Quote from Dr. Garrett Smith on November 12, 2018, 10:16 pm

Nutrition and bone disease in the dog and cat.

https://www.ncbi.nlm.nih.gov/pubmed/775753
"The most commonly encountered nutritional bone disease is nutritional secondary hyperparathyroidism. This is primarily of importance in the dog but is occasionally seen in kittens, particularly of the Siamese breed, and is often associated with the feeding of owner compiled, meat-rich diets. Classic rickets is now a rare clinical entity. Hypertrophic osteodystrophy is regularly seen in the larger breeds of dog and the aetiology remains obscure. Hypervitaminosis A associated with liver-rich diets is often encountered in the cat. Hypovitaminosis A has been described but its true clinical significance is unknown."

Poison/"Vitamin A" toxicity in cats from liver-rich diets is COMMON, yet Poison/"Vitamin A" deficiency is actually UNKNOWN.  I can describe a dream I had, it doesn't mean it is an actual real thing, and if something hasn't ever actually occurred to this point previously, why would we assume it exists now?

Hypervitaminosis A-induced hepatic fibrosis in a cat.

https://www.ncbi.nlm.nih.gov/pubmed/24563496
"CLINICAL SUMMARY: We report the first case of hepatic stellate cell lipidosis and hepatic fibrosis in a domestic cat that had been fed a diet based on raw beef liver. Radiographic examination revealed exostoses and ankylosis between vertebrae C1 and T7, compatible with deforming cervical spondylosis. Necropsy showed a slightly enlarged and light yellow to bronze liver. Microscopic and ultrastructural analyses of liver tissues revealed diffuse and severe liver fibrosis associated with hepatic stellate cell hyperplasia and hypertrophy. These cells showed immunopositive staining for α-smooth muscle actin and desmin markers. The necropsy findings of chronic liver disease coupled with osteopathology supported the diagnosis of hypervitaminosis A."

Hypervitaminosis A in the cat: a case report and review of the literature.

https://www.ncbi.nlm.nih.gov/pubmed/15994105
"A case of hypervitaminosis A with secondary entrapment and compression of the left brachial plexus nerve roots is described. A 9-year-old male castrated domestic shorthair, fed a home-made diet based on raw pork liver, was submitted for examination for a left forelimb lameness that evolved to paralysis over a 2-month period. Clinical examination revealed a flaccid paralysis and atrophy of all left forelimb muscles. An ipsilateral Horner's syndrome was also noted. Radiological examination of the cervical and thoracic spine showed massive new bone formation at the ventral aspect of the second cervical to sixth thoracic vertebra. The diagnosis of hypervitaminosis A was made, based on the clinical and radiographic findings, as well as the determination of serum vitamin A concentration, which was 630 microg/dl, three times above the upper normal limit for this species. Despite the unfavourable initial prognosis, the cat progressively regained function of the affected limb approximately 6 months after the diet was changed to a commercial canned food."

Note how the PROPER DIET fixed the cat's paralysis over a 6-MONTH period.

Hypervitaminosis A in a cat.

https://www.ncbi.nlm.nih.gov/pubmed/1639706
"A 10-year-old cat that was kept on a diet consisting largely of raw liver was evaluated because of lethargy, partial anorexia, and weight loss of several months' duration. The cat's head and neck were rigidly extended, and a hard mass was palpable in the ventral cervical region. Cervical and thoracic radiography revealed proliferative bony lesions of the cervical and thoracic vertebrae as well as of the sternum and costal cartilages. Serum vitamin A concentration was 4 times normal. For reasons unrelated to hypervitaminosis A, euthanasia and necropsy were performed 6 months after evaluation. The skull and the cervical and first few thoracic vertebrae were rigidly fused, and the vertebral architecture was altered by deposition of new bone. The sternum and costal cartilages were similarly affected. The historical, physical, radiographic, laboratory, and postmortem findings were consistent with the diagnosis of hypervitaminosis A. On the basis of findings in this cat, hypervitaminosis A should be suspected in any sick cat fed a diet consisting partly or completely of raw liver."

Severe retardation of growth with retention and displacement of incisors in young cats fed a diet of raw sheep liver high in vitamin A.

[no abstract, I think the title says enough though]