Page 323 - Problem-Based Feline Medicine

17 – THE CAT WITH WEIGHT LOSS AND A GOOD APPETITE 315

not the cat is an indoor or outdoor animal, and Since some parasites can be transmitted lactationally
whether or not it hunts and eats its prey. (T. cati), and infections are frequently more severe in
young cats, all young cats should be evaluated for intes-
While infection is common, disease is seen most com-
tinal parasites or treated against the common parasites
monly in young cats living in poorly cleaned multi-
of the region.
animal environments.
Infection rarely causes systemic changes. However, hema-
In these situations, episodes of disease may be seen in
tology may reveal an eosinophilia and, in severe cases,
kittens or cats of similar ages, and may be preceded by
low serum proteins may be found on serum biochemistry.
a stressful event such as an environment change, addi-
tion of new cats, or weaning, etc. With the exception of tapeworm segments, most intes-
tinal parasites are not noticed in the feces.
Clinical signs vary but typically include diarrhea and
vomiting (especially with T. cati infections), but Fecal floatation techniques are used to diagnose most
anorexia is not often present. intestinal parasites (round worms, hook worms and
● Ascarids: In adult cats, infections are usually sub- Isospora spp.). However, special techniques may be nec-
clinical, but kittens and young cats may develop essary for some parasites, such as C. parvum (special
vomiting, small bowel diarrhea, a pot-bellied stains or, possibly, fecal antigen tests), Giardia spp. (direct
appearance, poor coat condition and a failure to saline fecal smears or fecal antigen tests), or T. foetus
thrive. (PCR, ‘In Pouch’ culture or direct saline fecal smears).
● Hookworms: Infections cause less disease in cats
Rather than confirming the presence of an infection
than dogs, and most disease is seen in young adult
with fecal tests, a therapeutic trial with a suitable drug
cats that live in poorly cleaned, crowded conditions.
may be considered.
A heavy infection can cause weight loss, poor coat
condition and melena.
● Tapeworms: Infections are usually subclinical, but Differential diagnoses
heavy infections can cause anal pruritus, vomiting,
Differential diagnoses include most of the other causes
diarrhea, weight loss and, occasionally, intestinal
of weight loss with a good appetite. Inadequate nutri-
obstruction.
tion becomes the most likely differential when there
● Isospora spp.: Infections rarely cause clinical dis-
are no signs other than weight loss. However, the vari-
ease in adult cats unless they are stressed or
able presence of gastrointestinal signs is more sug-
immunocompromised. In kittens, infections can
gestive of some of the malassimilation syndromes
range from subclinical through to severe hemor-
such as IBD, exocrine pancreatic insufficiency, or
rhagic diarrhea.
early alimentary lymphosarcoma.
● C. parvum: Infections are usually subclinical, but
can also cause acute or chronic small bowel diar-
rhea, or result in lymphocytic-plasmacytic duodeni- Treatment
tis.
Roundworms and hookworms may be treated with
● G. lambia: Infections can be subclinical, or cause
pyrantel pamoate (20 mg/kg/day – two doses need to be
acute, chronic or episodic small bowel diarrhea
given 2–3 weeks apart) or fenbendazole (20–50
where intestinal malabsorption may result in
mg/kg/day usually given for 3–5 days, then repeated 2–3
mucoid, soft, foul-smelling feces.
weeks later) which are both safe and effective in cats.
● T. foetus: Infections can be subclinical or cause
chronic large bowel diarrhea. Tapeworms may be treated with praziquantel
(3.5–7.5 mg/kg SC, PO) or epsiprantel (2.75 mg/kg
Diagnosis PO). One dose is effective against D. caninum and
T. taeninaeformis.
Intestinal parasites should be suspected in any cat, but
especially those coming from a poorly cleaned multi- Isospora spp. may be treated with trimethoprim/sul-
animal environment in a geographic region with a high fonamide (15 mg/kg q 12 hours PO for 10–14 days),
prevalence of intestinal parasites. plus improved sanitation.