small mammals 4 pt 3 Flashcards
1
Q
Respiratory Disease – Sinusitis and Rhinitis etiology
A
- Common
- Stressful, since obligate nasal breathers
- Infectious
- Pasteurella multocida – most
common - Bordetella bronchiseptica
- Pseudomonas species
- Staphylococcus species
- Odontogenic rhinitis and nasal foreign bodies/rhinoliths are also common
2
Q
Sinusitis and Rhinitis in rabbits summary
A
- Upper respiratory tract disease is common in pet rabbits and can be caused
by a number of primary and secondary etiologies. Remember that rabbits are obligate nasal breathers because of the position of the elongated epiglottis engaged over the caudal margin of the soft palate. Due to the obligate nasal breathing nature of this species, disease of the upper respiratory tract is more severe and stressful in rabbits than in many other species. Numerous infectious diseases are associated with disease of the upper respiratory tract. The most common infectious diseases are due to bacterial agents, in particular, Pasteurella multocida. However, it is important to remember that other pathogens such as Bordetella bronchiseptica, Pseudomonas species, and Staphylococcus species can be involved. Odontogenic rhinitis and nasal foreign bodies/rhinoliths are also common - Note - otitis media may be associated with respiratory disease in rabbits, as infection can spread via the Eustachian tube to the tympanic bulla and middle and possibly inner ear
3
Q
Respiratory Disease – Sinusitis and Rhinitis clinical signs
A
- Nasal and/or ocular discharge
- Increased respiratory effort and rate, often worse with exertion
- Wet or matted fur beneath the eyes, nares, and on the medial forepaws
- Sneezing
- Weight loss
- Decreased appetite
- Lethargy
- Exercise intolerance
<><> - Nasal and/or ocular discharge
- Increased respiratory effort and rate, often worse with exertion
- Wet or matted fur beneath the eyes, nares, and on the medial forepaws
- Sneezing
- Weight loss
- Decreased appetite
- Lethargy
- Exercise intolerance
4
Q
Respiratory Disease – Sinusitis and Rhinitis how to stabilize
A
- Oxygen therapy if dyspneic
- IV/SC fluids (depending on the severity of dehydration)
- Incubator if hypothermic
- Remove obstructing crusting on nostrils, if present
5
Q
Respiratory Disease – Sinusitis and Rhinitis
- how to diagnose
A
- All of the following diagnostics should be offered to determine the
underlying cause of clinical signs. Comorbid diseases are common and may be the predisposing stressor to the development of clinical signs. All diagnostic tests should be done as soon as possible as rabbits have a high degree of compensation, which may confound the appreciable severity of the underlying condition. In case of financial constraints, prioritize tests based on the problem-oriented approach - CBC/biochemistry profile
- Whole body radiographs (plus focused thorax, three views)
- CT scan (head)
- Deep nasal culture (aerobic and anaerobic)
- Nasal cytology
- (Rhinoscopy if big enough and on selected cases)
6
Q
Respiratory Disease – Sinusitis and Rhinitis medical treatment
A
- Oxygen therapy
- Meloxicam – 0.5 mg/kg PO q12h for 30 days
- Antibiotics (based on culture results) – 6-8 week duration
- Syringe feeding q8h (50 ml/kg/day of Oxbow critical care herbivore
formula) - Nasolacrimal flushes as indicated, with an infusion of antibiotic drops (may
have some utility) - Treatment of otitis media/interna if present
- Cage rest/confinement
- (Nebulization on selected cases)
7
Q
Respiratory Disease – Sinusitis and Rhinitis surgical treatment
A
- If medical therapy fails to improve clinical signs, consideration for
rhinotomy with surgical debridement and infusion of topical antibiotics can
be considered - Different approaches can be done depending on the CT (dorsal, lateral, or
ventral). Will not do it without a CT scan - If odontogenic rhinitis, cheek teeth extraction may be needed of the upper
first or second check teeth (UPM1-2) - Rhinoscopic removal of foreign body or rhinolith (may also be done blindly
with small endoscopic forceps)
8
Q
Encephalitozoon cuniculi Infection etiology
A
- E.cuniculi- obligate
intracellular microsporidian - Zoonosis (wash hands)
9
Q
Encephalitozoon cuniculi Infection clinical signs
A
Clinical signs (neurologic) often appear following a stressful event in the rabbit’s
life
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* Three forms:
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Neurologic
* Behavioral changes
* Head tilt
* Nystagmus (vertical is an indication of a central vestibular
syndrome)
* Ataxia
* Rolling
* Seizures
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Ocular
* Phacoclastic uveitis
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Renal
* Often discovered incidentally on necropsy
* Chronic renal disease
10
Q
Encephalitozoon cuniculi Infection how to stabilize
A
- If severe neurological signs:
- Sedation with midazolam
- Place in a dark, quiet stress-free environment
- Other therapeutics:
- IV/SC fluids (depending on the severity of dehydration)
- Incubator if hypothermic - often these animals are hyperthermic
from rolling and may require active cooling - Oxygen therapy if dyspneic
11
Q
Encephalitozoon cuniculi Dx
A
- All the following diagnostics should be offered to determine the underlying
cause of clinical signs. Comorbid diseases are common and may be the predisposing stressor to the development of clinical signs. All diagnostic tests should be done as soon as possible as rabbits have a high degree of compensation, which may confound the appreciable severity of the underlying condition. In case of financial constraints, prioritize tests based on the problem-oriented approach - CBC/biochemistry profile
- Urinalysis and urine culture if indicated
- Whole body radiographs
- CT scan (head)
- CSF tap (an inflammatory count is highly suggestive of E. cuniculi, but not specific)
- ELISA (IgG, IgM) and CRP
- Requires 0.1 mL of serum or heparinized plasma
- Interpretation of results:
- IgM and IgG
- Common to have seropositive rabbits (ECUN IgG+);
however, infected rabbits carry significantly higher
titers of antibody - Mean titer of infected animals: 1:1324
- Infected rabbits also have significantly higher levels
of gamma globulins - Elevated IgM titers are associated with active
infection - Absence of IgM suggests exposure or previous
infection - High IgG without IgM seroconversion should still be
strongly considered as infected animals - IgM - ≥1:64, IgG ≥1:512 → posive predicve value
of 92% * CRP - Major acute phase protein in rabbits → increases with ANY systemic inflammatory process
- Elevation is not diagnostic of infection but is supportive of infection and should be interpreted in association with IgM and IgG titer
- Abnormal IgM and IgG in conjunction with elevated CRP → posive predicve value of 100%
12
Q
Encephalitozoon cuniculi Infection treatment
A
- Fenbendazole – 20 mg/kg PO q24h for 30 days
> Check CBC initially, at 2 weeks, and at the completion of treatment due to concerns for immune suppression
> May not work well, but no alternative - Meloxicam – 0.5 mg/kg PO q12h for 30 days
- Antibiotics (only if indicated or if suspicion/confirmation of otitis)
- Syringe feeding q8h (50 ml/kg/day of Oxbow critical care herbivore
formula) - Cage rest/confinement, until better adapted to neurological issues
13
Q
Medial and External Otitis etiology
A
- Common
- Often Pasteurella multocida
- Upper respiratory tract → middle ear (OM) → external ear canal (if the tympanic membrane ruptures) (OE) or → inner ear (OI), causing vestibular labyrinthitis
- If severe, can → brain
- In lop-eared breeds, predisposed to externa, can → interna
14
Q
Medial and External Otitis definition
A
- Ear disorders are common in rabbits, with otitis externa and media being
the most common and clinically relevant diseases. A primary otitis media may be caused by infection spreading from the upper respiratory tract through the auditory or Eustachian tubes. Infection may also spread from the middle ear to the ear canal (if the tympanic membrane ruptures) or to the inner ear, causing vestibular labyrinthitis. In severe cases, the infection can spread to the brain, causing severe neurologic signs, including seizures - Note - external otitis and lop-eared breeds predispose to medial otitis
15
Q
Medial and External Otitis
- clinical signs
A
- Vestibular signs resulting from otitis media and/or interna such as
nystagmus and a head tilt with varying severity and loss of balance and rolling, often in part due to Pasteurella multocida
<><><><> - Vestibular due to OM and/or OI
> Nystagmus, head tilt, loss of balance, rolling
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Facial nerve damage - Hemifacial paresis or a hemifacial spasm
> Facial droop/contracture
> Unable to blink
> Horner’s syndrome - Other neurological signs if involves brain
