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Paresis and paralysis of nerves. There is insufficient data on studies of the function of the peripheral central nervous system in wild and ornamental birds. The clinical symptoms of most diseases are nonspecific. Only with histological examinations, it is possible to accurately determine the lesions of the peripheral nervous system. Spinal cord diseases are accompanied by progressive paralysis of the legs.

Pathology and histological changes in the brain. When examining the brain, hemorrhages are found in the skin and nasal cavity. Sometimes focal forms of changes in the brain capsule are also formed. In addition, with an autopsy, hemorrhages are detected in the small and large brain in the form of foci. Histologically, purulent encephalitis, hemorrhages in the cerebellum, tumors, fungal hyphae and bacterial pathogens are histologically determined.

Differential diagnosis. Pituitary tumors, diseases of the inner ear.

Etiology. Injuries from a blow to the glass of the window, ceiling, etc. At the same time, birds have a concussion, hemorrhage.

Symptoms Due to damage to the central nervous system, parrots are dominated by clonic, clonic-tonic convulsions. The bird rotates rhythmically with its head to the left and right sides. She is not able to be perched and take food. At every sound, it makes a sound. The pupil of the eye is often narrowed. With bruises of the central nervous system, parrots periodically come in coma, the bird suddenly falls from a perch and lies on the floor with its eyes open for about half an hour. Brain lesions are also possible with opisthotonus, torticolis, while the bird lies in paralysis with widely spaced limbs, toes are compressed.

The disease is especially severe during an overdose of narcotic drugs, intoxication caused by herbicides, insecticides and medications.

Often the causes of the disease are infectious diseases: salmonellosis, streptococcosis, tuberculosis, Newcastle disease, psittacosis, polio.

The lack of a complex of vitamin B, especially B, and E, tumors, circulatory disorders, squeezing veins of the jagularis with an enlarged thyroid gland can lead to stagnation of blood in the brain and a severe convulsive state.

Treatment. For all disorders of the central nervous system, accompanied by convulsions, antibiotics, vitamins, cortisones, glucose and calcium are used. Often, after a visible cure, relapse occurs.

Mental disorders, hysteria. Parrots have a great predisposition to this group of diseases. They can occur during trapping, transportation, cell rearrangement, fright, at the sight of a new environment. In gray parrots, mental disorders are especially often manifested during the plumage.

Clinical signs are accompanied by a continuous cry, sometimes the bird makes abnormal sounds.

Prevention and therapy. Providing optimal content (preferably in a large cage), calm environment, pair breeding.

Neurological disorders in birds

Hello bird lovers!
Help! Yesterday I picked up a daw on the street. The bird is clearly sick. It can’t take off, although it moves its wings. He doesn’t eat on his own. Although not exhausted. When moving, it seems to “stumble”, falls, but gets up. Paws can not make grasping movements. Paralysis of the pharynx and tongue.
A few months ago I had a rook with similar symptoms. But a week later, the bird died with the phenomena of paralysis of the legs and wings.
I did not find any visible injuries on the jackdaw. Feces and urine leave. I feed by force.
I injected Ringer's solution, glucose, essenteale, fosprenil intravenously (I have experience using drugs in corvids).
Intramuscularly - ampicillin (according to my observations, corvidae tolerate well), and thiamine. Today I did not notice any improvement.
Tell me why this condition in a bird can be related.
M. b helminthic invasion (there is literature data), infection with central nervous system damage (only which? How to treat?), Poisoning? What else? Maybe someone came across a similar one? Thank you in advance for your reply!

Bird Class

Birds are the most diverse and numerous group of vertebrates. In nature, they play an important role, being part of the food chain. The birds eat insects, and they, in turn, feed on mammals. In addition, they are important for human activities - they are bred for meat, eggs, feathers, fat.

More than 10,500 modern bird species and about 20,300 subspecies are known. 789 species are common in Russia. The main feature of this class is the presence of wings and plumage, which covers the body of animals. The main mode of movement for many species is to fly, although some wings do not perform this function.

The ability to fly was reflected in the external and internal attributes that the Bird class possesses. The nervous system, digestive and respiratory systems differ in structure from the organs of other animals. For example, they have two types of breathing, enhanced metabolism and gas exchange.

Features of the structure of the nervous system of birds

Typically, the nervous system consists of nerves located in different parts of the body, as well as various parts of the brain. All these structures interact closely with each other. They represent a single mechanism that regulates the work of all body systems and is responsible for the reaction to environmental stimuli.

The organs of the nervous system of birds make up the central nervous system (spinal cord and brain) and peripheral parts (nerve endings, nerves of the spinal cord and brain). The structure of the brain has common features with vertebrates, although some features significantly distinguish it.

The structure of the nervous system and sensory organs of birds is directly related to their vital functions. Birds have a good sense of balance and coordination of movements necessary for them to fly. Thanks to this, they perfectly maneuver in the air.

Most species eat mobile food. Whether it be insects, fish, rodents or reptiles, it is important for birds to navigate well in space and have excellent vision, hearing and quick reaction. The organs responsible for these functions are best developed in birds.

Brain

A hundred years ago, it was believed that birds are not capable of complex actions. Ludwig Edinger put forward the theory that their brain is made up of subcortical nodes that are responsible for instincts and simple functions. Later it turned out that the nervous system of birds is very similar to the human.

The largest part of the brain is the forebrain. It consists of two hemispheres with a smooth surface, filled with subcortical nuclei. They are responsible for spatial orientation, behavior, mating, eating. The hemispheres are connected to a sufficiently large cerebellum, which regulates the coordination of movements.

The medulla oblongata is part of the brain stem. This department is responsible for functions important for the life of the bird: blood circulation, respiration, digestion, etc. The midbrain is well developed, it consists of two tubercles that are responsible for processing auditory and visual information.

Birds have a large pituitary gland, but their pineal gland and diencephalon are underdeveloped. The total number of cranial nerves is 12 pairs, but the eleventh pair is weakly separated from the tenth.

Spinal cord

The central nervous system of birds also includes the spinal cord. It is divided conditionally from the brain. Inside it is a cavity or central channel. The spinal cord is protected from above by three membranes - soft, arachnoid and hard, and cerebrospinal fluid separates them from the central canal.

In the lumbar and brachial regions, the spinal cord of birds has small thickenings. Here, nerves diverge from him, which connect to the front and rear limbs. Thus, the pelvic and brachial plexus is formed.

In the region of the lower back, the central channel has an expanded rhombic fossa, which is covered by the membrane of connective tissue. The branches of the lumbar and brachial plexuses of the spinal cord are responsible for the work of the muscles of the corresponding limbs.

Difference from reptiles

Both classes belong to higher vertebrates, and birds are closest to reptiles in the structure of the nervous system. However, significant differences are observed between them. How is the nervous system of birds different from the nervous system of reptiles?

Birds and reptiles have the same parts of the brain. The difference is observed in the size of these departments, which is associated with a different way of life of animals. Reptiles have 12 pairs of nerves extending from the brain, and their spinal cord has thickenings in the lumbar and brachial regions.

The nervous system of birds differs primarily in the size of the brain, which significantly exceeds the brain of reptiles. Its mass is 0.05-0.09% (of body weight) in ratites and 0.2-8% in flying representatives of birds. The cortex of the forebrain hemispheres in birds is a relic or vestige. In reptiles, it is better developed due to the occurrence of sexual smell.

In birds, there is no sexual sense of smell, and the sense of smell itself is extremely poorly developed, with the exception of species that eat meat. In both classes, a significant proportion of the forebrain is formed by striped bodies at its bottom. They are responsible for analyzing and responding to incoming information.

Sensory organs

The least developed feelings in birds are the sense of smell and taste. Most species can hardly distinguish smells, with the exception of predators, for example, American vultures. The taste of food is determined by taste buds located at the base of the tongue and on the palate. There is no special need for them, since food is basically just swallowed.

Tactile receptors are located in different places. They are represented by the bodies of Grandi, Herbst or Merkel. In some species, they are located near the bases of large feathers on the skin, as well as on the beak in the wax. For this, owls have special feathers on their beaks, sandpipers and ducks have receptors in the jaw apparatus, and parrots have their tongues.

Birds are best developed for vision and hearing. Their ears are covered with feathers and devoid of the auricle. They consist of the inner, middle and rudiments of the outer ear. In sound sensitivity, they are superior to many mammals. Owls, salagans, guaharos have the ability to echolocation. The developed labyrinth of the inner ear provides birds with an excellent sense of balance.

Birds have acute monocular vision (in sovinocular). Some are able to see at a distance of one kilometer. The eyes are flattened and have a wide view. They are inactive, so birds often have to turn their heads. In some species, the angle of view is 360 degrees. The retina reacts even to ultraviolet light, and a flexible lens allows you to see even under water.

Intelligence

Over their long history, birds have shown the ability to cope with difficult situations, make calculations and be creative. They are able to memorize and reproduce various sounds and phrases of human speech.

For their needs, birds often use objects as tools. For example, with small elastic sticks, they can get insects in the bark of trees. The wood finch uses spines of cacti for these purposes, and some have learned how to make tools on their own.

Birds adapt pretty quickly to their environment. For example, tits learned to peck holes in caps of milk bottles, and sometimes even remove them. Species that feed on fish sometimes throw a false bait into a pond to attract prey.

Crows repeatedly throw a nut on the ground until it breaks. Eagles for the same purpose raise high into the air a turtle, which would seem to be securely hidden in a shell. Some birds, to break the shell of prey, throw stones at it.

Skin form of Marek's disease

It is found only in broiler chickens, since vaccination against Marek's disease is a prerequisite for the cultivation of egg or meat-egg cross chickens and is strictly carried out regardless of the size of the poultry farm. Moreover, in broilers older than one month of age, damage to the nervous system is very rare, and only in the initial stage of the disease. The presence of tumors on the internal organs and muscles is not recorded, they simply do not have time to develop, since by this time the chickens are sent for slaughter.

For the manifestation of damage to the nervous system itself, a prerequisite is raising a bird for more than 50-60 days (although exceptions are possible), which can often be found in small farms. By this age, tumors appear in the internal organs and muscles, the feather follicles are affected (the feather follicle epithelium is the only place where the virus is completely replicated), and growths form on the skin. Affected feather follicles (both single and multiple) increase in size due to the proliferation process occurring in them (8), while the skin of birds visually resembles fish scales. This pathognomonic sign can be found when a bird enters the slaughterhouse.


Fig. 12. The skin of birds visually resembles fish scales

In the classic course, Marek’s disease takes a nervous and / or ocular form.

Nerve form of Marek's disease

It occurs after the causative agent of this disease breaks the blood-brain barrier (9) and affects the brain and spinal cord with nerve trunks, including the sciatic and vagus nerves and plexuses (brachial, celiac, lumbosacral).

Due to the aforementioned stroma of nerves, it grows with connective tissue (10). This leads to a diffuse or focal thickening (11) of the nerves, to their loss of transverse striation, to a discoloration (from gray to grayish-yellow) and, as a result, to a violation of the trophism of the nervous tissue. The latter entails a disorder of the entire physiological system, metabolic processes, mechanisms of regulation and adaptation, depletion and, ultimately, causes the death of birds.

Depending on the damage to certain nerves, lameness, unnatural gait, paresis or paralysis of the limbs (12), tail, neck (13) can be observed.


Fig. 13. The presence of a tumor on the vagus nerve - vagus

SERGEEV writes:

Can I clarify the form and dosage?

In my opinion, helminthic invasion in the brain, although possible, is unlikely, if it is a bird, it is doomed, perhaps that is why it makes no sense to consider this possibility.
Infection - in theory, it is possible that the Newcastle virus can be affected, for example, pigeons have similar symptoms (although I didn’t see paralysis of the tongue and pharyngeal muscles), it was just phosprenic in practice, salmonellosis is not excluded - the nervous form gives it similar symptoms, again - ampicillin is already giving. In principle, other infections can produce something similar, like a variant of intoxication. It is possible to exclude (or confirm) infections only in one way - analysis, at least by litter.
Poisoning is also possible, it is difficult here. It makes little sense to use a sorbent - everything has been absorbed from the digestive tract (if it was through the gastrointestinal tract), which could, but you can also try - enterosgel, squeeze out a little, about 0.5 cm, and put into the beak between feedings. For some toxins, methylene blue is the antidote - it must be administered iv in, but whether it helps, and does it make sense not to inject iv (this is extremely difficult in birds), but im or n / a.

We are all crazy here. You're crazy, I'm crazy (L.Carroll, "Alice in Wonderland")

Nothing personal. But read to all consultants.

Ocular form of Marek's disease

Possible changes in the shape and size of the pupil, color (14) of the iris ("gray-eyed" or iridocyclitis associated with the disorganization of the pigment and its partial redistribution).
Pupil deformity occurs due to swelling of the iris tissue, causing it to fuse with the anterior surface of the lens, and, as a consequence, the contraction and deformation of the pupil. The pupil becomes stellate, polygonal, pear-shaped or slit-like, gradually decreases to the size of poppy seeds, and often quite overgrows. As a result of this, partial or complete blindness develops in affected birds.

Changing the color of the iris begins with the appearance around the pupil of whitish-gray spots or concentric areas of various shapes and sizes that merge with each other and spread throughout the iris, resulting in its depigmentation - "gray-eyed" (Fig. 14.15).


Fig. 14. Pupillary deformity and iris depigmentation


Fig. 15. Pupil deformity

Fourth link - the virus enters the environment with secretions from the respiratory and digestive organs, as well as with the scaly (desquamated) feather follicle epithelium (feather follicle epithelial cells are the site of mass production of infectious viruses).

Fifth link - establishing diagnosis. The diagnosis is based on the results of clinical, epizootological, pathological, anatomical, virological, histological and serological studies of blood serum for the presence of antibodies to the causative agent of this disease.
Affected internal organs, skin, muscles and blood serum are sent for virological and serological studies.
Affected eyes, internal organs, skin, muscles and peripheral nerves (brachial, femoral) are subject to histological and cytological examination.

Sixth link - treatment. No treatment methods have been developed to date.

Seventh link - preventive actions. A set of preventive measures is based on compliance with established veterinary and sanitary rules aimed at preventing the introduction of an infectious agent into the territory of poultry enterprises, in combination with specific prophylaxis of the disease through the use of vaccines (see table).
For specific prophylaxis, live (mass use), vector (Marek’s disease - Newcastle disease, Marek’s disease - Gamboro disease), inactivated and recombinant vaccines (are not widely used in industrial poultry farming) are used.

Vaccines for immunizing poultry head against Marek's disease

LivingInactivatedRecombinant
Strain FC -126Not usedMarek's disease, PB 1 strain + Newcastle disease
Strain Rispens CVI-988 + strain FC-126Marek's disease, strain FC-126 + ILT (infectious laryngotracheitis)
Strain Rispens CVI-988Marek's disease, strain vHVT013-69 + Gamboro disease, strain Faragher 52/70
Strain SB-1 + strain FS-126Marek's disease, strain FC-126 + Newcastle disease, strain D-26

Notes:

  1. The main component of dust is dandruff, which is an exfoliated skin cell and feather follicles.
  2. Both with blood flow, and with the release of leukocytes (lymphocytes) into the surrounding tissues and epithelial cells with independent movement.
  3. Due to the persistence of mainly T-lymphocytes and, to a lesser extent, B-cells.
  4. Birds become lifelong virus carriers and virus isolators.
  5. After stimulation (activation) by an antigen, T-lymphocytes are transformed into large, actively dividing cells - transformed T-lymphocytes.
  6. Nerves, including the visual ones, are infiltrated by lymphocytes, plasmocytes, and histiocytes.
  7. Lymphoid tumors of visceral organs and skin consist mainly of transformed T-lymphocytes.
  8. Proliferation is a type of inflammation in which the proliferation of new tissue elements predominates.
  9. The physiological barrier between the circulatory and central nervous system.
  10. Due to the penetration of infected lymphocytes into the stroma of nerves and their accumulation there.
  11. Sometimes with the presence of single or multiple nodules of various sizes, most often there is a unilateral thickening of the femoral nerves.
  12. Sagging wings, bending inward of the toes of the affected limb, with bilateral paresis or paralysis of the limbs, chickens can take a penguin pose or a twine pose. The twine posture is characterized by the retraction of one leg forward and the other back (or to the side).
  13. Lowering the head, bending the neck.
  14. Reddish, gray, grayish with patches of tan, sometimes green.


Author:
D.S. Khlyp, Independent Veterinary Consultant in Poultry Production, Prokhladny, Kabardino-Balkarian Republic

Conclusion

Birds have a more developed nervous system compared to reptiles. The brain is much larger in size, which allows you to perform more complex tasks, develop complex forms of behavior and adapt to different situations.

The nervous system of birds consists of the brain, spinal cord and twelve pairs of nerves. The front and middle parts of the brain, as well as the cerebellum, are well developed, which is primarily associated with the ability of birds to fly.

They have excellent hearing and vision. They distinguish not only the colors that are familiar to us, but also ultraviolet, and some have the ability to echolocation. Taste and smell are extremely poorly developed. The location of the tactile receptors is located in different parts of the body, depending on the species.

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