis? 2. How much of the population is likely to be infected?

Answer 29

1. Neurological presentation, eye lesions, chronic kidney disease 2. 50%- most sub-clinical/non-infectious

Question 30

How can a rabbit with encephalitozoonosis present with neurological signs?

Answer 30

* Head tilt * Nystagmus * Facial paralysis * Pareses/paralysis * Muscle weakness * Seizures

Question 31

What eye lesions and signs of CKD may rabbits get with encephalitozoonosis?

Answer 31

Eye lesions- * Phacoclastic uveitis * Lens opacity/rupture * Cataracts CKD * PUPD * Urine scald * Progressive weight loss * Supported by biochemistry/haematology

Question 32

How is E. cuniculi diagnosed?

Answer 32

Challenging Clinical signs not enough Serology: * IgM- indicate recent/active infection * IgG- indicate chronic infection or previous exposure * Always interpret restuls with other tests and CS PCR- urine or faeces- shedding spores intermittent Try radiography, biochem and haematology

Question 33

How is E. cuniculi treated?

Answer 33

Fembendazole SE- bone marrow supression Only treat with confirmed cases or high suspicion Anti-inflams- NSAIDS, corticosteroid contraindicated (immunosupression) Antibiotics- fluoroquinolones, doxycycline

Question 34

What additional care may be required for E. Cuniculi?

Answer 34

Ocular lesions: eye drops with NSAIDS, enucleation Seizures/rolling: Midazolam Supportive care: syringe feeding, fluids, padded cages, monitor eyes for keratitis

Question 35

What are the possible outcomes of E. cuniculi?

Answer 35

1. Recovery- likely to remain sub-clinical 2. Neurodefecits- mild head tilt 3. Enucleation- cope well post-op 4. CKD- managment and monitoring 5. Euthanasia

Question 36

How is E. cuniculi prevented?

Answer 36

* Serological testing and separating positives/negatives * Strict hygiene * Prophylactic fembendazole * Improve husbandry and diet * Reduce overcrowding