Page 966 - Problem-Based Feline Medicine

958 PART 11 CAT WITH AN ABNORMAL GAIT

Pathogenesis Prognosis

Any cause of substantially reduced tissue oxygenation Depends upon the underlying cause.
will cause weakness. Examples include severe anemia,
methemoglobinemia associated with acetaminophen TOXOPLASMOSIS*
(paracetamol) toxicity, cardiac disease, hydrothorax in-
cluding pyothorax and chylothorax, and severe broncho-
Classical signs
pulmonary disease or obstructive upper respiratory
disease. ● Most cats are asymptomatic.
● Signs are most severe in cats under 1 year
Clinical signs of age and especially young kittens.
● Lethargy, anorexia, dyspnea.
Signs may be generalized or localized and are most
● Uveitis, retinal hemorrhage.
easily seen in the mucous membranes, nail beds or
● ± Weakness.
conjunctiva.
Palor, cynaosis, decreased capillary refill times,
tachycardia and hypothermia are common associated Clinical signs
signs.
Most cats are asymptomatic.
Tachycardia, gallop rhythms, murmurs, coughing
Signs are most severe in cats under 1 year of age, espe-
and vomiting may accompany cardiac disorders.
cially young kittens, although any age of cat can be
Tachypnea, panting, and open-mouthed breathing affected.
may accompany respiratory disorders.
Lethargy, anorexia and dyspnea due to pneumonia are
Facial edema may be present with acetaminophen the most frequent signs of generalized infection.
toxicity.
Fever may be present.
Diagnosis Gastrointestinal or hepatic signs such as icterus, vomit-
ing and diarrhea and abdominal effusion may occur
PCVs and complete blood cell counts are used to deter-
as a result of diffuse organ involvement or from a
mine the presence of anemia.
granuloma.
Arterial blood gas analysis is used to determine relative
Toxoplasma gondii can affect any area of the nervous
tissue oxygenation.
system resulting in encephalitis, myelitis, peripheral
A pulse oximeter reading may aid in determining the neuropathy or myositis.
degree of oxygenation.
The organism damages the nerve and muscle either
Chest radiographs can be used to identify pulmonary primarily, or secondarily through associated inflam-
and cardiac diseases. mation.

In addition, an ECG and echocardiogram is useful Weakness may be present if the spinal cord, periph-
when evaluating for heart disease. eral nerves or muscles are involved.
Hyperesthesia on muscle palpation, stiff gait or shifting
Differential diagnosis leg lameness suggests myositis.
Other causes of weakness should not have cyanosis and Experimental innoculation with meospora coninum also
pallor. causes clinical signs in cats.

Treatment Diagnosis
Treat the underlying cause of the reduced oxygenation Diagnosis is based upon the presence of IgM anti-
and provide oxygen if signs are marked. bodies to Toxoplasmosa gondii, which appear within