Birds are a special class of animals whose representatives conquered the sky. And for this, mother nature rewarded them with a number of adaptations in the external and internal structure. The streamlined body shape, feathers, wings, lack of teeth, hollow bones, keel, double breathing, fast metabolism and the presence of goiter helped them in this.
What is avian goiter?
Many people associate the word "goiter" with a disease, but the goiter in a bird is a special organ that serves as a reservoir for food. It is an enlarged part of the esophagus, dividing it into two parts - upper and lower. Goiter in a bird is a protrusion of the stomach, which is clearly visible to the naked eye. It is lined with a mucous membrane with glands that secrete secretions. That is why, for some, the initial stage of digestion begins in this sac-like extension. In birds of the Pigeon and Pheasant families, striated muscles are attached to the goiter, which, when contracted, help food move into the glandular stomach.
According to its origin, goiter in birds can be divided into 2groups:
- The wall of the esophagus protrudes and forms a spindle-like reservoir. For example, hummingbirds, birds of prey.
- Short and limited at the top and bottom. For example, in parrots, chickens.
Now you have an idea what a goiter is in a bird. Where is this body located? In most birds, it is located on the right side of the neck above the collarbone.
Goiter is clearly visible in fed chicks. When palpated, an empty, he althy goiter is soft, and a full one is hard.
Do all birds have a goiter?
Goiter is best developed in birds that feed on grain. It is in this part of the digestive system that the complex biochemical processes of digestion begin. The food first swells, becomes soft and under the influence of its own enzymes and enzymes of saliva, mucus and symbiotic bacteria begins to decompose into its components. So, in this part of the esophagus, complex organic substances - proteins, fats and carbohydrates - undergo primary processing, breaking down into their components. This is typical for representatives of the order Chicken, Parrots.
For birds, which are characterized by a long period of starvation, the goiter serves as a food storage. For predators, this organ is, in fact, a garbage bag, since undigested food particles - bones, feathers, chitin, wool - get into it. After a certain time, the bird regurgitates them in the form of pellets - compressed, undigested food.
But there are also such birds, for example, ostriches, penguins, which have no goiter at all. Unites these birds and what they refer toflightless. What the ostrich lacks a goiter, it makes up for in its long neck and the fact that it swallows rocks to help it digest tough food.
Gastroliths and function
But not only ostriches swallow stones, so, for example, grouse do it. Gastroliths are stones that help digest tough plant foods. Birds find them and swallow them along with food. But in some birds, these solid particles go down into the stomach, into the muscular part, and remain there. That is why birds that are kept at home are recommended to put sand, small pebbles in a cage. Gastroliths function as teeth that modern birds lack.
Bird's milk - myth or reality?
According to legend, the birds of paradise fed their chicks with milk. And a person who tasted such milk became immune to diseases. Does this bird's milk exist?
During the incubation of chicks, pigeons undergo changes in the structure of the goiter. So, epithelial cells degenerate into fat. Then they are rejected and together with the mucus form a white cheesy liquid. This is bird or goiter milk, with which birds feed their offspring for a month in the wild and about two weeks in captivity. Such food, fatty and high-calorie, contributes to the rapid development of chicks. Goiter milk is produced by both females and males.
Flamingos also feed their offspring with a similar product, but their bird's milk contains an addition - semi-digested food.
Goiter in a bird: what else is it for?
In pigeons, the goiter is also a resonator, which is necessary for cooing, attracting females. It is he who is visible, he swells during courtship.
Desert birds (grouse) in this bag bring water to their offspring. It is one of the adaptations for survival in hot and dry climates.
The pelicans have the largest goiter, it is in it that the birds carry fish - for themselves and their chicks.
What is the risk of goiter damage
Goiter in a bird (protrusion of the stomach) is very important. Especially for those who eat plant foods and grains. If it is damaged, animals may die. Damage to the "pouch" for food is divided into 2 groups: external (external) and internal.
External damage most often occurs as a result of trauma: hitting a hard surface during flight; fight with a rival for a female, territory, food; bites of predators (cats). With such an injury, the integrity of the skin is violated, so the food falls out. Such a wound does not heal completely and the bird, while maintaining its appetite, dies of hunger.
Internal damage can occur due to crop overflow with swollen food or injury with a sharp object. That is why it is not recommended to feed wild birds with fresh brown bread. In this case, the goiter ruptures, and food from it gets under the skin. Feed can be felt or even seen in the throat area.
With such injuries, the birds can be saved if you contact a veterinarian in time, who will perform the operation and suture.
Goiter inflammation
One of the dangerous diseases that occurs in birds is inflammation of the goiter. Due to the ingestion of pathogenic bacteria or fungi, the normal functioning of the goiter glands is disrupted. They begin to produce a large amount of mucus. More often, this disease attacks pets that eat ready-made monotonous grain mixtures due to the lack of vitamin A in them. If the problem is not identified and treated in time, the infection spreads further, affecting the stomach and intestines. Birds may develop diarrhea. Signs of goiter inflammation are:
- grey slime;
- frequent swallowing movements;
- regurgitation of food;
- decrease in temperature;
- lack of appetite;
- intestinal upset.
Treatment is prescribed by a physician and includes antibiotic therapy and supplementation with vitamin A.
Goiter candidiasis
This is an inflammation of the goiter caused by a yeast-like fungus of the genus Candida. With this disease, a liquid with an unpleasant sour-milk odor accumulates in the sac. The animal does not eat, loses weight, the feather cover is stained with mucus. Can cope with this ailment: goiter massage, antibiotics and probiotics prescribed by a veterinarian.
Sagging goiter
This pathology occurs due to stretching of the goiter muscles. It looks like a bag hanging over the chest, while the muscle fibers lose their elasticity. After eating, this organ becomes very visible.
This disease canbe chronic if the bird often has inflammation of the goiter or due to irregular nutrition. Being very hungry, the bird eats a lot and stuffs its bag, the muscle fibers stretch and lose elasticity. It can even develop complete immobility. In a drooping goiter, food remains longer than usual, so the fermentation process begins and the gas formation that accompanies it. All this can lead to damage to this organ and its rupture. Unfortunately, if a bird has this disease, it is irreversible and incurable.
To prevent this from happening to birds kept at home, they should always have food in the feeder. The bird will get used to it and will not "clog" the goiter.
Yellow goiter or trichomoniasis
This disease is caused by unicellular parasites of Trichomonas. These organisms settle in the pharynx and goiter, the products of their vital activity is mucus. It travels down into the esophagus and can enter the windpipe, causing breathing problems. When the parasite enters the bloodstream, it infects the internal organs. By external signs, you can identify such birds: they swallow hard, fluff their feathers, do not eat, and eventually die.
This disease is transmissible, so patients need to be fenced off from other birds. The cage, the feeder are disinfected, the bedding is changed, prophylaxis is carried out for contact individuals, even if they do not show signs of the disease. Since Trichomonas can also infect humans, care must be taken.
Goiter in a bird (photo where you can see itprotrusion, you see in the article) - an integral part of the esophagus, which is necessary for:
- food accumulation;
- digestion;
- moving food into the stomach;
- nursing offspring.
Also goiter can be considered one of the important adaptations of birds for flight, as they need a lot of energy. And her birds receive additionally when splitting organic substances in the goiter. The proof of this can be considered the fact that flightless birds (ostrich and penguin) are devoid of goiter.
The he alth of the goiter sac in birds must be monitored constantly, because it is part of the digestive system. Minor, not to mention pathological, changes lead, as a rule, to the death of the bird.
