Page 368 - Problem-Based Feline Medicine

360 PART 6 CAT WITH WEIGHT LOSS OR CHRONIC ILLNESS

Clinical signs – A positive response to appropriate treatment pro-
vides a presumptive diagnosis.
Self-limiting small bowel diarrhea is common after
primary exposure, although it is often unrecognized. Routine hematology and biochemistry findings are
variable dependent on the tissues affected.
Acute fatal toxoplasmosis is recognized in kittens and
immuno-compromised cats. Thoracic radiography may reveal a pleural effusion and
diffuse interstitial or alveolar patterns.
Chronic toxoplasmosis is characterized by diverse
clinical signs depending on the tissue affected.

Respiratory distress due to pneumonia is common in CRYPTOCOCCOSIS
kittens and cats with acute infection.
Central nervous system disease, including ataxia Classical signs
and seizures, may occur either with acute or chronic
● Progressive chronic nasal discharge and
infection.
sneezing.
Icterus is common due to infection involving the liver. ● Soft tissue swelling over the nose,
polypoid masses in the nasal cavity.
Anterior or posterior uveitis may be the only obvious
● Neurological and ocular signs.
sign present in some cats.
Muscle stiffness or hyperesthesia. See main references on page 25 for details (The Cat
With Signs of Chronic Nasal Disease).
The disease may be chronic with weight loss and lack
of appetite. Occasionally, toxoplasma granulomas
(tissue cysts) form in the gastrointestinal tract or pan- Clinical signs
creas causing chronic vomiting.
Cryptococcosis is the most common systemic fungal
Diagnosis disease of the cat, and has a worldwide distribution.

Routine laboratory testing is not specific for toxo- It is most commonly acquired by inhalation, and so
plasmosis. clinical signs are often localized to the respiratory tract.
● Immune response leads to granuloma formation,
Diagnosis of toxoplasmosis may be made on:
leading to facial swellings and polypoid mass
● Rarely tachyzoites or bradyzoites may be identi-
lesions within the nasal cavity.
fied in tissues, broncho-alveolar lavage fluid,
● Stertor and inspiratory dyspnea may occur.
cerebrospinal fluid and effusions.
● Typically there is sneezing and mucopurulent
● Oocysts in the feces do not provide definitive diagno-
nasal discharge (unilateral and bilateral), which is
sis due to difficulties of identification.
commonly blood tinged.
– Shedding only occurs for 1 or 2 weeks follow-
ing initial infection, usually prior to illness. The central nervous system and eyes may be affected
● Serologic testing for antibodies is helpful, but not by direct extension from the nose.
definitive because clinically normal cats frequently ● Signs include depression, behavior changes, ataxia
have significant titers. The magnitude of the titers is and seizures.
not proportional to severity of the disease. ● Ocular signs include granulomatous chorioretinitis
– IgG titers may last for years and are common and uveitis.
in normal cats indicating previous infection.
Depression, inappetence (which occurs as a result of
A four-fold rise in IgG titer over 2–4 weeks sug-
the inability to smell the food) and weight loss are
gests active infection.
common.
– A positive IgM titer persists for approximately
3 months, so tends to indicate recent infection Skin involvement (papules and draining nodules) with
but may persist for much longer. peripheral lymphadenopathy may occur.