Cardiorespiratory disease Flashcards
Normal rabbit radiographic findings
- the thoracic cavity is small in comparison with the abdominal cavity
- the heart occupies a relatively large volume of the thoracic cavity
- ^ means that minor lung pathology can have big consequences clinically
- the small cranial lung lobes are not seen in as much detail as the caudal lobes
- the aorta and caudal vena cava should be visible
- the pulmonary vessels can be seen within the lungs
Clinical signs of respiratory dz in small mammals
- lethargy
- poor coat
- anorexia
- audible clicking
- sneezing
- ocular discharge (e.g. porphyrin)
- nasal discharge
- dyspnoea/ abdo heaving
- head tilt if middle ear involved
- open mouth breathing
- often see minimal, non-specific signs
Clinical signs of respiratory dz in reptiles
- lethargy
- anorexia
- weight loss
- difficulty breathing
- open mouth breathing
- wheezes or crackles
- ocular and/or nasal discharge
- stomatitis
Clinical signs of respiratory dz in birds
- lethargy
- anorexia
- ‘fluffed up’
- crusting around nares
- periorbital swelling
- dyspnoea or ‘tail bobbing’
- voice change
- tachypnoea
Degree of disease when you see signs of respiratory dz in birds (& why)
- very bad
- they hide symptoms well
- also their respiratory tract is very effective so if a bird is struggling to breathe there is a lot of damage
- they can go downhill very quickly
Common causes of respiratory dz in small mammals
- URT bacterial infections
- LRT bacterial infections
- viruses (respiratory or systemic)
- fungal infections
- parasitic (e.g. lungworm [ferrets])
- husbandry (allergy, dust, poor ventilation, stress, poor diet)
- dental disease
- circulatory causes
- trauma
- space occupying lesions
- foreign bodies
What can URT bacterial infections in small mammals & reptiles cause?
- rhinitis
- also affects structures outside of there respiratory tract, e.g. conjunctivitis, nasolacrimal duct infections, otitis media
- dental disease is often related to URT dz in small mammals
What can LRT bacterial infections in small mammals & reptiles cause?
- tracheitis
- bronchitis
- pneumonia
Examples of fungal infections in small mammals
- Aspergillosis – more likely if outdoor pets
Examples of circulatory causes of respiratory disease in small mammals
- heart disease (pulmonary oedema)
- arteriosclerosis
Examples of trauma causing respiratory dz in small mammals
- lung contusion
Examples of space occupying lesions causing respiratory dz in small mammals?
- abscesses
- tumours
What small mammals spp is Mycoplasma typically seen in?
- rats
- hence why LRT disease e.g. pneumonia, is often seen in rats
- can be passed onto other animals very easily
Common respiratory pathogens in Guinea Pigs
- Bordetella bronchiseptica
- Chlamydophila caviae
- Adenovirus
Common respiratory pathogens in rabbits
- Pasteurella multocida
- Bordetella bronchiseptica
Common respiratory pathogens in rats and mice
- Mycoplasma pulmonic
- Pasteurella pneumotropica
- Strep pneumoniae
- Sendai virus (mice)
Common respiratory viruses in reptiles (species examples)
- Herpes virus: tortoises
- adenovirus: lizards
- ophidian paramyxovirus (OPMV): snakes
Common causes of respiratory dz in reptiles
- URT bacterial infections
- LRT bacterial infections
- viruses
- fungal infections
- parasitic (e.g. lungworm [snakes], Rhabdias, Ascarids)
- husbandry (high or low temperature, high humidity levels, stress, poor ventilation)
- dental disease
- circulatory causes
- trauma
- space occupying lesions
- foreign bodies
Examples of fungal infections in reptiles
- candida
- aspergillosis
What dental dz can lead to stomatitis in reptiles?
- periodontal dz
Examples of circulatory causes of respiratory dz in reptiles
- septic endocarditis
- congestive heart failure
Examples of space occupying lesions in reptiles that cause respiratory dz?
- abscesses
- tumours
- reproductive dz
- coelomic effusions
- granulomas
What organism can URT infections in chelonians be related to?
- Mycoplasma
Common causes of respiratory dz in birds
- URT bacterial infections
- LRT bacterial infections
- viruses (respiratory or systemic)
- fungal infections
- parasitic (e.g. Syngamus trachea (gapeworm in chickens)
- husbandry (allergy, stress, low humidity, poor hygiene/ventilation, hypovitaminosis A)
- dental disease
- circulatory causes
- trauma
- space occupying lesions
- foreign bodies
What can URT bacterial infections cause in birds?
- rhinitis
- sinusitis
- conjunctivitis
What can LRT bacterial infections cause in birds?
- tracheitis
- bronchitis
- airsacculitis
- pneumonia e.g. Psittacosis (Chlamydia psittaci)
Circulatory causes of respiratory dz in birds
- heart disease (pulmonary oedema)
- arteriosclerosis
Virus causing respiratory dz in chickens
- infectious laryngotracheitis
Example of fungal infection causing respiratory dz in birds
- Aspergillosis
Examples of space occupying lesions that cause respiratory dz in birds
- tumours
- organomegaly
- reproductive dz
- obesity
- rhinoliths
- pulmonary fibrosis
- choanal atresia
- occluding fungal plaques
What animal is particularly susceptible to fumes and smokes?
- birds
What do foreign bodies in the respiratory tract cause in birds?
- granulomatous tracheitis
Diagnostic options
- imaging (radiography, CT, endoscopy, US)
- bacteriology (C&ST)
- PCR testing
- blood testing
What will the WBCc be for septic reptiles?
- low
Bloodwork (use)
- used to detect inflammatory process/infection, organ damage (e.g. liver or kidney)
- can be between normal ranges despite pathology of the respiratory tract
- can help determine severity and help with stabilisation (blood gases/acid-base)
Examples of respiratory pathogens you would PCR for
- Mycoplasma
- Herpes
What samples can you take to get a representative samples? (& what spp)
- deep nasal swab: rabbits
- nasal flush: birds
- nasolacrimal duct flush: rabbits
- lesion/oral swab (reptile PCR)
- BAL/trach lavage (2ml/kg)
Tx plan
- oxygen
- fluids and supportive nutrition
- nebulisation
- bronchodilator
- mucolytic
- anti-inflammatory
- tx for specific causes (e.g. ABs, furosemide, acyclovir, antifungals, antiparasitics, husbandry changes, surgery, etc)
What can nebulisation be useful for?
- thick secretions
What is F10 used for?
- used for reptiles, small mammals & birds
- AB, AF, AV effects
Sedation for exotics
- butorphanol/midazolam
Small mammal specifics: tx
- rabbits and rodents are obligate nasal breathers, open mouth breathing is always an emergency
- supportive nutrition is particularly important for hindgut fermenters
- regular nebulisation can increase time between flare ups
- bronchodilator e.g. terbutaline works well in a nebuliser
- mucolytic in food e.g. bromhexine
- NSAIDs e.g. meloxicam can help with laboured breathing
- rabbits are steroid sensitive so avoid using them if possible
Commonly used antibiotics in small mammals
- TMPS: 1st line & broad spec, licenced
- Doxycycline; e.g. Mycoplasma in rats
- Azithromycin (macrolide): also reduces lung inflammation
- Enrofloxacin (fluoroquinolone): not without C&ST
- Metrondizaole: for anaerobic infections e..g abscess (combination)
- Penicillin: e.g. streptococcus, pasteurella (parenteral only in rabbits)
Which antibiotics should NOT be used in hindgut fermenters?
- penicillins
- lincosamides
- aminoglycosides (possibly)
- cephalosporines
- erythromycin
Reptile specifics: tx
- if malnourished can use injectable vitamins or liquid ‘dosed’ supplements (e.g. Zolcal-D) whilst hospitalised in the short term, long term dietary changes will be needed also
- F10 is v useful in reptiles, because fungal causes or secondary infections are common, can be used as a mouth flush
- it’s vital to keep reptiles at their POTZ for their immune system to be working optimally and for drug metabolism
- heat vs ventilation
Heat vs ventilation in reptiles
- lack of ventilation will cause an increase in abnormal chemical structures in the environment
- stagnant air in the tank won’t move and will increase humidity -> these predispose to bacterial proliferation and therefore infection
- however, if you have a very high ventilation its hard to keep the heat at the right temperature
POTZ
- preferred optimal temperature zone
Commonly used antibiotics in reptiles
- gram negatives are common pathogens
- TMPS: e.g. 1st line broad spec, licensed
- doxycycline: e.g. mycoplasma in tortoises
- metronidazole: for protozoal and anaerobic infections
- ceftazidime: injectable q72h, practical
- enrofloxacin: (fluoroquinolone) not without C&ST
Bird specifics: tx
- oxygen is very important: they have a high oxygen demand due to high metabolic demand
- fluids and supportive nutrition, crop tubing is easy
- nebulisation is very effective due to their airway anatomy (i.e. oral meds don’t reach the air sacs well but nebulisation does)
- tx often multi-modal and given for a long duration, LRT can be hard to target
- birds have no diaphragm and a packed coelomic cavity: no uncommon for LRT clinical signs to be coelomic dz instead
Commonly used antibiotics in birds
- TMPS: 1st line, broad spec, licenced
- penicillin & co-amoxiclav: 1st line, broad spec
- metronidazole: if anaerobic (not poultry)
- doxycycline: e.g. Chlamydia psittaci
- enrofloxacin (fluoroquinolone): not with C&ST
- azithromycin (macrolide): e.g. Chlamydia psittaci
