Vitamin B deficiency

B vitamins are important for the nerves, muscles, skin, feathers and growth of young birds. The body does not store them in large amounts, so a deficiency can develop relatively quickly if the food is poor or if the bird cannot make use of what it eats. The most important are a lack of thiamine (B1), which affects the nervous system, and a lack of riboflavin (B2), which is most often seen in chicks.

The most common causes:

• spoiled, mouldy or long-stored food – B vitamins break down quickly with heat, moisture and light
• an all-fish diet – raw fish, and especially fish that has been frozen for a long time, contains the enzyme thiaminase, which breaks down vitamin B1; this is a common problem in fish-eating birds (herons, gulls, cormorants) being rehabilitated in human care
• long-term use of antibiotics, which disrupt the gut flora – and the gut flora itself produces some of the B vitamins
• prolonged diarrhoea and digestive diseases that cause poor absorption of vitamins
• a monotonous diet, e.g. only bread or only one type of seed
• in poultry: poorly formulated or over-stored feed for chicks and laying hens

Thiamine (B1) deficiency – neurological signs:

• loss of appetite, weakness and weight loss
• unsteady gait, loss of balance, falling over
• trembling, muscle spasms and, in more severe cases, seizures
• throwing the head back so that the bird is “stargazing”

Riboflavin (B2) deficiency – in chicks and young birds:

• toes curled inwards (so-called “curled toe paralysis”), the chick walks on its hocks or leans on its wings
• poor growth, weak legs, diarrhoea

Deficiency of other B vitamins (e.g. biotin, pantothenic acid, niacin):

• scabs and sores at the corners of the beak, around the eyes and on the soles of the feet
• peeling and reddened skin, scratching
• untidy, poorly developed plumage and increased feather loss

General signs are lethargy, loss of interest in the surroundings and sitting fluffed up. Because poisoning and infectious diseases can cause similar signs, the diagnosis should always be confirmed by a vet.

• the bird has spasms, is trembling or throws its head back
• it cannot stand, falls off the perch or topples over
• it has not eaten or drunk for more than a day
• chicks suddenly cannot walk or have curled toes
• the bird has diarrhoea and is visibly weakening

Thiamine deficiency can develop quickly and be life-threatening, but birds often respond very well to timely treatment.

The vet makes the diagnosis based on an examination, information about the diet and ruling out other causes such as poisoning, head injuries or infectious diseases. It is important to bring information about the food: what the bird eats, where the food comes from and how old it is.

Treatment:

• the vet prescribes B vitamins, often first by injection and then in the food
• treating the cause – diarrhoea, infection or a poor diet
• supportive care: fluids, warmth and feeding as instructed by the vet

With thiamine deficiency, improvement is often seen within a few hours to a day. In chicks with riboflavin deficiency, nerve damage can be permanent if treatment is started late.

• Put the bird in a cardboard box with air holes, in a warm, quiet, dimly lit place.
• Put a soft towel on the bottom so that it does not injure itself if it falls or has spasms. Do not put in high perches.
• Keep it apart from other birds.
• Offer food and water in shallow dishes, but do not force-feed it and do not pour water into its beak – a bird with neurological signs can easily inhale liquid.
• Throw away any suspect, mouldy or old food.
• Write down what the bird has eaten over the last few weeks, whether it has received any medication and when the first signs appeared. This will make the diagnosis easier for the vet.

For chicks with an unsteady gait, make sure they can easily reach food and water and are not trampled by other birds.

If it is a wild bird, hand it over to a wildlife rescue centre or a vet as soon as possible. Wild birds are protected in Croatia and may not be kept at home for long periods.

• Buy food in smaller quantities and store it in a dry, cool, dark place.
• Use good-quality pellets or ready-made mixes formulated for the bird species, along with fresh vegetables.
• Give chicks and laying hens feed formulated for their age.
• Do not feed fish-eating birds in rehabilitation only thawed fish without expert advice – supplements are decided on by the vet or the rescue centre.
• After antibiotic treatment, ask the vet whether the bird needs nutritional support.

Vitamin B deficiency is most often the result of spoiled or monotonous food, an all-fish diet or long-term antibiotic treatment. Neurological signs such as spasms and loss of balance require an urgent examination, and timely treatment often helps quickly. Fresh, varied and properly stored food is the best protection.