Tear Production, Intraocular Pressure, Ultrasound Biometric Features and Conjunctival Flora Identification in Clinically Normal Eyes of Two Italian Breeds of Chicken (Gallus gallus domesticus)

Abstract

Given the abundance of chickens in Italy, it is important for veterinarians to know the normal state of chickens’ eyes in order to identify any ophthalmic pathological changes. The aim of this study was to determine the normal values of select ocular parameters and to evaluate conjunctival microflora in two Italian chicken breeds. Sixty-six healthy chickens underwent a complete ophthalmic examination, which included a phenol red thread test (PRTT) for the evaluation of tear production and the assessment of intraocular pressure by rebound tonometry. B-mode ultrasound biometric measurements and conjunctival microflora identification were also performed in twenty-seven chickens. Mean PRTT was 23.77 ± 2.99 mm/15 s in the Livorno breed and 19.95 ± 2.81 mm/15 s in the Siciliana breed. Mean intraocular pressure was 14.3 ± 1.17 mmHg in the Livorno breed and 14.06 ± 1.15 mmHg in the Siciliana breed. Reference ranges for morphometric parameters were reported in the two breeds. Twenty-three chickens (85.18%) were bacteriologically positive. Chlamydia spp. antigen was detected in 14.81% of chickens. No positive cultures were obtained for fungi. Normal reference range values for selected ophthalmic parameters were obtained in clinically healthy chickens, which could facilitate accurate diagnosis and better management of ophthalmic diseases in these animals.

Effect of light intensity on the tear production, central corneal thickness, and intraocular pressure in broiler chickens

“…To reduce undesired fluctuation in IOP measures, animals were held upright during measurements, male, same‐age animals were enrolled, and measurements were performed by the same investigator. The mean intraocular pressure values obtained from the present study were different from previous studies 16,31,32 . The explanation for the observed variation could be due to the age, sex, and measurement times of the enrolled animals.…”

“…Ophthalmologic examination of avian species is standard procedure in veterinary ophthalmology. This examination is required in birds to assess the condition of the eyes, which can also be used as an indicator of the animal's overall health 16 . Light is an environmental factor that influences vision and eye structures.…”

“…This examination is required in birds to assess the condition of the eyes, which can also be used as an indicator of the animal's overall health. 16 Light is an environmental factor that influences vision and eye structures. The rate of eye growth and development can be controlled by exposing the chicks to light soon after hatching.…”

“…The mean intraocular pressure values obtained from the present study were different from previous studies. 16,31,32 The explanation for the observed variation could be due to the age, sex, and measurement times of the enrolled animals. According to Nickla and colleagues, chickens' intraocular pressure and eye growth are influenced by changes in light intensity.…”

Isolation of Corynebacterium spp. and Arcanobacterium spp. from a chicken with keratoconjunctivitis

“…gibi) opportunistik patojenler; memeli ve kanatlı hayvanlarda deri, eklem ve iç organlar gibi çeşitli organlarda suppuratif enfeksiyonlara da sebep olmaktadır (13). Yapılan çalışmalarda, Korineform grubu olarak tanımlanan Corynebacterium ve Arcanobacterium cinsi bakterilerin kanatlılarda pnömoni, endokarditis, septik artiritis (13), infeksiyöz konjunktivitis (14,15) ve miks enfeksiyonlara neden olduğu (16); penguen (14,17), leylek (18), kartal (19) ötücü kuşlar (20), ağaçkakan (21), kaz (22), papağan (7), turna (10), kanarya (16), pelikan (23) ve tavuk (12) gibi pek çok yabani ve evcil kanatlı hayvan türünden izole edildiği bildirilmektedir. Çalışmamızda, Korineform bakterilerin göz, akciğer ve kalpten saf olarak izole edilmesi araştırıcıların a b a b bulgularını desteklemektedir.…”