Botulism is a paralytic disease which is caused by the ingestion of a toxin produced by the bacterium Clostridium botulinum. Avian botulism can occur in any bird species but is most frequently seen in filter-feeding and dabbling water birds; shorebirds have also been known to develop botulism. Botulism occurs worldwide causing sickness and death in thousands of birds every year. Most cases occur during the warm summer months when water levels are low and oxygenation is poor, which creates ideal conditions for the bacterium.
Botulism is an ascending paralysis in birds, this means it starts from the legs and works its way up through the body. Birds in the early stages of botulism may lose the ability to fly, then lose the use of their legs and are only able to pull themselves along by using their wings. As the botulism disease advances the birds are no longer able to hold up their head, and those that are unable to leave the water will drown. Another tell-tale sign is the protrusion of the third eyelid crossing over the eye.
When rescuing birds that are affected with botulism it should go without saying ‘be careful!’, these birds are usually in or around water and this in itself can pose safety problems for rescuers. Before attempting a rescue ensure it is safe to do so and that you have all the equipment you are likely to require, this would include a suitable holding box for the bird, towels, gloves, something to give additional warmth i.e. a hot waterbottle filled with hot water from the tap and a net. Our How to Rescue blog will give you further information about rescuing a bird.
When you have a bird come into care with botulism you should not treat with medications unless there are signs of infection. Whilst botulism is bacterial it is the spores that cause the paralysis, not the bacteria, so antibiotics are not effective.
The only time antibiotics should be considered is when the bird has potentially inhaled some water - it was starting to drown as it was being rescued! Use a stethoscope to check for any odd sounds in the lungs or air sacs.
What to give:
Using a water-soluble eye lube apply to the eyes 3 times a day for around 3 days, this helps keep the eyes moist.
If unable to swallow give SQ fluids – e.g. Plasmalyte (or similar isotonic fluids) at 75-100ml/kg/per day - once to twice a day.
If the head is up and can swallow you can tube fluids – Plasmalyte at 75-100ml/kg/per day - you can divide twice a day.
Use Activated Charcoal or Metamucil twice a day – this will help absorb any bacteria that may still be in the gut. NB - This is no longer thought to be that useful since the symptoms appear 18 to 24 hours after ingestion of the infected materials. If you want to give it just the once - that should be enough to mop up any lingering toxins.
Nursing Care tips:
Ensure the bird has its head supported and has padding underneath the body to help take the weight of the bird, this will allow the bird to breathe easier.
Use the puppy pee pads or similar for easy and regular cleaning and monitoring of faeces.
Keep the birds' vent area clean, if allowed to get dirty the feathers will get damaged. You can do this by holding the birds’ vent under warm running water and gently rub the faeces off the feathers.
Keep flies off the birds or you could end up with a second problem – maggots!
If the bird is running a temperature prop them up in a basin or tub with cool water. Ensure that their head is up, monitor their temperature and as soon as they have cooled remove them. Do not leave them unattended.
Swim the birds as soon as they are stable and, on their way, to recovering, this seems to help with accelerating the recovery time. Do not leave them unattended.
Monitor their weight and body condition – Crucial!
Food can usually be offered or tubed once they are alert and holding their heads up. SQ fluids can be continued to be given if necessary.
Don’t forget to wash your hands properly after handling the birds, even if you have been wearing gloves!
Make detailed notes from the time of admission to the outcome. Don’t skimp on the making of notes, you never know when you may need to refer back to them.
Mandy Robertson - Wildlife Rehabilitator
In collaboration with
Dr Lynn Miller - General Manager for the New Zealand Bird Rescue Charitable Trust
(All photos and videos are the copyright of Wild Bird Care – NZ)
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