RIBOFLAVINE 



to grow at the normal rate/^, is the hair became rough, dry and thin, 

 whilst mottled erythematous eruptions developed on the skin, accom- 

 panied by scaling and ulceration. The lens of the eye became opaque, 

 and cataracts were frequently formed. The animals developed hypo- 

 glycaemia and a normocytic anaemia, and acquired an abnormal gait. 

 At autopsy, changes in the corneal epithelium were observed, together 

 with microscopic haemorrhages in the adrenals, and lipoid degenera- 

 tion of the proximal tubules. 



A similar picture was observed in ribofla vine-deficient dogs, which 

 lost weight, developed dermatitis, conjunctivitis, vascularis at ion and 

 opacity of the cornea, and muscular weakness in the hind quarters.^* 

 Some of the dogs exhibited fatty liver, a condition more generally 

 associated with choline deficiency (see page 590), and tachycardia. 

 They also developed a microcytic, hypochromic anaemia. 



Riboflavine has also been shown to be essential for foxes, ^^ in 

 which the deficiency symptoms resemble those in the dog, and for 

 horses ^^ and monkeys. ^^ Rhesus monkeys on a ribofla vine-deficient 

 diet developed a dermatitis on the face, hands, legs and groin, together 

 with a hypochromic, normocytic anaemia ; in addition, they exhibited 

 muscular inco-ordination. Some of the monkeys also developed fatty 

 livers, and these were not due to inanition. Riboflavine was also 

 shown to be essential for the cow, although adequate amounts are 

 generally provided by bacterial synthesis in the rumen or intestine 

 (see page 183). Symptoms of riboflavine deficiency have, however, 

 been observed in the calf ; ^^ these included hyperaemia of the buccal 

 mucosa, lesions of the cornea, of the mouth along the edges of the 

 lips, and around the navel, loss of appetite, poor growth, scorns, 

 excess salivation and lachrymation, and loss of hair. No vascularisa- 

 tion of the cornea or opacity of the lens was observed. 



Effect in Birds and Fish 



Little has been reported concerning the effect of riboflavine de- 

 ficiency in birds. Riboflavine is known to be necessary for the growth 

 of chickens, ^^ ducklings ^o and turkey poults ; ^^ in its absence, chickens 

 developed " curled-toe paralysis ", whilst young turkeys grew slowly 

 and developed dermatitis. The hatchability of hen eggs appeared to 

 depend on the amount of riboflavine present in the diet, eggs laid by 

 ribofla vine-deficient hens showing a high embryo mortality. 22 



On a riboflavine-deficient diet, young rainbow trout {Salmo 

 gairdnerii irideiis) developed haemorrhagic eyes, livers, nose and 

 operculum, together with an anaemia, which was partially cured by 

 riboflavine, pyridoxine and choline and completely cured by whole 

 liver.2^ 



170 



