SYMPTOMS
Usually first noticed as a small swelling, often reddened, at the base of the foot.
It can show up as a pea-size swelling of the web of skin between the toes or a large raised area on the bottom of the foot, often with a scab area in the centre. The bird may limp, or frequently rest one foot. The foot will become hot to the touch and look visibly inflamed. If left untreated it can grow considerably, distort the toes, become filled with pus and may eventually kill the bird if the infection within the foot causes a secondary systemic bacterial infection.
CAUSES
Initially, the cause of bumblefoot can be as simple as rough splinters on a perch puncturing the foot. Prickles and splinters on the ground may damage the bird’s foot as it is scratching around. Another common cause in birds housed inside as well as on free range is when mud or faeces builds up a coating on the foot pads which in turn keeps the skin beneath it wet and warm. This causes the skin to soften and allows penetration of bacteria. The organisms which cause the infection, after entry through a wound or softened skin can include Staphylococcus aureus,
H. coli or Corynebacterium which are commonly found everywhere in the environment.
TREATMENT
If left untreated the infection may rapidly develop within days. Ideally a course of antibiotics from the vet -the earlier the better — would be the ideal treatment. Once a bird is on antibiotics, it’s important to keep the foot clean and use an antibacterial spray like Vetadine or Aerotet Forte. Keep the bird on clean, soft dry bedding. Recovery should be about 7 days.
Home remedies may be effective in some instances to relieve the infection without needing to have vet treatment. Bathing and disinfecting and applying ointments such as calendula or comfrey cream to the area morning and evening may reduce the infection and swelling allowing the area to naturally heal.
However, if an infection has gone too far and a large bleeding scab is present or there is a hardened core in the lump, surgery may be required. While lancing the swelling and removing the core or pus and treating the resultant hole is possible (online descriptions of this are available), this is a surgical procedure which should be performed by a vet who can use appropriate pain medication required under NZ’s Animal Welfare rules.
Whenever a hen becomes paralysed, the first assumption of many people is that it is a sign of Marek’s Disease, and that is certainly what NZ Lifestyle Block reader Jo Kelly thought when one of her young hens toppled over a few days after it started laying aged 19 weeks.
Jo already had four adult birds, and then bought three more brown Shaver layer chicks aged six weeks.
«At 19 weeks old one of them started laying. Three days later she got sick and died. I read up and thought it could have been Marek’s as she became paralysed and fell over etc.
«The symptoms seem very much like how you describe Marek’s: she lay on her side with a leg out straight to the side and a wing out straight, and she toppled over if put upright. She was like that for three days and then we euthanased her.”
A few weeks later another of the young birds began displaying the same symptoms, falling over when Jo touched her, but this one seemed to recover by the next morning.
Jo’s questions for Sue were:
• Could it have been mild symptoms and she is now recovered?
• Is this something I am doing wrong or is it a disease they have carried and only appears once they are mature?
• Is it likely to spread through them all and can I replace them if they die or will the disease live on in the coop?
«The place I bought the pullets from said that they raised 80 chicks at a time and then sold 20 to pay for the rest.”
NZ Lifestyle Block poultry expert Sue Clarke replies: it is going to depend on whether they are genuine Shaver Browns reared by a professional rearer in isolation from other stock (critical to the Marek’s disease vaccination’s effectiveness) or actually cross-bred birds with Shaver Browns as the mother, or day old Shaver Brown chicks that were bought from the hatchery but reared along with a lot of other birds from different sources.
All true Shaver Brown chicks are vaccinated against Marek’s disease at one day old. While the vaccine isn’t 100% effective, it is more than 98% effective. However, for it to be that effective, the vaccinated chicks must be kept separate from all other poultry (including a broody hen) for at least three weeks after hatching or the vaccine will not work.
Some unscrupulous people on Trade Me sell chicks as Shaver Browns when they are actually crossbreds they have bred themselves from a brown Shaver hen and a spare rooster.
That said, your problem doesn’t exactly sound like Marek’s disease either, with birds just dropping dead. When you say paralysed, did they just sit down (squat) and refuse to move? Marek’s usually results in them lying on one side with a leg stretched out in front of them, and death is not sudden — they usually die of starvation over a week or more. They catch it in the first couple of weeks of life and die often 3-4 months later.
Assuming they were true Shaver Browns then they would have been vaccinated against Marek’s disease on hatching, and had they been reared in isolation from other birds in that crucial first few weeks then the vaccine would have been effective.
However, if there was any transfer of manure, feathers, dust or droppings, even on the bottom of buckets or shoes, or between the older birds and the newly-arrived chicks, the chances of them picking up the virus would have been increased before the vaccine had time to work. However, normally the disease does not kill every bird that catches it.
Lying on one side with the wing out does indicate a neurological problem and that includes Marek’s disease, but I’m just wondering if there is any possibility of them eating something toxic? Nightshade berries, some garden plants like box, and karaka can all cause neurological symptoms like paralysis or convulsions.
The other thing you can do is check the condition of your remaining birds, comparing them to each other (body condition, reaction to being handled, weight). Their weight can tell you a lot about how well a bird is doing. Feel the amount of flesh they have either side of the breast bone: does the keel bone feel pointed or just nicely covered? Is their crop filled to about the size of a small apple?
Other health checks can include:
• Are they are drinking normally?
• Do they have easy access to feed or are they being bullied away?
• How much feed are they eating per day?