Page 273 - Problem-Based Feline Medicine

16 – THE CAT WITH ACUTE DEPRESSION, ANOREXIA OR DEHYDRATION 265

● Lily poisoning* (p 290)
Acute depression occurs following ingestion. Later depression is due to acute renal failure. Other signs
include vomiting, polyuria, oliguria or anuria and painful and swollen kidneys.
● Snake bite envenomation* (p 291)
Acute weakness caused by snake venom neurotoxins may present as acute depression. Other signs
depend on the specific snake toxins, which include procoagulants, hemolysins, nephrotoxins, myotoxins
and local cytotoxins.
● Drug therapy*** (p 268)
Many drugs can cause anorexia.
Traumatic
● Trauma*** (p 266)
Trauma may cause primary and secondary depression, anorexia and dehydration. External signs of
trauma may be subtle or obvious. Shorn nails are often evident. A fractured jaw and tongue lacera-
tions or puncture wounds cause pseudoanorexia and impede drinking.

● Pain*** (p 268)
Pain may contribute to the depression and anorexia seen in many of the disorders listed in all cate-
gories above. Other signs of pain include vocalization (spontaneous and evoked by palpation),
defensive aggression evoked by palpation, lameness, hunched posture (abdominal pain) and reluc-
tance to move.

● Depressed and critically sick cats may still purr, and
INTRODUCTION the presence of purring should not be interpreted as
an indication of mild illness.
MECHANISM? Anorexia refers to a reduced appetite. Anorexia may be
complete or partial. (“Inappetence” is commonly used to
Depression, anorexia and dehydration are non-
refer to partial anorexia. In this chapter “anorexia” will be
specific signs that frequently occur together and
used to refer to a reduced appetite regardless of severity.)
accompany most diseases.
● Primary anorexia is due to anosmia, behavioral
● The severity of the signs varies with the primary
factors or neurologic disorders.
disease and the temperament of the animal.
– The smell of food is important to appetite stimu-
● Signs may be stable or progressive.
lation, especially in cats.
● Various non-specific (e.g. acute phase response)
– Behavioral (psychologic) factors causing
and specific (e.g. uremia) mechanisms may be
anorexia include fear, change in routine and
involved, depending on the primary disease.
unpalatable food.
Depression refers to dullness, lethargy and withdrawal – Central neurologic disorders may impair the
from contact (hiding). The animal is less responsive, but appetite center in the hypothalamus.
not to the extent that it would be considered stuporous ● Secondary anorexia occurs when a primary dis-
or comatose. Depression may result from a primary neu- ease process affects the cytokine, endocrine and
rologic disorder or be secondary to diseases of other neurologic control of appetite.
organs. Weakness, behavioral factors (e.g. anxiety), and – Most disorders may result in secondary anorexia
depression of the reticular activating system may con- by various mechanisms.
tribute to depression due to non-neurologic disorders. – This is the most common cause of anorexia in cats.