Top Endocrine Publications of 2012: Canine and Feline Endocrine Nutrition

In my 11th and last compilation of canine and feline endocrine publications of 2012, I’m finishing up with endocrine nutrition and treatment of obesity in dogs and cats. Starting in February of 2014, I'm planning to start posting the endocrine publications for 2013. I'm only waiting for the final papers published in December to come out so they can be included in my lists and reviews.

Listed below are 31 research papers written in 2012 that deal with a variety of topics concerning endocrine nutrition or obesity in the dog and cat. Remember that adipose tissue is the largest endocrine gland in the body, making a number of hormones, including leptin, adiponectin, and resistin. These hormones generally influence energy metabolism, which is of great interest to the understanding and treatment of type 2 diabetes and obesity.

These papers range from the studies of the effects of calcium deficiency in growing and adult dogs (1) to studies of the effect of dietary fat intake on circulating lipids in cats (2); from cause, prevalence, and management of obesity in dogs and cats (3,4,12-16,21,25-27,30) to the effect of nutrition on calcium oxalate and calcium excretion in cats (7,8); and from the effects on dietary L-carnitine supplementation on metabolism in cats (4) to the changes in fat-free mass and leptin in hyperthyroid cats before and after treatment (11,18).

Other research studies include the influence of dietary composition on the circulating glucose and insulin response to feeding (9,10) to factors that regulate serum leptin and adiponectin concentrations in dogs and cats (12,20,21,23) and studies of the role of dietary selenium and iodine on nutrition and metabolism (22,31). Finally, this lists also includes a excellent paper on dietary hyperthyroidism in dogs (19) — where we are reminded that not all dogs with thyrotoxicosis have a hyperfunctioning thyroid carcinoma!

2012 Papers on Endocrine Nutrition and Obesity:

1. Becker N, Kienzle E, Dobenecker B. Calcium deficiency: a problem in growing and adult dogs: two case reports. Tierarztl Prax Ausg K Kleintiere Heimtiere 2012;40:135-139. 
2. Butterwick RF, Salt C, Watson TD. Effects of increases in dietary fat intake on plasma lipid and lipoprotein cholesterol concentrations and associated enzyme activities in cats. Am J Vet Res 2012;73:62-67. 
3. Cave NJ, Allan FJ, Schokkenbroek SL, et al. A cross-sectional study to compare changes in the prevalence and risk factors for feline obesity between 1993 and 2007 in New Zealand. Prev Vet Med 2012;107:121-133. 
4. Center SA, Warner KL, Randolph JF, et al. Influence of dietary supplementation with l-carnitine on metabolic rate, fatty acid oxidation, body condition, and weight loss in overweight cats. Am J Vet Res 2012;73:1002-1015. 
5. Clark MH, Hoenig M, Ferguson DC, et al. Pharmacokinetics of pioglitazone in lean and obese cats. J Vet Pharmacol Ther 2012;35:428-436. 
6. Corbee RJ, Tryfonidou MA, Meij BP, et al. Vitamin D status before and after hypophysectomy in dogs with pituitary-dependent hypercortisolism. Domest Anim Endocrinol 2012;42:43-49. 
7. Dijcker JC, Hagen-Plantinga EA, Everts H, et al. Dietary and animal-related factors associated with the rate of urinary oxalate and calcium excretion in dogs and cats. Vet Rec 2012;171:46. 
8. Dijcker JC, Kummeling A, Hagen-Plantinga EA, et al. Urinary oxalate and calcium excretion by dogs and cats diagnosed with calcium oxalate urolithiasis. Vet Rec 2012;171:646. 
9. Elliott KF, Rand JS, Fleeman LM, et al. A diet lower in digestible carbohydrate results in lower postprandial glucose concentrations compared with a traditional canine diabetes diet and an adult maintenance diet in healthy dogs. Res Vet Sci 2012;93:288-295. 
10. Farrow H, Rand JS, Morton JM, et al. Postprandial glycemia in cats fed a moderate carbohydrate meal persists for a median of 12 hours -- female cats have higher peak glucose concentrations. J Feline Med Surg 2012;14:706-705. 
11. Finch NC, Welsh CP, Hibbert A. Changes in fat-free mass (FFM) in cats undergoing radioactive iodine therapy. J Feline Med Surg 2012;14:652-653.
12. German AJ. Barking up the wrong tree: what's the deal with obesity, adiponectin and inflammation in dogs? Vet J 2012;194:272-273.
13. German AJ, Holden SL, Morris PJ, et al. Long-term follow-up after weight management in obese dogs: the role of diet in preventing regain. Vet J 2012;192:65-70. 
14. German AJ, Holden SL, Wiseman-Orr ML, et al. Quality of life is reduced in obese dogs but improves after successful weight loss. Vet J 2012;192:428-434. 
15. Haring T, Haase B, Zini E, et al. Overweight and impaired insulin sensitivity present in growing cats. J Anim Physiol Anim Nutr (Berl) 2012; doi: 10.1111/j.1439-0396.2012.01322.x. 
16. Hoenig M. The cat as a model for human obesity and diabetes. J Diabetes Sci Technol 2012;6:525-533. 
17. Hutchinson D, Freeman LM, McCarthy R, et al. Seizures and severe nutrient deficiencies in a puppy fed a homemade diet. J Am Vet Med Assoc 2012;241:477-483. 
18. Jaillardon L, Burger M, Siliart B. Leptin levels in hyperthyroid cats before and after treatment. Vet Rec 2012;170:155. 
19. Köhler B, Stengel D, Neiger R. Dietary hyperthyroidism in dogs. J Small Anim Pract 2012;53:182-184. 
20. Mazaki-Tovi M, Abood SK, Schenck PA. Effect of omega-3 polyunsaturated fatty acids and body condition on serum concentrations of adipokines in healthy dogs. Am J Vet Res 2012;73:1273-1281. 
21. Ricci R, Bevilacqua F. The potential role of leptin and adiponectin in obesity: a comparative review. Vet J 2012;191:292-298. 
22. Todd SE, Thomas DG, Bosch G, et al. Selenium status in adult cats and dogs fed high levels of dietary inorganic and organic selenium. J Anim Sci 2012;90:2549-2555. 
23. Tvarijonaviciute A, Ceron JJ, Martinez-Subiela S, et al. Serum and urinary adiponectin in dogs with renal disease from leishmaniasis. Vet Rec 2012;171:297. 
24. Tvarijonaviciute A, German AJ, Martinez-Subiela S, et al. Analytical performance of commercially-available assays for feline insulin-like growth factor 1 (IGF-1), adiponectin and ghrelin measurements. J Feline Med Surg 2012;14:138-146. 
25. Tvarijonaviciute A, Ceron JJ, Holden SL, et al. Obesity-related metabolic dysfunction in dogs: a comparison with human metabolic syndrome. BMC Vet Res 2012;8:147. h
26. Tvarijonaviciute A, Tecles F, Martinez-Subiela S, et al. Effect of weight loss on inflammatory biomarkers in obese dogs. Vet J 2012;193570-572. 
27. Tvarijonaviciute A, Ceron JJ, Holden SL, et al. Effects of weight loss in obese cats on biochemical analytes related to inflammation and glucose homeostasis. Domest Anim Endocrinol 2012;42:129-141. 
28. Verbrugghe A, Hesta M, Daminet S, et al. Nutritional modulation of insulin resistance in the true carnivorous cat: a review. Crit Rev Food Sci Nutr 2012;52:172-182. 
29. Verkest KR, Fleeman LM, Morton JM, et al. Association of postprandial serum triglyceride concentration and serum canine pancreatic lipase immunoreactivity in overweight and obese dogs. J Vet Intern Med 2012;26:46-53. 
30. Verkest KR, Rand JS, Fleeman LM, et al. Spontaneously obese dogs exhibit greater postprandial glucose, triglyceride, and insulin concentrations than lean dogs. Domest Anim Endocrinol 2012;42:103-112.
31. Zicker S, B. S. Focus on nutrition: the role of iodine in nutrition and metabolism. Compendium 2012;34:E1-E4. 

Top Endocrine Publications of 2012: Canine & Feline Parathyroid & Calcium Disorders

In my third compilation of the canine and feline endocrine publications of 2012, I’m moving on to disorders of the parathyroid gland, including the clinical problems of hypercalcemia and hypocalcemia.

Listed below are 22 research papers written in 2012 that deal with a variety of topics and issues related to calcium, parathyroid or vitamin D metabolism.

These range from iatrogenic hypoparathyroidism following parathyroid or thyroid surgery (1,20,21) to dietary hypocalcemia in growing dogs (2,14); from paraneoplastic hypercalcemia (3) to puerperal tetany (eclampsia) and hypocalcemia associated with whelping (6); and from dietary and animal-related factors associated with urinary calcium and calcium oxalate stones (7,8) to circulating PTH concentrations in cats with secondary hyperparathyroidism due to renal disease (9).

Other papers discuss the use of intraoperative PTH measurements during parathyroidectomy to help predict cure in dogs with primary hyperparathyroidism (10) to characterization of a mutation that causes vitamin D-dependent rickets in cats (11); from a study of hypovitaminosis D in dogs with endotoxemia (12) to the effect of prednisolone therapy on calcium and vitamin D metabolism in dogs (16,17); from studies of the outcome of dogs with thyroid or parathyroid carcinoma treated with surgical excision (20,21) to an evaluation of calcium and phosphate homeostasis in hyperthyroid cats with chronic kidney disease.

References:

1. Arbaugh M, Smeak D, Monnet E. Evaluation of preoperative serum concentrations of ionized calcium and parathyroid hormone as predictors of hypocalcemia following parathyroidectomy in dogs with primary hyperparathyroidism: 17 cases (2001-2009). J Am Vet Med Assoc 2012;241:233-236. 
2. Becker N, Kienzle E, Dobenecker B. Calcium deficiency: a problem in growing and adult dogs: two case reports. Tierarztl Prax Ausg K Kleintiere Heimtiere 2012;40:135-139. 
3. Bergman PJ. Paraneoplastic hypercalcemia. Top Companion Anim Med 2012;27:156-158. 
4. Brockley LK, Heading KL, Jardine JE, et al. Polyostotic lymphoma with multiple pathological fractures in a six-month-old cat. J Feline Med Surg 2012;14:285-291. 
5. Corbee RJ, Tryfonidou MA, Meij BP, et al. Vitamin D status before and after hypophysectomy in dogs with pituitary-dependent hypercortisolism. Domest Anim Endocrinol 2012;42:43-49. 
6. Davidson AP. Reproductive causes of hypocalcemia. Top Companion Anim Med 2012;27:165-166. 
7. Dijcker JC, Hagen-Plantinga EA, Everts H, et al. Dietary and animal-related factors associated with the rate of urinary oxalate and calcium excretion in dogs and cats. Vet Rec 2012;171:46. 
8. Dijcker JC, Kummeling A, Hagen-Plantinga EA, et al. Urinary oxalate and calcium excretion by dogs and cats diagnosed with calcium oxalate urolithiasis. Vet Rec 2012;171:646. 
9. Finch NC, Syme HM, Elliott J. Parathyroid hormone concentration in geriatric cats with various degrees of renal function. J Am Vet Med Assoc 2012;241:1326-1335. 
10. Graham KJ, Wilkinson M, Culvenor J, et al. Intraoperative parathyroid hormone concentration to confirm removal of hypersecretory parathyroid tissue and time to postoperative normocalcaemia in nine dogs with primary hyperparathyroidism. Aust Vet J 2012;90:203-209. 
11. Grahn RA, Ellis MR, Grahn JC, et al. A novel CYP27B1 mutation causes a feline vitamin D-dependent rickets type IA. J Feline Med Surg 2012;14:587-590. 
12. Holowaychuk MK, Birkenheuer AJ, Li J, et al. Hypocalcemia and hypovitaminosis D in dogs with induced endotoxemia. J Vet Intern Med 2012;26:244-251. 
13. Hong HH, Chou TA, Yang JC, et al. The potential effects of cholecalciferol on bone regeneration in dogs. Clin Oral Implants Res 2012;23:1187-1192. 
14. Hutchinson D, Freeman LM, McCarthy R, et al. Seizures and severe nutrient deficiencies in a puppy fed a homemade diet. J Am Vet Med Assoc 2012;241:477-483. 
15. Kovalik M, Mellanby RJ, Evans H, et al. Ciclosporin therapy is associated with minimal changes in calcium metabolism in dogs with atopic dermatitis. Vet Dermatol 2012;23:481-491. 
16. Kovalik M, Thoday KL, Berry J, et al. Prednisolone therapy for atopic dermatitis is less effective in dogs with lower pretreatment serum 25-hydroxyvitamin D concentrations. Vet Dermatol 2012;23:125-130, e127-128.
17. Kovalik M, Thoday KL, Evans H, et al. Short-term prednisolone therapy has minimal impact on calcium metabolism in dogs with atopic dermatitis. Vet J 2012;193:439-442. 
18. Nunamaker EA, Sherman JG. Oral administration of lanthanum dioxycarbonate does not alter bone morphology of normal cats. J Vet Pharmacol Ther 2012;35:193-197. 
19. Pineda C, Aguilera-Tejero E, Raya AI, et al. Feline parathyroid hormone: validation of hormonal assays and dynamics of secretion. Domest Anim Endocrinol 2012;42:256-264. 
20. Sawyer ES, Northrup NC, Schmiedt CW, et al. Outcome of 19 dogs with parathyroid carcinoma after surgical excision. Vet Comp Oncol 2012;10:57-64. 
21. Tuohy JL, Worley DR, Withrow SJ. Outcome following simultaneous bilateral thyroid lobectomy for treatment of thyroid gland carcinoma in dogs: 15 cases (1994-2010). J Am Vet Med Assoc 2012;241:95-103. 
22. Williams TL, Elliott J, Syme HM. Calcium and phosphate homeostasis in hyperthyroid cats - associations with development of azotaemia and survival time. J Small Anim Pract 2012;53:561-571. 

Top Endocrine Publications of 2011: Canine & Feline Parathyroid & Calcium Disorders

In my fourth compilation of the canine and feline endocrine publications of 2011, I’m moving on to disorders of the parathyroid gland, including the clinical problems of hypercalcemia and hypocalcemia.

Listed below are 20 research papers written in 2011 that deal with a variety of topics and issues related to calcium, parathyroid or vitamin D metabolism.

These range from the hypercalcemia of malignancy (4,14,17,18) to metabolic causes of seizures (1); from calcium oxalate stones (2,6,15) to idiopathic hypercalcemia in cats (10); from hypercalcemia and soft tissue mineralization associated with Heterobilharzia americana infection, the causative agent of canine schistosomiasis (3,10) to
hypercalcemia causes by blastomycosis in a cat (19); and from surgical hypoparathyroidism (5) to ionized hypocalcemia in dogs following trauma (11).

Other papers discuss clinical issue ranging from hypercalcemia associated with canine hypothyroidism (12) to treatment of rickets in a cat (13); from a study of hypovitaminosis D in dogs with inflammatory bowel disease (8) to a review of osteocalcin, a hormone secreted by osteoblasts that may play an important role in energy metabolism (7).

References:

1. Brauer C, Jambroszyk M, Tipold A. Metabolic and toxic causes of canine seizure disorders: A retrospective study of 96 cases. Vet J 2011;187:272-275. 
2. Buckley CM, Hawthorne A, Colyer A, et al. Effect of dietary water intake on urinary output, specific gravity and relative supersaturation for calcium oxalate and struvite in the cat. Br J Nutr 2011;106 Suppl 1:S128-130.
3. Corapi WV, Ajithdoss DK, Snowden KF, et al. Multi-organ involvement of Heterobilharzia americana infection in a dog presented for systemic mineralization. J Vet Diagn Invest 2011;23:826-831. 
4. Dank G, Rassnick KM, Kristal O, et al. Clinical characteristics, treatment, and outcome of dogs with presumed primary hepatic lymphoma: 18 cases (1992-2008). J Am Vet Med Assoc 2011;239:966-971. 
5. de Brito Galvao JF, Chew DJ. Metabolic complications of endocrine surgery in companion animals. Vet Clin North Am Small Anim Pract 2011;41:847-868. 
6. Dijcker JC, Plantinga EA, van Baal J, et al. Influence of nutrition on feline calcium oxalate urolithiasis with emphasis on endogenous oxalate synthesis. Nutr Res Rev 2011:1-15. 
7. Fernandez-Real JM, Ricart W. Osteocalcin: a new link between bone and energy metabolism. Some evolutionary clues. Curr Opin Clin Nutr Metab Care 2011;14:360-366. 
8. Gow AG, Else R, Evans H, et al. Hypovitaminosis D in dogs with inflammatory bowel disease and hypoalbuminaemia. J Small Anim Pract 2011;52:411-418. 
9. Graves TK. When normal is abnormal: keys to laboratory diagnosis of hidden endocrine disease. Top Companion Anim Med 2011;26:45-51. 
10. Hanzlicek AS, Harkin KR, Dryden MW, et al. Canine schistosomiasis in Kansas: five cases (2000-2009). J Am Anim Hosp Assoc 2011;47:e95-e102. 
11. Holowaychuk MK, Monteith G. Ionized hypocalcemia as a prognostic indicator in dogs following trauma. J Vet Emerg Crit Care (San Antonio) 2011;21:521-530. 
12. Lobetti RG. Hypercalcaemia in a dog with primary hypothyroidism. J S Afr Vet Assoc 2011;82:242-243. 
13. MacKenzie JM, Crawford J, Ghantous S. Successful therapy of vitamin D-dependant rickets in a kitten. J Am Anim Hosp Assoc 2011;47:290-293. 
14. Marconato L, Stefanello D, Valenti P, et al. Predictors of long-term survival in dogs with high-grade multicentric lymphoma. J Am Vet Med Assoc 2011;238:480-485. 
15. Palm C, Westropp J. Cats and calcium oxalate: strategies for managing lower and upper tract stone disease. J Feline Med Surg 2011;13:651-660. 
16. Phillips AM, Fawcett AC, Allan GS, et al. Vitamin D-dependent non-type 1, non-type 2 rickets in a 3-month-old Cornish Rex kitten. J Feline Med Surg 2011;13:526-531. 
17. Rebhun RB, Kent MS, Borrofka SA, et al. CHOP chemotherapy for the treatment of canine multicentric T-cell lymphoma. Vet Comp Oncol 2011;9:38-44. 
18. Saba C, Ellis A, Cornell K. Hypocalcemia following surgical treatment of metastatic anal sac adenocarcinoma in a dog. J Am Anim Hosp Assoc 2011;47:e173-177. 
19. Stern JA, Chew DJ, Schissler JR, et al. Cutaneous and systemic blastomycosis, hypercalcemia, and excess synthesis of calcitriol in a domestic shorthair cat. J Am Anim Hosp Assoc 2011;47:e116-120. 
20. Whitney JL, Barrs VR, Wilkinson MR, et al. Use of bisphosphonates to treat severe idiopathic hypercalcaemia in a young Ragdoll cat. J Feline Med Surg 2011;13:129-134.

Q & A: Calcitriol versus Vitamin D3: What's the Difference?

What is the difference between calcitriol and vitamin D3? They both appear to be 1,25-hydroxycholecalciferol.

How about vitamin D2? It that form active at all in dogs and cats with renal failure?

My Response:

Vitamin D is a fat-soluble vitamin that exists in various forms (1). The chemical structure of vitamin D was established in the early 1930's. The main forms are vitamin D2 (ergocalciferol), found in plants, yeasts and fungi and vitamin D3 (cholecalciferol) of animal origin. Vitamin D2 and D3 are not biologically active; rather, they must be modified in the body to have any effect.

Vitamin D2 or D3 must then be first hydroxylated in the liver and then in the kidneys to become active. At this point, as biologically active 1,25-OH-cholecalciferol (also called calcitriol), this form of vitamin D can exert its endocrine effects (1).

By the early 1970's, it had become clear that calcitriol was the active form of vitamin D. It is over 1,000 times as potent as Vitamin D2 and D3 in binding to the vitamin D receptor.

The sun
Vitamin D has long been considered an essential dietary ingredient, but in several species, including humans, sheep, cattle, horses, and pigs, vitamin D3 can be formed in the skin from a cholesterol metabolite (7-dehydrocholesterol) after exposure to natural sun light.

In dogs and cats, however, this skin production of vitamin D3 does not occur (2), so they are dependent entirely on a dietary source of vitamin D.

Food
Large amounts of vitamin D are not found in adequate amounts in most foods. It’s found in fish, cod liver oil, mushrooms, liver and eggs – but usually not in substantial amounts (except in cod liver oil). Thus, getting enough vitamin D naturally from whole foods is difficult.

Both vitamin D2 and D3 have been commercially synthesized and both forms seem to be effective at maintaining blood levels of vitamin D in the body.

Use of vitamin D in renal disease
In severe renal failure, the kidneys cannot produce adequate amounts of the biologically active vitamin D, and this commonly leads to abnormalities of calcium and phosphorus metabolism (3). Oral administration of active calcitriol to animals with chronic kidney disease helps compensate for the reduced production of the active hormone (4).

It is critical to understand that administration of vitamin D2 and D3 will not work to raise active vitamin D concentrations in these animals with renal disease. Active calcitriol must be used as the form of vitamin D to treat these animals (4).

References

1. Lips P. Vitamin D physiology. Prog Biophys Mol Biol. 2006;92:4-8.
2. How KL, Hazewinkel HA, Mol JA. Dietary vitamin D dependence of cat and dog due to inadequate cutaneous synthesis of vitamin D. Gen Comp Endocrinol. 1994;96:12-18.
3. Gerber B, Hässig M, Reusch CE. Serum concentrations of 1,25-dihydroxycholecalciferol and 25-hydroxycholecalciferol in clinically normal dogs and dogs with acute and chronic renal failure. Am J Vet Res. 2003;64:1161-1166.
4. Hostutler RA, DiBartola SP, Chew DJ, et al. Comparison of the effects of daily and intermittent-dose calcitriol on serum parathyroid hormone and ionized calcium concentrations in normal cats and cats with chronic renal failure. J Vet Intern Med. 2006;20:1307-1313.