What diseases are associated with OW+O pets?
1. Orthopedic disorders: Arthritis* in both cats and dogs e.g. Hip dysplasia, Knee Ligament Rupture, Disc disease (esp. Dachshunds).
*Arthritis in cats is being diagnosed much more frequently. This is probably the most commonly recognized obesity related problem.
Obesity is a major risk factor for orthopedic disorders (Dr..German, London).
2. Endocrine diseases: Diabetes, Hypothyroidism*, Insulinoma
Obesity is a major determinant to insulin resistance and hyperinsulinemia (esp. in cats)
Overweight and Obese pets have decreased glucose tolerance
*Hypothyroidism incidence is <1%, but OW+O is 22-44% of animals, so not a common direct cause.
3. Metabolic disorders: Pancreatitis*, Hepatic lipidosis (link very clear in cats), Hyperlipidemia and Dyslipidemia, [*Increased incidence in obese dogs, exact relation is in study.]
4. USMI- Urethral Sphincter Mechanism Incompetence: (Urine puddling when pets lie down) Usually occurs in spayed female dogs (Occasionally neutered males). Typically responds to long-term estrogen/testosterone or Propalin, but some respond to weight loss only. It is believed to be caused by displacement of the bladder sphincter into the pelvis caused by excessive abdominal fat.
5. Cancer - Increased risk of transitional cell carcinoma of the bladder, mammary adenocarcinoma in dogs & insulinomas. The association has not been fully verified with MAC or other cancers due to study costs, but there is a known association in humans (some breast cancers, colonic/rectal, renal and esophageal cancers).
6. Miscellaneous conditions:
- Certain dermatologic (skin) conditions: e.g. peri-vulvar dermatitis, fold pyodermas
- Increased dandruff and hair matting (mostly in cats and likely due to the decreased ability to groom)
- Pressure sores (in severe obesity, from lying down too much/poor mobility)
- Decreased immune function (reported in obese dogs making them more susceptible to infections)
- Airway problems: Tracheal collapse (e.g. Yorkies), Brachycephalic syndrome (e.g. Pugs, Bull dogs).
Why does being OW or O predispose to disease?
1. ‘Mechanical or physical’ effects
- Requires a lot more energy to move and carry all the excess weight, which damages joints or strains the intervertebral spaces (e.g. paralysis in Dachshunds). In young dogs it leads to more laxity in joints (e.g. hip dysplasia). If not the cause, it makes it harder to use limbs with abnormal joints or with spinal conditions, thereby increasing morbidity.
- Excess fat constricts the upper airways exacerbating respiratory conditions. e.g. collapsing trachea (Yorkies, small breeds), brachycephalic syndrome (pugs, bull dogs, etc)
- Rear end infections and inflammations because the animal can’t groom.
- Peri-vulvar fold dermatitis because the thigh fat blocks the flow of urine
- More prone to heat stroke on hot days (insulating effect of fat)
2. Excess production of ADIPOKINES by Fat (WAT)
-Adipose tissue is a highly metabolically active endocrine organ, producing adipokines that are linked to inflammation and the inflammatory response