| Air sacs, inflammation | Infectious Catarrh, Ornithosis, Mycoplasmosis | 
| Balance disorders | Salmonellosis, Paramyxovirus infection , Streptococcus infection | 
| Breast, blueish | Oxigen deficit caused by a respiratory disease or by insufficient loft ventilation; feed mixture too high in protein | 
| Breastbone, deformation of the | Rickets = see Annual prevention plan - Young pigeons | 
| Breath, short of | Salmonellosis (organic form), Ornithosis, Mycoplasmosis | 
| Breathing rapid | Aspergillosis | 
| Canker | Trichomoniasis | 
| Condition, general, impaired | Infectious Catarrh, Ornithosis, Trichomoniasis , Young Bird Sickness | 
| Conjunctivitis, bilateral | Infectious Catarrh, Ornithosis, Haemophilus Catarrh | 
| Conjunctivitis, unilateral | Ornithosis | 
| Consumption, complete | Worm Infestation, Tuberculosis | 
| Crop mucosa, swollen | Young Bird Sickness, Trichomoniasis | 
| Crop puffy | Young Bird Sickness | 
| Crop, sour, water-filled | Young Bird Sickness, Candida infection (Trush), crop oclusion by foreign bodies | 
| Debility | Coccidiosis, E.coli infection, Hexamitiasis, Staphylococcus infection | 
| Diarrhoea, bloody | Hexamitiasis, Salmonellosis, E.coli infection, Worm infestation, Coccidiosis (high grade) | 
| Diarrhoea, greenish | Salmonellosis | 
| Diarrhoea, malodorous | Hexamitiasis, Coccidiosis | 
| Diarrhoea, muco-aqueous | Infectious Catarrh, Ornithosis, Hexamitiasis, Salmonellosis, E.coli infection, Coccidiosis (medium grade) | 
| Diarrhoea, rice water-like | Hexamitiasis | 
| Disorder, systemic | E.coli infection, Streptococcus infection | 
| Down moulting, cessation | Infectious Catarrh, Ornithosis, Trichomoniasis | 
| Droppings, formed but in puddles | Paramyxovirus infection | 
| Droppings, mucoid in yellow-green puddles | Young Bird Sickness | 
| Droppings, soft | Coccidial infestation, Worm infestation, Stress | 
| Droppings, sourish-smelling | Trichomoniasis | 
| Droppings, wet | Infectious Catarrh, Ornithosis, Stress, Trichomoniasis , Hexamitiasis, Coccidiosis | 
| Eggs, poor hatchability | Salmonellosis | 
| Eggs, thin shells | Deficit of calcium and/or vitamin D and/or phosphorus | 
| Elbow joint, thickening | Salmonellosis | 
| Emaciation, acute (going light) | E.coli infection, Young Bird Sickness, Coccidiosis | 
| Enteritis, acute | Hexamitiasis, Salmonellosis, E.coli infection, Coccidiosis | 
| Eye discharge, watery | Salmonellosis, E.coli infection, Mycoplasmosis | 
| Eyelid, swollen | Infectious Catarrh, Trichomoniasis | 
| Eyelids, severe swelling | Haemophilus Catarrh | 
| Feather formation, inadequate | Ectoparasites (feather lice), Nutritional deficits | 
| Feather-pulling | Ectoparasites, Deficit of protein and/or calcium, Candida infection (Trush) | 
| Feathers, loss of | Ectoparasites (body mange mites) | 
| Feed intake, increased | Worm Infestation | 
| Feed intake, reduced | Trichomoniasis , Hexamitiasis, Coccidiosis, E.coli infection | 
| Fly, reluctance | Infectious Catarrh, Ornithosis, Trichomoniasis , Young Bird Sickness | 
| Growth retardation, nestlings | Trichomoniasis , Salmonellosis, Candida infection (Trush) | 
| Joint, swollen | Salmonellosis, Gout | 
| Lacrimal sac, bulging of the | Haemophilus Catarrh | 
| Laryngeal deposits, whitish yellow | Infectious Catarrh, Ornithosis, Trichomoniasis | 
| Leg joint, thickening | Salmonellosis, Gout | 
| Leg paralysis | Salmonellosis, Paramyxovirus infection | 
| Listlessness | Infectious Catarrh, Ornithosis, Trichomoniasis , Coccidiosis | 
| Mortality, nestlings | Streptococcus infection, Trichomoniasis | 
| Movements, twisting | Paramyxovirus infection , Salmonellosis | 
| Mucus (beak), stringy | Infectious Catarrh, Ornithosis, Trichomoniasis | 
| Nasal discharge, aqueouse | Infectious Catarrh, Ornithosis, Trichomoniasis | 
| Nasal discharge, mucopurulent | Infectious Catarrh, Ornithosis, Trichomoniasis , Mycoplasmosis | 
| Nasal discharge, yellowish brown | Infectious Catarrh, Ornithosis, Trichomoniasis | 
| Neck, torsion of the | Salmonellosis, Paramyxovirus infection , Streptococcus infection | 
| Nervousness | Ectoparasites | 
| Newcastle Disease | Paramyxovirus infection | 
| Nictitating membrane, inflammation | Haemophilus Catarrh | 
| Nose scratching | Infectious Catarrh, Ornithosis, Trichomoniasis | 
| Nose wattle, grey | Infectious Catarrh, Ornithosis, Trichomoniasis | 
| Overturning | Paramyxovirus infection | 
| Paratyphus | Salmonellosis | 
| Performance, rapid reduction | Young Bird Sickness, Salmonellosis | 
| Performance, reduced | Infectious Catarrh, Trichomoniasis , Coccidiosis | 
| Plumage, puffed-up | Coccidial infestation, Worm infestation | 
| Plumage, rough | Worm infestation, Ectoparasites | 
| Proliferations, scabby | Pigeon Pox | 
| Rattling | Infectious Catarrh, Ornithosis, Mycoplasmosis , Trichomoniasis | 
| Respiration, difficulty in | Infectious Catarrh, Ornithosis, Trichomoniasis , Herpesvirus infection | 
| Respiratory murmurs | Infectious Catarrh, Mycoplasmosis , Trichomoniasis | 
| Restlessness | Ectoparasites | 
| Rickets | see Annual prevention plan - Young pigeons | 
| Salmonella typhi murium | The causative organisms which produce Salmonellosis in pigeons. | 
| Septicaemia | Bacterial infections (E.coli, Streptococcus) | 
| Sneezing | Infectious Catarrh, Ornithosis, Trichomoniasis | 
| Throat mucosa, reddening | Trichomoniasis , Young Bird Sickness, Infectious Catarrh | 
| Throat mucosa, white to grey dots | Salivary stones (Sialoliths) | 
| Throat mucosa, yellow dots | Trichomoniasis | 
| Throat, swelling of the mucosa | Trichomoniasis , Infectious Catarrh | 
| Timidity | Paramyxovirus infection | 
| Tongue, greenish furring | Aspergillosis | 
| Umbilical abscess, squabs | Trichomoniasis | 
| Umbilical infection, squabs | Trichomoniasis | 
| Vitality, reduced | Trichomoniasis , Worm infestation, Ectoparasites | 
| Vomiting | Young Bird Sickness, Worm infestation, Field poisening, Candida infection (Trush) | 
| Walking backwards | Paramyxovirus infection | 
| Water intake, excessive | Paramyxovirus infection , Coccidiosis | 
| Water intake, increased | see Wet Droppings, Hexamitiasis, E.coli infection | 
| Water intake, reduced | Infectious Catarrh | 
| Weakness, nestlings | Infectious Catarrh | 
| Weight, loss of | Hexamitiasis, Salmonellosis, Worm infestation, Trichomoniasis , Coccidiosis | 
| White dots (throat) | Salivary stones (Sialoliths) | 
| Wind pipe (trachea), inflammation of | Infectious Catarrh, Ornithosis, Trichomoniasis | 
| Wing paralysis | Salmonellosis | 
| Yellow dots (throat) | Trichomoniasis |