Small Animal Diseases

Question 1

Addison’s Disease

(Hypoadrenocorticism)

Answer 1

• Hypoadrenocorticism (Addison’s Disease) is a Deficiency in Corticosteroid Hormones (glucocorticoids, mineralocorticoids)
• Patients are usually young (age four to five years) but any age dog can be affected. (This disease can occur in cats but is very rare.)
• There is a genetic predisposition for Addison’s disease in the standard poodle and bearded collie.
• Female dogs are affected twice as often as males
• At first signs are vague: listlessness, possibly some vomiting or diarrhea. –> symptoms wax and wane with stress.
• Eventually, the disease comes to a head in a phenomenon known as an Addisonian crisis.
  
  • The animal collapses in shock due to his inability to adapt to the caloric and circulatory requirements of stress.
  • Blood sugar may drop dangerously low.
  • Potassium levels soar and disrupt the heart rhythm because there is not enough conserved sodium to exchange for potassium.
  • Heart rate slows, arrhythmias result. The patient may not survive this episode
• About 30% of dogs with Addison’s disease are diagnosed at the time of an Addisonian crisis. Approximately 90% of the adrenal cortex must be non-functional before clinical signs are observed
• In a similarly unexpected way, regurgitation of undigested food due to abnormal nerve function in the esophagus (a condition called megaesophagus) can be caused ultimately by Addison’s disease. Megaesophagus has many causes but it is important not to forget Addison’s disease.
• Addison’s disease can also manifest with chronic waxing/waning diarrhea and/or poor appetite which would suggest a gastrointestinal problem such as inflammatory bowel disease

Question 2

FeLV

Answer 2

• Prevelance of 1-2% in healthy cats

1. Abortive Infection - Immune system kills off all the infected cells - wont have any viral antigen (not common)-neg on serology
2. Regressive Infection - Also not very common-amounts pretty good response: early on or when it infects the BM. that cat manages to get rid of all that antigen (still neg.) - but the virus did integrate a bit of viral DNA into the cats DNA - therefore essentially has latent infection that can recrudesce later on - stress
3. Progressive Infection - By far most common-will become infected with the virus, have circulating antigen that you can test for-this will limit life expectancy-will succumb to clinical signs of the disease within 3-5 year of getting disease-survival time is about 2.5-3 years when you look at the literature - Majority of cats!

*Spread in saliva and nasal secretions by persistently infected cats*