Acral mutilation and analgesia in 13 French spaniels

Abstract

Acral mutilation and analgesia (AMA) is reported in 13 French spaniels in Canada. This newly recognized disorder shares striking similarities in clinical features and biopsy findings to the other acral mutilation syndromes or hereditary sensory neuropathies reported in German short-haired pointer dogs, English pointer dogs and English springer spaniels. Clinical signs are first noted between 3.5 and 12 months of age. Affected dogs lick, bite and severely self-mutilate their distal extremities resulting in ulcers with secondary bacterial infection. Auto-amputation of claws, digits and footpads occurs in severe cases. Single or multiple feet can be affected. Affected dogs walked on their severely mutilated feet without evidence of pain, lameness, or ataxia. The majority of the dogs were euthanized within days to months of diagnosis.

A Point Mutation in a lincRNA Upstream of GDNF Is Associated to a Canine Insensitivity to Pain: A Spontaneous Model for Human Sensory Neuropathies

“…One affected dog had never shown self-mutilation marks leading us to consider insensitivity to pain as the first clinical sign for this disease. As described in Paradis et al , no signs of autonomic disturbances were detected by neurological exams [21] and motor abilities and proprioception were normal in all dogs.…”

“…The collection of 173 blood samples with pedigree information allowed us to design a large pedigree and to confirm the monogenic recessive inheritance of the disease in this breed as previously described [21]. Affected dogs presented with severe self-mutilations with insensitivity to pain only in the feet (Fig 1A).…”

“…These dogs showed the “affected” homozygous haplotype, while owners did not detect the insensitivity to pain. This observation reflects the difficulty to diagnose insensitivity to pain in dogs, which contributed to the spreading of this severe disorder in the four related breeds [18,19,21]. This feature led us to consider self-mutilation, probably triggered by small fractures of toes or other injuries [21], as a consequence of the insensitivity to pain.…”

“…Indeed, a large number of inherited motor and sensory neuropathies were reported in the dog species [9,15]. Since 1960’s, symptoms similar to human HSANs were described in four sporting breeds, with the first cases reported in German short-haired Pointers (GP) in 1964 [16,17], then in English Pointers (EP), English Springer Spaniel (ESS) and more recently in French Spaniel (FS) [16,18–21]. For these four breeds, the hallmarks of the disease are loss of pain sensation and feet ulceration.…”

“…The pathologic process thus seems to only affect sensory neurons, primarily their development, followed by progressive postnatal degeneration of unmyelinated fibers [18–20]. In addition, pedigree analyses in these breeds revealed a recessive autosomal mode of inheritance such as in human type II-V HSANs [2,21]. …”