Feline Weight Loss

ArticleLast Updated November 20113 min readPeer Reviewed

Consider these factors and diagnostic options when evaluating weight loss in cats.

History

Ask about:

  • Duration of weight loss

  • Other clinical signs (eg, vomiting/regurgitation, diarrhea)

  • Time when patient last appeared/acted normal

  • Changes in diet or eating behavior

  • Changes in environment (eg, humans, other animals, routines, placement of food bowls)

  • Dropping of food or difficulty in prehending/chewing

  • Evidence of orofacial pain

  • Travel history

  • Changes in water intake/urination

  • Changes in attitude, energy, activity/mobility

  • Changes in litter box use (eg, volume, frequency, character, color)

Examination

Includes:

  • Body weight

  • % weight change* and BCS

  • Muscle condition (normal/wasted) 

  • Blood pressure evaluation

  • Coat condition

  • Funduscopic examination

  • Oral examination

  • Abdominal palpation

  • Pulse quality

  • Thyroid palpation<sup†sup>

  • Thoracic auscultation

Appetite

Good appetite

  • Inadequate intake

    • Poor quality/insufficient quantity of food

  • Maldigestion/malabsorption

    • IBD

    • Lymphoma

    • EPI

    • Systemic fungal infection (if regionally likely or if travel history indicates risk)

  • Excessive nutrient loss

    • Diabetes mellitus

    • Hyperthyroidism

    • Parasitism

    • Cachexia (cardiac or neoplastic)

    • Protein-losing nephropathy

    • Protein-losing enteropathy

  • Overutilization

    • Pregnancy/lactation

    • Strenuous workload

Unable to eat

  • Oral neoplasia

  • Orofacial/dental fracture

  • Dental disease

  • Dental pain

  • Neuropathy

  • Retrobulbar neoplasia/abscess

  • Oral/pharyngeal/esophageal disease

Poor appetite

  • Drug therapy (eg, antibiotics, chemotherapeutic agents)

  • FeLV/FIV

  • Chronic kidney disease

  • Acute/chronic renal failure

  • Cholangitis/hepatitis, hepatic lipidosis

  • Pancreatitis

  • Biliary tree disease

  • Neoplasia

  • IBD

  • Systemic fungal infection

  • CNS disease

  • Bored with diet<sup‡sup>

  • Distress (environmental, social)<sup§sup>

  • Nasal disease

  • Foreign body

  • Abscess

  • Fever

Body system suggested?

Yes

  • Perform MDB & additional diagnostics appropriate for body system

    • Orofacial: stabilize for thoroughdental/oral assessment with dental+/- skull imaging under anesthesia; if mass present, biopsy

    • Abdominal: imaging, cobalamin/folate levels, fTLI (if EPI suspected), fPLI in conjunction with abdominal imaging(if pancreatitis suspected)

    • Thoracic: imaging

    • Urogenital: UP/C if persistent proteinuria with inactive urine sediment

No

  • Offer variety of diets

  • Perform MDB & diagnostics

    • CBC with differential and cell morph-ology, serum biochemical profile, retroviral serology, total T4 (older cats), urinalysis, fecal testing (numerous types)

    • Abdominal imaging

    • Thoracic imaging

    • Cobalamin/folate levels

Assess results

  • Normal

    • Perform biopsies

      • Includes:

        • GI (surgical/endoscopic)

        • Stomach, intestine, pancreas, liver, mesenteric lymph node, spleen

      • Normal - Consider CNS disease

      • Abnormal

        • IBD

        • Neoplasia

        • Fungal disease

  • Abnormal

    • Includes:

      • Renal insufficiency

      • Renal failure

      • FeLV/FIV

      • Hepatopathy

      • Neoplasia

      • Hyperthyroidism

      • Parasitic infection

      • Cardiomyopathy

* Percentage of weight change = (previous weight – today’s weight)/previous weight ¥ 100† Presence/absence of mass does not rule in/out hyperthyroidism‡ Offer a variety of diets; recheck weight in 10–14 days: if no weight gain, perform MDB; if weight gain, continue with new diet/recheck weight in 14 days§ If history reveals stress: enrich environment with opportunities to hide and perch, move feeding station to quiet and safe place, add feeding stations (easy access, etc)

BCS = body condition score, CBC = complete blood count, CNS = central nervous system, EPI = exocrine pancreatic insufficiency, FeLV = feline leukemia virus, FIV = feline immunodeficiency virus, fPLI = feline pancreatic lipse immunoreactivity, fTLI = feline trypsinogen-like immunoreactivity, GI = gastrointestinal, IBD = inflammatory bowel disease, MDB = minimum database, T4 = thyroxine, UP/C = urine protein:creatinine ratio

For related articles, see the following:Safe Weight Reduction in an Obese Diabetic CatAssessing Weight Loss in Cats


MARGIE SCHERK, DVM, Diplomate ABVP (Feline Practice), opened Cats Only Veterinary Clinic in Vancouver in 1986 and practiced there until 2008. Her interests include all things feline, in particular analgesia, the peculiarities of the feline digestive system, and enabling more positive interactions with cats. Dr. Scherk has published several clinical trials and written numerous book chapters. In addition, she is co-editor of the Journal of Feline Medicine and Surgery. She also has served extensively at the American Association of Feline Practitioners and other veterinary organizations and is an active international speaker who is also involved in online continuing education.