‘Despite all that has been urged as to the importance of dealing at the earliest possible moment with any tendency to rickets (rachitis), there appear still to be a large number of people who wait until it is too late to deal effectively with such cases. It cannot be too clearly emphasised that rickets must be looked for in puppies before the legs begin to bend and the knuckles to show weakness. Some years ago, Dr. Mellanby, whose researches in this matter have been of untold benefit to dog-lovers, published a description of the early symptoms of this evil complaint, in the course of which he pointed out that the appearance of rickets in a dog is comparable with that of a rickety child. Two photos. [sic] were given to illustrate the writer’s description – those of a little child and of a Retriever puppy, side by side. Each photo. showed clearly the swollen ends of the bones and the enlargements at the cartilage junctions of the ribs. These vary in different animals, but a large, quickly-growing puppy nearly always has more prominent junctions in this position even in a normal state. In other cases, the swelling may be more developed on the inside of the chest, and can only be appreciated after the death, although the animal is really rachitic. In very bad cases the cartilage junctions may be drawn in, giving the chest a very deformed appearance, and the abdomen ins usually prominent in rachitic dogs, and a furrow, corresponding with that often visible in a child, is sometimes seen. As to the signs of on-coming rachitis, Dr. Mellanby pointed out that, as with children, one of the first signs of rickets is a tendency to become lethargic. “The intense interest of the normal, healthy puppy in all its surroundings disappears to a large extent, and there is great diminution in its small movements. Often the animal loses the desire to bark, and in this respect resembles a ‘good’ child with rickets. The muscles are flabby, The muscles are flabby, and are unable to contract to allow the animal to run quickly. Long before the bone changes are sufficiently severe to be an impediment, the animal may be incapable of running at any speed. Sometimes the effort to run is lamentable, although the appearance of the puppy would not lead anyone to suspect this disability.’

Relevant passage from Mellanby:

'The appearance of rickets in a dog (Fig. 2) is comparable to that of a rachitic child (Fig. 1). The swollen epiphyseal ends of the bones are unmistakable, more particularly at the growing ends of the radius and ulna. This swelling can be well seen in Fig. 2, which is a photograph of a retriever with rickets. The costochondral junctions also enlarge and, if the dog has a smooth coat, its rickety rosary can often be easily seen. In this work, however, but little reliance has been placed on the swelling of the costochondral junctions, for it has been found to be so variable from animal to animal. A large quickly growing puppy nearly always has more prominent junctions in this position even in a normal state. In other cases, the swelling maybe more developed on the inside of the chest, and can only be appreciated after death, although the animal is really rachitic. In very bad cases the costochondral junctions may be drawn in, giving the chest a very deformed appearance. Again, the abdomen is usually prominent in rachitic dogs, and a sulcus corresponding with the well-known Harrison's sulcus of a child is sometimes seen.

As in children, the animal often becomes more lethargic and listless as the rachitic changes develop. The intense interest of the normal healthy puppy in all its surroundings disappears to a large extent, and there is great diminution in its small movements. Often the animal loses its desire to bark, and in this respect resembles a ' good ' child with rickets. The muscles are flabby and are unable to contract to allow the animal to run quickly. Long before the bone changes are sufficiently severe to be an impediment the animal may be incapable of running at any speed. Sometimes the effort to run is lamentable, although the appearance of the puppy would not lead any one to suspect this disability. The power to run has often been used by me to test the relative development of the disease in various members of an experimental series, and, although the method is crude, it is sometimes possible to state with reasonable accuracy how the experiment is proceeding.' (8-9)